NEUROCRINE BIOSCIENCES, INC. PURCHASE AGREEMENT

Documents Incorporated by Reference. The documents incorporated or deemed to be incorporated by reference in the Time of Sale Document or the Final Offering Memorandum, at the time such documents were or hereafter are filed with the SEC, complied and will comply, in all material respects with the requirements of the Securities Exchange Act of 1934, as amended, and the rules and regulations of the SEC thereunder (collectively, the “Exchange Act”) and did not or will not (in the case of documents filed with the SEC after the date hereof) contain an untrue statement of a material fact or omit

to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading. There are no contracts or other documents required pursuant to the Exchange Act to be described in such incorporated documents or to be filed as exhibits to such incorporated documents which have not been described or filed as required.

Company’s Accounting System. The Company and each of its subsidiaries make and keep accurate books and records and maintain a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles as applied in the United States and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for

assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences. The Company is not aware of any material weakness in the Company’s internal control over financial reporting (whether or not remediated) and since December 31, 2016, there has been no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

No Material Adverse Change. Except as otherwise disclosed in the Time of Sale Document and the Final Offering Memorandum, subsequent to the respective dates as of which information is given in the Time of Sale Document and the Final Offering Memorandum: (i) there has been no material adverse change, or any development that would reasonably be expected to result in a material adverse change, in the condition, financial or otherwise, or in the earnings, business, operations or prospects, whether or not arising from transactions in the ordinary course of business, of the Company and its subsidiaries, considered as one entity (any such change is called a “Material Adverse Change”); (ii) the Company and its subsidiaries, considered as one entity, have not incurred any material liability or obligation, indirect, direct or contingent, not in the ordinary course of business nor entered into any material transaction or agreement not in the ordinary course of business; and (iii) there has been no dividend or distribution of any kind declared, paid or made by the Company or, except for dividends paid to the

Company or other subsidiaries, any of its subsidiaries on any class of capital stock or repurchase or redemption by the Company or any of its subsidiaries of any class of capital stock.

No Conflicts. The issue and sale of the Securities, the execution, delivery and performance of this Agreement, the Indenture and the Securities, the consummation of the transactions contemplated hereby and thereby (including the issuance of the

Conversion Shares) and the application of the proceeds from the sale of the Securities as described under “Use of Proceeds” in the Time of Sale Document will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, impose any lien, charge or encumbrance upon any property or assets of the Company and its subsidiaries, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement, license, lease or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject; (ii) result in any violation of the provisions of the charter or by-laws (or similar organizational documents) of the Company or any of its subsidiaries; or (iii) result in any violation of any statute or any judgment, order, decree, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties or assets, except, with respect to clauses (i) and (iii), conflicts or violations that would not reasonably be expected to result in a Material Adverse Change.

All Necessary Permits. The Company and each subsidiary possess such valid and current certificates, authorizations or permits issued by the appropriate state, federal or foreign

regulatory agencies or bodies necessary to conduct their respective businesses, and neither the Company nor any subsidiary has received, or has any reason to believe that it will receive, any notice of proceedings relating to the revocation or modification of, or non-compliance with, any such certificate, authorization or permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would reasonably be expected to result in a Material Adverse Change.

Intellectual Property Rights. The Company and its subsidiaries own, possess or can acquire or license on reasonable terms sufficient trademarks, trade names, patent rights, copyrights, domain names, licenses, approvals, trade secrets and other similar rights (collectively, “Intellectual Property Rights”) reasonably necessary to conduct their businesses as now conducted; except to the extent failure to own, possess, license or acquire such Intellectual Property Rights would not result in a Material Adverse Change. Neither the Company nor any of its subsidiaries has received, or has any reason to believe that it will receive, any notice of infringement or conflict with asserted Intellectual Property Rights of others. Except as would not be reasonably likely to result, individually or in the aggregate, in a Material Adverse Change (i) to the Company’s knowledge, there is no infringement, misappropriation or violation by third parties of any of the Intellectual Property Rights owned by the Company; (ii) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others challenging the rights of the Company and its subsidiaries in or to any such Intellectual Property Rights, and the Company is unaware of any facts which would form a reasonable basis for any such claim, that would, individually or in the aggregate, together with any other claims in this Section 1(w) result in a Material Adverse Change; (iii) the

