EXHIBIT 2.1
                      AGREEMENT AND PLAN OF REORGANIZATION
         THIS AGREEMENT AND PLAN OF  REORGANIZATION  is made and entered into as
of the 28th day of April 1997,  by and among  AGOURON  PHARMACEUTICALS,  INC., a
California corporation ("Agouron"),  Agouron Acquisition Corporation, a Delaware
corporation and wholly-owned  subsidiary of Agouron ("Acquisition  Corporation")
and  ALANEX  CORPORATION,   a  Delaware  corporation   ("Target").   Target  and
Acquisition  Corporation are herein  sometimes  referred to as the  "Constituent
Corporations."
                                    Recitals
         A. The  parties  intend  that,  subject  to the  terms  and  conditions
hereinafter  set forth,  Acquisition  Corporation  will be merged  with and into
Target (the  "Merger") on the date provided for in Article 6 hereof.  Subject to
the terms of this  Agreement,  among other things,  all  outstanding  securities
(including all outstanding options and warrants, whether vested or unvested, and
any other rights to acquire Target  securities) of Target will be converted into
shares,  or rights to acquire shares,  of common stock, no par value, of Agouron
("Agouron Common") in accordance with the provisions set forth in Section 1.5 of
this Agreement.
         B. The  parties  hereto  desire to enter  into this  Agreement  for the
purpose of setting forth certain representations,  warranties and covenants made
by each  to the  other  as an  inducement  to  enter  into  the  Merger  and the
conditions precedent to the consummation of the Merger.
         C.       For purposes of this Agreement,  Debar ERA, Inc., The ▇▇▇ and 
▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇ Family 1990 Trust, ▇▇▇▇▇▇ ▇. ▇▇▇▇▇, M.D. and ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ 
are collectively referred to as the "Principal Stockholders."
         NOW,  THEREFORE,  in  consideration  of the  premises and of the mutual
provisions,  agreements and covenants  herein  contained,  Agouron,  Acquisition
Corporation and Target agree as follows:
                                    ARTICLE 1
                                   THE MERGER
         1.1      Agreement to Acquire Target.  Subject to the terms of this 
Agreement,  Target shall be acquired by Agouron through the merger of 
Acquisition  Corporation with and into Target.
         1.2     Effective Time of the Merger.  The Merger shall become 
effective at the date and time (the "Effective Time") when a properly executed 
Certificate of Merger is duly filed with the Secretary of State of the State of 
Delaware, which filing  shall  be  made  as soon as  practicable  following  
fulfillment  of the conditions  set  forth in  Article 5 hereof,  or at such 
time  thereafter  as is provided in such Certificate.
         1.3      Effects of the Merger.  At the Effective Time:
                  (a)  Acquisition  Corporation  shall be  merged  with and into
Target and the separate  corporate  existence of Acquisition  Corporation  shall
cease. Target shall continue as the surviving corporation (hereinafter sometimes
called the "Surviving  Corporation") and shall succeed,  without other transfer,
to all the rights and properties of Acquisition Corporation and shall be subject
to all the debts and liabilities of Acquisition  Corporation as if the Surviving
Corporation had itself incurred them;
                  (b) the Certificate of  Incorporation of Target shall continue
as the Certificate of Incorporation of Surviving  Corporation,  except that such
Certificate  of  Incorporation  shall be amended and restated in its entirety in
substantially  the form attached  hereto as Exhibit A (the "Amended and Restated
Certificate").  The  purposes  of  the  Surviving  Corporation  shall  be  those
contained in the Amended and Restated Certificate.  The authorized capital stock
of the  Surviving  Corporation  shall be 100  shares of Common  Stock,  $.01 par
value;
                  (c)  the  bylaws  of  Acquisition  Corporation,  as in  effect
immediately  prior to the Effective Time,  shall be and become the bylaws of the
Surviving  Corporation  without change or amendment  until  altered,  amended or
repealed as provided for in such bylaws or by law;
                  (d)      the directors and officers of the Surviving 
Corporation shall be as follows:
                  Directors:
                  ▇▇▇▇▇ ▇▇▇▇▇▇▇                  Director
                  Officers:
                  ▇▇▇▇▇▇ ▇. ▇▇▇▇▇, M.D.          President
                  ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇               Chief Financial Officer
                  ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇               Secretary
                  (e)      the Merger shall, from and after the Effective Time, 
have all the effects set forth in this Agreement and as provided by applicable 
law.
         1.4      Additional  Actions.  If, at any time after the Effective 
Time, the Surviving Corporation shall consider or be advised that any further 
deeds, bills of sale,  assignments  or  assurances  in law or any other actions 
or things are necessary or desirable (a) to vest, perfect or confirm,  of record
or otherwise, in the Surviving Corporation,  its rights, title or interest in, 
to or under any of the rights,  property or assets of Acquisition Corporation as
a result of, or in  connection  with,  the Merger or (b)  otherwise to carry out
the purposes of this  Agreement,  Acquisition  Corporation and its proper 
officers and directors shall be deemed to have  granted to the  Surviving 
Corporation  an  irrevocable power of attorney to execute and deliver all such 
proper  deeds,  bills of sale, assignments  and  assurances in law and to take 
and do all such other actions as may be necessary  or  desirable  to vest,  
perfect or confirm any and all right, title and  interest in, to and under such
rights,  properties  or assets in the Surviving Corporation and otherwise to 
carry out the purposes of this Agreement; and the proper  officers and  
directors of the Surviving  Corporation  are fully authorized in the name of 
Acquisition  Corporation or otherwise to take any and all such actions.
         1.5     Effect on Securities.  As of the Effective Time, subject to 
Section 1.8, by virtue of the Merger and without any action on the part of 
Agouron,  the Constituent  Corporations  or any  stockholder  thereof,  the  
securities of the Constituent Corporations outstanding at the Effective Time 
shall be converted or treated as follows:
                  (a) Capital Stock of Acquisition  Corporation.  All issued and
outstanding shares of capital stock of Acquisition Corporation shall continue to
be issued  and shall be  converted  into 100  shares of Common  Stock,  $.01 par
value,  of the Surviving  Corporation.  Each stock  certificate  of  Acquisition
Corporation  evidencing  ownership of any such shares shall continue to evidence
ownership of such shares of capital stock of the Surviving Corporation.
                  (b)  Cancellation of Target-Owned  Stock. All shares of Target
equity,  if any,  that  are  owned  directly  or  indirectly  by  Target  or any
subsidiary  of  Target  shall be  cancelled,  and no stock of  Agouron  or other
consideration shall be delivered in exchange therefor.
                  (c) Conversion of Target Common.  Subject to Sections  1.5(b),
1.5(f),  and 1.8, each share of Target Common  Stock,  $.001 par value  ("Target
Common"),  issued and outstanding  immediately  prior to the Effective Time, and
all rights  existing with respect  thereto,  shall cease to be  outstanding  and
shall be converted,  without any action on the part of the holder thereof,  into
the right to receive  that  number of shares of  Agouron  Common  determined  by
utilizing the Exchange Ratio as defined in, and in accordance with,  Section 1.6
below.
                  (d)  Assumption of Target  Warrants.  At the  Effective  Time,
Agouron  shall  assume the warrant (the  "Target  Warrant")  to purchase  Target
Common then  outstanding,  which shall  thereafter  be deemed to be a warrant to
purchase,  in lieu of the shares of Target  common stock  previously  subject to
such  Target  Warrant,  that  number of shares of  Agouron  Common  equal to the
product of the number of Target Common shares subject to the Target Warrant,  to
the extent not exercised or terminated  prior to the Effective Time,  multiplied
by the Exchange Ratio as defined in and in accordance with Section 1.6 below and
rounded  downward to the nearest  whole  share,  at an exercise  price per share
equal to the exercise  price per share under the Target  Warrant  divided by the
Exchange  Ratio as  defined  in and in  accordance  with  Section  1.6 below and
rounded  upward to the nearest whole cent,  subject to the provisions of Section
1.5(g). The term,  exercisability and vesting schedule,  if applicable,  and all
other terms of the Target Warrant will otherwise be unchanged.
                  (e)  Assumption  of  Stock  Options  and  Agreements.  At  the
Effective  Time,  Agouron  shall assume all options to purchase  Target  Common,
whether  vested or  unvested,  issued  under the  Target's  1993 Stock Plan,  as
amended,  or its 1996 Equity  Incentive  Plan,  or pursuant to any other  option
agreements outstanding as of the Effective Time (collectively "Target Options").
Each of the Target  Options  shall be assumed  without any action on the part of
the holder  thereof as of the  Effective  Time.  The number of shares of Agouron
Common that the holder of an assumed  Target Option shall be entitled to receive
upon the exercise of such option shall be the number of whole shares  determined
by  multiplying  the number of shares of Target  Common  subject to such option,
determined  immediately  before the  Effective  Time,  by the Exchange  Ratio as
defined and in accordance with Section 1.6 below. The option price of each share
of Agouron Common subject to an Target Option shall be the amount (rounded up to
the nearest  whole cent)  obtained by dividing the  exercise  price per share of
Target  Common  at which  such  option is  exercisable  immediately  before  the
Effective Time by the Exchange  Ratio as defined and in accordance  with Section
1.6 below,  subject to the  provisions  of Section  1.5(g).  The  assumption  of
options as provided herein shall not give the holders of such options additional
benefits or additional  vesting rights which they did not have immediately prior
to the Effective Time or relieve the holders of any  obligations or restrictions
applicable  to their  options  or the shares  obtainable  upon  exercise  of the
options.  Only whole shares of Agouron  Common shall be issued upon  exercise of
any Target  Option  rounded  downward  to the  nearest  whole  share.  The term,
exercisability and vesting schedule,  if applicable,  and all other terms of the
Target Options will otherwise be unchanged. Following the Closing, Agouron shall
send to each holder of an assumed  Target  Warrant  and Target  Option a written
notice  setting forth (i) the number of shares of Agouron Common subject to such
assumed Target Warrant and Target Option,  and (ii) the exercise price per share
of Agouron  Common  issuable  upon exercise of such assumed  Target  Warrant and
Target Option. At the time of the closing of the Merger, Agouron shall file with
the Securities and Exchange  Commission (the "SEC") a registration  statement on
Form S-8  registering the shares of Agouron Common issuable upon exercise of the
assumed Target Options.
                  (f) Fractional  Shares. No fractional shares of Agouron Common
shall be issued,  but in lieu  thereof each holder of Target  Common,  who would
otherwise be entitled to 
receive a fraction of a share of Agouron  Common (after aggregating  all  
fractional  shares of Agouron  Common to be  received  by such holder)  shall 
receive from Agouron an amount of cash (rounded up to the nearest
whole  cent)  equal to the  product  of (i) the  fraction  of a share of Agouron
Common to which such holder would  otherwise  be entitled,  and (ii) the average
closing price per share of Agouron Common as reported on The Nasdaq Stock Market
for the five (5) trading days prior to and including the execution  date of this
Agreement.
                  (g) Escrow  Shares.  An amount of Agouron  Common (the "Escrow
Shares")  representing  twenty percent (20%) of the aggregate  number of Agouron
Common, and when exercised (the date of exercise  hereinafter referred to as the
"Exercise  Date") the Agouron  Common  underlying the assumed Target Options and
Target  Warrants  received in the Merger,  shall,  pursuant to this Agreement be
delivered by Agouron promptly following the Effective Time, or the Exercise Date
as the case may be,  into the "Escrow  Fund" as defined in, and  pursuant to the
terms  of the  Escrow  Agreement  attached  hereto  as  Exhibit  B (the  "Escrow
Agreement").  During the period that Agouron Common  remains in the Escrow,  the
exercise of any Target  Option or Target  Warrant  will require the deposit into
the Escrow Fund of twenty percent (20%) of the resulting  Agouron Common issued.
If a holder of Target  Common,  Target Option or Target Warrant does not execute
the Escrow Agreement,  the shares of Agouron Common which would have been placed
in escrow  will be held by Agouron  and  released  upon the same  conditions  as
required by the Escrow Agreement.  The Escrow Shares shall be held in the Escrow
Fund and released  therefrom  when and as provided by the Escrow  Agreement  and
this Agreement, subject to the conditions, requirements and agreements set forth
in  this  Agreement   (including,   without   limitation,   the  indemnification
provisions),  and not be assignable or  transferable  unless and until  released
pursuant to the Escrow Agreement and this Agreement.  At the final settlement of
the Escrow Fund,  the number of shares of Agouron  Common  attributable  to each
outstanding Target Option or Target Warrant will be adjusted to equal the number
of shares the holder of such shares would have received if the Target Options or
Target  Warrants had been exercised at the Closing Date of the Merger and placed
in the Escrow Fund.
         1.6      Exchange of Certificates.
                  (a)  Agouron  To  Provide  Common  Stock.  Promptly  after the
Effective  Time,  Agouron shall make available for exchange,  in accordance with
this Article 1, and subject,  among other things, to the provisions of Article 8
hereof,  the shares of Agouron Common  issuable  pursuant to Section 1.5 of this
Agreement in exchange for all of the outstanding Target Common.
                  (b)   Exchange   Ratio.   "Target   Securities"   shall   mean
collectively  shares of Target  Common,  options  outstanding  to acquire Target
Common (the "Target  Options") and warrants to purchase  shares of Target Common
(the "Target Warrants") outstanding immediately prior to the Effective Time. The
Parties agree that the Exchange  Ratio will be determined by using the following
formulae:
       Target Securities =  Target Common + Target Options + Target Warrants
        Exchange Ratio =     1,000,000           [1,000,000 = 0.1888606]
                          --------------          ---------
                          Target Securities       5,294,910
                                                  example: as of date hereof
                  Based on the above  example,  the Exchange  Ratio is 0.1888606
Agouron Common shares for each Target Share.  It is further  understood that the
maximum  number of shares of Agouron  Common  which will either be issued in the
Merger or become subject to outstanding  options or warrants  assumed by Agouron
in the Merger is  1,000,000,  subject to  adjustment  as  
provided in Article 9. Stockholders  of Target  will  receive  cash in lieu of 
any  fractional  Agouron Common to which they would otherwise be entitled as 
provided in Section 1.5(f).
