Exclusive Agency Agreement for Common Stock Financing between Curis, Inc. and Leerink Swann & Company (September 28, 2004)

Exhibit 1.1

September 28, 2004

Mr. Daniel R. Passeri

President and Chief Executive Officer

Curis, Inc.

61 Moulton Street

Cambridge, MA 02138

Dear Mr. Passeri:

The Proposed Financing shall occur through a directed registered sale under the Securities Act of 1933, as amended (the “Act”) and in compliance with applicable state securities laws. Our undertaking herein shall be subject to, among other things, the terms and conditions set forth in this Agreement, our due diligence investigation of the Company, the continuance of the Company without material adverse change, the absence of unfavorable market conditions in general and our continued satisfaction with the results of our ongoing review of the Company’s business and affairs. It is understood that execution of this Agreement does not assure the successful completion of the Proposed Financing.

The Company has filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-3 (No. 333-111525), which was declared effective on 3:00 p.m. E.S.T. on January 7, 2004 (the “Effective Date”), covering the registration of, among other things, the Securities under the Securities Act and including the related preliminary prospectus (the “Base Prospectus”). Promptly after execution and delivery of an agreement by the Company with Purchasers (as defined below) for purchase of the Shares in the Proposed Financing, the Company will prepare and file with the Commission a prospectus supplement specifically relating to the Securities (the “Prospectus Supplement”) pursuant to Rule 424(b) of the rules and regulations of the Commission under the Securities Act (the “Regulations”). The registration statement, as amended to the date of this Agreement, by any post-effective amendment and by any Prospectus Supplement, and including the exhibits thereto, schedules, if any, and the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act, at the time that it became effective, is herein called the “Registration Statement.” The Base Prospectus and the

Leerink Swann & Company is a member of NASD/SIPC

60 State Street Boston, Massachusetts 02109 Tel. 617 ###-###-#### Fax ###-###-#### www.leerink.com

Prospectus Supplement, including the documents incorporated by reference therein, are herein called, collectively, the “Offering Materials.”

In addition and regardless of whether the Proposed Financing is consummated, upon request by Leerink from time to time, the Company shall reimburse Leerink for all reasonable out-of-pocket expenses incurred by Leerink in connection with its engagement hereunder, including reasonable fees and expenses of its counsel, not to exceed in the aggregate $25,000.

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Leerink from engaging in future transactions involving companies in a similar industry to the Company or, provided no Confidential Information is directly used in connection with such engagement, be deemed to violate any of the terms hereof.

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Company, to Curis, Inc., 61 Moulton Street, Cambridge, MA 02138, Attention: Michael P. Gray, with a copy to Wilmer Cutler Pickering Hale and Dorr, 60 State Street, Boston, MA 02109, Attention: Cynthia T. Mazareas. Any notice delivered personally shall be deemed given upon receipt; any notice given by overnight courier shall be deemed given on the next business day after delivery to the overnight courier; and any notice given by certified mail shall be deemed given upon the second business day after certification thereof.

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Accepted and agreed to

this 28^th day of September, 2004.

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EXHIBIT A

This Exhibit A is entered into pursuant to, and is made a part of, the attached Agreement between Leerink and the Company. Capitalized terms used and not defined in this Exhibit A shall have the meanings assigned them in the attached Agreement.

The Company agrees to indemnify and hold harmless Leerink, its affiliates, and each of its partners, directors, officers, consultants, employees, advisors, representatives and controlling persons (each an “Indemnified Person”) from and against any claims, losses, damages, expenses or liabilities (collectively, “Losses”), including without limitation any reasonable time spent by Leerink’s professional and legal advisors (subject to the limitations set forth below), incurred in connection with investigating, preparing, defending, paying, settling or compromising any action, claim or proceeding to which any Indemnified Person may become subject and which is related to or arises out of the engagement set forth in the Agreement or the transactions contemplated thereby. The Company will not, however, be responsible to an Indemnified Person with respect to any Losses to the extent that a court of competent jurisdiction shall have determined by a final judgment not subject to further appeal that such Losses resulted substantially from actions taken or omitted to be taken by such or any other Indemnified Person due to the Indemnified Person’s or any other Indemnified Person’s gross negligence, bad faith, violation of law or willful misconduct.

