CONFIDENTIAL August 28, 2003 AGREEMENT

Field

The “Cellular Immunotherapy Field” shall be the activation, growth, modification or regulation of T cells for in vivo and ex vivo therapeutic purposes. The “Non-Cellular Immunotherapy Field” shall be in vivo, in vitro and ex vivo therapeutic purposes not included in the Cellular Immunotherapy Field, and shall include (by way of example and not by way of limitation) all non-T-cell technologies and stem cell technologies. The use of Xcellerate^™ Technology in HIV gene therapy applications is specifically excluded from both the Cellular Immunotherapy Field and the Non-Cellular Immunotherapy Field.

License

Xcyte will grant to TCTC (a) an exclusive, royalty-bearing license, with the right to sublicense, to use the Xcellerate^™ Technology to make, have made, use, import, sell, and offer for sale Licensed Products in the Cellular Immunotherapy Field in the Territory, and (b) a non-exclusive, royalty-bearing license with the right to sublicense, to use the Xcellerate^™ Technology to make, have made, use, import, sell, and offer for sale Licensed Products in the Non-Cellular Immunotherapy Field worldwide. These licenses

ii) The relevant assays for receiving QC, in-process QC and final product release testing;

iii) Relevant QA systems;

iv) Storage and handling of cryopreserved Xcellerated T-Cell Products; and

v) Shipping and receiving of PBMC leukapheresis products and final Xcellerated T Cell Products.

“Xcellerate Patent Rights” means the patents and patent applications listed on Exhibit B attached hereto and shall include all foreign counterparts claiming the benefit therefrom as well as any extension, continuation, continuation-in-part, divisional and re-issue applications thereof or issuing therefrom, to the extent Xcyte owns, licenses, or controls such rights.

Licensed Product(s) means products which: (1) in the absence of the license agreement would infringe at least one claim of Xcellerate Patent Rights in at least one of the countries in the Territory in which the product is made, used or sold (within the Cellular Immunotherapy Field), or one claim of Xcellerate Patent Rights in at least one country worldwide in which the product is made, used or sold (within the Non-Cellular Immunotherapy Field), or (2) use a process, equipment or device covered by a claim of Xcellerate Patent Rights in the country of use or (3) use the relevant “know-how” associated with the Xcellerate^™ Technology or the generation of Xcellerated T Cells ^™.

Territory

“Territory” specified as: Australia, New Zealand, Afghanistan, Bangladesh, Bhutan, Brunei, Burma, Cambodia, China (including Hong Kong), India, Indonesia, North Korea, South Korea, Laos, Malaysia, Mongolia, Nepal, Pakistan, Philippines, Singapore, Sri Lanka, Taiwan, Thailand, and Vietnam, as these borders exist today. The Territory shall expand to include the countries that may subsequently encompass any or all of each of the countries listed above. Notwithstanding anything to the contrary, in no event shall any Licensed Products be exported or embargoed to otherwise restricted countries or end users, in accordance with U.S. export control regulations.

Diligence

Within 12 months of TCTC’s US FDA approval of a Licensed Product in the Cellular Immunotherapy Field, Xcyte or its partners must initiate local registration and approval in worldwide markets outside the Territory. Unless Xcyte has a good business reason to not do so or has otherwise not secured the requisite regulatory approval or pricing authorization despite commercially reasonable efforts to do so, within 24 months, Xcyte or its licensees must actively market and sell such Licensed Products in the Cellular Immunotherapy Field outside the Territory or TCTC will have the right to market such Licensed Products in any country for which Xcyte or its licensees fails to market approved Licensed Products.

Financial Terms

Compensation to Xcyte will be paid for the following events:

(1) Within ten (10) days of the closing of the Financing – [*];

(2) Completion of technology transfer – [*];

(3) Xcyte holds pre-pivotal trial meeting with the U.S. FDA – [*];

(4) Enrollment of first patient in TCTC clinical trial – [*];

(5) Enrollment of first patient in Xcyte pivotal trial – US$[*].

“Completion of technology transfer” shall mean the training of TCTC personnel in Seattle, WA (where at least three consecutive pilot runs have been successfully performed by the TCTC team), and the transfer of documentation and associated controls to TCTC adequate to practice the Xcellerate^™ Technology. Payments for this milestone will be based on expenses as they are incurred, pursuant to a scheduled budget provided to TCTC in advance. In no event shall any payment owed to Xcyte for the “Completion of technology transfer” be delayed because of TCTC’s failure to meet its obligations to complete such technology transfer or its failure to send qualified personnel for training (i.e. persons with training and/or education customary for similar positions in the U.S. biotechnology industry). Xcyte shall provide the names and contacts of suppliers for the materials used in the manufacture, sale and marketing regarding the Xcellerate^™ Technology, and will arrange for the meeting of TCTC personnel and the contacts of such suppliers at TCTC’s request and generally take all reasonable steps to facilitate TCTC’s use of such suppliers.