                  (c)      (RESERVED)
                  (d)  Exchange  Procedures.  As soon as  practicable  after the
Effective Time, Agouron shall mail, to each holder of record of a certificate or
certificates   which   immediately  prior  to  the  Effective  Time  represented
outstanding  Target  Common (the  "Certificates")  whose Target  Common is being
converted into Agouron Common and cash pursuant to Section 1.5 of this Agreement
and who have not surrendered the  Certificates at the Closing,  instructions for
use in  effecting  the  surrender  of the  Certificates  in exchange for Agouron
Common. Upon surrender of a Certificate for cancellation to Agouron or Agouron's
transfer agent as Agouron may determine, the holder of such Certificate shall be
entitled to receive in  exchange  therefor  the  certificates  representing  the
number of shares of Agouron Common and payments in lieu of fractional  shares to
which the holder of Target  Securities  is  entitled  pursuant to Section 1.5 of
this Agreement and is represented by the Certificate so  surrendered;  provided,
however,  that the Escrow Shares shall be transferred  from  Agouron's  transfer
agent to the Escrow Agent,  to be held in escrow and  administered by the Escrow
Agent in accordance with the terms and provisions of the Escrow  Agreement.  The
delivery  of  the  Escrow   Shares  shall  be  made  on  behalf  of  the  Target
Securityholders  in accordance with the provisions  hereof,  with the same force
and effect as if such  shares had been  delivered  by Agouron  directly  to such
holders and  subsequently  delivered  by such holders to the Escrow  Agent.  The
shares or rights to shares so deposited  shall not be assignable or transferable
except as provided in the Escrow  Agreement.  Each  Certificate  so  surrendered
shall forthwith be cancelled.  In the event of a transfer of ownership of Target
Securities which is not registered in the transfer records of Target,  the stock
certificates  representing shares of Agouron Common and cash may be delivered to
a transferee if the Certificate  representing  the right to receive such Agouron
Common is  presented to Agouron and  accompanied  by all  documents  required to
evidence and effect such transfer and to evidence that any applicable taxes have
been paid or withheld.  Agouron shall follow the same  procedure with respect to
lost,  stolen or  mutilated  Certificates  as it follows  with  respect to lost,
stolen or mutilated Agouron certificates.  Unless and until any such Certificate
shall be so surrendered, or such procedures respecting lost, stolen or mutilated
Certificates are followed,  the holders of the Certificate shall not be entitled
to receive  certificates for the Agouron Common or cash for any fractional share
of Agouron Common and any dividends paid or other  distributions made to holders
of record  of  Agouron  Common  after the  Effective  Time  shall be paid to and
retained  by  Agouron  and paid over to such  holder  when such  Certificate  is
surrendered or such  procedures are  implemented in accordance with this Section
1.6(d).
         1.7     No  Further  Ownership  Rights in Target  Securities.  All  
Agouron Common or rights to Agouron Common  delivered upon the surrender for 
exchange of Target  Securities in  accordance  with the terms hereof shall be 
deemed to have been  delivered in full  satisfaction  of all rights  pertaining
to such Target Securities.  There shall be no further registration of transfers
on the transfer books  of  the  Surviving  Corporation  of  the  Target  
Securities  which  were outstanding  immediately  prior to the Effective  Time.
If, after the Effective Time,  Certificates  are presented to the Surviving  
Corporation for any reason, they shall be cancelled and exchanged only as 
provided in this Article 1.
         1.8     Dissenting Target Common. Target Common which is not voted in 
favor of the Merger and with respect to which a demand for payment and appraisal
shall have been properly made in accordance with the Delaware General  
Corporation Law ("Dissenting  Target  Common") shall not be converted into the 
right to receive Agouron  Common  and the holders  of such  Dissenting  Target 
Common  shall be entitled  only to such rights as may be granted to such holders
by the Delaware General  Corporation Law;  provided,  however,  that if a holder
of  Dissenting Target Common shall withdraw his or her demand for such payment 
and appraisal or shall become 
ineligible for such payment and appraisal, then as of the Effective Time or the 
occurrence of such event of withdrawal or  ineligibility,  whichever last 
occurs, such holder's Dissenting Target Common shall cease to be Dissenting
Target  Common and shall be converted into the right to receive,  and shall be
exchangeable  for, the Agouron Common into which such Dissenting Target Common
would have been converted pursuant to Section 1.5 hereof.
         1.9      Accounting Treatment.  The parties intend that the purchase 
method of accounting will be used by Agouron to account for the Merger.
                
         1.10     Tax Treatment.  The parties intend that the Merger will be a 
tax free  reorganization  within the meaning of Section 368 of the Internal 
Revenue Code of 1986, as amended (the "Code").
                                    ARTICLE 2
                    REPRESENTATIONS AND WARRANTIES OF TARGET
         Except as  otherwise  set forth in the  Schedules  attached  hereto (it
being agreed that any item set forth in Schedules  having relevance to more than
one of the  following  sections  of this  Agreement  shall be recited in full or
cross-referenced  in each applicable  section of the subject  Schedule),  Target
represents and warrants to Agouron and Acquisition Corporation as of the date of
this Agreement as follows:
         2.1     Organization.  Target is a corporation (a) duly organized,  
validly existing  and in good  standing  under the laws of the State of Delaware
and (b) duly  qualified and in good standing to do business as a foreign  
corporation in the State of  California.  Target is not required to be qualified
to do business in any other  jurisdiction  and the failure to be so  qualified  
will not have a material  adverse  effect on  Target,  its  assets or  business.
Target has all requisite corporate power and authority to own, lease and operate
its properties and to carry on its business as it is now being conducted.  
Target has delivered to  Agouron  true,  correct  and  complete  copies of  
Target's  Certificate  of Incorporation and Bylaws and all amendments thereto 
(the "Target  Certificate of Incorporation"  and the "Target Bylaws,"  
respectively),  and true,  correct and complete  copies of the minutes of all 
meetings and other  corporate  actions of the  directors,  committees of the 
directors and of the  stockholders  of Target since inception.
         2.2    Capital Structure. At the date hereof, the authorized capital 
stock of Target consists of 40,000,000  shares of Target Common,  par value 
$.001, and 10,000,000 shares of preferred stock, par value $.001 ("Target  
Preferred").  At the date hereof, (a) 3,833,824 shares of Target Common are 
issued  and outstanding;  (b) not less than  1,011,086  shares of Target Common
are reserved for issuance upon exercise of the Target Options; and (c) Target is
obligated to issue 450,000 additional shares of Target Common pursuant to the 
Target Warrant. No  shares  of Target  Preferred  are  issued or  outstanding  
or  reserved  for issuance.  Target  has  attached  hereto as  Schedule  2.2 a 
true,  correct  and complete list of holders of Target  Common,  Target  
Options,  and of the Target Warrant,  showing the number of shares,  options and
warrants  held by each such stockholder, optionholder and warrantholder.
                  To the best knowledge of Target, all of the outstanding Target
Common,  Target  Options  and  Stock  Warrant  were  issued in  compliance  with
applicable  exemptions  from  registration   provisions  of  federal  and  state
securities  laws.  All of the  outstanding  shares  of  Target  Common  are duly
authorized,  validly  issued,  fully paid and  nonassessable  and not subject 
to preemptive rights created by statute,  Target's  Certificate of Incorporation
or Bylaws or any agreement to which Target is a party or is bound.
         2.3     Obligations With Respect to Capital Stock.  Target has provided
or shall provide any required   notices  of  the  Merger  or  the   transactions
contemplated  hereby  including the assumptions  provided for in Sections 1.5(d)
and  (e)  hereof  to  (or  obtain  required  consents  for  the  Merger  or  the
transactions  contemplated  hereby  including  the  assumptions  provided for in
Sections  1.5(d) and (e) hereof) the holders of all Target Options and the Stock
Warrant.  Except as set forth in Schedule 2.2, there are no equity securities of
any  class  of  Target,  or any  security  or  obligation  exchangeable  into or
exercisable  for such  equity  securities,  issued,  reserved  for  issuance  or
outstanding.  Except  as set  forth  in  Schedule  2.2,  there  are no  options,
warrants,  calls,  rights,  commitments  or agreements of any character to which
Target is a party or by which it is bound obligating Target to issue, deliver or
sell,  or cause to be issued,  delivered or sold,  additional  shares of capital
stock of Target or  obligating  Target to grant,  extend or enter  into any such
option,  warrant, call, right,  commitment or agreement. To the best of Target's
knowledge,  except as set forth on  Schedule  2.3,  there are no voting  trusts,
proxies or other  agreements  or  understandings  with  respect to the voting of
shares of capital stock of Target.
         2.4      Equity  Investments.  Target does not own and has not  
subscribed  or  otherwise  agreed to purchase  any equity  interest,  directly  
or  indirectly,  in any corporation, partnership, joint venture, firm or other
entity.
         2.5     Authority.  Target has all requisite corporate power and 
authority to enter into this Agreement and, subject to satisfaction of the 
conditions set forth herein (including, without limitation, Section 5.1(a)) and 
the approval of this Agreement and the transactions contemplated thereby by 
Target's stockholders,  to consummate the transactions  contemplated  hereby and
thereby. The execution and delivery by Target of this Agreement,  and the
consummation of the transactions contemplated hereby, have been duly authorized 
by all necessary corporate action on the part of Target. This Agreement, the 
Escrow Agreement and related  agreements  have been duly executed and  delivered
by Target,  and such agreements  constitute  valid and  binding  obligations  of
Target  enforceable against  Target  in  accordance  with  their  terms,  
subject  to the  effect of applicable bankruptcy, insolvency,  reorganization,  
moratorium or other similar federal  or state  laws  affecting  the  rights of 
creditors  and the effect or availability of rules of law governing specific  
performance,  injunctive relief or other equitable remedies (regardless of
whether any such remedy is considered in a  proceeding  at law or in equity). 
Provided  the  conditions  set forth in Article 5 are satisfied,  the execution 
and delivery of this Agreement does not, and the consummation of the 
transactions  contemplated hereby will not, conflict with, or result in any 
violation of or default (with or without  notice or lapse of time, or both) 
under, or give rise to a right of termination, cancellation or acceleration  of 
any  obligation or to loss of a material  benefit under (a) any provision  of  
Target's  Certificate  of  Incorporation  or  Bylaws  or (b)  any agreement  or 
instrument,  permit,  license,  judgment,  order or any  state or federal law, 
applicable to Target or its properties or assets, other than any such conflicts,
violations, defaults, terminations, cancellations or accelerations which 
individually or in the aggregate would not have a material adverse effect on 
Target taken as a whole.  Target has prepared and delivered to Agouron,  and
attached  hereto as Schedule  2.5, a full and complete list of all necessary  
consents,   waivers  and  approvals  ("Consents")  of  third  parties applicable
to the  operations  of Target  that are  required  to be obtained by Target in 
connection with the execution and delivery of this Agreement by Target and the 
performance of Target's obligations hereunder.
                  No  Consent,  order  or  authorization  of,  or  registration,
declaration  or filing with, any court,  administrative  agency or commission or
other governmental  authority or instrumentality (a "Governmental  Entity"),  is
required  by or with  respect to Target in  connection  with the  execution  and
delivery of this Agreement by Target and the  consummation  of the  transactions
contemplated  hereby,  except for (a) the filing of a Certificate  of Merger and
related certificates  with the office of the Secretary of State of the State of
Delaware, (b) such Consents, approvals, orders,  authorizations,  registrations,
declarations and filings as may be required under  applicable  federal and state
securities  laws  and the  laws of any  foreign  country,  and  (c)  such  other
Consents,  
approvals, orders,  authorizations,  registrations,  declarations and
filings which if not obtained or made would not have a material  adverse  effect
on Target.
         2.6     Financial  Statements.  Target has furnished to Agouron its 
audited balance  sheets as of December 31, 1995 and 1996 and the related  
statements  of operations,  changes in stockholders'  equity,  and cash flows
for the three (3) fiscal years ended  December 31, 1996, and attached as
Schedule 2.6 are Target's unaudited  balance  sheet as of March 31,  1997 and 
the  related  statements  of operations and cash flows for the three (3) months
then ended. The balance sheet at March 31, 1997 is hereinafter  referred to as 
the "Target Balance Sheet," and all such financial  statements are  hereinafter 
referred to collectively as the "Target  Financial  Statements."  The  Target  
Financial  Statements  have  been prepared  in  accordance  with GAAP  applied 
on a  consistent  basis  during the periods involved, except as noted in the 
Notes to the Financial Statements,  and are in  accordance  with  Target's  
books and  records,  and fairly  present the financial  position of Target and 
the results of its  operations  as of the date and for the  periods  indicated  
thereon,  subject in the case of the  unaudited portion of the Target  Financial
Statements,  to normal  recurring  adjustments which will not be material and 
the absence of footnote disclosures.  At the date of the Target  Balance Sheet 
(the "Target  Balance  Sheet Date"),  Target had no liabilities or obligations,
secured or unsecured  (whether  accrued,  absolute, contingent  or otherwise)  
not reflected on the Target  Balance Sheet except for liabilities  and  
obligations  as may have  arisen  in the  ordinary  course  of business  prior 
to the date of the Target  Balance Sheet and which,  under GAAP, would not have
been required to be reflected on the Target Balance Sheet.
         2.7     Business  Changes.  Since the Target Balance Sheet Date,  
except as otherwise contemplated by this Agreement, Target has conducted its 
business only in the ordinary and usual course and,  without  limiting the  
generality  of the foregoing:
                  (a) There have been no changes in the condition  (financial or
otherwise),  business,  stockholder's  equity,  assets,  properties,  employees,
operations,  obligations or liabilities of Target which, in the aggregate,  have
had or may be  reasonably  expected  to have a  material  adverse  effect on the
condition,  business,  stockholder's equity, assets, properties or operations of
Target.
                  (b) Target has not issued,  nor authorized  for issuance,  nor
entered into any commitment to issue, any equity  security,  bond, note or other
security  of Target,  except for Target  Common  issuable  upon the  exercise of
Target Warrants and Target Options.
                  (c)      Target has not incurred  additional  debt for
borrowed  money,  nor incurred any  obligation or liability  except in the 
ordinary and usual course of business.
                  (d)  Target  has not paid any  obligation  or  liability,  nor
discharged,  settled or satisfied  any claim,  lien or  encumbrance,  except for
current liabilities in the ordinary and usual course of business.
                  (e)      Target has not authorized, declared or made any 
dividend payment or other distribution on or with respect to any share of 
capital stock of Target.
                  (f)      Target has not purchased,  redeemed or otherwise  
acquired or committed  itself to acquire,  directly or  indirectly,  any share 
or shares of capital stock of Target.
                  (g)  Target  has  not   mortgaged,   pledged,   or  otherwise,
voluntarily or involuntarily,  encumbered or granted a lien or security interest
in any of its assets or properties, except for liens for current taxes which are
not yet delinquent and purchase-money  liens arising out of the purchase or sale
of services or products  made in the  ordinary  and usual  course of business or
other liens arising in the ordinary course of business.
                  (h) Except as contemplated  by this Agreement,  Target has not
disposed of, or agreed to dispose of, by sale, lease, license or otherwise,  any
asset or property,  tangible or intangible,  except,  in the case of such assets
and property, in the ordinary and usual course of business.
                  (i) Except for short-term  investment  securities,  Target has
not purchased or agreed to purchase or otherwise  acquire any  securities of any
corporation,  partnership,  joint venture,  firm or other entity; Target has not
made any  expenditure  or  commitment  for the purchase,  license,  acquisition,
construction or improvement of a capital asset.
                  (j)  Other   than   this   Agreement   and  the   transactions
contemplated hereby, Target has not entered into any transaction or contract, or
made any  commitment to do the same,  except in the ordinary and usual course of
business.
                  (k)      Target has not sold, assigned,  transferred or 
conveyed, or committed itself to sell, assign,  transfer or convey, any 
Proprietary Rights (as defined in Section 2.17).
