As filed with the Securities and Exchange Commission on April 17,July 2, 2015

Registration No. 333-333–

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

CURIS, INC.

(Exact Namename of Registrantregistrant as Specifiedspecified in Its Charter)its charter)

4 Maguire Road

Lexington, Massachusetts 02421

(617) 503-6500

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Ali Fattaey, Ph.D.

President and Chief Executive Officer

Curis, Inc.

4 Maguire Road

Lexington, Massachusetts 02421

(617) 503-6500

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copy to:

Steven D. Singer, Esq.

Cynthia T. Mazareas, Esq.

Wilmer Cutler Pickering Hale and Dorr LLP

60 State Street

Boston, Massachusetts 02109

Telephone: (617) 526-6000

Telecopy: (617) 526-5000

Approximate date of commencement of proposed sale to the public: As soon as practicablepublic: From time to time after the effective date hereof.this registration statement becomes effective.

If the only securities being registered on this formForm are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ¨

If any of the securities being registered on this formForm are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  x

If this formForm is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this formForm is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If delivery ofthis Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the prospectus is expected to be madeCommission pursuant to Rule 434, please462(e) under the Securities Act, check the following box.  ¨

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ¨

Indicate by check mark whether the Registrantregistrant 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” inRule 12b-2 of the Exchange Act. (Check one):

CALCULATION OF REGISTRATION FEE

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the Commission acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This registration statement contains two prospectuses:

The base prospectus immediately follows this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be specified in a prospectus supplement to the base prospectus. The sales agreement prospectus immediately follows the base prospectus. The common stock that may be offered, issued and sold by us under the sales agreement prospectus is included in the $200,000,000 of securities that may be offered, issued and sold by us under the base prospectus.

The information in this prospectus is not complete and may be changed. The selling stockholder named in this prospectusWe may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and the selling stockholder named in this prospectus iswe are not soliciting offers to buy these securities in any jurisdiction where the offer or sale is not permitted.

Subject to completion, dated April 17,July 2, 2015

$200,000,000

PROSPECTUS

17,120,131 SHARES OF COMMON STOCKCommon Stock

Preferred Stock

Warrants

This prospectus relates to the resale of up to 17,120,131 shares of our common stock by the selling stockholder listed on page 6, including its transferees, pledgees or donees or other successors, which covers shares of our common stock, issued to the selling stockholder in a private placement. We are registering these shares on behalf of the selling stockholder, to be offered and sold by it from time to time.

We will not receive any proceeds from the sale of the shares.

The selling stockholder identified in this prospectus, or its pledgees, donees, transferees or other successors-in-interest, may offer the sharesand sell securities from time to time through publicin one or private transactions at prevailing market prices,more offerings of up to $200,000,000 in aggregate offering price. This prospectus describes the general terms of these securities and the general manner in which these securities will be offered. We will provide the specific terms of these securities in supplements to this prospectus. The prospectus supplements will also describe the specific manner in which these securities will be offered and may also supplement, update or amend information contained in this document. You should read this prospectus and any applicable prospectus supplement before you invest.

We may offer these securities in amounts, at prices relatedand on terms determined at the time of offering. The securities may be sold directly to prevailing market pricesyou, through agents, or at privately negotiated prices.through underwriters and dealers. If agents, underwriters or dealers are used to sell the securities, we will name them and describe their compensation in a prospectus supplement.

Our common stock is tradedlisted on the NASDAQ Global Market under the symbol “CRIS.” On April 15, 2015, the closing sale price of the common stock on NASDAQ Global Market was $2.85 per share. You are urged to obtain current market quotations for the common stock.

Investing in our common stockthese securities involves a high degree of risk.certain risks. See “Risk Factors” beginning on page 4.included in any accompanying prospectus supplement and in the documents incorporated by reference in this prospectus for a discussion of the factors you should carefully consider before deciding to purchase these securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined ifpassed upon the adequacy or accuracy of this prospectus is truthful or complete.prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is                     , 2015.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, which we refer to as the SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may from time to time sell any combination of the securities described in this prospectus in one or more offerings for an aggregate initial offering price of up to $200,000,000.

This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide one or more prospectus supplements that will contain specific information about the terms of the offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and the accompanying prospectus supplement together with the additional information described under the heading “Where You Can Find More Information” beginning on page 1 of this prospectus.