“Xcyte holds pre-pivotal trial meeting with the U.S. FDA” shall mean that Xcyte holds a pre-pivotal trial meeting with the U.S. FDA and, either (i) within 30 days of such meeting, Xcyte does not receive a written notice stating that Xcyte cannot proceed with a pivotal trial, or (ii) the U.S. FDA notifies and requires Xcyte to cure certain outstanding issues prior to moving forth with a pivotal trial, and Xcyte actually cures such issues.

Structure

TCTC has been established under the laws of Taiwan as an independent corporate entity based in Taiwan. In consideration for the license grant described herein, TCTC will pay Xcyte within 5 days of the closing of the Financing a lump-sum up-front payment in an exact amount of U.S. dollars needed to purchase [*] of TCTC common stock as calculated after the completion of the Financing. Within one day of receiving the lump-sum up-front payment, Xcyte will use all of the lump-sum up-front payment to purchase such shares of stock from TCTC. TCTC will issue to Xcyte shares of TCTC common stock with rights and restrictions no less

Royalty

TCTC will pay to Xcyte a [*]% royalty on annual Net Sales of all Licensed Products developed primarily by TCTC, which are commercialized by TCTC or its agents within the Cellular Immunotherapy Field in the Territory (and outside the Territory to the extent applicable pursuant to the “Diligence” section.).

Sublicense

TCTC shall have the right to sublicense the Xcellerate^™ Technology in the Cellular Immunotherapy Field in the Territory and in the Non-Cellular Immunotherapy Field worldwide with the prior written consent of Xcyte, which consent shall not be unreasonably withheld. TCTC will pay Xcyte a percentage of any sublicense initiation fee, milestone payments, equity investments or any other non-royalty payments owed to TCTC from sublicensees of Xcellerate^™ Technology based on the timing of such sublicense payments as set forth below. Any such sublicenses shall obligate the sublicensee to comply with the provisions of this Agreement and maintain the quality and safety of Licensed Products based on the Xcellerate^™ Technology.

Date Such Payment Received Payable by TCTC

Within 0-5 years of the Effective Date

[*]

Between 5 and 6 years of the Effective Date

[*]

Between 6 and 7 years of the Effective Date                [*]

Between 7 and 8 years of the Effective Date                [*]

Between 8 and 9 years of the Effective Date                [*]

Between 9 and 10 years of the Effective Date              [*]

More than 10 years after the Effective Date                 [*]

Notwithstanding the above, TCTC shall not be obligated to pay to Xcyte any portion of any amounts received from any sublicensee objectively attributable to research and development activities (market value) or amounts received from a sublicensee reasonably allocated to consideration for TCTC equity, or the license or sublicense of any intellectual property other than the Xcellerate Patent Rights, or products other than the Licensed Products, or reimbursement for patent or other expenses. Any non-cash compensation received by TCTC shall be valued at Fair Market Value, and Xcyte’s share of the non-cash compensation may be paid to Xcyte either in cash or in the same form of non-cash compensation that TCTC received (at TCTC’s sole discretion).

Patent Rights

Xcyte shall own the entire right to improvements on the Xcellerate^TM Technology that are invented by Xcyte solely or jointly with TCTC. TCTC shall own the entire right to any improvements to the Xcellerate^TM Technology that are invented by TCTC without the co-inventorship of Xcyte (the “TCTC Improvements”), provided, however, that TCTC shall grant to Xcyte a fully-paid, royalty-free (except as stated below), perpetual, exclusive, worldwide license (excluding the Territory) to make, have made, use, import, sell, and offer for sale Licensed Products incorporating TCTC Improvements only in the Cellular Immunotherapy Field with the right to sublicense. To the extent that such TCTC Improvements relate to clinical indications for Licensed Products that are developed primarily by TCTC, such products bear a Mutual Royalty as set forth above. The parties will negotiate in good faith additional royalty and/or other consideration for any TCTC Improvements that substantially improve the efficacy or substantially lower the manufacturing cost of a Licensed Product whether or not that Product already requires a Mutual Royalty payment to TCTC or does not require such a payment in the absence of the TCTC Improvements. If the parties cannot otherwise mutually agree, the Technical Dispute Resolution

set forth below will be used to determine if the TCTC Improvements substantially improve the efficacy or substantially lower the manufacturing costs of the Licensed Product and the amount of additional royalties that should be paid to TCTC. The parties agree that minor improvements or optimizations will bear no additional royalty.