                  (l)  Except as set forth in  Schedule  2.7(l),  Target has not
adopted or amended any bonus,  incentive,  profit-sharing,  stock option,  stock
purchase, pension, retirement, deferred-compensation, severance, life insurance,
medical or other benefit plan,  agreement,  trust,  fund or arrangement  for the
benefit of  employees  of any kind  whatsoever,  nor entered into or amended any
agreement  relating to  employment,  services as an  independent  contractor  or
consultant,  or  severance  or  termination  pay,  nor  agreed  to do any of the
foregoing.
                  (m) Target has not  effected or agreed to effect any change in
its  directors,  officers  or key  employees  except  as  contemplated  by  this
Agreement  and to Target's  best  knowledge no officer or key employee of Target
has  indicated  that he or she intends to terminate his or her  employment  with
Target.
                  (n) Target has not effected or committed  itself to effect any
amendment or modification in its Certificate of Incorporation or Bylaws,  except
as contemplated in this Agreement.
                  (o) To the best  knowledge  of  Target,  no  statute  has been
enacted nor has any rule or regulation been adopted by the States of Delaware or
California  nor to the knowledge of  management of Target,  has any statute been
enacted  nor has any rule or  regulation  been  adopted by any state  where laws
apply to the  business of Target or any federal  agency or  authority  which may
reasonably  be expected to have a material and adverse  effect on the  condition
(financial or otherwise),  business,  stockholder's equity, assets,  properties,
employees,  operations,  obligations  or liabilities of Target which has not yet
been reflected in the operating results of Target.
                  (p) Schedule 2.7 represents a true and correct  listing of all
known purchase  commitments as of the date hereof,  and, to the best of Target's
knowledge,  there are no additional purchase  commitments  totaling in excess of
$100,000.
         2.8      Properties.
                  (a) Target owns no real  property.  Target's  audited  balance
sheet at December 31, 1996 or the Target  Balance Sheet reflects all of the real
and  personal  property  used by Target in its  business  or  otherwise  held by
Target,  except for (i)  property  acquired or disposed of in the  ordinary  and
usual course of the business of Target since the date of such balance sheet, and
(ii) real and personal property not required under GAAP to be reflected thereon.
Except as reflected in the notes to Target's audited  balance sheet at 
December 31, 1996, or in the Target 
Balance Sheet, Target has good and marketable  title to all assets and  
properties  listed on the Target  Balance Sheet or thereafter acquired,  free 
and clear of any material  imperfections of title,  lien, claim, encumbrance, 
restriction, charge or equity of any nature whatsoever, except for the lien of 
current taxes not yet delinquent and minor liens that have arisen in the  
ordinary  course  of business  and  that  do not  (in  any  case or in the 
aggregate)  materially detract from the value of the assets subject  thereto or 
materially  impair  the operations  of  Target.  All of the  fixed  assets  and 
properties  reflected on Target's audited balance sheet at December 31, 1996, or
the Target Balance Sheet or thereafter acquired are in good condition and repair
in all material respects and are suitable for the conduct of Target's  business 
as it is now being conducted.
                  (b)  Target  is,  and at all  times  has been in all  material
respects,  in compliance  with all local,  state and federal  statutes,  orders,
rules,  ordinances  and  regulations  relating to pollution or protection of the
environment,   including,   without  limitation,  laws  relating  to  exposures,
emissions,  discharges,  releases or threatened releases of Hazardous Substances
and  the  reporting  thereof  into  or on  land,  ambient  air,  surface  water,
groundwater, personal property or structures (including the protection, cleanup,
removal,   remediation  or  damage  thereof),   or  otherwise   related  to  the
manufacture,   processing,  distribution,  use,  treatment,  storage,  disposal,
transport, discharge or handling of Hazardous Substances. "Hazardous Substances"
shall mean any pollutant,  contaminant,  material, substance or waste regulated,
restricted or  prohibited  by any law,  regulation or ordinance or designated by
any governmental  agency to be hazardous,  toxic,  radioactive,  biohazardous or
otherwise a danger to health or the environment.
                  (c)  Target  maintains  on  its  premises  certain   Hazardous
Substances  which it uses in the  ordinary  course  of its  business,  including
certain  radioactive,  chemical,  and  biological  substances,  all of which are
maintained in material compliance with applicable federal and state regulations.
To the best knowledge of Target,  Schedule 2.8(c) sets forth an accurate listing
of such items.  Target has not disposed of any Hazardous  Substances  (excluding
small amounts of office products that may be deemed Hazardous  Substances) on or
about such  premises.  To the best knowledge of Target,  no release,  discharge,
spillage  or  disposal  of any  Hazardous  Substance  and no soil,  water or air
contamination  by any Hazardous  Substance has occurred or is occurring in, from
or on the premises  the result of which would have an adverse  effect on Target.
Target has hired ▇▇▇▇▇▇ ▇▇▇▇ and  Associates and P.W.N.,  to Target's  knowledge
licensed and bonded  hazardous  waste  disposal  brokers,  to dispose of its low
level radioactive waste and hazardous waste,  respectively.  Target leases space
from General Atomics in a facility that contains multiple tenants. Target is not
aware of the existence of any  underground  storage tanks or of the existence of
any discharge of Hazardous  Substances at the facility by General Atomics or any
other tenant or subtenant  located in the General  Atomics  facility;  provided,
however, that Target has not conducted any independent investigation of the site
nor has Target commissioned a phase one or other environmental assessment of the
facility to identify  the  existence  of any  underground  storage  tanks or the
existence  of any  discharge  of  Hazardous  Substances  at the General  Atomics
facility by any person or entity.  To Target's  knowledge,  the General  Atomics
facility  contains  asbestos.  Target  has not,  and to its  knowledge,  General
Atomics has not, tested the General Atomics facility for radon contamination.
                  (d) There have been no judicial or administrative  proceedings
or other investigations and there are no judicial or administrative  proceedings
or other investigations pending or, to the best knowledge of Target,  threatened
alleging violation by Target of any local, state or federal laws respecting land
use, pollution or protection of the environment  including,  without limitation,
laws  regulating  the use,  storage,  transportation  or disposal  of  Hazardous
Substances and Target has not received any notice of any investigation, claim or
proceeding against Target by any individual or governmental  entity relating to
Hazardous  Substances and Target is not aware of any fact or circumstance  which
could involve Target in any environmental litigation, proceeding,  investigation
or claim or impose any environmental liability upon Target.
                  (e) Target has provided Agouron with a complete list, attached
hereto as Schedule 2.8(e), of all real property leased by Target or under option
to purchase by Target.  To Target's best  knowledge all such property  leased by
Target is held under valid,  subsisting and  enforceable  leases and to Target's
best  knowledge  neither  real  property  owned  or  leased  by  Target  nor the
operations of Target  thereon,  violate any applicable  material  building code,
zoning requirement or classification,  or pollution control ordinance or statute
relating to the property or to such  operations,  and such  nonviolation  is not
dependent, in any instance, on so-called nonconforming use exemptions.
                  (f) Target  has  provided  Agouron  with a true,  correct  and
complete list, attached hereto as Schedule 2.8(f), of all permits,  consents and
approvals  which to  Target's  best  knowledge  Target is required to have under
local, state or federal laws respecting land use, pollution or protection of the
environment  for the  construction  of its  facilities  and the operation of its
business.  Target has obtained each and every one of such permits,  consents and
approvals  and is, and at all times has been, in material  compliance  with each
and every one of the material terms and conditions thereof.  Further, all of the
listed permits,  consents and approvals are in full force and effect,  none have
been  modified,  and there is no  proceeding  pending  which  may  result in the
reversal,  rescission,  termination,  modification  or  suspension  of any  such
permit, consent or approval.
                  (g) Target has kept all records and made all filings  required
to be made by Target by all applicable local, state and federal laws relating to
land use,  pollution  and  protection  of the  environment  with  respect to all
exposures,  emissions,  discharges  and releases  into the  environment  and the
proper use, storage,  transportation  and disposal of all Hazardous  Substances,
except  where  such  failure  will not have a  material  adverse  effect  on the
operations of Target or result in a material liability.
         2.9     Personal  Property.  A true,  correct and complete list  
(excluding computer software  described in Schedule 2.29) of all tangible 
personal property having an individual  cost basis in excess of $10,000 (the 
"Scheduled  Assets") used in the  conduct of  Target's  business  as of the date
hereof (as it is now being  conducted  and it is proposed  to be  conducted)  is
attached  hereto as Schedule  2.9.  The  Scheduled  Assets are in good  
condition  and repair in all material respects and are suitable for the conduct
of Target's business as it is now being conducted.
         2.10    Taxes. Except as disclosed in Schedule 2.10, Target has duly 
filed with the appropriate United  States, state, local and foreign governmental
agencies all tax returns and reports  required to be filed (subject to permitted
extensions applicable to such filings), which returns are accurate and complete,
and has  paid or  accrued  in  full  all  taxes,  duties,  charges,  withholding
obligations  and  other  governmental  liabilities  as  well  as  any  interest,
penalties, assessments or deficiencies, if any, due to, or claimed to be due by,
any Governmental Entity. (All such items are collectively  referred to herein as
"Taxes".)  The Target  Balance  Sheet fully  accrues or reserves all current and
deferred Taxes. Target is not a party to any pending action or proceeding,  nor,
to the best knowledge of Target, is any such action or proceeding  threatened by
any  Governmental  Entity for the  assessment or collection of Taxes.  Since the
Balance Sheet Date,  no liability for Taxes has been incurred  other than in the
ordinary  course  of  business.  Target is not a party to any Tax  sharing,  Tax
allocation,  Tax  indemnity  or  statute  of  limitations  extension  or  waiver
agreement  and in  the  past  five  (5)  years  has  not  been  included  on any
consolidated, combined or unitary return with any entity.
         2.11    Compensation. Target has provided Agouron with a true, correct
and complete list of all directors, officers, employees or consultants of Target
as of April 15, 1997, specifying their names and job designations, their dates 
of hire,  the total  amount  paid or payable as wages,  salaries  or other forms
of direct compensation, and the basis of such  compensation,  whether  fixed or
commission or a combination thereof.  Target has provided and attached hereto as
Schedule 2.11, a 
list setting forth all amounts  (whether  currently  payable or
payable  in the  future)  relating  to a change  in  control  of Target to which
current or former  officers,  directors  or  employees of Target are entitled or
would become entitled after the Merger,  under the terms of any benefit or other
arrangements.
         2.12    Increases in  Compensation.  Except as set forth on Schedule 
2.12, since April 15, 1997,  Target has not paid or committed  itself to pay to 
or for the benefit of any of its directors, officers, employees or stockholders 
any compensation  of any kind other than  Target  Options  and wages,  salaries
and benefits at times and rates in effect  on April 15, 1997,  subject  to wage
increases  of less than ten  percent  paid or  payable to  employees  other than
officers and directors, nor has it effected or agreed to effect any amendment or
supplement  to any  employee  profit  sharing,  stock  option,  stock  purchase,
pension, bonus, incentive,  retirement,  medical reimbursement,  life insurance,
deferred compensation or any other employee benefit plan or arrangement.
         2.13     Compliance with Law.
                  (a) All material licenses,  franchises,  permits,  clearances,
consents,  certificates  and other  evidences  of  authority of Target which are
necessary to the conduct of Target's business  ("Permits") are in full force and
effect and Target is not in violation of any Permit in any material respect. The
business of Target has been conducted in compliance  with all  applicable  laws,
regulations,   orders  and  other  requirements  of  governmental   authorities,
including,   without  limiting  the  generality  of  the  foregoing,  all  laws,
regulations  and orders  relating to employment  practices and  procedures,  the
health  and  safety of  employees  and  export  controls,  except  where any non
compliance  has not had,  or would not have,  a material  adverse  effect on the
condition  (financial or otherwise),  business,  stockholder's  equity,  assets,
properties or operations of Target taken as a whole.
                  (b) There have been no judicial or administrative  proceedings
or other investigations and there are no judicial or administrative  proceedings
or other investigations pending or, to the best knowledge of Target,  threatened
alleging  violation by Target of any local,  state or federal laws,  regulations
and orders  respecting  the business of Target  including,  without  limitation,
laws,  regulations and orders promulgated under the Food and Drug Administration
Act and any foreign,  state or local agencies regulating clinical  laboratories;
and Target has not received any notice of any investigation, claim or proceeding
against  Target by any such  governmental  entity and Target is not aware of any
fact  or  circumstance  which  could  involve  Target  in any  such  litigation,
proceeding, investigation or claim or impose any such liability upon Target.
         2.14     Litigation.  There  is no  claim, dispute, action, proceeding,
notice,  order,  suit,  appeal or  investigation,  at law or in equity,  pending
against Target, or involving any of its assets or properties,  before any court,
agency,  authority,  arbitration  panel or other tribunal  (other than those, if
any, with respect to which service of process or similar notice has not yet been
made on  Target),  and to Target's  best  knowledge  none have been  threatened.
Target  is aware  of no  facts  which,  if  known  to  stockholders,  customers,
governmental  authorities  or other  persons,  would  result in any such  claim,
dispute, action, proceeding,  suit or appeal or investigation which would have a
material  adverse effect on the condition  (financial or  otherwise),  business,
stockholder's  equity,  assets,  properties  or  operations of Target taken as a
whole.  Target is not subject to any order,  writ,  injunction  or decree of any
court,  agency,  authority,  arbitration  panel or other tribunal,  nor is it in
default with respect to any notice, order, writ, injunction or decree.
         2.15     Contracts.
                  (a) Target  has  provided  Agouron  with a true,  correct  and
complete list,  attached hereto as Schedule 2.15, of each executory contract and
agreement in the following categories to 
which Target is a party, or by which it is bound in any respect:  (i) agreements
for the purchase,  sale, lease or other disposition of equipment, goods, 
materials, research and development,  supplies, studies or capital  assets,  or
for the  performance  of  services,  in any case involving  more  than  $10,000
(ii)  contracts  or  agreements  for the  joint performance  of work or 
services,  and all other joint venture or  collaborative agreements;  
(iii)  management or employment  contracts,  consulting  contracts,
collective  bargaining  contracts,  termination and severance  agreements;  (iv)
notes,  mortgages,   deeds  of  trust,  loan  agreements,   security  agreement,
guarantees,  debentures,  indentures,  credit  agreements and other evidences of
indebtedness;  (v) pension, retirement,  profit-sharing,  deferred compensation,
bonus,  incentive,  life insurance,  hospitalization  or other employee  benefit
plans  or  arrangements  (including,   without  limitation,   any  contracts  or
agreements  with trustees,  insurance  companies or others  relating to any such
employee  benefit plan or  arrangement);  (vi) except as otherwise  described in
Section  2.24,  stock  option,  stock  purchase,  warrant,  repurchase  or other
contracts or agreements relating to any share of capital stock of Target;  (vii)
contracts or agreements with agents, brokers,  consignees,  sale representatives
or  distributors;  (viii)  contracts or agreements  with any director,  officer,
employee,  consultant,  stockholder or relative thereof; (ix) powers of attorney
or similar  authorizations  granted by Target to third  parties;  (x)  licenses,
sublicenses,  royalty  agreements  and other  contracts or  agreements  to which
Target is a party, or otherwise subject,  relating to technical assistance or to
Proprietary Rights as defined below, except for off-the-shelf  business software
licenses;  (xi) confidentiality or similar agreements which restrict the actions
or rights of  Target;  and (xii) to the  extent  not  listed  elsewhere  in this
Agreement,  all other material  contracts.  As to any such contract or agreement
which is not in writing, Schedule 2.15 provides an accurate summary thereof.