Intellectual Property Rights owned by the Company and its subsidiaries and, to the Company’s knowledge, the Intellectual Property Rights licensed to the Company and its subsidiaries have not been adjudged by a court of competent jurisdiction invalid or unenforceable, in whole or in part, and there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others challenging the validity or scope of any such Intellectual Property Rights, and the Company is unaware of any facts which would form a reasonable basis for any such claim that would, individually or in the aggregate, together with any other claims in this Section 1(w) result in a Material Adverse Change; (iv) there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others that the Company or its subsidiaries infringe, misappropriate or otherwise violate any Intellectual Property Rights or other proprietary rights of others, the Company and its subsidiaries have not received any written notice of such claim and the Company is unaware of any other facts which would form a reasonable basis for any such claim that would reasonably be expected, individually or in the aggregate, together with any other claims in this Section 1(w) to result in a Material Adverse Change; and (v) to the Company’s knowledge, no employee of the Company or a subsidiary of the Company is in or has ever been in violation in any material respect of any term of any employment contract, patent disclosure agreement, invention assignment agreement, non-competition agreement, non-solicitation agreement, nondisclosure agreement or any restrictive covenant to or with a former employer where the basis of such violation relates to such employee’s employment with the Company or a subsidiary of the Company, or actions undertaken by the employee while employed with the Company or a subsidiary of the Company and would reasonably be expected to result, individually or in the aggregate, in a Material Adverse Change. To the Company’s knowledge, all material technical information developed by and belonging to the Company and its subsidiaries for which they have not sought, and do not intend to seek, to patent or otherwise protect pursuant to applicable intellectual property laws has been kept confidential or disclosed only under obligations of confidentiality. The Company is not a party to or bound by any options, licenses or agreements with respect to the Intellectual Property Rights of any other person or entity that are required to be set forth or incorporated by reference in the Time of Sale Document and the Final Offering Memorandum and are not described therein. None of the technology employed by the Company or any of its subsidiaries has been obtained or is being used by the Company or any of its subsidiaries in violation of any contractual obligation binding on the Company or any of its subsidiaries or, to the Company’s knowledge, any of its or its subsidiaries’ officers, directors or employees or otherwise in violation of the rights of any persons, except in each case for such violations that would not reasonably be expected to result in a Material Adverse Change.

ERISA Compliance. The Company and its subsidiaries and any “employee benefit plan” (as defined under the Employee Retirement Income Security Act of 1974, as amended, and the regulations and published interpretations thereunder (collectively, “ERISA”)) established or maintained by the Company, its subsidiaries or their “ERISA Affiliates” (as defined below) are in compliance in all material respects with ERISA. “ERISA Affiliate” means, with respect to the Company or a subsidiary, any member of any group of organizations described in Sections 414(b),(c),(m) or (o) of the Internal Revenue Code of 1986, as amended, and the regulations and published interpretations thereunder (the

“Code”) of which the Company or such subsidiary is a member. No “reportable event” (as defined under ERISA) has occurred or is reasonably expected to occur with respect to any “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates. No “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates, if such “employee benefit plan” were terminated, would have any “amount of unfunded benefit liabilities” (as defined under ERISA). Neither the Company, its subsidiaries nor any of their ERISA Affiliates has incurred or reasonably expects to incur any liability under (i) Title IV of ERISA with respect to termination of, or withdrawal from, any “employee benefit plan” or (ii) Sections 412, 4971, 4975 or 4980B of the Code. Each “employee benefit plan” established or maintained by the Company, its subsidiaries or any of their ERISA Affiliates that is intended to be qualified under Section 401(a) of the Code is so qualified and nothing has occurred, whether by action or failure to act, which would reasonably be expected to result in the loss of such qualification.

No Outstanding Loans or Other Extensions of Credit. Since the adoption of Section 13(k) of the Exchange Act, neither the Company nor any of its subsidiaries has extended or maintained credit, arranged for the extension of credit, or renewed any extension of credit, in the form of a personal loan, to or for any director or executive

officer (or equivalent thereof) of the Company and/or such subsidiary except for such extensions of credit as are expressly permitted by Section 13(k) of the Exchange Act.