If the indemnification provided for herein should be, for any reason whatsoever, unenforceable, unavailable or otherwise insufficient to hold each Indemnified Person harmless, the Company shall pay to or on behalf of each Indemnified Person contributions for Losses so that the Indemnified Person ultimately bears only a portion of such Losses as is appropriate (i) to reflect the relative benefits received by such Indemnified Person on the one hand and the Company on the other hand in connection with this engagement and any transactions contemplated hereby or (ii) if the allocation on the basis set forth in the immediately preceding clause (i) is not permitted by applicable law, to reflect not only the relative benefits referred to in such clause (i) but also the relative fault of the Indemnified Person and the Company as well as any other relevant equitable considerations; provided, however, that in no event shall the aggregate contribution of all Indemnified Persons to all Losses exceed the amount of the fees actually received by Leerink pursuant to the Agreement. The respective relative benefits received by all Indemnified Persons and the Company shall be deemed to be in the same proportion as the aggregate fee paid to Leerink pursuant to the Agreement bears to the total consideration paid or contemplated to be paid to, or received by, the Company or its stockholders, as the case may be, in connection with transactions contemplated by the Agreement, whether or not such transactions are consummated. The relative fault of each Indemnified Person and the Company shall be determined by reference to, among other things, whether the actions or failures to act were by such Indemnified Person or the Company, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such action or failure to act. Notwithstanding the foregoing, no Indemnified Person shall have any obligation to investigate or verify the information provided to Leerink by the Company in connection with their providing financial advisory services under the Agreement, and the Company shall be solely liable for any Losses related to or arising out of the use of such information that is inaccurate for any reason.

The Company also agrees that no Indemnified Person shall have any liability to the Company or its affiliates, directors, officers, employees, Leerink, consultants, advisors, representatives, control persons or stockholders, directly or indirectly, related to or arising out of the Agreement or any transactions contemplated thereby, in connection with claims by third parties except Losses incurred by the Company to the extent a court of competent jurisdiction shall have determined by a final judgment not subject to further appeal that such Losses resulted primarily from actions taken or the failure to take actions by such Indemnified Person due to such Indemnified Person’s gross negligence, bad faith, violation of law or willful misconduct. In no event, regardless of the legal theory advanced, shall any Indemnified Person be liable for any consequential, indirect, incidental or special damages of any nature. Leerink likewise indemnifies the Company in the event of gross negligence, bad faith, material violation of law or willful misconduct on the part of any Leerink party, subject to the limit of the fees actually paid to Leerink hereunder.

In case any proceeding shall be instituted involving any Indemnified Person, such Indemnified Person shall promptly notify the Company in writing. The failure of an Indemnified Person to provide such prompt notice shall not reduce such Indemnified Person’s right to indemnification or contribution hereunder to the extent that such failure does not materially prejudice the Company’s ability to defend such proceeding. The Company shall retain counsel reasonably satisfactory to Leerink to represent the Indemnified Persons and any others the Company may designate in

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such proceeding, shall have sole control of the defense of any such proceeding and shall pay the fees and disbursements of such counsel related to such proceeding. In any such proceeding, any Indemnified Person shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such Indemnified Person, except to the extent that (i) the Company and the Indemnified Person shall have mutually agreed to the retention of such counsel at the Company’s expense or (ii) the named parties to any such proceeding (including any impleaded parties) include both the Company or any others the Company may designate and one or more Indemnified Persons, and representation of the Indemnified Persons and such other parties by the same counsel would be inappropriate due to actual or potential differing interests between them. In any case in which one or more Indemnified Persons are entitled to separate counsel due to such actual or potential differing interests, the Company shall not be liable for the expenses of more than one separate counsel, and such counsel shall be designated in writing by Leerink. The Company shall have sole control of any settlement of any proceeding for which it is obligated to provide indemnification hereunder. Notwithstanding the foregoing the Company shall not, without the prior written consent of the Indemnified Person, effect any settlement of, or consent to the entry of any judgment in connection with, any pending or threatened proceeding in respect of which such Indemnified Person is or could have been a party and indemnity or contribution could have been sought hereunder by such Indemnified Person, unless such settlement or judgment includes an unconditional release of such Indemnified Person from all liability on claims that are the subject matter of the proceeding.

The obligations of the Company referred to above shall be in addition to any rights that any Indemnified Person may otherwise have and shall inure to the benefit of and be binding upon any successors, assigns, heirs and personal representatives of any Indemnified Person or the Company.

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