                  (b) Neither  Target nor any of its  officers  has entered into
any contract or agreement  containing  covenants limiting the right of Target to
compete in any business or with any person. As used in this Agreement, the terms
"contract"  and  "agreement"  include  every  contract,  agreement,  commitment,
understanding and promise, whether written or oral.
         2.16     No Default.
                  (a) Each of the  contracts,  agreements  or other  instruments
referred to in Section 2.15(a) of this Agreement is, to Target's best knowledge,
a legal, binding and enforceable obligation by or against Target, subject to the
effect of applicable bankruptcy, insolvency, reorganization, moratorium or other
similar  federal or state laws  affecting the rights of creditors and the effect
or  availability  of rules of law  governing  specific  performance,  injunctive
relief or other  equitable  remedies  (regardless  of whether any such remedy is
considered in a proceeding at law or in equity). To Target's best knowledge,  no
party with whom Target has an agreement or contract is in default  thereunder or
has breached any terms or provisions thereof which is material to the conduct of
Target's business.
                  (b)  Target  has  performed,   or  is  now   performing,   the
obligations  of, and  Target is not in  default  (nor would by the lapse of time
and/or  the  giving  of notice be in  default)  in  respect  of,  any  contract,
agreement or commitment  binding upon it or its assets or  properties  which are
material  to the  conduct  of its  business.  Except  for those  matters  which,
individually  or in the  aggregate,  do not and  will not  materially  adversely
affect the business of Target,  no third party has raised any claim,  dispute or
controversy  with respect to any of the executory  contracts of Target,  nor has
Target received notice or warning of alleged nonperformance, delay in delivery 
or other  noncompliance  by Target with respect to its obligations  under any of
those contracts, nor, to the best knowledge of Target, are there any facts which
exist  indicating  that any of  those  contracts  may be  totally  or  partially
terminated or suspended by the other parties thereto.
         2.17     Proprietary Rights.
                  (a)  Schedule  2.17 sets forth in writing a true,  correct and
complete list of all patents and  applications  for patents,  trademarks,  trade
names, service marks, and copyrights, and applications therefore,  together with
the jurisdiction by, or in which such patents and applications have been issued,
registered  or  filed,  owned by  Target or in which  Target  has any  rights or
licenses. Schedule 2.17 also provides a listing of all agreements of Target with
each current  officer,  employee or consultant of Target  providing  Target with
title  and  ownership  to  patents,  patent  applications,   trade  secrets  and
inventions  developed or used by Target in its business.  All of such agreements
so described are valid,  enforceable and legally binding,  subject to the effect
or  availability  of rules of law  governing  specific  performance,  injunctive
relief or other  equitable  remedies  (regardless  of whether any such remedy is
considered in a proceeding at law or in equity).
                  (b)  Target  owns or  possesses  or has the  right  to  obtain
licenses or other rights to use all patents, patent applications, trade secrets,
copyrights,  inventions, drawings, designs, proprietary know-how or information,
or other rights with respect thereto  (collectively  referred to as "Proprietary
Rights"),  which are material to and are used in Target's business, and the same
are  sufficient  to conduct  Target's  business  as it has been and is now being
conducted.
                  (c) To Target's best  knowledge,  the  operations of Target do
not  conflict  with or  infringe,  and no one has  asserted  to Target that such
operations conflict with or infringe,  any Proprietary Rights or any trademarks,
trade  names or service  marks  (collectively  referred  to as  "Marks")  owned,
possessed or used by any third party.  There are no claims,  disputes,  actions,
proceedings,  suits or  appeals  pending  against  Target  with  respect  to any
Proprietary  Rights or Marks  (other than those,  if any,  with respect to which
service of process or similar notice may not yet have been made on Target),  and
none, to the best knowledge of Target,  has been threatened  against Target.  To
Target's  best  knowledge,  there  are no facts or  alleged  facts  which  would
reasonably serve as a basis for any claim that Target does not have the right to
use, free of any rights or claims of others, all Proprietary Rights and Marks in
the research, development, manufacture, use, sale or other disposition of any or
all products or services presently being used,  furnished or sold in the conduct
of Target's business as it has been and is now being conducted.
                  (d) As an attachment to Schedule 2.17, Target has delivered to
Agouron a list of any inter parties  proceedings  before any patent or trademark
authority to which Target is a party,  a  description  of the subject  matter of
each proceeding, and the current status of each proceeding,  including,  without
limitation,  interferences, priority contests, oppositions, and protests. To the
extent not otherwise included in the foregoing list, Target will also include in
such list any pending applications for reissue or reexamination of a patent.
                  (e)  Target  has  taken the  measures  described  on  Schedule
2.17(e) in order to maintain the  confidentiality of the processes and formulae,
research  and  development  results  and other  know-how,  the value of which to
Target is contingent upon maintenance of the confidentiality thereof.
                  (f) Each  employee  and  officer  of  Target  has  executed  a
Proprietary Information And Inventions Agreement ("Inventions Agreement") in the
form attached hereto as Schedule 2.17(f). To Target's best knowledge no employee
of Target is in  violation  of any  material  term of any  employment  contract,
Inventions  Agreement,  noncompetition  agreement,  or any  other  contract  or 
agreement  relating to the relationship of any such employee with Target, or, to
the knowledge of management of Target, any previous employer.
                  (g) To Target's best knowledge,  Target's  Proprietary  Rights
are free of any  unresolved  ownership  disputes with respect to any third party
and to Target's best knowledge there 
is no  unauthorized  use,  infringement or misappropriation of any of such
Proprietary Rights by any third party, including any employee or former employee
of Target.
         2.18     Insurance.  Target has provided Agouron with true, correct and
complete  copies of all policies of insurance to which Target is a party or is a
beneficiary  or named  insured.  A list of such policies is attached as Schedule
2.18.  Target has in full force and effect,  with all premiums due thereon paid,
such  policies of  insurance.  Target has  received no notices of  cancellation,
termination  or  non-renewal  with  respect  to such  policies  and has not been
refused any  insurances,  nor has its coverage  been  limited,  by any insurance
carrier.  All the  insurable  properties  of Target are  insured in amounts  and
coverages and against risks and losses as set forth on Schedule 2.18. There have
been no claims  asserted  under any of the insurance  policies of Target for the
period from Target's inception to the date of this Agreement.
         2.19     Bank Accounts. Target has furnished to Agouron a true, correct
and complete list, attached as Schedule 2.19, setting forth the names and 
addresses of all banks, other institutions and state governmental departments at
which Target has accounts, money market accounts, deposits or safety deposit 
boxes, or special deposits required to be held by such state governmental 
departments with the nature of such account and the names of all persons
authorized to draw on or give instructions  with respect to such accounts or 
deposits,  or to have access thereto,  and  the  names  and  addresses  of all  
persons,  if any,  holding  a power-of-attorney  on behalf of  Target.  All cash
in such  accounts  is held in demand  deposits  and is not  subject to any  
restriction  or  limitation  as to withdrawal.
         2.20    Brokers or Finders.  Other than ▇▇▇▇▇▇ Brothers, Target has not
dealt with any broker or finder in connection with the transactions contemplated
by this  Agreement.  Other than  certain  payments  which will be owed to ▇▇▇▇▇▇
Brothers,  Target has not incurred, and shall not incur, directly or indirectly,
any liability for any brokerage or finders' fees or agents'  commissions  or any
similar   charges  in  connection   with  this  Agreement  or  any   transaction
contemplated hereby.
         2.21     Certain  Advances.  Except as set forth on Schedule  2.21,  
there are no receivables of Target owing from directors, officers, employees,  
consultants or stockholders of Target, or owing by any affiliate of any director
or officer of Target.
         2.22     Related  Parties.  To Target's best knowledge, no officer or
director of Target, or any affiliate of any such person, has, either directly or
indirectly,  (a) an  interest  in any  corporation,  partnership,  firm or other
person or entity  which  competes,  or to Target's  knowledge  potentially  will
compete,  directly or indirectly,  with Target, or (b) a beneficial  interest in
any  contract or  agreement to which Target is a party or by which Target may be
bound.  For  purposes  of this  Section  2.22,  there shall be  disregarded  any
interest  which arose solely from the ownership of less than a five percent (5%)
equity interest in a corporation whose stock is regularly traded on any national
securities exchange or in the over-the-counter market.
         2.23    Employees  and  Union  Activities.  Target has complied  in all
material  respects  with all  applicable  state  and  federal  laws  related  to
employment.  None of  Target's  employees  is  represented  by any  union or are
parties to any collective  bargaining  arrangement,  and to the knowledge of the
management  of Target no attempts  are being made to organize or unionize any of
the Target employees.
         2.24     Benefit Plans.
                  (a) Target has  identified  on  Schedule  2.24 each  "employee
benefit  plan," as defined in Section  3(3) of the  Employee  Retirement  Income
Security Act of 1974, as amended ("ERISA"), and all other plans, agreements,  or
arrangements involving direct or indirect compensation (including any employment
agreements entered into between Target and any 
employee of Target, but excluding worker's compensation,  unemployment  
compensation and other government-mandated programs) currently or previously 
maintained,  contributed to or entered into by Target for the benefit of any 
employee or former  employee of Target under which Target has any present or 
future  obligation  or  liability  (collectively,  the "Employee  Plans"). 
Copies of all Employee Plans (and, if  applicable,  related trust   agreements),
all   amendments   thereto  and  all   material   written interpretations   
thereof,   including   (without   limitation)   summary   plan descriptions, 
have been made  available to Agouron,  together with (a) the most
recent annual report (Form 5500), including,  if applicable,  Schedule B thereto
prepared  in  connection  with any such  Employee  Plan and (b) the most  recent
actuarial  valuation  prepared in connection with any such Employee Plan. Target
has  identified  to  Agouron  which  of  its  Employee  Plans,  individually  or
collectively,  constitute  an "employee  pension  benefit  plan,)' as defined in
section 3(2) of ERISA (collectively, the "Pension Plans").
                  (b) No Pension Plan is subject to Title IV of ERISA, Part 3 of
Subtitle  B of Title I of ERISA or  section  412 of the Code.  No  Pension  Plan
constitutes  or has since the enactment of ERISA  constituted  a  "multiemployer
plan," as defined in section 3(37) of ERISA.  No  "prohibited  transaction,"  as
defined  in  section  406 of  ERISA  or  section  4975  of the  Code,  excluding
transactions effected pursuant to a statutory or administrative  exemption,  has
occurred  with respect to any Employee Plan which is covered by Title I of ERISA
which  would make  Target or any  officer  or  director  thereof  subject to any
liability  under Title I of ERISA or liable for any tax pursuant to section 4975
of the Code.
                  (c) To the best  knowledge  of Target,  (i) each  Pension Plan
which  is  intended  to be  qualified  under  section  401(a)  of the Code is so
qualified and has been so qualified during the period from its adoption to date,
except to the extent that the requirements for qualification may be satisfied by
adopting  retroactive  amendments  under  section  401(b)  of the  Code  and the
regulations  thereunder or under section 1140 of the Tax Reform Act of 1986, and
(ii) each  trust  forming a part of each such  Pension  Plan is exempt  from tax
pursuant to section  501(a) of the Code.  Target has made  available  to Agouron
copies of the most recent Internal  Revenue Service  determination  letters with
respect  to each  such  Pension  Plan.  Each  Pension  Plan has been  maintained
substantially in compliance with its terms and with the applicable  requirements
of ERISA and the Code.
                  (d) Target has furnished to Agouron copies or  descriptions of
each employment,  severance or other similar contract, arrangement or policy and
each plan,  agreement,  policy or  arrangement  (written or oral)  providing for
insurance coverage (including any self-insured arrangements), vacation benefits,
severance  benefits,  disability  benefits,  early  retirement  benefits,  death
benefits,  hospitalization benefits, retirement benefits, deferred compensation,
profit-sharing,  bonuses,  stock options,  stock purchase,  phantom stock, stock
appreciation or other forms of compensation  or  post-retirement  benefits which
(i) is not an Employee Plan, (ii) is entered into, maintained or contributed to,
as the case may be, by Target and (iii) covers any  employee or former  employee
of Target.  Such  contracts,  plans and  arrangements  as are  described in this
Section   2.24(d)  are  herein   referred  to   collectively   as  the  "Benefit
Arrangements."  Each Benefit  Arrangement  has been  maintained  in  substantial
compliance  with its terms and with the  requirements  prescribed by any and all
statutes,  orders,  rules and  regulations  which are applicable to such Benefit
Arrangements.
                  (e) There has been no amendment to, written  interpretation or
announcement  (whether  or not  written)  by  Target  relating  to, or change in
employee   participation  or  coverage  under,  any  Employee  Plan  or  Benefit
Arrangement  which would increase  materially  the expense of  maintaining  such
Employee Plan or Benefit  Arrangement above the level of the expense incurred in
respect thereof for the fiscal year ended December 31, 1996.
                  (f) Target has materially  complied with the  requirements  of
section 4980B of the Code with respect to any "qualifying  event" (as defined in
section  4980B(f)(3) of the Code)  
occurring  prior to and including the Closing Date,  and to the  actual  
knowledge  of  Target,  no tax  payable on account of section  4980B of the Code
has been  incurred  with  respect  to any  current or former employee of Target.
                  (g) Each Employee Plan or Benefit Arrangement  complies in all
material respects with all applicable requirements of (i) the Age Discrimination
in Employment Act of 1967, as amended, and the regulations thereunder,  and (ii)
Title VII of the Civil  Rights  Act of 1964,  as  amended,  and the  regulations
thereunder.
                  (h) There is no pending or, to the best  knowledge  of Target,
threatened  claim  or  litigation  relating  to any  Employee  Plan  or  Benefit
Arrangement.
         2.25    Underlying  Documents.  All documents furnished to Agouron as 
set forth on the Schedules attached hereto are true, correct, and complete 
copies, and  there  are no  amendments  or  modifications  thereto,  that  have 
not been disclosed to Agouron.
         2.26    Full  Disclosure.  Any information furnished  by or on behalf 
of Target to Agouron in writing pursuant to this Agreement (including, without
limitation,  all  information  and financial data  pertaining to Target) and any
information contained in the Schedules attached hereto, at any time prior to the
Effective Time, does not and will not contain any untrue statement of a material
fact and does not and will not omit to state any material fact necessary to make
any statement, in light of the circumstances under which such statement is made,
not misleading.
         2.27    Information  Statement and Other  Information.  On the date 
Target mails to the  Target  stockholders  its  information  statement  and  
disclosure documents  relating to the Merger and on the date its  stockholders' 
meeting is held, and on the Effective Time, Target's  information  statement and
disclosure documents  will  contain all  material  statements  concerning  
Target which are required to be set forth therein in accordance  with any  
applicable  federal or state  securities or corporate  laws,  except for any 
disclosure  obligations of Agouron  under any  federal or state  securities  
laws,  and at such  respective times,  the  information  statement  will not 
include any untrue  statement of a material fact  concerning  Target or omit to 
state any material fact  concerning Target required to be stated therein or 
necessary to make the statements therein not misleading in light of the 
circumstances in which they were made.