You should rely only on the information contained in or incorporated by reference in this prospectus, any accompanying prospectus supplement or in any related free writing prospectus filed by us with the SEC. We have not authorized anyone to provide you with different information. This prospectus and any accompanying prospectus supplement do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus or such accompanying prospectus supplement or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful. You should assume that the information different from that contained orappearing in this prospectus, any prospectus supplement, the documents incorporated by reference in this prospectus. The selling stockholder is offering to sell, and seeking offers to buy, shares of our common stock only in jurisdictions where offers and sales are permitted. The information contained in thisany related free writing prospectus is accurate only as of the datetheir respective dates. Our business, financial condition, results of this prospectus, regardless of the time of delivery of this prospectus or of any sale of common stock.

PROSPECTUS SUMMARY

This summary highlights important features of this offering and the information included or incorporated by reference in this prospectus. This summary does not contain all of the information that you should consider before investing in our common stock. You should read the entire prospectus carefully, especially the risks of investing in our common stock discussed under “Risk Factors.”

CURIS, INC.

We are a biotechnology company focused on the development and commercialization of innovative drug candidates for the treatment of human cancers. Our current pipeline of drug candidates includes CUDC-907, a dual HDAC and PI3K inhibitor, CUDC-427, a small molecule antagonist of IAP proteins, and CUDC-305, an oral HSP90 inhibitor. We are also engaged in a broad collaboration with Aurigene Discovery Technologies Limited, or Aurigene, in the areas of immuno-oncology and precision oncology. We are also party to a collaboration agreement with Genentech, a member of the Roche Group, under which Genentech and Roche are developing and commercializing Erivedge^®, the first and only FDA-approved medicine for the treatment of advanced basal cell carcinoma.

Our principal executive offices are located at 4 Maguire Road, Lexington, Massachusetts 02421, our telephone number at that address is (617) 503-6500 and our Internet address is www.curis.com. The information on our Internet website is not incorporated by reference in this prospectus, and you should not consider it to be a part of this document. Our website address is included as an inactive textual reference only. Unless the context requires otherwise, requiresall references in this prospectus to “Curis,” “we,” “us,” “our,” “Curis,” the “Company” and “our”similar designations refer to Curis, Inc. and its consolidated subsidiaries.

Curis™ is our trademark and Erivedge^® is a trademark of Genentech. The Curis logo is a trademark of Curis in the United States and in other select countries. We may indicate U.S. trademark registrations and U.S. trademarks with the symbols “^®” and “™”, respectively. Other third-party logos and product/trade names are registered trademarks or trade names of their respective owners.

THE OFFERINGWHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at http://www.curis.com. Our website is not a part of this prospectus and is not incorporated by reference in this prospectus. You may also read and copy any document we file at the SEC’s Public Reference Room, 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the operation of the Public Reference Room.

This prospectus is part of a registration statement we filed with the SEC. This prospectus omits some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information and exhibits in the registration statement for further information about us and our consolidated subsidiaries and the securities we are offering. Statements in this prospectus concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements.

INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference much of the information we file with the SEC, which means that we can disclose important information to you by referring you to those publicly available documents. The information that we incorporate by reference in this prospectus is considered to be part of this prospectus. Because we are incorporating by reference future filings with the SEC, this prospectus is continually updated and those future filings may modify or supersede some of the information included or incorporated in this prospectus. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus or in any document previously incorporated by reference have been modified or superseded.

This prospectus incorporates by reference the documents listed below (File No. 000-30347) and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act (in each case, other than those documents or the portions of those documents not deemed to be filed) between the date of the initial registration statement and the effectiveness of the registration statement and following the effectiveness of the registration statement until the offering of the securities under the registration statement is terminated or completed:

RISK FACTORS

InvestingAn investment in our common stock involves a high degree of risk. YouBefore deciding whether to invest in our common stock, you should consider carefully consider the risks described below and uncertainties describeddiscussed under the sections captioned “Risk Factors” contained in our most recent Annual Report onForm 10-K as revised or supplemented bywell as our subsequent Quarterly Reports onForm 10-Q and other filings we make with the SEC from time to time, which are incorporated by reference herein in their entirety, together with other information in this prospectus, the information and documents incorporated by reference in this prospectus, and in any free writing prospectus that we have authorized for use in connection with this offering. The risks and uncertainties described in our most recent Annual Report on Form 10-K, as revised or supplemented by our subsequent Quarterly Reports on Form 10-Q are not the only ones facing our company. Additional risks and uncertainties may also impair our business operations. If any of the followingthese risks actually occur,occurs, our business, financial condition, or results of operations would likely suffer. In that case,or cash flow could be seriously harmed. This could cause the trading price of our common stock could fall, and you may loseto decline, resulting in a loss of all or part of the money you paid to buy our common stock.your investment.