Compliance with Sanctions Laws. Neither the Company nor any of its subsidiaries, directors or officers, nor, to the knowledge of the Company, any other employee, agent or

affiliate or other person authorized to act on behalf of the Company or any of its subsidiaries is currently the subject or the target of any sanctions administered or enforced by the U.S. Government, (including, without limitation, the Office of Foreign Assets Control of the U.S. Department of the Treasury or the U.S. Department of State and including, without limitation, the designation as a “specially designated national” or “blocked person”), the United Nations Security Council, the European Union, Her Majesty’s Treasury, or other relevant sanctions authority (collectively, “Sanctions”), nor is the Company, any of its subsidiaries located, organized or resident in a country or territory that is the subject or the target of Sanctions, including, without limitation, Cuba, Iran, North Korea, Sudan, Syria and Crimea (each, a “Sanctioned Country”); and the Company will not directly or indirectly use the proceeds of the offering of the Securities hereunder, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other person or entity (i) to fund or facilitate any activities of or business with any person that, at the time of such funding or facilitation, is the subject or the target of Sanctions, (ii) to fund or facilitate any activities of or business in any Sanctioned Country or (iii) in any other manner that will result in a violation by any person (including any person participating in the transaction, whether as underwriter, advisor, investor or otherwise) of Sanctions. For the past five years, the Company and its subsidiaries have not knowingly engaged in and are not now knowingly engaged in any dealings or transactions with any person that at the time of the dealing or transaction is or was the subject or the target of Sanctions or with any Sanctioned Country.

Health Care Laws. The Company, its subsidiaries and their respective directors, officers, employees, and, to the Company’s knowledge, agents (while acting in such capacity) are, and at all times since January 1, 2014 have been, in material compliance with, all health care laws applicable to the Company or its subsidiaries or any of its products or activities, including, but not limited to, the federal Anti-Kickback Statute (42 U.S.C. § 1320a-7b(b)), the Civil Monetary Penalties Laws (42 U.S.C. § 1320a-7a), the civil False Claims Act (31 U.S.C. §§ 3729 et seq.), the Criminal False Statements Law (42 U.S.C. § 1320a-7b(a)), the Physician Payments Sunshine Act (42 U.S.C. § 1320-7h), all criminal laws relating to health care fraud and abuse, including but not limited to 18 U.S.C. §§ 286 and 287, the Health Insurance Portability and Accountability Act of 1996 (42 U.S.C. §§ 1320d et seq.) as amended by the Health Information Technology for Economic and Clinical Health Act (42 U.S.C. §§ 17921 et seq.), the exclusion laws (42 U.S.C. § 1320a-

7), the Federal Food, Drug and Cosmetic Act (21 U.S.C. §§ 301 et seq.), the Controlled Substances Act (21 U.S.C. §§ 801 et seq.), Medicare (Title XVIII of the Social Security Act), Medicaid (Title XIX of the Social Security Act), the collection and reporting requirements, and the processing of any applicable rebate, chargeback or adjustment, under applicable rules and regulations relating to the Medicaid Drug Rebate Program (42 U.S.C. § 1396r-8) and any state supplemental rebate program, Medicare average sales price reporting (42 U.S.C. § 1395w-3a), the Public Health Service Act (42 U.S.C. § 256b), the VA Federal Supply Schedule (38 U.S.C. § 8126) or under any state pharmaceutical assistance program or U.S. Department of Veterans Affairs agreement, and any successor government programs, each as amended, the regulations promulgated pursuant to such laws, and any other state or federal law, accreditation standards, regulation, memorandum, opinion letter, or other issuance which imposes requirements on the manufacturing, development, testing, labeling, marketing or distribution of pharmaceutical products, kickbacks, patient or program charges, recordkeeping, documentation requirements, referrals, the hiring of employees or acquisition of services or supplies from those who have been excluded from government health care programs, quality, safety, privacy, security, licensure, accreditation or any other aspect of providing health care or pharmaceutical services (collectively, the “Health Care Laws”). The Company has not received any notification, correspondence or any other written or oral communication, including notification of any pending or threatened claim, suit, proceeding, hearing, enforcement, investigation, arbitration or other action (“Action”) from any court, arbitrator, third-party or governmental or regulatory authority, including, without limitation, the United States Food and Drug Administration (“FDA”), the Drug Enforcement Agency, the Centers for Medicare & Medicaid Services, the U.S. Department of Justice, and the U.S. Department of Health and Human Services Office of Inspector General, of potential or actual non-compliance by, or liability of, the Company or its subsidiaries under any Health Care Laws, and to the knowledge of the Company, no such Action is threatened. To the Company’s knowledge, there are no facts or circumstances that would reasonably be expected to give rise to liability of the Company under any Health Care Laws. The Company is not a party to any corporate integrity agreements, monitoring agreements, deferred prosecution agreements, consent decrees, settlement orders, or similar agreements with or imposed by any governmental or regulatory authority.