Technical Dispute Resolution

If the issue is scientific, regulatory or marketing (“technical”) in nature and cannot be resolved by the parties respective officers, the parties agree to submit such technical issue to an independent three-member board for resolution. The three-member board shall consist of one independent technical consultant in the scientific, regulatory or marketing field, as is appropriate to the nature of the issue, designated by each party. The two such designated technical consultants selecting a third independent consultant in the same field to comprise the three-member technical board. The decision of the three-member board shall be binding upon the parties.

Patent Maintenance

Xcyte shall control and TCTC shall bear or reimburse all future reasonable costs of preparation, prosecution, and maintenance in the Territory of the Xcellerate Patent Rights to be licensed to TCTC. For the period beginning on the Effective Date of this Agreement, Xcyte shall pay such costs and TCTC shall reimburse such costs within ten (10) days after invoice, provided that TCTC has approved such costs in advance in accordance with this Section. TCTC will not be obligated to bear or reimburse any such costs if the Financing does not close. TCTC shall be copied in a timely manner on all material written correspondence and memoranda describing material oral correspondence will be prepared and sent to TCTC related to the preparation, prosecution, and maintenance of the Xcellerate Patent Rights between Xcyte and Xcyte’s attorney. TCTC retains the right to advise Xcyte regarding patent preparation, prosecution, and maintenance in a reasonable amount of time before the submission of any such documents or payments. In particular, Xcyte will notify TCTC in writing at least 30 days before the filing of an original, divisional, continuation, CIP, reissue, or reexamination filing in the U.S., a foreign original patent application (such as in Taiwan or other non-PCT country), a PCT filing, or a PCT national stage filing and will include an estimate of the cost of such a filing. TCTC will indicate in writing whether or not they will reimburse such filing costs within 15 days of receiving the written notice from Xcyte. TCTC will otherwise have the right to decline prosecution of any patent or application licensed to TCTC and such patents or applications will be excluded from the license in the relevant country.

Its:

Its:

May 22, 2003 to July 31, 2003

August 1, 2003 to October 15, 2003

October 16, 2003 to November 15, 2003

Purpose

(0001) License agreement between Xcyte Therapies and Taiwan Cell Therapy Company.

Field

(0002) The “Cellular Immunotherapy Field” shall be the activation, growth, modification or regulation of T cells for in vivo and ex vivo therapeutic purposes. The “Non-Cellular Immunotherapy Field” shall be in vivo, in vitro and ex vivo therapeutic purposes not included in the Cellular Immunotherapy Field, and shall include (by way of example and not by way of limitation) all non-T-cell technologies and stem cell technologies. The use of Xcellerate^TM Technology in HIV gene therapy applications is specifically excluded from both the Cellular Immunotherapy Field and the Non-Cellular Immunotherapy Field.

License

(0003) Xcyte will grant to TCTC (a) an exclusive, royalty-bearing license, with the right to sublicense, to use the Xcellerate^TM Technology to make, have made, use, import, sell, and offer for sale Licensed Products in the Cellular Immunotherapy Field in the Territory, and (b) a non-exclusive, royalty-bearing license with the right to sublicense, to use the Xcellerate^TM Technology to make, have made, use, import, sell, and offer for sale Licensed Products in the Non-Cellular Immunotherapy Field worldwide. These licenses shall not permit TCTC to make, use, sell or export Licensed Products outside of the Territory other than as described in the “Diligence” section of this Appendix, except within the Non-Cellular Immunotherapy Field, nor allow any agent or other third party to make, use, sell or export Licensed Products outside of the Territory, other than described in the “Diligence” section of this Appendix, except within the Non-Cellular Immunotherapy Field. TCTC shall use its best efforts to prevent third parties from making, using, selling or exporting the

Field), or (2) use a process, equipment or device covered by a claim of Xcellerate Patent Rights in the country of use or (3) use the relevant “know-how” associated with the Xcellerate^TM Technology or the generation of Xcellerated T Cells ^TM.

Territory

(0007) “Territory” specified as: Australia, New Zealand, Afghanistan, Bangladesh, Bhutan, Brunei, Burma, Cambodia, China (including Hong Kong), India, Indonesia, North Korea, South Korea, Laos, Malaysia, Mongolia, Nepal, Pakistan, Philippines, Singapore, Sri Lanka, Taiwan, Thailand, and Vietnam, as these borders exist today. The Territory shall expand to include the countries that may subsequently encompass any or all of each of the countries listed above. Notwithstanding anything to the contrary, in no event shall any Licensed Products be exported or embargoed to otherwise restricted countries or end users, in accordance with U.S. export control regulations.