SPECIAL NOTE REGARDING FORWARD-LOOKING INFORMATIONCONSOLIDATED RATIO OF EARNINGS TO COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS

This prospectusThe following table sets forth our consolidated ratio of earnings to combined fixed charges and preferred stock dividends for each of the documents we incorporateperiods indicated. You should read this table in conjunction with the consolidated financial statements and notes incorporated by reference herein include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, which we refer to as the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, which we refer to as the Exchange Act. in this prospectus.

For purposes of these statutes,calculating the ratios above, earnings consist of net income from continuing operations plus provision for income taxes and fixed charges. Fixed charges include interest expense and the interest portion of rent expense which is deemed to be representative of the interest factor.

We did not pay any statement contained in this prospectus or in the documents we incorporate by reference herein other than a statement of historical fact, may be a forward-looking statement, including statements regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans and objectives of management. In some cases, you can identify forward-looking statements by such terms as “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “project,” “should,” “would” or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. Forward-looking statements may include, but are not limited to, statements about:

Our actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including the factors referred to under the heading “Risk Factors” on page 4 of this prospectus and in the “Risk Factors” section of our most recent Annual Report on Form 10-K, as well as our most subsequent Quarterly Reports on Form 10-Q. If one or more of these factors materialize, or if any underlying assumptions prove incorrect, our actual results, performance or achievements may vary materially from any future results, performance or achievements expressed or implied by these forward-looking statements.$4.4 million, respectively.

You should consider these factors and the other cautionary statements made in this prospectus and the documents we incorporate by reference herein as being applicable to all related forward-looking statements wherever they appear in this prospectus or the documents incorporated by reference. While we may elect to update forward-looking statements wherever they appear in this prospectus or the documents incorporated by reference herein, we do not assume, and specifically disclaim, any obligation to do so, whether as a result of new information, future events or otherwise.

USE OF PROCEEDS

We will not receive anyintend to use the net proceeds from the sale of shares by the selling stockholder.

The selling stockholder will pay any underwriting discounts and commissions and expenses incurred by the selling stockholder for brokerage, accounting, tax or legal services or any other expenses incurred by the selling stockholder in disposing of the shares. We will bear all other costs, fees and expenses incurred in effecting the registration of the shares covered bysecurities offered under this prospectus including, without limitation, all registrationfor general corporate purposes unless otherwise indicated in the applicable prospectus supplement. General corporate purposes may include to conduct further preclinical testing and filing fees, NASDAQ Global Market listing fees and fees and expensesclinical studies of our counselproduct candidates, to fund other research and our accountants.

DESCRIPTION OF TRANSACTION WITH AURIGENE

Collaboration, License and Option Agreement

In January 2015, we entered into an exclusive, multi-year collaboration agreement with Aurigene that is focused on discovery, development and commercializationexpenses, the in-licensing of individual drug candidates inor drug programs, the fields of immuno-oncology and precision oncology. As part of the collaboration agreement, Aurigene granted to us the option to exclusively license multiple compounds, including the designated development candidates discovered using their small molecule technology that address molecular targets within the scope of the collaboration. Within the collaboration, Aurigene is responsible for conducting all discovery and preclinical activities, including IND-enabling studies and providing Phase 1 clinical trial supply of the investigational agent, and we are responsible for all clinical development, regulatory and commercialization efforts worldwide, excluding India and Russia, for each candidate for which we exercise an option to obtain a license. We will also make specified payments to Aurigene, including option exercise fees, pre-IND milestones for the first four programs, as well as milestone payments and royalties on any products we successfully commercialize under the collaboration. The lead compounds under the collaboration are orally-available small molecule antagonists of programmed death ligand-1 immune checkpoint target and orally-available small molecule inhibitors of Interleukin-1 receptor-associated kinase 4 in the precision oncology field.

Stock Purchase Agreement

In connection with the collaboration agreement, we issued to Aurigene 17,120,131 shares of our common stock in partial consideration for the rights granted to us under the collaboration agreement. The shares were issued pursuant to a stock purchase agreement with Aurigene dated January 18, 2015. Pursuant to the purchase agreement, Aurigene has agreed that the shares shall be subject to a lock-up restriction such that Aurigene will not, during the period ending on January 18, 2017, without our prior written consent, (a) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, contract to dispose of, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934 and the rules and regulations of the Securities and Exchange Commission, or SEC, promulgated thereunder, with respect to any of the shares, (b) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of such shares, in cash or otherwise, or (c) publicly announce an intention to effect any transaction specified in clause (a) or (b). Notwithstanding the foregoing, Aurigene is permitted to take any of the actions described under clauses (a)-(c) with respect to:

(i) up to an aggregate of

(A) 25% of the shares from and after July 18, 2015,

(B) 50% of the shares from and after January 18, 2016, and

(C) 75% of the shares from and after July 18, 2016, and

(ii) any or all of the shares after any public announcement with respect to an acquisition of Curis by a third partycompanies or any changebusinesses that complement our business, repayment and refinancing of control of Curis.