         2.28    Preliminary Prospectus.  The section entitled "Business" 
contained in the preliminary  prospectus  dated October 15, 1996, filed by 
Target with the SEC ("Preliminary  Prospectus") as part of Pre-Effective  
Amendment No. 4 to the Registration  Statement  on  Form  S-1  (Reg.  No.  
333-09929),   when  read  in conjunction with the section entitled "Risk 
Factors," did not contain any untrue statement of a material fact or omit to 
state a material fact necessary in order to make the statements made, in the 
light of the circumstances  under which they were made, not misleading as of 
October 15, 1996.  Target has not undertaken any obligation  to update,  and has
not  updated,  any  disclosure  contained in the Preliminary Prospectus.
         2.29    Computer  Programs  and  Databases.  Schedule 2.29 describes in
reasonable detail each of Target's  proprietary  computer programs and databases
used by Target in its drug discovery efforts, including the computer language in
which each of the programs is written (collectively the "Programs").  Target has
used the  Programs to develop its combinatorial  libraries  and Target has used 
certain of its combinatorial libraries to produce lead compounds,  including the
lead compounds described in Schedule 2.31. Target has provided to Agouron a true
and complete copy of the Alanex  Proprietary  Software User's Manual documenting
the key modules of Target's proprietary LiBrain software. The source code of the
Programs  is documented  in a manner  that is useable by a computer  programmer 
experienced with ISIS  databases,  MDL  programming  language and C programming 
language.  The Programs  routinely perform  substantially in accordance with the
written specifications set forth in Schedule 2.29, so as to produce the results 
set forth in
Schedule  2.29,  however,  there is no  guarantee  that use of the 
Programs will lead to the  discovery of lead  compounds or the  optimization  of
lead compounds. Target owns or has valid licenses to the Programs.
         2.30    Chemical  Libraries.  Schedule 2.30 accurately describes in all
material  respects  the number of  compounds,  purity,  and form of  synthesized
chemical  compounds  in Target's  library as of April 15,  1997.  Schedule  2.30
contains a list of reactions with reaction  codes and schematics  that have been
entered into Target's  database as of April 15, 1997. The listed  reactions have
been  validated  and entered into the  database and each such  reaction has been
used in the  construction  of one or  more  libraries.  As of  April  15,  1997,
Target's   combinatorial   library  contained  over  190,000  samples  that  are
immediately  retrievable.  All such samples were  synthesized in accordance with
the practices and procedures  outlined in Schedule 2.30. Target has followed the
practices  and  procedures  described  in  Schedule  2.30  with  respect  to the
construction,  synthesis,  maintenance,  and use of the  combinatorial  chemical
library.  To Target's  best  knowledge  and  belief,  the library is adequate to
deliver compounds for Target's current screening requirements.
         2.31    Target's Program Status. Schedule 2.31 accurately describes in 
all material respects Target's drug discovery programs  as of April  18, 1997,
including the number of compounds  screened,  the number of lead compounds,  the
program's molecular target or target's,  therapeutic use, commercial rights, and
other information related to Target's programs.
                                    ARTICLE 3
                        REPRESENTATIONS AND WARRANTIES OF
                       AGOURON AND ACQUISITION CORPORATION
         Except as  otherwise  set forth in the  Schedules  attached  hereto (it
being agreed that any item set forth in such Schedules  having relevance to more
than one of the following sections of this Agreement shall be recited in full or
cross-referenced  in each applicable section of the subject  Schedule),  Agouron
and Acquisition  Corporation represent and warrant to Target, and to and for the
benefit  of the  Target  Securityholders  as of the  date of this  Agreement  as
follows:
         3.1     Organization.  Each of Agouron and Acquisition Corporation is a
corporation (a) duly organized,  validly existing and in good standing under the
laws of the  State  of  California  and  Delaware,  respectively;  and (b)  duly
qualified  and in good  standing  to do  business  in  California  and  Delaware
respectively.  Each of Agouron and  Acquisition  Corporation  has all  requisite
power and authority to own, lease and operate its properties and to carry on its
business as now being conducted, and possesses all licenses,  franchises, rights
and privileges material to the conduct of its respective business.
         3.2    Acquisition  Corporation Capital Structure.  The authorized 
capital stock of Acquisition  Corporation  consists of 100 shares of Common 
Stock,  $.01 par  value  ("Acquisition  Corporation  Common").  Upon  the  
execution  of this Agreement,  100 shares of Acquisition Corporation Common were
validly issued and outstanding and were held by Agouron of record and
beneficially.
         3.3    Authority.  Agouron and Acquisition Corporation have all 
requisite corporate power and authority to enter into this Agreement and the 
related agreements  contemplated  herein, and, subject to satisfaction of the 
conditions set forth  herein,  to  consummate  the  transactions  contemplated  
hereby and thereby. The execution and delivery of this Agreement and the related
agreements contemplated hereby and thereby and the consummation of the 
transactions contemplated  hereby and  thereby  have been duly  authorized  by 
all  necessary corporate  action on the part of Agouron and Acquisition  
Corporation and by the stockholders  of  Acquisition  Corporation.   This  
Agreement  and  the  related agreements contemplated hereby and thereby have 
been duly executed and delivered by  Agouron  and  Acquisition  Corporation  and
constitute  valid  and  binding obligations of Agouron and Acquisition 
Corporation,  enforceable against each of them in  accordance  with  their 
terms,  subject  to the  effect of  applicable bankruptcy, insolvency,  
reorganization,  moratorium or other similar federal or state laws affecting the
rights of creditors and the effect or availability of rules of law governing 
specific  performance,  injunctive  relief  or  other equitable  remedies  
(regardless  of whether any such remedy is  considered in a proceeding at law or
in equity).  Provided the conditions set forth in Article 5 are  satisfied,  the
execution and delivery of this  Agreement,  and the related agreements  
contemplated hereby do not, and the consummation of the transactions
contemplated  hereby will not,  conflict  with, or result in any violation of or
default (with or without  notice or lapse of time, or both) under,  or give rise
to a right of termination,  cancellation or acceleration of any obligation or to
loss of a material benefit,  or result in the creation of any lien,  encumbrance
or  restriction in favor of any third party upon any of the assets or properties
of Agouron,  under (a) any provision of the Articles of  Incorporation or Bylaws
of Agouron,  (b) any provision of the Certificate of  Incorporation or Bylaws of
Acquisition  Corporation  or (c) any agreement or instrument,  permit,  license,
judgment,  order,  statute,  law,  ordinance,  rule or regulation  applicable to
Agouron or  Acquisition  Corporation or their  respective  properties or assets,
other than any such conflicts, violations, defaults, terminations, cancellations
or  accelerations  which  individually  or in the  aggregate  would  not  have a
material adverse effect on Agouron and Acquisition Corporation taken as a whole.
         3.4    Agouron Capital Structure.  The authorized capital stock of 
Agouron consists of 75,000,000 shares of Common  Stock, no par value, and 
2,000,000 shares of Preferred  Stock,  no par value. At the close of business on
March 31, 1997 (a) 13,669,169  shares of Agouron Common were issued and  
outstanding;  (b) 5,447,473  shares of Agouron  Common were reserved for 
issuance upon exercise of options (the "Agouron Options") under the 1985 Stock 
Option Plan, the 1990 Stock Option  Plan and the 1996  Stock  Option  Plan,  of 
which  3,983,706  options to purchase  shares were  outstanding and (c) 139,617 
shares of Agouron Common were reserved  for  issuance  under the Agouron  
Employee  Stock  Purchase  Plan.  In November,  1996,  Agouron adopted a 
stockholder  rights plan  contemplating  the issuance of rights to  purchase  
Series B Preferred  Stock to  Agouron's  common shareholders.  Except as set 
forth above,  there are no equity securities of any class of Agouron, or any 
security or obligation exchangeable into or exercisable for any equity  
securities  of Agouron  issued or  outstanding  or reserved  for issuance.  
Except as set forth above, there are no options (other than under the Agouron  
stock  option  plans  referred  to  above),  warrants,  calls,  rights, 
commitments,  or  agreements  of any character to which Agouron is a party or by
which it is bound obligating  Agouron to issue,  deliver or sell, or cause to be
issued,  delivered  or sold,  additional  shares  of  Agouron  capital  stock or
obligating  Agouron  to grant,  extend or enter into any such  option,  warrant,
call, right, commitment, or agreement.
         All of the outstanding  shares of Agouron Common are, and any shares of
Agouron  Common  issuable  upon  exercise  of any  Agouron  Option,  when issued
pursuant to such exercise,  will be duly authorized, validly issued, fully paid
and nonassessable.
         3.5    Shares of Agouron  Common.  The shares of Agouron Common will, 
when issued and delivered to the Target Stockholders in  accordance  with  this
Agreement, be duly authorized, validly issued, fully paid and nonassessable, and
issued in compliance with applicable federal and state securities laws.
         3.6     Brokers  or  Finders.  Other than PaineWebber Incorporated and
Westview Securities Inc., neither Agouron nor Acquisition  Corporation has dealt
with any broker or finder in connection  with the  transactions  contemplated by
this  Agreement.  Other than certain  payments which will be owed to PaineWebber
Incorporated  and Westview  Securities  Inc.,  neither  Agouron nor  Acquisition
Corporation has incurred,  and neither shall incur, directly or indirectly,  any
liability  for any  brokerage  or  finders'  fees or agents  commissions  or any
similar   charges  in  connection   with  this  Agreement  or  any   transaction
contemplated hereby.
         3.7    Agouron Financial Statements.  Agouron has delivered to Target a
complete and accurate  copy of each report,  schedule  (other than  registration
statements),  and definitive proxy statement filed by Agouron with the SEC on or
after June 30, 1996 (the "Agouron SEC Reports"),  which are all such reports and
documents (other than registration  statements)  required to be filed by Agouron
with the SEC  since  June 30,  1996.  Each of the sets of  financial  statements
(including,  in each case,  any notes  thereto)  contained  in the  Agouron  SEC
Reports (i)  complied as to form in all  material  respects  with the  published
rules and  regulations  of the SEC  applicable  thereto;  (ii) was  prepared  in
accordance  with GAAP  applied on a  consistent  basis  throughout  the  periods
involved  (except as may be  indicated in the notes  thereto);  and (iii) fairly
presents the financial  position of Agouron at the respective  dates thereof and
the results of operations and cash flows for the periods indicated.
         3.8    Litigation.  Except as may be disclosed in the Agouron SEC 
Reports, there  are no legal  proceedings  to which  Agouron  is a party or of 
which  its property  is subject  which are  material in  relation  to  Agouron's
financial statements.
         3.9    Absence of Changes. Between June 30, 1996, the date of Agouron's
last audited financial statement, and the date of this Agreement,  there has not
been any  event  that has had or will  have a  material  adverse  effect  on the
business, assets, properties,  operations, or condition (financial or otherwise)
of Agouron.
         3.10   Eligibility  to Use Form S-3.  As of the date of this Agreement,
Agouron is  eligible  to use SEC Form S-3 to  register  for resale the shares of
Agouron  Common to be issued to the Target  Stockholders  in the Merger and will
take all actions necessary in order to maintain such eligibility until such time
as the shares of Agouron Common to be issued to the Target  Stockholders  in the
Merger are registered,  such registration statement has become effective and for
a period of one (1) year following the Closing.
         3.11   Disclosure. None of the information to be supplied by Agouron or
Acquisition  Corporation for inclusion in Target's  information  statement to be
sent to holders of Target Common will at the time such information  statement is
supplied to Target,  contain any untrue  statement of a material fact or omit to
state any material fact  required to be stated  therein or necessary in order to
make the statements therein, in light of the circumstances under which they were
made, not misleading.
                                    ARTICLE 4
                              ADDITIONAL AGREEMENTS
         4.1    Legal Conditions to the Merger. Each party will take all 
reasonable actions  necessary to comply promptly with all legal requirements 
which may be imposed  on such party with  respect to the Merger and will  
promptly  cooperate with and furnish  information to the other parties hereto in
connection with any such requirements  imposed upon the other parties in 
connection with the Merger. Each party will take all reasonable actions to 
obtain (and to cooperate with the other  parties,  if any, in  obtaining)  any  
consent,  authorization,  order or approval of, or any exemption  by, any  
governmental  authority,  or other third party,  required to be  obtained or 
made by such party,  if any (or by the other parties), in connection with the
Merger or the taking of any action contemplated thereby or by this Agreement.
         4.2    Target  Stockholders'  Approval.  Target  agrees to use its best
efforts  to  promptly  submit  this  Agreement  and any  related  matters to its
stockholders for approval, by means of an information statement, all as provided
by law and its Certificate of Incorporation  and Bylaws, at a meeting which will
be held as soon as practicable after the date of this Agreement.
         4.3    Delivery  of Stock  Certificates.  Subject to the provisions of
Article 8 hereof,  Agouron  will issue and  deliver as and when  required by the
provisions  of this  Agreement,  the  certificates  representing  the  shares of
Agouron  Common into which the shares of Target Common  outstanding  immediately
prior to the Effective Time shall have been converted.
         4.4    Good Faith.  Each party shall act in good faith in an attempt to
cause to be satisfied all the conditions  precedent to its obligations and those
of the other parties to this Agreement over which it has control or influence.
         4.5    Update to Disclosures.  Without limiting a party's right to rely
on the representations and warranties as of the date of this Agreement,  each 
party shall provide the other parties with updates to the disclosures provided 
or made available to such parties as to material  facts which arise  between the
date of this  Agreement  and the Closing  Date and which,  if they had occurred
and been known prior to the date of this Agreement, would have been required to 
have been disclosed  in order to make the  representations  and  warranties  
contained  in Article  2 or 3, as the case may be,  true  and  correct  as of
the date of this Agreement.
         4.6    No  Solicitation.  Unless and until this Agreement  shall have 
been terminated  pursuant  to  Section  10.1  hereof,  neither  Target nor any
of its officers,  directors,  agents,  representatives or affiliates shall, 
directly or indirectly,  take any of the following actions with any party other
than Agouron and its  designees:  (i)  solicit,  initiate  or,  except  as  
required  by law, including  actions  which  the  Target  Board  of  Directors 
determines  (after consultation  with legal counsel) are required  pursuant to 
its fiduciary duties under   applicable  law,   participate  in  or  encourage  
any  negotiations  or discussions   with   respect  to  any  offer  or  proposal
to  acquire  all  or substantially all of Target's  business,  properties or 
capital stock whether by merger,  purchase of assets, tender offer or otherwise,
(ii) except as required by law, including actions which the Target Board of 
Directors  determines (after consultation  with legal counsel) are required 
pursuant to its fiduciary duties under applicable law, disclose any information 
not customarily  disclosed to any person  concerning  Target's  business and 
properties or afford to any person or entity access to its properties,  books or
records, or (iii) assist or cooperate with any person to make any  proposal to 
consummate a  transaction  of the type referred  to in clause (i).  In the event
Target  shall  receive  any offer or proposal, directly or indirectly, of the 
type referred to in clause (i) or (iii) above,  or any request for  disclosure 
or access  pursuant to clause (ii) above, Target shall  promptly  inform Agouron
as to any such offer or proposal and will cooperate  with Agouron by furnishing
any  information  Agouron may  reasonably request.  If Target  or any  Target  
Stockholder  shall  engage in any  activity described in clause (i) through 
(iii)  above,  whether or not required to do so pursuant to fiduciary  duty or 
by law, and as a result thereof this Agreement is terminated,  Target shall be 
liable to Agouron in the amount of $1,000,000 which shall be Agouron's sole and 
exclusive remedy.