Diligence

(0008) Within 12 months of TCTC’s US FDA approval of a Licensed Product in the Cellular Immunotherapy Field, Xcyte or its partners must initiate local registration and approval in worldwide markets outside the Territory. Unless Xcyte has a good business reason to not do so or has otherwise not secured the requisite regulatory approval or pricing authorization despite commercially reasonable efforts to do so, within 24 months, Xcyte or its licensees must actively market and sell such Licensed Products in the Cellular Immunotherapy Field outside the Territory or TCTC will have the right to market such Licensed Products in any country for which Xcyte or its licensees fails to market approved Licensed Products.

Japan

(0009) To the extent that Xcyte licenses the Xcellerate^TM Technology to a third party (“Japan Licensee”) to make, have made, use, import, sell, and offer for sale Licensed Products within the Cellular Immunotherapy Field in Japan, Xcyte shall pay TCTC a portion of any compensation received by Xcyte from a Japan Licensee as a result of such license based on the timing of such payments, as follows, provided that, TCTC has used and continues to use diligence and commercially reasonable efforts to develop, gain regulatory approval and commercialize and market Licensed Products. Xcyte may reasonably require sufficient evidence of such diligence and efforts prior to payment. In addition, TCTC will use reasonable efforts to assist Xcyte to license its technology in Japan.

(0012) To the extent not covered above, in the event that Xcyte shall receive revenues reasonably attributable to the Xcellerate^™ Technology in or from Japan within the Cellular Immunotherapy Field, separate and apart from revenues from a Japan licensee, TCTC shall be entitled to share in such revenues in the same proportion as if those revenues had been received from a Japan licensee.

(0013) Xcyte and TCTC agree to negotiate in good faith in the Second Agreement terms that would protect TCTC’s share of compensation relating to the Xcellerate^™ Technology in the Cellular Immunotherapy Field in Japan pursuant to the terms stated herein in the event of Xcyte’s dissolution, liquidation, cessation of business, or winding up.

Structure

(0014) TCTC has been established under the laws of Taiwan as an independent corporate entity based in Taiwan. In consideration for the license grant described herein, TCTC will pay Xcyte within 5 days of the closing of the Financing a lump-sum up-front payment in an exact amount of U.S. dollars needed to purchase [*]% of TCTC common stock as calculated after the completion of the Financing. Within one day of receiving the lump-sum up-front payment, Xcyte will use all of the lump-sum up-front payment to purchase such shares of stock from TCTC. TCTC will issue to Xcyte shares of TCTC common stock with rights and restrictions no less favorable than those given to other TCTC founders. The Financing will include TCTC shares and attached warrants for purchase of additional shares within one-year and two-year periods at prices above the per share price paid in this offering. Xcyte will not be receiving any warrants in connection with this Financing. The [*]% ownership will be calculated including all shares issued and outstanding at the closing of the Financing, but will not include the dilution resulting from the issuance of the shares underlying the warrants. In addition, at the time that the shares are issued, Xcyte must enter into a restricted stock agreement with TCTC which shall be identical to the restricted stock agreements between all other founders and TCTC. TCTC agrees that in no event shall the restrictions on Xcyte’s shares be worse than the most lenient restrictions on shares held by the other founders. [*] If and for so long as Xcyte does not have a representative on the TCTC board of directors, Xcyte shall have the right to attend the board of directors meetings as an observer and to receive at the same time, such information as is provided to other directors and notice and copies of all information furnished to directors in connection with all meetings of TCTC’s board of directors,

(subject to reasonable confidentiality restrictions). TCTC shall assist Xcyte at Xcyte’s sole expense in finding a translator for the TCTC board meetings and for the information furnished to the directors in connection with all meetings of TCTC’s board of directors; however, TCTC assumes no further responsibility for the accuracy or timeliness of the translations of such meetings or materials. Xcyte shall have the right to receive quarterly written progress and financial reports in English. TCTC and Xcyte shall create a joint steering committee to coordinate manufacturing, quality systems, clinical development and marketing activities. The milestone payments in Section 0016 below are contingent on the payment of the lump-sum up-front payment from TCTC to Xcyte and Xcyte’s subsequent purchase of TCTC stock as set forth in this Section 0014.

Financing

(0015) As described above in Paragraph 11b (“Break-Up Fee”), on or prior to the Effective Date (which will be the Closing Date) of the Second Agreement, TCTC will raise a minimum of US$25 million (or binding commitments therefore) in an equity financing round (the “Financing”). Prior to the Effective Date of the Second Agreement, Xcyte shall have received either (1) commitment letter(s) to receive US$ 10 Million in any combination of equity financing, outside grants or license transaction payments (not including any TCTC payments) or (2) commitment letter(s) signed by at least three of Xcyte’s major investors to fund their pro rata share of such US$10 Million (taking into account outside grants or licensed transaction payments, not including TCTC payments) to Xcyte.