Registration Rights Agreement

In connection with the issuance of the shares, we entered into a registration rights agreement with Aurigene dated January 18, 2015. Pursuant to the terms of the registration rights agreement, we have agreed to file a resale registration statement on Form S-3 (or such other form as is then available to effect a resale registration of the shares) with the SEC on or prior to April 20, 2015, to register for resale the shares. Additionally, at any time after July 18, 2015, Aurigene may request registration of all or a portion of the shares on Form S-3 (or such other form as is then available to effect a registration of the shares for sale to the public), subject to specified conditions, including that no such registration will be effected for any shares that are then subject to the lock-up agreement described above. Subject to specified conditions, we are not required to effect more than two such demand registrations for Aurigene.debt, working capital and capital expenditures. We have also given Aurigene “piggyback” registration rights such that whenever we propose to register sharesnot determined the amount of our common stock for our own account or the account of others, Aurigene will have the right to include some or all of its shares in such registration, provided that no such registration will be effected for any shares that are then subject to the lock-up agreement described above. The registration rights agreement also contains other customary terms and conditions of the parties with respect to the registration of the shares.

The foregoing summary descriptions of the collaboration agreement, purchase agreement and registration rights agreement do not purportnet proceeds to be complete and are qualified in their entirety by reference toused specifically for such purposes. As a result, management will retain broad discretion over the full textallocation of such agreements, each of which was filed as an exhibit to our Annual Report on Form 10-K for the year ended December 31, 2014 and are incorporated by reference herein.net proceeds.

SELLING STOCKHOLDER

We issued the shares of common stock covered by this prospectus in a private placement. For additional information regarding the issuance of the common stock, please see “Description of Transaction with Aurigene” beginning on page 5 of this prospectus. We are registering the shares of common stock in order to permit the selling stockholder to offer the shares for resale from time to time.

Except as set forth herein, selling stockholder has not held any position or office with, or has not otherwise had a material relationship with, us or any of our subsidiaries within the past three years.

The following table sets forth, to our knowledge, certain information about the selling stockholder as of April 13, 2015.

Beneficial ownership is determined in accordance with the rules of the SEC and includes voting or investment power with respect to shares. Unless otherwise indicated below, to our knowledge, the person named in the table has sole voting and investment power with respect to such person’s shares of common stock. The inclusion of any shares in this table does not constitute an admission of beneficial ownership for the person named below.

* Less than one percent.

(1)

We do not know when or in what amounts the selling stockholder may offer shares for sale. The selling stockholder might not sell any or all of the shares offered by this prospectus. Because the selling stockholder may offer all or some of the shares pursuant to this offering, and because there are currently no agreements, arrangements or understandings with respect to the sale of any of the shares, we cannot estimate the number of the shares that will be held by the selling stockholder after completion of the offering. However, for purposes of this table, we have assumed that, after completion of the offering, none of the shares covered by this prospectus will be held by the selling stockholder.

(2)

This information is based on a Schedule 13G filed with the SEC on January 28, 2015 by Aurigene Discovery Technologies Limited. The principal business address of Aurigene Discovery Technologies Limited is 39-40, KIADB Industrial Area, Phase II, Electronic City Hosur Road, Bangalore – 560100 Karnataka India.

DESCRIPTION OF CAPITAL STOCK

The following description of our capital stock is intended as a summary only.only and therefore is not a complete description of our capital stock. This description is based upon, and is qualified by reference to, our restated certificate of incorporation, as amended, or our certificate of incorporation, our amended and restated by-laws, as amended, or our by-laws, and applicable provisions of General Corporation Law of the State of Delaware which we refer to as the DGCL. This summary is not complete.corporate law. You should read our restated certificate of incorporation as amended, and amended and restated by-laws, as amended, which are filed as exhibits to the registration statement of which this prospectus forms a part, for the provisions that are important to you.

As of March 31, 2015, ourOur authorized capital stock consists of 225,000,000 shares of common stock and 5,000,000 shares of preferred stock.