Manufacturing of Products. The manufacture of Company products by or on behalf of the Company is being conducted in compliance in all material respects with all applicable Health Care Laws, including, without limitation, the FDA’s current good manufacturing practice regulations at 21 C.F.R. Parts 210-211 for products sold in the United States, and the respective counterparts thereof promulgated by governmental authorities in countries outside the United States. Except as disclosed in the Time of Sale Document and the Final Offering Memorandum or as would not reasonably be expected to result a Material Adverse Change, during the three (3) year period ending on December 31, 2016, the Company has not had any product or manufacturing site (whether Company-owned or that of a contract manufacturer for Company products) subject to a governmental authority (including FDA) shutdown or import or export prohibition, nor received any FDA Form 483 or other governmental authority notice of inspectional observations, “warning letters,” “untitled letters,” requests to make changes to the Company products,

processes or operations, or similar correspondence or notice from the FDA or other governmental authority alleging or asserting material noncompliance with any applicable Health Care Laws. To the Company’s knowledge, neither the FDA nor any other governmental authority is considering such action.

Securities Law Compliance. To (i) advise the Initial Purchasers promptly after obtaining knowledge (and, if requested by the Representatives, confirm such advice in writing) of (A) the issuance by any U.S. or non-U.S. federal or state securities commission of any stop order suspending the qualification or exemption from qualification of any of the Securities for offer or sale in any jurisdiction, or the initiation of any proceeding for such purpose by any U.S. or non-U.S. federal or state securities commission or other regulatory authority, or (B) the happening of any event at any time prior to the

completion of the offering of the Securities that makes any statement of a material fact made in the Time of Sale Document, any Company Additional Written Communication or the Final Offering Memorandum, untrue or that requires the making of any additions to or changes in the Time of Sale Document, any Company Additional Written Communication, or the Final Offering Memorandum, to make the statements therein, in the light of the circumstances under which they were made, not misleading, (ii) use its reasonable best efforts to prevent the issuance of any stop order or order suspending the qualification or exemption from qualification of any of the Securities under any securities or “Blue Sky” laws of U.S. state or non-U.S. jurisdictions and (iii) if, at any time, any U.S. or non-U.S. federal or state securities commission or other regulatory authority shall issue an order suspending the qualification or exemption from qualification of any of the Securities under any such laws, use its reasonable best efforts to obtain the withdrawal or lifting of such order at the earliest possible time.

Preparation of Amendments and Supplements to Offering Documents. So long as the Initial Purchasers shall hold any of the Securities, (i) if any event shall occur as a result of which it becomes necessary or advisable to amend or supplement the Time of Sale Document or the Final Offering Memorandum to correct any untrue statement of a material fact or omission to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, to prepare, at the expense of the Company, an appropriate amendment or supplement to the

Time of Sale Document and the Final Offering Memorandum (in form and substance reasonably satisfactory to the Representatives) so that as so amended or supplemented, the Time of Sale Document and the Final Offering Memorandum will not include an untrue statement of material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading and (ii) if in the reasonable judgment of the Company it becomes necessary or advisable to amend or supplement the Time of Sale Document or the Final Offering Memorandum so that the Time of Sale Document and the Final Offering Memorandum will contain all of the information specified in, and meet the requirements of, Rule 144A(d)(4) of the Securities Act, to prepare an appropriate amendment or supplement to the Time of Sale Document or the Final Offering Memorandum (in form and substance reasonably satisfactory to the Representatives) so that the Time of Sale Document or the Final Offering Memorandum, as so amended or supplemented, will contain the information specified in, and meet the requirements of, such rule.