Financial Terms

(0016) Compensation to Xcyte will be paid for the following events:

(0018) “Xcyte holds pre-pivotal trial meeting with the U.S. FDA” shall mean that Xcyte holds a pre-pivotal trial meeting with the U.S. FDA and, either (i) within 30 days of such meeting, Xcyte does not receive a written notice stating that Xcyte cannot proceed with a pivotal trial, or (ii) the U.S. FDA notifies and requires Xcyte to cure certain outstanding issues prior to moving forth with a pivotal trial, and Xcyte actually cures such issues. The parties agree that if the “pre-pivotal trial meeting” milestone is met prior to the signing of the Second Agreement, TCTC will make the milestone payment to Xcyte within ten (10) days of the Effective Date of the Second Agreement. “Enrollment of first patient in TCTC clinical trial” shall mean that either TCTC enrolls its first patient in a TCTC clinical trial, or six months passes since TCTC first receives the required regulatory permission to proceed with enrollment in a clinical trial.

(0019) The parties agree that milestones 1 through 5 are anticipated to occur within the first 12 months following the signing of the Second Agreement. Nothing in this Section shall be construed to alter, nullify or otherwise affect the obligations of either party set forth in Section 0016 above.

Royalty

(0020) TCTC will pay to Xcyte a [*]% royalty on annual Net Sales of all Licensed Products developed primarily by TCTC, which are commercialized by TCTC or its agents within the Cellular Immunotherapy Field in the Territory (and outside the Territory to the extent applicable pursuant to the “Diligence” section.).

expense of expenditures beyond that in the selection and formatting of such data.

All regulatory filings with the U.S. FDA or other regulatory agencies outside of the Territory relating to Licensed Products in the Cellular Immunotherapy Field shall identify Xcyte as the sponsor, provided that if Xcyte does not intend to act as the sponsor, it shall so notify TCTC within 10 days of TCTC’s written request. If Xcyte fails to take substantive actions towards initiating the filing within 30 days of TCTC’s request, TCTC shall have the right to file for such approval directly. Notwithstanding anything to the contrary, Xcyte shall have the right in all cases to participate in all meetings with a governmental regulatory agency and promptly advise and approve all TCTC’s regulatory filings to be filed with the U.S. FDA or other regulatory agencies outside of the Territory relating to Licensed Products in the Cellular Immunotherapy Field, and both parties shall jointly own such regulatory filings. Xcyte shall have the right to review at least 30 days in advance all regulatory filings with the U.S. FDA or other regulatory agencies outside of the Territory relating to Licensed Products in the Non-Cellular Immunotherapy Field

(0023) In the event that one or more products in the Cellular Immunotherapy Field that is directly competitive with and in the same indication as TCTC’s Licensed Product are sold in such a country in the Territory, the portion of the aforementioned royalties payable to Xcyte on Licensed Products within the Cellular Immunotherapy Field and not payable by Xcyte to its sublicensors will be reduced on a country by country basis by [*] the percentage that the total of such sales of such one or more competing products represent of TCTC’s sales of relevant product of that country, but in no event shall this reduction result in less than payment of [*] of the payment otherwise due to Xcyte. Xcyte shall have the right, in the first instance, to enforce its patent rights in the Territory, but in the event it fails or declines to do so, the Second Agreement shall address TCTC’s ability to do so.

(0024) The royalties payable to Xcyte assume that Xcyte is required to pay [*]% for various in-licensed technology. In countries where the sublicense rate is lower than [*]%, the royalty payable to Xcyte by TCTC will be reduced by the same amount as of the Effective Date of the Agreement. In addition, subsequent to the Effective Date of the Agreement, if Xcyte negotiates a lower royalty rate for any Xcyte in-licensed technology, the aforementioned royalty rates payable to Xcyte by TCTC will be

reduced by [*] of the savings, provided that if the reduction of royalty rates is due to one or more lump-sum payments that are otherwise not a royalty percentage of the amount of sales on the Licensed Product(s) made by Xcyte to its sublicensor(s), TCTC’s royalty rates to Xcyte will only be reduced if TCTC (at TCTC’s sole option) pays Xcyte [*]% of such lump-sum payments.

(0025) Royalties with respect to each Licensed Product in each country shall be payable for the period of time equal to the longer of (a) 15 years from the date of first commercial sale or (b) until the expiration of all covering patent claims in the Xcellerate^TM Technology in such country.

(0026) Royalties payable to Xcyte from sublicensed Licensed Products will be the same as if TCTC had sold the Licensed Product directly without a sublicense.

(0027) Net Sales shall be defined as total gross sales invoiced less all usual and customary returns, commissions, shipping charges, duties, taxes, and allowances. The obligation to pay royalties is imposed only once with respect to the same Licensed Product.