Common Stock

Annual Meeting.Annual meetings of our stockholders are held on the date designated in accordance with our amended and restated by-laws, as amended.by-laws. Written notice must be mailed to each stockholder entitled to vote not less than ten nor more than 60 days before the date of the meeting. The presence in person or by proxy of the holders of record of a majority of our issued and outstanding shares entitled to vote at such meeting constitutes a quorum for the transaction of business at meetings of the stockholders. Special meetings of the stockholders may be called for any purpose or purposes by the chairman of the board of directors, the chief executive officer (or if there is no chief executive officer, the president) or the board of directors. Except as may be otherwise provided by applicable law, our restated certificate of incorporation as amended, or amended and restated amended and restatedour by-laws, as amended, all elections shall be decided by a plurality, and all other questions shall be decided by a majority, of the votes cast by stockholders entitled to vote thereon at a duly held meeting of stockholders at which a quorum is present.

Voting Rights. For all matters submitted to a vote of stockholders, each holder of common stock is entitled to one vote for each share registered in his or her name on our books. Our common stock does not have cumulative voting rights. As a result, holders of a majority of our outstanding common stock can elect all of the directors who are up for election in a particular year.

Dividends. If our board of directors declares a dividend, holders of common stock will receive payments from our funds that are legally available to pay dividends. However, this dividend right is subject to any preferential dividend rights we may grant to the persons who hold preferred stock, if any is outstanding.

Liquidation and Dissolution. If we are liquidated or dissolve, the holders of our common stock will be entitled to share ratably in all the assets that remain after we pay our liabilities and any amounts we may owe to the persons who hold preferred stock, if any is outstanding.

Other Rights. Holders of the common stock have no right to:

Holders of shares of the common stock are not required to make additional capital contributions.

Transfer Agent and Registrar. Computershare Trust Company, N.A. is transfer agent and registrar for the common stock.

Preferred Stock

As of March 31,June 30, 2015, no shares of preferred stock were outstanding.

We are authorized to issue “blank check” preferred stock, which may be issued in one or more series upon authorization of our board of directors. Our board of directors is authorized to fix the designation of the series, the number of authorized shares of the series, dividend rights and terms, conversion rights, voting rights, redemption rights and terms, liquidation preferences and any other rights, powers, preferences and limitations applicable to each series of preferred stock. The authorized shares of our preferred stock are available for issuance without further action by our stockholders, unless such action is required by applicable law or the rules of any stock exchange on which our securities may be listed. If the approval of our stockholders is not required for the issuance of shares of our preferred stock, our board may determine not to seek stockholder approval. The specific terms of any series of preferred stock offered pursuant to this prospectus will be described in the prospectus supplement relating to that series of preferred stock.

A series of our preferred stock could, depending on the terms of such series, impede the completion of a merger, tender offer or other takeover attempt. Our board of directors will make any determination to issue suchpreferred shares based upon its judgment as to the best interests of our stockholders. Our directors, in so acting, could issue preferred stock having terms that could discourage an acquisition attempt through which an acquirer may be able to change the composition of our board of directors, including a tender offer or other transaction that some, or a majority, of our stockholders might believe to be in their best interests or in which stockholders might receive a premium for their stock over the then-current market price of the stock.

The preferred stock has the terms described below unless otherwise provided in the prospectus supplement relating to a particular series of preferred stock. You should read the prospectus supplement relating to the particular series of preferred stock being offered for specific terms, including:

The preferred stock will, when issued, be fully paid and non-assessable. Unless otherwise specified in the prospectus supplement, each series of preferred stock will rank equally as to dividends and liquidation rights in all respects with each other series of preferred stock. The rights of holders of shares of each series of preferred stock will be subordinate to those of our general creditors.

Rank. Unless otherwise specified in the prospectus supplement, the preferred stock will, with respect to dividend rights and rights upon our liquidation, dissolution or winding up of our affairs, rank:

The term “equity securities” does not include convertible debt securities.

Dividends. Holders of the preferred stock of each series will be entitled to receive, when, as and if declared by our board of directors, cash dividends at such rates and on such dates described in the prospectus supplement. Different series of preferred stock may be entitled to dividends at different rates or based on different methods of calculation. The dividend rate may be fixed or variable or both. Dividends will be payable to the holders of record as they appear on our stock books on record dates fixed by our board of directors, as specified in the applicable prospectus supplement.

Dividends on any series of preferred stock may be cumulative or noncumulative, as described in the applicable prospectus supplement. If our board of directors does not declare a dividend payable on a dividend payment date on any series of noncumulative preferred stock, then the holders of that noncumulative preferred stock will have no right to receive a dividend for that dividend payment date, and we will have no obligation to pay the dividend accrued for that period, whether or not dividends on that series are declared payable on any future dividend payment dates. Dividends on any series of cumulative preferred stock will accrue from the date we initially issue shares of such series or such other date specified in the applicable prospectus supplement.