Payment of Expenses. The Company agrees to pay all costs, fees and expenses incurred in connection with the performance of its obligations hereunder and in connection with the offering of the Securities hereunder, including without limitation (i) all expenses incident to the issuance and delivery of the Securities (including all printing and engraving costs), (ii) all fees and expenses (including reasonable fees and expenses of counsel) of the Trustee and the Company’s transfer agent, (iii) all necessary issue, transfer and other stamp taxes in connection with the issuance and sale of the Securities to the Initial Purchasers, (iv) all fees and expenses of the Company’s counsel, independent public or certified public accountants and other advisors, (v) all costs and expenses incurred in connection with the preparation, printing, filing, shipping and distribution of the Time of Sale Document and the Final Offering Memorandum (including financial statements, exhibits, schedules, consents and certificates of experts), and all amendments and supplements thereto, and this Agreement, (vi) all filing fees, attorneys’ fees and expenses incurred by the Company in connection with qualifying or registering (or obtaining exemptions from the qualification or registration of) all or any part of the Securities for offer and sale under the state securities or blue sky laws, and, if requested by the Representatives, preparing and printing a “blue sky survey”, and any

supplements thereto, advising the Initial Purchasers of such qualifications, registrations, determinations and exemptions, (vii) all fees and expenses (including fees and expenses of counsel) of the Company in connection with approval of the Securities by DTC for “book-entry” transfer, (viii) all fees charged by rating agencies in connection with the rating of the Securities, (ix) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the offering of the Securities, including, without limitation, expenses associated with the preparation or dissemination of any electronic road show, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations with the prior approval of the Company, and travel and lodging expenses of the representatives, employees and officers of the Company and of the Representatives and any such consultants, and (viii) the fees and expenses associated with listing the Conversion Shares on the NASDAQ and/or any other exchange. Except as provided in this Section 5, Section 8, and Section 9 hereof, the Initial Purchasers shall pay their own expenses, including the fees and disbursements of their counsel.

Additional Offering Materials. Not to, and not to authorize or permit any person acting on its behalf to, (i) distribute any offering material in connection with the offer and sale of the Securities other than the Time of Sale Document and the Final Offering

Memorandum and any amendments and supplements to the Preliminary Offering Memorandum or the Final Offering Memorandum prepared in compliance with this Agreement or (ii) solicit any offer to buy or offer to sell the Securities by means of any form of general solicitation or general advertising (including, without limitation, as such terms are used in Regulation D under the Securities Act) or in any manner involving a public offering within the meaning of Section 4(2) of the Securities Act.

Company Lock-Up. During the period commencing on and including the date hereof and continuing through and including the 90^th day following the date of the Final Offering Memorandum (the “Lock-up Period”), the Company will not, without the prior written consent of the Representatives (which consent may be withheld at the sole discretion of the Representatives), directly or indirectly: (i) sell, offer to sell, contract to sell or lend any Common Stock or Related Securities (as defined below); (ii) effect any short sale, or establish or increase any “put equivalent position” (as defined in Rule 16a-1(h) under the Exchange Act) or liquidate or decrease any “call equivalent position” (as defined in Rule 16a-1(b) under the Exchange Act) of any Common Stock or Related Securities; (iii) pledge, hypothecate or grant any security interest in any Common Stock or Related Securities; (iv) in any other way transfer or dispose of any Common Stock or Related Securities; (v) enter into any swap, hedge or similar arrangement or agreement that transfers, in whole or in part, the economic risk of ownership of any Common Stock or Related Securities, regardless of whether any such transaction is to be settled in securities, in cash or otherwise; (vi) announce the offering of any Common Stock or Related Securities; (vii) file any registration statement under the Securities Act in respect of any Common Stock or Related Securities (other than as contemplated by this Agreement or a registration statement on Form S-8 relating to the Company’s equity incentive plans); or (viii) publicly announce the intention to do any of the foregoing; provided, however, that the Company may issue Common Stock (i) pursuant to transactions relating to any director or employee equity incentive plan, stock ownership plan or dividend reinvestment plan of the Company in effect at the date of the Time of Sale Document and described in the Time of Sale Document (including the issuance of securities thereunder, the issuance of Common Stock upon the exercise of options issued

pursuant thereto, and the issuance of Common Stock upon the vesting of restricted stock units issued pursuant thereto), (ii) pursuant to the conversion of securities or the exercise of warrants outstanding at the date of the Time of Sale Document and described in the Time of Sale Document, (iii) to one or more counterparties in connection with the consummation a strategic partnership, joint venture, collaboration or the acquisition or license of any business products or technology; provided that, with respect to this subsection (iii), (1) the sum of the aggregate number of Common Stock so issued shall not exceed 5% of the total outstanding shares of Common Stock immediately following the completion of this offering of Securities and (2) prior to the issuance of such shares of Common Stock each recipient of Common Stock agrees in writing not to sell, offer, dispose of or otherwise transfer any such shares of Common Stock during such Lock-up Period without the prior written consent of the Representatives (which consent may be withheld at the sole discretion of the Representatives). For purposes of the foregoing, “Related Securities” shall mean any options or warrants or other rights to acquire Shares or any securities exchangeable or exercisable for or convertible into Shares, or to acquire other securities or rights ultimately exchangeable or exercisable for, or convertible into, Shares.