         4.7    Exempt Transaction.  Each party shall take all actions necessary
or advisable for the issuance of shares of Agouron Common in connection with the
Merger to qualify as a transaction  exempt from the  registration  provisions of
Section 5 of the  Securities  Act of 1933,  as amended,  pursuant to Rule 506 of
Regulation D promulgated  thereunder ("Regulation  D"). In connection  with the 
distribution to the Target Stockholders of the  Information  Statement,  Target
agrees to use its best efforts to cause each Target  Stockholder  to complete an
investment  representation   letter  in  a  form   provided   by   Agouron   (a
"Representation  Letter")  provided that any expense  Target incurs shall not be
included in the  expenses  subject to Article 9. To the extent  that  Agouron or
counsel for Agouron reasonably  determines that a holder of Target Common is not
sophisticated  for purposes of Rule 506 of  Regulation  D, Target agrees that it
shall retain a "Purchaser  Representative" (as defined in Rule 501 of Regulation
D) to assist such  holder(s) in  evaluating  the  Information  Statement and the
investment   decision   represented  by  this  Agreement  and  the  transactions
contemplated hereby (including, without limitation, the Merger).
         4.8    Lock-up. Each of the Principal Stockholders of Target agrees not
to sell more than 25% of the Agouron Common, including  Agouron Common issued on
exercise of Target  Options,  received  in the Merger  within the first 12 month
period  following  the  Closing  Date and will not sell more  than a  cumulative
aggregate of 75% of such shares  received in the Merger during the subsequent 12
month  period  without the written  permission  of  Agouron.  This lockup  shall
terminate at the end of the 24th month following the Closing Date.
         4.9    Adjustments of Agouron Common. If, prior to Closing, Agouron 
shall effect a stock split, reverse stock split, consolidation,  
reclassification,  or other similar  change to its capital stock or make any
distribution  of capital stock or any security  convertible  into Agouron 
capital stock to the holders of Agouron  capital  stock,  the  holders of Target
Common and Target  Options and Target  Warrants shall have the right to receive 
upon such stock split,  reverse stock split,  consolidation,  reclassification,
or distribution  that number of shares of Agouron Common such Holder would have
been entitled to receive had the Closing been held  immediately  prior to such
stock split,  reverse stock split, consolidation, reclassification, or 
distribution.
         4.10   S-8 Registration of Agouron Common.  At the time of closing of 
the Merger,  Agouron shall prepare and file with the SEC a registration 
statement on Form S-8  registering  for sale the  shares  of  Agouron  Common 
issuable  upon exercise of the Target Options.
         4.11   Certain   Federal  Income  Tax Matters.   Target,  Agouron  and
Acquisition  Corporation acknowledge and agree that (i) each of them intends the
Merger to constitute a  reorganization  within the meaning of Section  368(a) of
the Internal  Revenue  Code of 1986,  as amended  (the  "Code"),  (ii) they will
report the Merger as such a  reorganization  in any and all federal,  state, and
local income tax returns  filed by them,  and (iii)  Agouron shall not knowingly
take any action which will destroy the tax free status of the Merger,  provided,
however,  Agouron  may rely on an opinion of  Pillsbury,  Madison & Sutro LLP in
this regard.
         4.12   Exchange  Act  Filings.  Agouron  and  Acquisition   Corporation
acknowledge and agree that the Target Securityholders ability to sell the shares
of Agouron  Common to be received by each of them in the Merger may be dependent
on the timely filing by Agouron of all reports which are required to be filed by
Agouron pursuant to Section 13 of the Securities Exchange Act of 1934 ("Exchange
Act").  Consequently,  Agouron agrees to use its best efforts to timely file all
Exchange  Act  reports  required to be filed by it pursuant to Section 13 of the
Exchange Act.
         4.13   Listing of Agouron Common.  Agouron shall use its best efforts 
to obtain approval for the listing on The Nasdaq Stock Market, subject to 
official notice of issuance,  of the shares of Agouron  Common to be issued to
the Target Securityholders in the Merger.
         4.14   Best Efforts. During the period from the date of this Agreement 
to the Closing Date,  (i) Target shall use its best efforts to cause the 
conditions set forth in Section 5.1, to the extent it has control over such 
conditions, and Section 5.2 to be satisfied on a timely basis,  and 
(ii) Agouron and Acquisition Corporation  shall use their best efforts to cause 
the conditions  set forth in Section 5.1, to the extent either of them has 
control over such conditions, and Section 5.3 to be satisfied on a timely basis.
         4.15    Notification  of Breach.  During the period from the date of 
this Agreement  to the  expiration  of the Escrow,  Target,  Agouron and 
Acquisition Corporation,  as the case may be, shall promptly notify the others 
of any action or inaction by any of them or any other person which shall render
inaccurate in any  material  respect  any of the  respective  representations 
and  warranties contained herein.
         4.16   Public  Announcement.  Agouron and Target shall consult with 
each other before issuing any press release or otherwise making any public 
statements with respect to the Merger and 
the transactions  contemplated thereby and shall mutually  agree as to the  
timing and  content  of such press release or public statement.  Without 
limiting the generality of the foregoing, neither Target nor Agouron  shall  
(and  neither  Target  nor  Agouron  shall  permit  any  of  its representatives
to)  issue  any  press  release  or make any  public  statement regarding this 
Agreement or the Merger, or any  transactions  contemplated hereby or  thereby, 
without  the other  party's  prior  consent,  except as  otherwise required to 
be made under applicable law.
         4.17   Tax  Representations.  Agouron and Acquisition Corporation  hall
provide ▇▇▇▇▇▇ Godward LLP with  customary  representation  letters which ▇▇▇▇▇▇
Godward  LLP will rely upon in  rendering  its tax  opinion as  contemplated  by
Section 5.3(g).
                                    ARTICLE 5
                              CONDITIONS PRECEDENT
         5.1    Conditions to Obligations of Agouron, Acquisition Corporation 
and Target to Effect the Merger. The obligations of Agouron, Acquisition 
Corporation and Target to effect the Merger shall be subject to the satisfaction
on or prior to the  Closing  Date of the  following  conditions  unless  waived
by  Agouron, Acquisition Corporation and Target:
                  (a) Stockholder  Approval.  This Agreement shall have been 
approved and adopted by the required affirmative vote of the holders of the 
outstanding shares of Target Common.
                  (b) Government Approvals. All authorizations, consents, orders
or approvals  of, or  declarations  or filings  with,  or  expiration of waiting
periods imposed by, any governmental authority necessary for the consummation of
the transactions  contemplated by this Agreement including any such requirements
under  applicable  federal  or state  securities  laws  shall  have been  filed,
occurred or been obtained,  other than filings with and approvals by governments
relating to the Merger if failure to make such filings or obtain such  approvals
would not be materially adverse to Agouron or Target.
                  (c) Third-Party Approvals.  Any and all notices to or consents
or approvals required from third parties in order to consummate the transactions
contemplated  herein  relating to contracts,  agreements,  licenses,  leases and
other instruments,  material to the respective  businesses of Agouron and Target
shall have been given or obtained, as the case may be.
                  (d) Legal Action. No temporary restraining order,  preliminary
injunction or permanent injunction or other order preventing the consummation of
the Merger  shall have been  issued by any  federal or state court and remain in
effect,  and no  litigation  seeking the issuance of such an order or injunction
shall be pending which,  in the good faith judgment of Target or Agouron,  has a
reasonable probability of resulting in such order, injunction or damages. In the
event any such order or injunction shall have been issued,  each party agrees to
use its reasonable efforts to have any such injunction lifted.
                  (e) Statutes.  No statute,  rule or regulation shall have been
enacted by any Governmental  Entity which would (i) make the consummation of the
Merger illegal, (ii) prohibit Agouron's or Surviving  Corporation's ownership or
operation of all or a material  portion of the business or assets of Target,  or
compel Agouron or Surviving  Corporation to dispose of or hold separate all or a
material portion of the business or assets of Target, as a result of the Merger,
or (iii) render Agouron,  Target or Acquisition Corporation unable to consummate
the Merger, except for any waiting period provisions.
         5.2    Conditions to Obligations of Agouron and Acquisition 
Corporation. The obligations of Agouron and Acquisition  Corporation to effect 
the Merger are subject to the  satisfaction  on or prior to the Closing  Date of
the  following additional conditions, unless waived by Agouron:
                  (a)  Representations  and Warranties.  The representations and
warranties  of Target set forth in this  Agreement  shall be true,  correct  and
complete in all  material  respects  (without  such  qualification  reducing the
intended meaning of such representations and warranties) as of the Closing Date,
and Agouron  shall have  received a certificate  or  certificates  signed by the
chief executive officer of Target to such effect.
                  (b)  Performance of  Obligations of Target.  Target shall have
performed in all respects all  obligations  required to be performed by it under
this  Agreement  prior to the Closing  Date,  and Agouron  shall have received a
certificate signed by the chief executive officer of Target to such effect.
                  (c)  Opinion of Target's Counsel.  Agouron shall have received
an opinion dated the Closing Date of ▇▇▇▇▇▇ Godward LLP., counsel to Target,  
substantially in the form attached hereto as Exhibit D.
                  (d)  Resignation  of Target Board of Directors.  Each director
of Target shall have  submitted  his or her  resignation  to be effective no l
ater than the Effective Time.
                  (e)  Due Diligence  Review.  Agouron shall have  completed,  
to its  satisfaction,  a due diligence  review of Target and not have discovered
any material adverse condition in the financial condition, assets or liabilities
of Target.
                  (f)  Employment and Non-Compete  Agreements.  Execution of 
mutually acceptable employment and non-compete agreements with ▇▇▇▇▇▇ ▇. ▇▇▇▇▇,
M.D., ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇, Atsuo Kuki, and ▇▇▇▇ ▇▇▇.
                  (g)  Consents.  Target shall have obtained all material 
consents, waivers, and approvals set forth on Schedule 2.5. 
                  (h)  No Material  Adverse Change.  There shall not have been a
material  adverse change in the business,  assets,  properties,  operations,  or
conditions (financial or otherwise) of Target since December 31, 1996.
                  (i)  Escrow Agreement.  An Escrow Agreement in the form 
attached hereto shall have been duly executed and delivered by Target.
                  (j)  Dissenting Target Common.  The number of Dissenting 
Target Common shall not exceed six percent (6%) of the Target Common outstanding
at the record date set by Target for the stockholder's  meeting called for the 
purposes of approving the transactions referred to herein.
         5.3     Conditions to Obligations of Target.  The  obligations of 
Target to effect the Merger are  subject to the  satisfaction  on or prior to 
the Closing Date of the following additional conditions unless waived by Target:
                  (a)  Representations  and Warranties.  The representations and
warranties of Agouron and  Acquisition  Corporation  set forth in this Agreement
shall be true,  correct and  complete in all  material  respects  (without  such
qualification   reducing  the  intended  meaning  of  such  representations  and
warranties) as of the Closing Date, except as otherwise  contemplated  herein or
therein,  and Target  shall  have  received  a  certificate  signed by the chief
executive officer of Agouron to such effect.
                  (b)  Performance  of  Obligations  of Agouron and  Acquisition
Corporation.  Agouron and  Acquisition  Corporation  shall have performed in all
respects all  obligations  required to be performed by them under this Agreement
prior to the Closing Date,  and Target shall have received a certificate  signed
by the chief executive officer of Agouron to such effect.
                  (c) Opinion of Agouron's  Counsel.  Target shall have received
an opinion dated the Closing Date of Agouron's General Counsel,  or of Pillsbury
Madison & Sutro,  counsel to Agouron,  substantially in the form attached hereto
as Exhibit C.
                  (d)  Trading.  There shall not have occurred and be in effect
at the Effective  Time any suspension in trading of shares of Agouron Common on 
any exchange or quotation system on which Agouron Common is trading.
                  (e)  No Material  Adverse Change.  There shall not have been a
material  adverse change in the business,  assets,  properties,  operations,  or
conditions (financial or otherwise) of Agouron since June 30, 1996.
                  (f)  Listing of Additional Shares.  The filing with The Nasdaq
Stock  Market of a  Notification  Form for  Listing of  Additional  Shares  with
respect to the shares of Agouron Common  issuable to the Target  Securityholders
in the Merger shall have been made.
                  (g)  Tax  Opinion.  The Target  Securityholders  shall have  
received an opinion of ▇▇▇▇▇▇  Godward LLP in a customary  form to the effect 
that the Merger qualifies as a tax-free reorganization within Section 368(a) of
the Code.
                  (h)  Employment and  Noncompetition  Agreements.  gouron shall
have  executed  and  delivered  to each of  ▇▇▇▇▇▇  ▇.  ▇▇▇▇▇,  M.D.,  ▇▇▇▇▇▇▇▇▇
▇▇▇▇▇▇▇▇,  Atsuo Kuki, and ▇▇▇▇ ▇▇▇ an employment  agreement and  noncompetition
agreements,  each containing terms and conditions  acceptable to each respective
party.
                  (i)  Escrow Agreement.  An Escrow Agreement in the form 
attached hereto shall have been duly executed and delivered by Agouron and the
Escrow Agent.
                                    ARTICLE 6
                                     CLOSING
         6.1    Closing Date.  The Closing under this Agreement (the "Closing")
shall be held not more than two (2) business days following the later of (a) the
approval of the Merger by the stockholders of Target at the Target stockholders'
meeting and (b)  satisfaction  of all other conditions  precedent to the Merger 
specified  in this  Agreement,  unless  duly waived  by the party  entitled  to 
satisfaction  thereof.  Such date on which the  Closing  is to be held is herein
referred to as the "Closing  Date." The Closing  shall be held at the offices of
▇▇▇▇▇▇ Godward LLP in San Diego, California,  at 10:00 A.M. on the Closing Date,
or at such other time and place as Agouron,  Acquisition  Corporation and Target
may agree upon in writing.  The parties will use their best efforts to close the
Merger within  twenty-five (25) days of the execution of this Agreement,  but in
any event, not later than May 31, 1997. 
         6.2   Filing Date.  Subject to the provisions of this Agreement, on the
Closing Date a fully executed and acknowledged  Certificate of Merger along with
any required related certificates of Target and Acquisition  Corporation meeting
the requirements of the Delaware General 
Corporation Law shall be filed with the office of the  Secretary of the State o
Delaware,  all in  accordance  with the provisions of this Agreement and
applicable law.
