UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark one)

For the fiscal year ended December 31, 2008

OR

Commission File Number 000-30347

CURIS, INC.

(Exact Name of Registrant as Specified in Its Charter)

45 Moulton Street

Cambridge, Massachusetts 02138

(Address of principal executive offices) (Zip Code)

617-503-6500

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes  ¨    No  x

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).    Yes  ¨    No  x

The aggregate market value of the registrant’s common stock held by non-affiliates of the registrant (without admitting that any person whose shares are not included in such calculation is an affiliate) based on the last reported sale price of the common stock on June 30, 2008 was approximately $62,390,000.

As of February 24, 2009, there were 63,653,698 shares of the registrant’s common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

The registrant has filed a definitive proxy statement pursuant to Regulation 14A within 120 days of the end of the fiscal year ended December 31, 2008. Portions of such proxy statement are incorporated by reference into Items 10, 11, 12, 13, 14 of Part III of the Annual Report on Form 10-K, as amended.

EXPLANATORY NOTE

Curis, Inc. is filing this Amendment No. 1 (“Amendment No. 1”) to its Annual Report on Form 10-K for the fiscal year ended December 31, 2008, as originally filed with the SEC on February 26, 2009 (the “Original 10-K”), for the purpose of: (1) amending Part III Item 12 thereof to include disclosure regarding securities authorized for issuance under equity compensation plans; and (2) amending and restating Part III Item 15(a)(3) “List of Exhibits” to add new certifications in accordance with Rule 13a-14(a) of the Exchange Act, which are filed as exhibits with this 10-K/A.

This Amendment No. 1 does not change the previously reported financial statements or any of the other disclosure contained in the Original 10-K.

PART III

Securities Authorized for Issuance Under Equity Compensation Plans

The following table provides information as of December 31, 2008 regarding compensation plans (including individual compensation arrangements) under which our equity securities are authorized for issuance.

Beginning on January 1, 2001 and continuing through January 1, 2010, the number of shares of common stock reserved for issuance under the 2000 Stock Incentive Plan is automatically increased by the lesser of 1,000,000 shares or 4% of outstanding stock on January 1 of each year.

The other information required by this Item 12 is set forth in our proxy statement for our 2009 annual meeting of stockholders under the heading Security Ownership of Certain Beneficial Owners and Management, which information is incorporated herein by reference.

(a)(3) List of Exhibits. The list of Exhibits filed as a part of this annual report on Form 10-K as amended by this Amendment No. 1 is set forth on the Exhibit Index immediately preceding such Exhibits, and is incorporated herein by reference.

SIGNATURE

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: November 13, 2009

EXHIBIT INDEX