Comfort Letter. The Representatives shall have received from Ernst & Young LLP, the registered public or certified public accountants of the Company for the year ended December 31, 2016 and subsequent periods, (A) a customary initial comfort letter delivered according to Statement of Auditing Standards No. 72 (or any successor bulletin), dated the date hereof, in form and substance reasonably satisfactory to the Representatives and its counsel, with respect to the financial

statements and certain financial information contained in the Time of Sale Document and the Final Offering Memorandum, and (B) a customary “bring-down” comfort letter, dated the applicable Closing Date, in form and substance reasonably satisfactory to the Representatives and its counsel, to the effect that Ernst & Young LLP which includes, among other things, a reaffirmation of the statements made in its initial letter furnished pursuant to clause (A) with respect to such financial statements and financial information contained in the Time of Sale Document and the Final Offering Memorandum.

No Suspension in Trading; Banking Moratorium. Subsequent to the execution and delivery of this Agreement there shall not have occurred any of the following: (i) trading in the Company’s common stock shall have been suspended by the SEC or the NASDAQ or a suspension or limitation of trading generally in securities on the New York Stock Exchange, the NASDAQ, the NASDAQ Global Market, or the NASDAQ Capital Market, or any setting of limitations on prices for securities occurs on any such exchange or market, (ii) the declaration of a banking moratorium by any governmental authority has occurred or the taking of any action by any governmental authority after the date

hereof in respect of its monetary or fiscal affairs, (iii) a suspension or limitation of trading in securities of the Company or (iv) a material disruption in settlement or clearing services that, in the case of clause (i) or (ii) of this paragraph, in the Representatives’ sole judgment, would reasonably be expected to have a material adverse effect on the financial markets in the United States or elsewhere.

Notifications and Other Indemnification Procedures. As promptly as reasonably practicable after receipt by an indemnified party under this Section of notice of the commencement of any action for which such indemnified party is entitled to indemnification under this Section, such indemnified party will, if a claim in respect thereof is to be made against the indemnifying party under this Section, notify the indemnifying party of the commencement thereof in writing; but the omission to so notify the indemnifying party (i) will not relieve such indemnifying party from any liability under Section 8(a) or (b) above unless and only to the extent it is materially prejudiced as a proximate result thereof and (ii) will not, in any event, relieve the

indemnifying party from any obligations to any indemnified party other than the indemnification obligation provided in Section 8(a) and (b) above. In case any such action is brought against any indemnified party, and it notifies the indemnifying party of the commencement thereof, the indemnifying party will be entitled to participate therein and, to the extent that it may elect, jointly with any other indemnifying party similarly notified by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to assume the defense thereof, with counsel reasonably satisfactory to such indemnified party; provided, however, that if (i) the use of counsel chosen by the indemnifying party to represent the indemnified party would present such counsel with a conflict of interest, (ii) the defendants in any such action include both the indemnified party and the indemnifying party, and the indemnified party shall have concluded that a conflict may arise between the positions of the indemnifying party and the indemnified party in conducting the defense of any such action or that there may be one or more legal defenses available to it and/or other indemnified parties that are different from or additional to those available to the indemnifying party, or (iii) the indemnifying party shall not have employed counsel reasonably satisfactory to the indemnified party to represent the indemnified party within a reasonable time after receipt by the indemnifying party of notice of the institution of such action, then, in each such case, the indemnifying party shall not have the right to direct the defense of such action on behalf of such indemnified party or parties and such indemnified party or parties shall have the right to select separate counsel to defend such action on behalf of such indemnified party or parties at the expense of the indemnifying party. After notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof and approval by such indemnified party of counsel appointed to defend such action, the indemnifying party will not be liable to such indemnified party under this Section for any legal or other expenses, other than reasonable costs of investigation, subsequently incurred by such indemnified party in connection with the defense thereof, unless (i) the indemnified party shall have employed separate counsel in accordance with the proviso to the immediately preceding sentence (it being understood, however, that in connection with such action the indemnifying party shall not be liable for the fees and expenses of more than one separate counsel (in addition to local counsel) in any one action or separate but substantially similar actions in the same jurisdiction arising out of the same general allegations or circumstances, designated by the Initial Purchasers in the case of Section 8(a) or the Company in the case of Section 8(b), representing the indemnified parties under such Section 8(a) or (b), as the case may be, who are parties to such action or actions), (ii) the indemnifying party has authorized in writing, in advance, the employment of counsel for the indemnified party at the expense of the indemnifying party or (iii) the indemnifying party shall not have employed counsel satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of commencement of the action, in each of which cases the fees and expenses of counsel shall be at the expense of the indemnifying party and shall be paid as they are incurred. After such notice from the indemnifying party to such indemnified party, the indemnifying party will not be liable for the costs and expenses of any settlement of such action effected by such indemnified party without the prior written consent of the indemnifying party (which consent shall not be unreasonably withheld), unless such