         6.3    Registration Procedures and Expenses.  Agouron shall:
                  (a) as soon as  practicable  (but in any event  within  thirty
(30) days  following  the Closing and issuance of shares of Agouron  Common with
respect thereto (the "Issuance")),  prepare and file with the SEC a registration
statement on Form S-3 (the "Registration  Statement") for the registration of an
aggregate of (i) twenty-five percent (25%) of the shares of Agouron Common to be
issued to the Principal  Stockholders in the Merger; and (ii) forty-nine percent
(49%) of the  shares of  Agouron  Common to be issued to the  holders  of Target
Common  (other  than the  Principal  Stockholders)  in the  Merger,  in order to
register  with  the  SEC  the  resale  of  such  Agouron  Common  by the  Target
Stockholders from time to time through the underwriters, agents or otherwise, in
negotiated or market  transactions or through the automated  quotation system of
The Nasdaq Stock Market or the facilities of any national securities exchange on
which Agouron Common is then traded or in privately negotiated transactions;
                  (b) use best  efforts,  subject to the  receipt  of  necessary
information from the Target Stockholders, to cause the Registration Statement to
become effective promptly after such Registration  Statement is filed by Agouron
with the SEC;
                  (c) use best  efforts  to  prepare  and file with the SEC such
amendments and  supplements to each  Registration  Statement and each prospectus
used in  connection  therewith  as may be  necessary  to keep  the  Registration
Statement  effective  for a period of one (1) year  following  the Issuance (the
"Registration Period") or, if earlier, until all of the Agouron Common have been
sold pursuant thereto;  provided,  however,  that Agouron shall not be deemed to
have  used best  efforts  to keep the  Registration  Statement  effective  if it
voluntarily takes any action that would result in the Target Stockholders (other
than for limited  lock-up periods for all officers of Agouron as may be required
by underwriters in any public offerings of Agouron securities) not being able to
sell  any of  their  respective  Agouron  Common  pursuant  to the  Registration
Statement  unless (i) such action is required  under  applicable law or taken by
Agouron  in good  faith  and for  valid  business  reasons,  including,  without
limitations,  the acquisition or divestiture of assets and (ii) Agouron promptly
(but in any event within thirty (30) days) files such amendments and supplements
with the SEC;
                  (d)  furnish to the Target  Stockholders  with  respect to the
Agouron Common registered under the Registration Statement such number of copies
of  the  Registration   Statement  (and  exhibits   thereto),   prospectuses  or
preliminary  prospectuses in conformity with the  requirements of the Securities
Act in order to facilitate the public sale or other  disposition of such Agouron
Common by the Target Stockholders;
                  (e) file  documents  required  of Agouron  for normal blue sky
clearance in states reasonably  specified in writing by any Target  Stockholder;
provided,  however, that Agouron shall not be required to qualify to do business
or consent to service of process in any  jurisdiction  in which it is not now so
qualified or has not so consented;
                  (f) file with The Nasdaq Stock Market a Notification  Form for
Listing of Additional Shares, if applicable, with respect to such Agouron Common
and pay all fees and expenses incurred in connection therewith;
                  (g)  bear all expenses in  connection  with the  procedures of
this  Section 6.3 and the  registration  of the  Securities  pursuant to the  
Registration Statement, provided Target Stockholders shall be responsible for 
their own selling costs; and
                  (h)  file the  reports  required  to be filed by it under  the
Securities  Act and the  Exchange  Act and the rules and  regulations  adopted 
by the SEC thereunder.
         6.4     Indemnification.
                  (a) For the purposes of this  Section  6.4, the term  "Selling
Stockholders"  shall mean the Target  Stockholders  who received  Agouron Common
pursuant to the terms of this Agreement, and such Target Stockholders' trustees,
and each person who controls the Target  Stockholders  within the meaning of the
Securities Act;
                  (b) the term "Registration  Statement" shall include any final
prospectus,  exhibit,  supplement,  or amendment  included in or relating to the
Registration Statement referred to in Section 6.3; and
                  (c)  the  term  "untrue   statement"  shall  mean  any  untrue
statement  or alleged  untrue  statement  of a material  fact  contained  in the
Registration  Statement,  or any  omission  or alleged  omission to state in the
Registration  Statement  a  material  fact  required  to be stated  therein,  or
necessary to make the statements  therein,  in light of the circumstances  under
which such statement is made, not misleading.
                  Agouron agrees to indemnify and hold  harmless,  to the extent
permitted by law, each Selling Stockholder and each person, if any, who controls
such  Selling  Stockholders  within the meaning of Section 15 of the  Securities
Act, from and against any losses, claims,  damages, or liabilities to which such
Selling  Stockholders may become subject (under the Securities Act or otherwise)
insofar as such losses,  claims,  damages, or liabilities  (including reasonable
legal fees and other expenses incurred in the investigation and defense thereof)
arise  out of, or are  based  upon,  any  untrue  statement  or arise out of any
failure by  Agouron to fulfill  any  undertaking  included  in the  Registration
Statement  or any  violation  by Agouron of any rule or  regulation  promulgated
under the Securities Act or any state securities laws applicable to Agouron, and
Agouron will  reimburse such Selling  Stockholder or controlling  person for any
reasonable  legal  or  other  expenses  reasonably  incurred  in  investigating,
defending,  or  preparing  to  defend  any such  action,  proceeding  or  claim;
provided,  however,  that  Agouron  shall  not be liable in any such case to the
extent that such loss,  claim,  damage,  or liability arises out of, or is based
upon, an untrue statement made in such Registration Statement based upon written
information  furnished to Agouron by or on behalf of such Selling Stockholder or
Target,  or any statement or omission in any prospectus that is corrected in any
subsequent prospectus that was delivered to the Selling Stockholder prior to the
written confirmation of the pertinent sale or sales by the Selling Stockholder.
                  The Selling Stockholders agree to indemnify and hold harmless,
to the extent permitted by law,  Agouron (and each person,  if any, who controls
Agouron within the meaning of Section 15 of the Securities  Act, each officer of
Agouron who signs the Registration  Statement and each director of Agouron) from
and against losses,  claims,  damages,  and liabilities to which Agouron (or any
such officer,  director,  or  controlling  person) may become subject (under the
Securities  Act or  otherwise),  insofar as such losses,  claims,  damages,  or 
liabilities (or actions or proceedings in respect thereof) arise out of, or are 
based upon, any untrue statement  contained in a Registration  Statement if such
untrue  statement  was made based upon  written information  furnished by or on 
behalf of the Selling  Stockholder,  and the Selling  Stockholder will reimburse
Agouron (or such officer,  director, or controlling person), as the case may be,
for any reasonable legal or other expenses reasonably incurred in investigating,
defending, or preparing to defend any such action,  proceeding,  or claim. In no
event shall the  liability  of the Selling  Stockholder  hereunder be greater in
amount  than  the  dollar amount  of  the  proceeds  received  by  the  Selling 
Stockholder upon the sale of Agouron Common giving rise to such  indemnification
obligation.
                  Promptly after receipt by any  indemnified  person of a notice
of a claim or the beginning of any action in respect of which indemnity is to be
sought  against an  indemnifying  person  pursuant  to this  Section  6.4,  such
indemnified person shall notify the indemnifying person in writing of such claim
or the commencement of such action,  and, subject to the provisions  hereinafter
stated,  in case any such action shall be brought against an indemnified  person
and such indemnifying person shall have been notified thereof, such indemnifying
person  shall be entitled to  participate  therein,  and, to the extent it shall
wish, to assume the defense  thereof,  with counsel  reasonably  satisfactory to
such  indemnified  person.  After  notice from the  indemnifying  person to such
indemnified  person  of  its  election  to  assume  the  defense  thereof,  such
indemnifying person shall not be liable to such indemnified person for any legal
expenses subsequently incurred by such indemnified person in connection with the
defense  thereof;  provided,  however,  that if there  exists  or shall  exist a
conflict of interest that would make it inappropriate under applicable standards
or professions  conduct,  in the written  opinion of counsel to the  indemnified
person,  for the same counsel to represent both the indemnified  person and such
indemnifying  person, the indemnified person shall be entitled to retain its own
counsel at the expense of such indemnifying person;  provided,  however, that no
indemnifying  person shall be responsible for the fees and expenses of more than
one separate counsel for all indemnified parties. The failure of any indemnified
party to notify an  indemnifying  party of any claim  against  such  indemnified
party in respect of which  indemnity may be sought  hereunder  shall not relieve
the  indemnifying  party from any liability  unless (and only to the extent) the
indemnifying  party was  prejudiced by such failure,  and in no event shall such
failure  relieve the  indemnifying  party from any other  liability which it may
have to such indemnified party.
         6.5    Contribution. If the indemnification provided for in this
Article 6 is  unavailable  to the  indemnified parties in respect of any losses,
claims, damages,  liabilities,  or judgments referred to herein,  then each 
indemnifying party, in lieu of indemnifying such indemnified  party,  shall 
contribute to the amount  paid or payable by such  indemnified  party as a 
result of such  losses, claims, damages, liabilities, and judgments in such 
proportion as to reflect the relative  fault of Agouron on the one hand and each
Selling  Stockholder  on the other in connection  with the statements, 
omissions,  or acts which resulted in such losses, claims,  damages,  
liabilities,  or judgments, as well as any other relevant equitable 
considerations. The relative fault of Agouron on the one hand and of each
Selling  Stockholder  on the other shall be  determined by reference to, among 
other things, the acts of Agouron and of each Selling Stockholder that
gave rise to the losses, claims, damages,  liabilities, or judgments referred to
herein, whether the untrue or alleged untrue statement of a material fact or the
omission or alleged  omission to state a material  fact  relates to  information
supplied  by such party,  and the party's  relative  intent,  knowledge,  access
information and opportunity to correct of fraudulent  misrepresentation  (within
the  meaning of  subsection  11(f) of the  Securities  Act) shall be entitled to
contribution   from  any  person   who  was  not   guilty  of  such   fraudulent
misrepresentation.
                                    ARTICLE 7
              SURVIVAL OF REPRESENTATIONS, WARRANTIES AND COVENANTS
         7.1    All  representations, warranties and covenants contained in this
Agreement with respect to Target,  Acquisition  Corporation  and Agouron and any
certificate  or  other  instrument  delivered  by or on  behalf  of any of  them
pursuant to this Agreement  shall be continuous and shall survive the Closing of
the Merger for a period that will  terminate  (except as to matters of fraud and
intentional misrepresentation or intentional breach by the officers or directors
of Target) on the first  anniversary of the Closing Date (the "Escrow  Period");
provided  however,  that  thereafter  the  provisions  of Article 8 hereof shall
survive with respect to any claim made on or before the expiration of the Escrow
Period  until  such time as such  claim has been  finally  decided,  settled  or
adjudicated.  Notwithstanding anything contained herein to the contrary, neither
Agouron nor the Target  Stockholders,  as the case may be,  shall make any claim
and  there  shall  be no  liability  for  
any  inaccuracy  in or  breach  of any representation,  warranty,  or covenant
for any matter  disclosed to Agouron or Target,  as the case may be, or which  
Agouron  or  Target,  as the case may be, expressly  waives in writing in order 
to consummate the Merger.  For purposes of this  Agreement,  each statement or 
other item of  information  set forth in the Schedules  attached  hereto or in 
any update to the schedules shall be deemed to be a  representation  and 
warranty made by the party preparing such schedules in this Agreement.
         7.2    Indemnification by Target Stockholders.  Subject to the 
limitations contained  in Section  7.1,  this  Section 7.2 and Section 8, from 
and after the Effective  Time,  the Target  Stockholders  shall hold  harmless  
and  indemnify Agouron from and against,  and shall  compensate and reimburse 
Agouron for, any Damages (as defined in Section 7.6) which are directly or 
indirectly suffered or incurred by Agouron or to which Agouron may otherwise 
become subject (regardless of whether or not such Damages relate to any 
third-party  claim) and which arise from or as a  result  of,  or are  directly
or  indirectly  connected  with any inaccuracy in or breach of any 
representation or warranty made by Target in this Agreement.  Pursuant to 
Section 8.1(a),  Agouron's sole recourse for any Damages with respect to which 
indemnification is sought under this Section 7 shall be to the Escrow Shares.  
In no event shall a Target  Stockholder's  liability for any Damages  with  
respect to which  indemnification  is sought be in excess of such Target  
Stockholder's  pro  rata  amount  of the  Escrow  Shares  and no  Target 
Stockholder  shall have any  personal  liability  for any  Damages  except  with
respect  to  Damages  determined  by a  court  of  competent  jurisdiction  in a
proceeding  from which no further  appeal is  permitted to be taken to have been
primarily caused by fraud or intentional misrepresentation or intentional breach
by the officers or directors of Target.
         7.3    Indemnification by Agouron and Acquisition Corporation.  Subject
to the limitations contained in Sections 7.1 and this Section 7.3, from and 
after the Effective Time, Agouron shall hold harmless and indemnify each of the 
Target Stockholders from and against, and shall compensate and reimburse each of
the Target  Stockholders for, any Damages which are directly or indirectly  
suffered or  incurred  by any of the  Target  Stockholders  or to which any of 
the Target Stockholders  may otherwise  become  subject  (regardless of whether 
or not such Damages relate to any third-party claim) and which arise from or as
a result of, or are directly or indirectly  connected with any inaccuracy in or 
breach of any representation  or warranty made by Agouron or  Acquisition  
Corporation in this Agreement. Agouron shall only be liable under this Section 
to the extent Damages exceed  $200,000  and shall not be liable to the extent  
Damages  exceed  twenty percent (20%) of the consideration delivered by Agouron
in the Merger.
         7.4      Notice; Defense of Claim.
                  (a) If any party entitled to indemnification under Section 7.2
or Section 7.3 (the "Indemnified Party") shall receive notice or otherwise learn
of the  assertion  by  any  other  person  or  entity  of  any  claim  or of the
commencement  by any such person or entity of any action (a "Third Party Claim")
with  respect  to which a party  may be  obligated  to  provide  indemnification
pursuant  to  Section  7.2 or  Section  7.3  (the  "Indemnifying  Party"),  such
Indemnified  Party shall give written notice thereof to the  Indemnifying  Party
with ten (10)  business  days after  becoming  aware of such Third Party  Claim;
provided,  however,  that the failure of any Indemnified Party to give notice as
provided in this  Section 7.4 shall not  relieve the  Indemnifying  Party of its
obligations  under Section 7.2 or Section 7.3, as the case may be, except to the
extent that the  Indemnifying  Party  actually is  prejudiced by such failure to
give  notice.  Such notice shall  describe  the Third Party Claim in  reasonable
detail,  and shall  indicate the amount  (estimated if necessary) of the Damages
that has been or may be sustained by such Indemnified  Party.  Thereafter,  such
Indemnified  Party  shall  deliver  to the  Indemnified  Party  within  five (5)
business  days after the  Indemnified  Party's  receipt  thereof,  copies of all
notices and documents  received by the  Indemnified  Party relating to the Third
Party Claim (including court papers).