(0028) All royalty payments will be made on a quarterly basis in US dollars based on published currency exchange rates. Sales records will be available for audit.

Sublicense

(0029) TCTC shall have the right to sublicense the Xcellerate^TM Technology in the Cellular Immunotherapy Field in the Territory and in the Non-Cellular Immunotherapy Field worldwide with the prior written consent of Xcyte, which consent shall not be unreasonably withheld. TCTC will pay Xcyte a percentage of any sublicense initiation fee, milestone payments, equity investments or any other non-royalty payments owed to TCTC from sublicensees of Xcellerate^TM Technology based on the timing of such sublicense payments as set forth below. Any such sublicenses shall obligate the sublicensee to comply with the provisions of the Second Agreement and maintain the quality and safety of Licensed Products based on the Xcellerate^TM Technology.

Date Such Payment Received

Payable by TCTC

Between 5 and 6 years of the Effective Date of the Second Agreement [*]

Between 6 and 7 years of the Effective Date of the Second Agreement [*]

Between 7 and 8 years of the Effective Date of the Second Agreement [*]

Between 8 and 9 years of the Effective Date of the Second Agreement [*]

Between 9 and 10 years of the Effective Date of the Second Agreement [*]

More than 10 years after the Effective Date of the Second Agreement [*]

Notwithstanding the above, TCTC shall not be obligated to pay to Xcyte any portion of any amounts received from any sublicensee objectively attributable to research and development activities (market value) or amounts received from a sublicensee reasonably allocated to consideration for TCTC equity, or the license or sublicense of any intellectual property other than the Xcellerate Patent Rights, or products other than the Licensed Products, or reimbursement for patent or other expenses. Any non-cash compensation received by TCTC shall be valued at Fair Market Value, and Xcyte’s share of the non-cash compensation may be paid to Xcyte either in cash or in the same form of non-cash compensation that TCTC received (at TCTC’s sole discretion).

Due Diligence

(0030) TCTC will use diligence and commercially reasonable efforts to develop, gain regulatory approval and commercialize and market Licensed Products in the Cellular Immunotherapy Field. TCTC will provide Xcyte with quarterly updates reporting progress in English with regard to TCTC’s efforts to develop and commercialize Licensed Products, including the activities by TCTC, its subsidiaries, sublicensees, business partners, independent contractors, and other agents, subject to confidentiality obligations.

Marketing

(0031) TCTC and its sublicensees, if any, will be solely responsible for marketing, sale and distribution of Licensed Products in the Territory and, when applicable, outside the

Territory. For the Licensed Products in the Cellular Immunotherapy Field, Xcyte will support and TCTC will cooperate with Xcyte to ensure marketing positioning and the marketing message is reasonably consistent with Xcyte’s U.S. marketing to maintain reasonable continuity of promotion and a reasonable level of global branding. TCTC and its employees and agents must not use Xcyte’s name, “Xcellerate,” “Xcellerated T Cells”, any other trademarks or tradenames owned by Xcyte or any adaptation of the foregoing thereof without the prior written consent of Xcyte which consent will not be unreasonably withheld.

(0032) TCTC shall use best efforts to design all clinical trials relating to any Licensed Products to protect patient safety and demonstrate efficacy. TCTC shall not proceed with any clinical trials relating to any Licensed Product in the Cellular Immunotherapy Field until Xcyte has reasonably determined that such clinical trial (and its accompanying protocols, marketing strategy, etc.) will not interfere with U.S., European Community, or Japanese regulatory approvals or otherwise adversely affect the clinical development, regulatory approval or commercialization of Licensed Products in the U.S., German, Italian, Spanish, French, Benelux, Japanese markets or the markets of the United Kingdom. Following TCTC’s submission to Xcyte of the plans of such a clinical trial (and its accompanying protocols, marketing strategy, etc), Xcyte will notify TCTC in writing whether or not the clinical trial interferes with the above-described regulatory approvals or adversely affects the clinical development, regulatory approval, or commercialization of Licensed Products in the U.S., German, Italian, Spanish, French, Benelux, Japanese markets or the markets of the United Kingdom within 60 days of submission of the TCTC plans. TCTC shall provide a copy of the protocol for any clinical trial of Licensed Products in the Non-Cellular Immunotherapy Field to Xcyte for review at least 30 business days prior to the start of such clinical trial.

TCTC shall immediately notify Xcyte of any Serious Adverse Event or Unexpected Adverse Events (each as defined by the FDA at 21 CFR, part 312.32), which may occur during the course of any clinical trial involving Licensed Products in either the Cellular Immunotherapy Field or the Non-Cellular Immunotherapy Field. All such notifications will be promptly confirmed in writing.