No dividends may be declared or paid or funds set apart for the payment of any dividends on any parity securities unless full dividends have been paid or set apart for payment on the preferred stock. If full dividends are not paid, the preferred stock will share dividends pro rata with the parity securities.

No dividends may be declared or paid or funds set apart for the payment of dividends on any junior securities unless full dividends for all dividend periods terminating on or prior to the date of the declaration or payment will have been paid or declared and a sum sufficient for the payment set apart for payment on the preferred stock.

Liquidation Preference. Upon any voluntary or involuntary liquidation, dissolution or winding up of our affairs, then, before we make any distribution or payment to the holders of any common stock or any other class or series of our capital stock ranking junior to the preferred stock in the distribution of assets upon any liquidation, dissolution or winding up of our affairs, the holders of each series of preferred stock shall be entitled to receive out of assets legally available for distribution to stockholders, liquidating distributions in the amount of the liquidation preference per share set forth in the prospectus supplement, plus any accrued and unpaid dividends thereon. Such dividends will not include any accumulation in respect of unpaid noncumulative dividends for prior dividend periods. Unless otherwise specified in the prospectus supplement, after payment of the full amount of their liquidating distributions, the holders of preferred stock will have no right or claim to any of our remaining assets. Upon any such voluntary or involuntary liquidation, dissolution or winding up, if our available assets are insufficient to pay the amount of the liquidating distributions on all outstanding preferred stock and the corresponding amounts payable on all other classes or series of our capital stock ranking on parity with the preferred stock and all other such classes or series of shares of capital stock ranking on parity with the preferred stock in the distribution of assets, then the holders of the preferred stock and all other such classes or series of capital stock will share ratably in any such distribution of assets in proportion to the full liquidating distributions to which they would otherwise be entitled.

Upon any such liquidation, dissolution or winding up and if we have made liquidating distributions in full to all holders of preferred stock, we will distribute our remaining assets among the holders of any other classes or series of capital stock ranking junior to the preferred stock according to their respective rights and preferences and, in each case, according to their respective number of shares. For such purposes, our consolidation or merger with or into any other corporation, trust or entity, or the sale, lease or conveyance of all or substantially all of our property or assets will not be deemed to constitute a liquidation, dissolution or winding up of our affairs.

Redemption. If so provided in the applicable prospectus supplement, the preferred stock will be subject to mandatory redemption or redemption at our option, as a whole or in part, in each case upon the terms, at the times and at the redemption prices set forth in such prospectus supplement.

The prospectus supplement relating to a series of preferred stock that is subject to mandatory redemption will specify the number of shares of preferred stock that shall be redeemed by us in each year commencing after a date to be specified, at a redemption price per share to be specified, together with an amount equal to all accrued and unpaid dividends thereon to the date of redemption. Unless the shares have a cumulative dividend, such accrued dividends will not include any accumulation in respect of unpaid dividends for prior dividend periods. We may pay the redemption price in cash or other property, as specified in the applicable prospectus supplement. If the redemption price for preferred stock of any series is payable only from the net proceeds of the issuance of shares of our capital stock, the terms of such preferred stock may provide that, if no such shares of our capital stock shall have been issued or to the extent the net proceeds from any issuance are insufficient to pay in full the aggregate redemption price then due, such preferred stock shall automatically and mandatorily be converted into the applicable shares of our capital stock pursuant to conversion provisions specified in the applicable prospectus supplement. Notwithstanding the foregoing, we will not redeem any preferred stock of a series unless:

In addition, we will not acquire any preferred stock of a series unless:

However, at any time we may purchase or acquire preferred stock of that series (1) pursuant to a purchase or exchange offer made on the same terms to holders of all outstanding preferred stock of such series or (2) by conversion into or exchange for shares of our capital stock ranking junior to the preferred stock of such series as to dividends and upon liquidation.

If fewer than all of the outstanding shares of preferred stock of any series are to be redeemed, we will determine the number of shares that may be redeemed pro rata from the holders of record of such shares in proportion to the number of such shares held or for which redemption is requested by such holder or by any other equitable manner that we determine. Such determination will reflect adjustments to avoid redemption of fractional shares.