indemnifying party waived in writing its rights under this Section, in which case the indemnified party may effect such a settlement without such consent.

Contribution. In circumstances in which the indemnity agreements provided for in this Section is unavailable to, or insufficient to hold harmless, an indemnified party in respect of any losses, claims, damages, liabilities or expenses (or actions in respect thereof), each indemnifying party, in order to provide for just and equitable contributions, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages, liabilities or expenses (or actions in respect thereof) in such proportion as is appropriate to reflect (i) the relative benefits received by the indemnifying party or parties, on the one hand, and the indemnified party, on the other hand, from the Offering or (ii) if the allocation provided by the foregoing clause (i) is not permitted by applicable law, not only such relative benefits but also the relative fault of the indemnifying party or parties, on the one hand, and the indemnified party, on the other hand, in connection with the statements or omissions or alleged statements or omissions that resulted in such losses, claims, damages or liabilities (or actions in respect thereof). The relative benefits received by the Company, on the one hand, and the Initial Purchasers, on the other hand, shall be deemed to be in the same proportion as the total proceeds from the Offering (before deducting expenses) received by the Company bear to the total discounts and commissions received by the Initial Purchasers. The relative fault

of the parties shall be determined by reference to, among other things, 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 the Company, on the one hand, or the Initial Purchasers pursuant to Section 8(b) above, on the other hand, the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission or alleged statement or omissions, and any other equitable considerations appropriate in the circumstances.

Governing Law; Jurisdiction; Waiver of Jury Trial; Venue. This Agreement shall be governed by, and construed in accordance with, the laws of the State of New York. The Company hereby expressly and irrevocably (i) submits to the non-exclusive jurisdiction of the federal and state courts sitting in the Borough of Manhattan in the City of New York in any suit or proceeding arising out of or relating to this Agreement or the

Transactions, and (ii) waives (a) its right to a trial by jury in any legal action or proceeding relating to this Agreement, the Transactions or any course of conduct, course of dealing, statements (whether verbal or written) or actions of the Initial Purchasers and for any counterclaim related to any of the foregoing and (b) any obligation which it may have or hereafter may have to the laying of venue of any such litigation brought in any such court referred to above and any claim that any such litigation has been brought in an inconvenient forum.

/s/ ▇▇▇▇▇▇ ▇▇▇▇▇

/s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇

Initial Purchasers

▇▇▇▇▇▇▇▇▇ LLC

Barclays Capital Inc.

▇.▇. ▇▇▇▇▇▇ Securities LLC

Leerink Partners LLC

▇▇▇▇▇▇ ▇. ▇▇▇▇▇ & Co. Incorporated

▇.▇. ▇▇▇▇▇▇▇▇▇▇ & Co., LLC

Total

Effective Date

May 2, 2017

May 15, 2018

May 15, 2019

May 15, 2020

May 15, 2021

May 15, 2022

May 15, 2023

May 15, 2024

if such stock price is between two stock prices in the table above or the effective date is between two effective dates in the table above, then the number of additional shares will be determined by a straight-line interpolation between the numbers of additional shares set forth for the higher and lower stock prices in the table and the earlier and later effective dates in the table above, as applicable, based on a 365- or 366-day year, as applicable; and

if the stock price is greater than $250.00 (subject to adjustment in the same manner as the stock prices set forth in the column headings of the table above are adjusted, as described in the Preliminary Offering Memorandum under the caption “Description of Notes—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change—Adjustment of Stock Prices and Number of Additional Shares”), or less than $53.28 (subject to adjustment in the same manner), per share, then no additional shares will be added to the conversion rate.