Patent Rights

(0033) Xcyte shall own the entire right to improvements on the Xcellerate^TM Technology that are invented by Xcyte solely or jointly with TCTC. TCTC shall own the entire right to any improvements to the Xcellerate^TM Technology that are invented by

TCTC without the co-inventorship of Xcyte (the “TCTC Improvements”), provided, however, that TCTC shall grant to Xcyte a fully-paid, royalty-free (except as stated below), perpetual, exclusive, worldwide license (excluding the Territory) to make, have made, use, import, sell, and offer for sale Licensed Products incorporating TCTC Improvements only in the Cellular Immunotherapy Field with the right to sublicense. To the extent that such TCTC Improvements relate to clinical indications for Licensed Products that are developed primarily by TCTC, such products bear a Mutual Royalty as set forth in this Appendix. The parties will negotiate in good faith additional royalty and/or other consideration for any TCTC Improvements that substantially improve the efficacy or substantially lower the manufacturing cost of a Licensed Product whether or not that Product already requires a Mutual Royalty payment to TCTC or does not require such a payment in the absence of the TCTC Improvements. If the parties cannot otherwise mutually agree, the Technical Dispute Resolution set forth below will be used to determine if the TCTC Improvements substantially improve the efficacy or substantially lower the manufacturing costs of the Licensed Product and the amount of additional royalties that should be paid to TCTC. The parties agree that minor improvements or optimizations will bear no additional royalty.

Patent Maintenance

(0034) Xcyte shall control and TCTC shall bear or reimburse all future reasonable costs of preparation, prosecution, and maintenance in the Territory of the Xcellerate Patent Rights to be licensed to TCTC pursuant to the Second Agreement upon the closing of the Second Agreement. For the period beginning on the Effective Date of this Agreement and the closing date of the Second Agreement, Xcyte shall pay such costs and TCTC shall reimburse such costs within ten (10) days after the close of the Second Agreement, provided that TCTC has approved such costs in advance in accordance with this Section. TCTC will not be obligated to bear or reimburse any such costs if the Second Agreement does not close. TCTC shall be copied in a timely manner on all material written correspondence and memoranda describing material oral correspondence will be prepared and sent to TCTC related to the preparation, prosecution, and maintenance of the Xcellerate Patent Rights between Xcyte and Xcyte’s attorney. TCTC retains the right to advise Xcyte regarding patent preparation, prosecution, and maintenance in a reasonable amount of time before the submission of any such documents or payments. In particular, Xcyte will notify TCTC in writing at least 30 days before the filing of an original, divisional, continuation, CIP, reissue, or reexamination filing in the U.S., a foreign original

patent application (such as in Taiwan or other non-PCT country), a PCT filing, or a PCT national stage filing and will include an estimate of the cost of such a filing. TCTC will indicate in writing whether or not they will reimburse such filing costs within 15 days of receiving the written notice from Xcyte. TCTC will otherwise have the right to decline prosecution of any patent or application licensed to TCTC and such patents or applications will be excluded from the license in the relevant country. However, if TCTC has reimbursed Xcyte for filing, prosecution or maintenance fees for a particular patent or application in Australia, China (including Hong Kong), Singapore, South Korea and Taiwan (hereafter the “Major Countries”) and continues to do so, or if TCTC has reimbursed Xcyte for filing, prosecution, or maintenance fees for all of the Major Countries in which Xcyte has filed (without abandonment) or legitimately proposes to file a particular patent, and continues to do so, then neither Xcyte nor its licensees or assigns will enforce the corresponding patent or application or otherwise seek relief against TCTC or its licensees, assigns, distributors, importers, exporters or customers for any past, present or future act of making, have made, selling, importing, exporting or using any Licensed Product in a country in the Territory other than the Major Countries (hereafter “Minor Countries”) subsequent to the time that TCTC declines to reimburse Xcyte for the preparation, prosecution or maintenance costs of a particular patent or application in that Minor Country. Furthermore, neither Xcyte nor its licensees or assigns will enforce such patent or application or otherwise seek relief against TCTC or its licensees, assigns, distributors, importers, exporters or customers for any past, present or future act of making, have made, selling, importing, exporting or using the Know-How in that Minor Country.

Legal/Regulatory Compliance

(0035) TCTC shall comply with all regulations and laws in each country in which it operates.