                  (b) If,  promptly after receipt by the  Indemnifying  Party of
notice of any Third Party Claim as provided in Section 7.4(a),  the Indemnifying
Party shall give written notice to the Indemnified Party stating that it intends
to assume the defense  thereof,  at its own cost, then the defense of such Third
Party Claim,  including  selection  of counsel  reasonably  satisfactory  to the
Indemnified  Party, shall be by the Indemnifying Party and the Indemnified Party
shall  make no payment on such  Third  Party  Claim as long as the  Indemnifying
Party is conducting a good faith and diligent  defense.  The  Indemnified  Party
shall make available all information and assistance that the Indemnifying  Party
may reasonably  request and shall cooperate with the Indemnifying  Party in such
defense. Notwithstanding the foregoing, the Indemnified Party shall at all times
have the right to fully  participate in such defense at its own expense directly
or through  counsel.  If no such  notice to assume the  defense  against a Third
Party Claim is received by the Indemnified  Party from the  Indemnifying  Party,
the  Indemnified  Party  shall,  at  the  expenses  of the  Indemnifying  Party,
undertake  the defense of such Third Party Claim,  with counsel  selected by the
Indemnified  Party,  and shall have the right to  compromise  or settle the same
exercising reasonable judgment.
                  (c) No Third Party Claim made  against any  Indemnified  Party
shall be settled  without the prior written consent of the  Indemnifying  Party.
Notwithstanding  anything else in this Section 7.4 to the contrary,  neither any
Target  Stockholder nor Agouron shall settle or compromise any Third Party Claim
unless such  settlement  or compromise  contemplates  as an  unconditional  term
thereof of the giving by such  claimant  or  plaintiff  to each  related  Target
Stockholder or Agouron, as the case may be, a written release from all liability
with respect to such Third Party Claim.
         7.5      Further Limitations on Indemnification.  Notwithstanding the 
foregoing, the right to indemnification under this Section 7 shall be subject to
the following:
                  
                  (a) No Target  Stockholder  shall have liability under Section
7.2 except to the extent that the Damages  exceed  $400,000 in the aggregate for
all Target Stockholders, in which event Target Stockholders shall be liable only
to the extent the aggregate  Damages exceed $400,000,  subject to the provisions
of this Section 7.
                  (b) No  indemnification  shall be payable  pursuant to 
Sections 7.2 or 7.3, as the case may be, after the  termination of the Escrow  
Period,  except for claims for Damages made prior to such date but not then 
resolved.
                  (c) All indemnification claims made under Section 7.2 shall be
satisfied in full by the  cancellation  of that number of Escrow Shares having a
value  determined in accordance  with the terms of the Escrow  Agreement and all
indemnification  claims  made under  Section 7.3 shall be  satisfied  in full by
Agouron  by a payment  in cash  equal to the  amount of  Damages  for which such
Indemnified Party is entitled to  indemnification  under this Section 7 pro rata
to the indemnified  parties  immediately  prior to the termination of the Escrow
Period.
                  (d) The  limitations of Sections  7.5(a),  7.5(b),  and 7.5(c)
shall  not  apply to any claim for  Damages  that are  determined  by a court of
competent jurisdiction in a proceeding from which no further appeal is permitted
to  be  taken  to  have  been   primarily   caused   by  fraud  or   intentional
misrepresentation  or  intentional  breach of any officer or director of Target,
Agouron or Acquisition Corporation.
                  (e) In determining  the amount of any indemnity under Sections
7.2 or 7.3,  the  Damages  shall  be  reduced  (including,  without  limitation,
retroactively) by any insurance proceeds, tax benefit, or other similar recovery
or offset realized,  directly or indirectly,  by the Indemnified  Party actually
recovered  by or on behalf of such  Indemnified  Party in  reduction of the loss
giving rise to the claim for Damages.
         7.6    Definitions of "Damages." For the  purpose  of this  Section 7,
"Damages" shall include any loss,  damage,  injury,  liability,  claim,  demand,
settlement, judgment, award, fine, penalty, fee (including reasonable attorneys'
fees),  charge,  cost  (including  costs of  investigation),  or expenses of any
nature  (provided  that  any such  Damages  on which  Agouron  or the  Surviving
Corporation  is entitled to receive or has  received  payment on or prior to the
end of the  applicable  Escrow  Period  shall be reduced by any and all  amounts
received by Agouron under any  insurance  policy of Target in place prior to the
Effective Time). Damages shall not include lost profits,  lost savings, or other
direct, special,  incidental,  or consequential damages whether such damages are
based on tort,  contract,  or any other legal theory, and even if the Indemnitee
has been advised of the  possibility of such damages,  except to the extent such
Damages are included in amounts paid to third parties.
                                    ARTICLE 8
                                     ESCROW
         8.1    Escrow Obligations of Target Securityholders.  Agouron  shall be
entitled to recover  from the Escrow Fund (as defined  below) all Damages  which
Agouron may suffer or incur to the extent of and by reason of the  inaccuracy or
breach  of  any of the  representations,  warranties  and  covenants  of  Target
contained  in  this  Agreement  or any  documents,  certificates  or  agreements
delivered   pursuant   hereto.    Other   than   for   fraud   and   intentional
misrepresentation,  Agouron  agrees that the Escrow Fund shall be its  exclusive
remedy for recovery of any such Damages.
         8.2    Escrow Fund.  On the Closing Date, immediately  upon issuance by
Agouron,  and on behalf of the Target  Securityholders,  the  Escrow  Shares (as
defined in Section 1.5(g)) shall be deposited with the escrow agent (the "Escrow
Agent"),  such deposit to  constitute  an escrow fund (the "Escrow  Fund") to be
governed by the terms set forth herein and in the Escrow  Agreement to be signed
by all parties thereto, in substantially the form which is attached as Exhibit B
hereto.  Upon  compliance  with the terms  hereof,  Agouron shall be entitled to
obtain  relief from the Escrow Fund for all Damages  covered by the  obligations
provided for in Section 8.1 hereof.
         8.3    Escrow Period. The Escrow Fund shall remain in existence until
the end of the Escrow Period, except as otherwise provided by the Escrow 
Agreement.
                  
                                    ARTICLE 9
                               PAYMENT OF EXPENSES
         Agouron, Acquisition Corporation and Target shall each pay its own fees
and  expenses  incurred  incident to the  preparation  and  carrying  out of the
transactions  herein  contemplated  (including  legal,  accounting  and travel).
Provided however, to the extent Target's fees and expenses (including investment
banking,  legal and accounting)  exceed $600,000,  the total number of shares of
Agouron  Common  subject to the Merger will be reduced by the excess of Target's
fees and expenses over $600,000  divided by the average  closing market price of
one  share of  Agouron  Common  for the  five-day  trading  period  prior to and
including the Closing Date.
                                   ARTICLE 10
                        TERMINATION, AMENDMENT AND WAIVER
         10.1 Termination.  This Agreement may be terminated at any time prior 
to the Effective Time, whether before or after the approval by the stockholders 
of Target:
             
                  (a) By mutual written consent of Agouron, Acquisition 
Corporation and Target;
                  (b) By Agouron or Acquisition Corporation, if there has been a
material  breach of this  Agreement on the part of Target with respect to any of
its covenants,  representations  or warranties  contained herein and such breach
has not been cured within 10 business  days after  written  notice  thereof from
Agouron or Acquisition Corporation;
                  (c) By  Target,  if there has been a  material  breach of this
Agreement on the part of Agouron or Acquisition  Corporation with respect to any
of their  covenants,  representations  or warranties  contained  herein and such
breach has not been cured within 10 business days after written  notice  thereof
from Target;
                  (d) By  Agouron,  Acquisition  Corporation  or Target  if: (i)
there shall be a final nonappealable order of a federal or state court in effect
preventing  consummation of the Merger; (ii) there shall be any action taken, or
any statute, rule, regulation or order enacted,  promulgated or issued or deemed
applicable  to  the  Merger  by  any   Governmental   Entity  which  would  make
consummation of the Merger illegal; or (iii) there shall be any action taken, or
any statute, rule, regulation or order enacted,  promulgated or issued or deemed
applicable to the Merger by any  Governmental  Entity,  which would (A) prohibit
Agouron's or Target's ownership or operation of all or a material portion of the
business of Target,  or compel  Agouron or Target to dispose of or hold separate
all or a material  portion of the  business  or assets of Target or Agouron as a
result of the Merger or (B) render  Agouron,  Acquisition  Corporation or Target
unable to consummate the Merger.  The party desiring to terminate this Agreement
shall give written notice of such termination to the other parties;
                  (e) By Target if Target reasonably  determines that the timely
satisfaction  of any  condition  set  forth in  Sections  5.1 or 5.3 has  become
impossible  (other  than as a result  of any  failure  on the part of  Target to
comply with or perform any covenant or obligation of Target as set forth in this
Agreement  or in any other  agreement  or  instrument  delivered  to  Agouron or
Acquisition Corporation); or
                  (f) By  Agouron  if  Agouron  reasonably  determines  that the
timely satisfaction of any condition set forth in Sections 5.1 or 5.2 has become
impossible  (other  than as a result of any  failure  on the part of  Agouron or
Acquisition  Corporation to comply with or perform any covenant or obligation of
Agouron or  Acquisition  Corporation  as set forth in this  Agreement  or in any
other agreement or instrument delivered to Target).
         10.2    Effect  of  Termination.  In the  event  of termination of this
Agreement as provided  above,  this Agreement  shall  forthwith  become void and
there  shall  be no  liability  on  the  part  of  either  Agouron,  Acquisition
Corporation or Target, except for liability arising out of the breach by a party
hereto of any of its  representations,  warranties,  covenants or agreements set
forth in this Agreement prior to its termination.
         10.3    Amendment.  This Agreement may not be amended except by an 
instrument in writing signed on behalf of all the parties hereto.
                 
         10.4   Waiver.  At any time prior to the  Effective  Time, the parties
hereto  may (a)  mutually  extend  the  time for the  performance  of any of the
obligations or other acts of the parties hereto,  (b) waive any  inaccuracies in
the  representations  and warranties by another party contained herein or in any
document  delivered by such party pursuant hereto to and (c) waive compliance by
another party with any of the  agreements or conditions  contained  herein.  Any
agreement  on the part of the  parties  hereto to any such  extension  or waiver
shall be valid  only if set forth in a writing  signed on behalf of the party to
be bound.
                                   ARTICLE 11
                                     GENERAL
         11.1   Notices. Any notice, request, instruction or other document to 
be given  hereunder  by any party to the other shall be in writing and delivered
personally or sent by certified mail, postage prepaid, by courier service, or by
telecopy with confirmation copy sent by one of the above methods, as follows:
                  Agouron Pharmaceuticals, Inc.
                  ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇
                  ▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇  ▇▇▇▇▇
                  Attention:   ▇▇▇▇▇ ▇▇▇▇▇▇▇, President
                  Fax:  ▇▇▇-▇▇▇-▇▇▇▇
with a copy to:
                  Agouron Pharmaceuticals, Inc.
                  ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇
                  ▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇  ▇▇▇▇▇
                  Attention:   ▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇, Vice President and General
                               Counsel
                  Fax:  ▇▇▇-▇▇▇-▇▇▇▇
and to:
                  Alanex Corporation
                  ▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇
                  ▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇  ▇▇▇▇▇
                  Attention:   ▇▇▇▇▇▇ ▇. ▇▇▇▇▇, M.D. President
                  Fax:  ▇▇▇-▇▇▇-▇▇▇▇
with a copy to:
                  ▇▇▇▇▇▇ Godward LLP
                  ▇▇▇▇ ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇▇
                  ▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇  ▇▇▇▇▇
                  Attention:   ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇, Esq.
                  Fax:  ▇▇▇-▇▇▇-▇▇▇▇
or to such other persons as may be designated in writing by the parties, by a 
notice given as aforesaid.
         11.2    Headings.  The headings of the several  sections of this 
Agreement are inserted for  convenience of reference only and are not intended
to affect the meaning or interpretation of this Agreement.
         11.3    Counterparts.  This Agreement may be executed in counterparts,
and when so executed each  counterpart  shall be deemed to be an original,  and
said counterparts together shall constitute one and the same instrument.
         11.4    Binding  Nature.  This  Agreement  shall be binding  upon and 
inure to the benefit of the parties  hereto.  No party may assign or transfer
any rights under this Agreement.
         11.5    Merger  of  Documents.  This  Agreement and all agreements and
documents  contemplated  hereby constitute one agreement and are  interdependent
upon each other in all  respects,  and shall  constitute  the  entire  agreement
between the parties  hereto with respect to the subject matter hereof and shall,
except as to the  provisions  contained in Sections 10, 11, and 15 of the Letter
of intent executed by the parties on April 8, 1997, and the Mutual  Confidential
Disclosure  Agreement  executed on March 19, 1997 which shall continue to apply,
supersede all previous negotiations,  understandings,  agreements,  commitments,
and writings  with respect to such subject  matter.  Except as expressly  stated
herein or in any of such other documents,  no party makes any representations or
warranties of any kind.
         11.6   Incorporation of Schedules.  All Exhibits and Schedules attached
hereto are by this reference  incorporated  herein and made a part hereof for 
all purposes as if fully set forth herein.
         11.7 Applicable Law. This Agreement shall be governed by, construed and
enforced in  accordance  with the laws of the State of  California as applied to
contracts entered into solely between residents of, and to be performed entirely
in, such state.
         IN WITNESS WHEREOF,  Agouron,  Acquisition  Corporation and Target have
caused this Agreement to be executed and attested by their respective  officers,
hereunto duly authorized, all as of the date first above written.
                                            AGOURON:
                                            Agouron Pharmaceuticals, Inc.,
                                            a California corporation
                                            By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇
                                                -----------------------------
                                                ▇▇▇▇▇ ▇▇▇▇▇▇▇, President
                                            ACQUISITION CORPORATION:
                                            Agouron Acquisition Corporation,
                                            a Delaware corporation
                                            By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇
                                                -----------------------------
                                                ▇▇▇▇▇ ▇▇▇▇▇▇▇, President
                                            TARGET:
                                            Alanex Corporation,
                                            a Delaware corporation
                                            By: /s/ ▇▇▇▇▇▇ ▇. ▇▇▇▇▇
                                                -----------------------------
                                                ▇▇▇▇▇▇ ▇. ▇▇▇▇▇, M.D., President
                             EXHIBITS AND SCHEDULES
EXHIBITS
       A          Amended and Restated Certificate
       B          Escrow Agreement
       C          Opinion of Pillsbury Madison & Sutro
       D          Opinion of ▇▇▇▇▇▇ Godward LLP
SCHEDULES
       2.2        Common, Option, and Warrant Holders
       2.3        Voting Trusts
       2.5        Required Consents
       2.6        ▇▇▇▇▇ ▇▇, ▇▇▇▇ ▇▇▇▇▇▇▇ Sheet and December 31, 1995 and 1996 
                  Financial Statements
       2.7        Business Changes
       2.8(c)     Environmental
       2.8(e)     Properties
       2.8(f)     Permits, Consents, and Approvals
       2.9        Personal Property
       2.10       Taxes
       2.11       Employee List
       2.12       Increases in Compensation
       2.15       Contracts
       2.17       Patents and Trademarks
       2.18       Insurance Policies
       2.19       Bank Accounts
       2.24       Employee Benefits
       2.29       Proprietary Computer Programs
       2.30       Description of Chemical Libraries
       2.31       Status of Drug Discovery Programs
[Pursuant to Regulation  229.601(b)(2),  Agouron has omitted the above  
 schedules and agrees to furnish  supplementally  a copy of any omitted 
 schedule to the Commission  upon request.]