Unless otherwise specified in the prospectus supplement, we will mail notice of redemption at least 30 days but not more than 60 days before the redemption date to each holder of record of preferred stock to be redeemed at the address shown on our stock transfer books. Each notice shall state:

If notice of redemption has been given and we have set aside the funds necessary for such redemption in trust for the benefit of the holders of any shares called for redemption, then from and after the redemption date, dividends will cease to accrue on such shares, and all rights of the holders of such shares will terminate, except the right to receive the redemption price.

Voting Rights. Holders of preferred stock will not have any voting rights, except as required by law or as indicated in the applicable prospectus supplement.

Unless otherwise provided for under the terms of any series of preferred stock, no consent or vote of the holders of shares of preferred stock or any series thereof shall be required for any amendment to our certificate of incorporation that would increase the number of authorized shares of preferred stock or the number of authorized shares of any series thereof or decrease the number of authorized shares of preferred stock or the number of authorized shares of any series thereof (but not below the number of authorized shares of preferred stock or such series, as the case may be, then outstanding).

Conversion Rights. The terms and conditions, if any, upon which any series of preferred stock is convertible into our common stock will be set forth in the applicable prospectus supplement relating thereto. Such terms will include the number of shares of common stock into which the shares of preferred stock are convertible, the conversion price, rate or manner of calculation thereof, the conversion period, provisions as to whether conversion will be at our option or at the option of the holders of the preferred stock, the events requiring an adjustment of the conversion price and provisions affecting conversion in the event of the redemption.

Transfer Agent and Registrar. The transfer agent and registrar for the preferred stock will be set forth in the applicable prospectus supplement.

Provisions of Our Restated Certificate of Incorporation and Amended and Restated By-laws and Delaware Law That May Have Anti-Takeover Effects

Board of Directors. Our amended and restated by-laws as amended, provide for a board of directors divided as nearly equally as possible into three classes. Each class is elected to a term expiring at the divisionannual meeting of stockholders held in the third year following the year of such election. The number of directors comprising our board of directors into three classes as nearly equal in size as possible with staggered three-year terms.is fixed from time to time by the board of directors.

Removal of Directors by Stockholders. Our amended and restated by-laws as amended, provide that directors may be removed only for cause by the affirmative vote of the holders of 75% of the shares of our capital stock issued, outstanding and entitled to vote. Our amended and restated by-laws as amended, require the affirmative vote of the holders of at least 75% of our outstanding voting securities to amend or repeal the provision relating to the division of our board of directors into three classes.

Stockholder Nomination of Directors. Our amended and restated by-laws as amended, provide that a stockholder must notify us in writing of any stockholder nomination of a director not earlier than the 90^th day and not later than the 60^th day prior to such

meeting; provided, if less than 70 days’ notice or prior public disclosure of the date of the meeting is given to stockholders, such nomination shall have been mailed or delivered to the Secretary not later than the close of business on the 10^th day following the date on which the notice of the meeting was mailed or such public disclosure was made, whichever occurs first.

No Action By Written Consent. Our restated certificate of incorporation as amended, provides that our stockholders may not act by written consent and may only act at duly called meetings of stockholders.

Delaware Business Combination Statute.Statute. Section 203 of the General Corporation Law of the State of Delaware, which we refer to as the DGCL, is applicable to us. Section 203 of the DGCL restricts some types of transactions and business combinations between a corporation and a 15% stockholder. A 15% stockholder is generally considered by Section 203 to be a person owning 15% or more of the corporation’s outstanding voting stock. Section 203 refers to a 15% stockholder as an “interested stockholder.” Section 203 restricts these transactions for a period of three years from the date the stockholder acquires 15% or more of our outstanding voting stock. With some exceptions, unless the transaction is approved by the board of directors and the holders of at least two-thirds of the outstanding voting stock of the corporation, Section 203 prohibits significant business transactions such as:

The shares held by the interested stockholder are not counted as outstanding when calculating the two-thirds of the outstanding voting stock needed for approval.

The prohibition against these transactions does not apply if:

Directors’ Liability

Our certificate of incorporation provides that a member of the board of directors will not be personally liable to us or our stockholders for monetary damages for breaches of their legal duties to us or our stockholders as a director, except for liability:

Our certificate of incorporation also allows us to indemnify directors and officers to the fullest extent authorized by Delaware law, and we have entered into indemnification agreements with our directors.