Second Agreement

(0036) The Second Agreement, which shall be drafted by either Xcyte or TCTC’s counsel (to be mutually determined in good faith), and which shall be subject, in all respects, to the approval of both parties and their respective counsels, shall contain reasonable and customary terms which address, at a minimum: Assignment; Term and Termination; Indemnification for patent infringement or violation of trade secrets; Infringement and Litigation; Xcyte and TCTC Development Obligations; Payment terms; Reports and audits; Perfection of TCTC technology rights in the event of Xcyte bankruptcy, insolvency, liquidation, or forced sale of Xcyte to another party; Disclaimer of Warranties, Indemnification by TCTC and by Xcyte; Adherence to Quality

Standards; Insurance (product liability and personal injury); General and Technical Dispute Resolution through binding arbitration; Xcyte Development Obligations; and Due Diligence. Furthermore, subject to applicable laws, judgments, and other similar restrictions, the Second Agreement shall provide for the continuation of sublicenses from Xcyte’s suppliers to TCTC for components and materials necessary to practice the Xcellerate^™ Technology in the event that Xctye closes, files for bankruptcy or otherwise ceases doing business. Alternatively, subject to applicable laws, judgments, and other similar restrictions, Xcyte must provide in the Second Agreement for the transfer of such sublicenses from the suppliers to TCTC before Xcyte closes, files for bankruptcy or otherwise ceases doing business.

(0037) In addition, the Second Agreement shall include a representation by TCTC that the requisite funds for the Financing have been committed by investors, and shall also contain the Break-Up Fee defined in the Agreement.

General Dispute Resolution

(0038) If the parties themselves cannot mutually resolve a dispute with regard to this Agreement and the Second Agreement, and the issue is not technical in nature, the issue shall be decided by binding arbitration according to the rules of the American Arbitration Association (“AAA”) in Taipei, Taiwan, if Xcyte is the party initiating arbitration, and in Seattle, Washington, if TCTC is the party initiating arbitration. The arbitration shall be conducted by a single arbitrator mutually chosen by the parties. If one of the parties does not agree with using a single arbitrator, the arbitration will be conducted by a panel of three arbitrators appointed in accordance with AAA rules. All arbitration proceedings and decisions will be in English.

Technical Dispute Resolution

(0039) If the issue is scientific, regulatory or marketing (“technical”) in nature regarding either the Agreement or the Second Agreement and cannot be resolved by the parties respective officers, the parties agree to submit such technical issue to an independent three-member board for resolution. The three-member board shall consist of one independent technical consultant in the scientific, regulatory or marketing field, as is appropriate to the nature of the issue, designated by each party. The two such designated technical consultants selecting a third independent consultant in the same field to comprise the three-member technical board. The decision of the three-member board shall be binding upon the parties.

Indemnification for Patent Infringement

(0040) In the event of a claim of infringement of patents by third parties in the practice of Xcellerate Patent Rights by TCTC, Xcyte agrees to negotiate in good faith in the Second Agreement a process to either indemnify, defend, reduce the royalty or otherwise resolve the issue.

Xcyte Development Obligations

(0041) TCTC is entering into this Agreement in the expectation that Xcyte will diligently pursue regulatory approval of certain Licensed Products with the U.S. FDA. There are milestones which are payable upon completion of identified events which represent partial payment for the license. However, TCTC will only receive full value for its license payments if Xcyte is successful in obtaining U.S. FDA approval for several Products. Consequently, during the period (the “Inactive Period”) that Xcyte or its successors, agents, or assigns has failed to use reasonable efforts for at least six (6) months out of the immediately preceding two (2) years to pursue its first U.S. FDA approval of Licensed Products before achieving the first U.S. FDA Product approval, (A) TCTC’s obligations to pay royalties will be permanently reduced to paying a royalty equal to Xcyte’s payment obligations on Xcellerate Patent Rights for all remaining periods covered by this license agreement and (B) TCTC shall have the right to access clinical data and FDA regulatory filings related to Xcyte products in the Cellular Immunotherapy Field owned by Xcyte. During the Inactive Period, Xcyte shall not prevent TCTC or its agent from pursuing FDA approval on such products, provided that TCTC or its agent provides Xcyte prior written notice of its intentions and meets standards customary for established U.S. pharmaceutical companies when pursuing such approval. TCTC’s rights pursuant to this Section shall be subject to Xcyte’s and TCTC’s obligations under applicable agreements, laws and regulations.

Tax Exemption

(0042) Xcyte is entering into this Agreement with the expectation that TCTC will make certain milestone, royalty and sublicense payments to Xcyte in exchange for its grant of valuable intellectual property rights to TCTC. TCTC acknowledges that Xcyte will only receive full value for its license grant to TCTC herein if the payments to be made to Xcyte stated herein are not subject to the 20% Taiwan withholding tax. Therefore, as a condition to Xcyte entering into the Second Agreement, TCTC shall use best efforts to assist Xcyte in securing any necessary exemptions from the applicable tax authorities, at Xcyte’s cost, to ensure that the payments to be made to Xcyte pursuant to this Collaboration shall be exempt from Taiwan withholding taxes. Xcyte will use its best efforts in obtaining such tax exempt status.