DESCRIPTION OF WARRANTS

We may issue warrants to purchase preferred stock or common stock. We may offer warrants separately or together with one or more additional warrants, preferred stock or common stock, or any combination of those securities in the form of units, as described in the applicable prospectus supplement. If we issue warrants as part of a unit, the accompanying prospectus supplement will specify whether those warrants may be separated from the other securities in the unit prior to the expiration date of the warrants. The applicable prospectus supplement will also describe the following terms of any warrants:

PLAN OF DISTRIBUTION

The shares covered by thisWe may sell securities:

In addition, we may issue the securities as a dividend or distribution or in a subscription rights offering to our existing security holders. This prospectus may be offeredused in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

We may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. We will, in the prospectus supplement relating to such offering, name any agent that could be viewed as an underwriter under the Securities Act, and solddescribe any commissions that we must pay. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis.

The distribution of the securities may be effected from time to time byin one or more transactions:

Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

The term “selling stockholder” includes donees, pledgees, transferees or other successors-in-interest selling shares received after the date of this prospectus from the selling stockholder as a gift, pledge, partnership distribution or other non-sale related transfer. The selling stockholder will act independently of us in making decisionssupplement with respect to the timing, manner and sizesecurities of each sale. Such sales may be made on one or more exchanges or ina particular series will describe the over-the-counter market or otherwise, at prices and under terms then prevailing or at prices related to the then current market price or in negotiated transactions. The selling stockholder may sell its shares by one or more of, or a combination of the following methods:offering of the securities, including the following:

In addition, any shares that qualify for sale pursuant to Rule 144 may be sold under Rule 144 rather than pursuant to this prospectus.

To the extent required, this prospectus may be amendedpublic offering or supplemented from time to time to describe a specific plan of distribution. In connection with distributions of the shares or otherwise, the selling stockholder may enter into hedging transactions with broker-dealers or other financial institutions. In connection with such transactions, broker-dealers or other financial institutions may engage in short sales of the common stock in the course of hedging the positions they assume with the selling stockholder. The selling stockholder may also sell the common stock short and redeliver the shares to close out such short positions. The selling stockholder may also enter into option or other transactions with broker-dealers or other financial institutions which require the delivery to such broker-dealer or other financial institution of shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction). The selling stockholder may also pledge shares to a broker-dealer or other financial institution, and, upon a default, such broker-dealer or other financial institution may effect sales of the pledged shares pursuant to this prospectus (as supplemented or amended to reflect such transaction).

In effecting sales, broker-dealers or agents engaged by the selling stockholder may arrange for other broker-dealers to participate. Broker-dealers or agents may receive commissions, discounts or concessions from the selling stockholder in amounts to be negotiated immediately prior to the sale.

In offering the shares covered by this prospectus, the selling stockholder and anybroker-dealers who execute sales for the selling stockholder may be deemed to be “underwriters” within the meaning of the Securities Act in connection with such sales. Any profits realized by the selling stockholderpurchase price and the compensation of any broker-dealer may be deemed to be underwriting discounts and commissions.

In order to comply with the securities laws of certain states, if applicable, the shares must be sold in such jurisdictions only through registered or licensed brokers or dealers. In addition, in certain states the shares may not be sold unless they have been registered or qualified for sale in the applicable state or an exemption from the registration or qualification requirement is available and is complied with.

We have advised the selling stockholder that the anti-manipulation rules of Regulation M under the Exchange Act may apply to sales of shares in the market and to the activities of the selling stockholder and its affiliates. In addition,proceeds we will make copies of this prospectus available to the selling stockholder for the purpose of satisfying the prospectus delivery requirements of the Securities Act. The selling stockholder may indemnify any broker-dealer that participates in transactions involvingreceive from the sale of the shares against certain liabilities, including liabilities arising undersecurities;

At

If any underwriters or agents are utilized in the sale of the securities in respect of which this prospectus is delivered, we will enter into an underwriting agreement or other agreement with them at the time a particular offer of shares is made, if required, a prospectus supplement will be distributed thatsale to them, and we will set forth in the numberprospectus supplement relating to such offering the names of shares being offeredthe underwriters or agents and the terms of the related agreement with them.

If a dealer is utilized in the sale of the securities in respect of which this prospectus is delivered, we will sell such securities to the dealer, as principal. The dealer may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

If we offer securities in a subscription rights offering includingto our existing security holders, we may enter into a standby underwriting agreement with dealers, acting as standby underwriters. We may pay the name of any underwriter, dealer or agent,standby underwriters a commitment fee for the securities they commit to purchase price paid by any underwriter, any discount, commissionon a standby basis. If we do not enter into a standby underwriting arrangement, we may retain a dealer-manager to manage a subscription rights offering for us.

Remarketing firms, agents, underwriters, dealers and other item constituting compensation, any discount, commission or concession allowed or reallowed or paidpersons may be entitled under agreements which they may enter into with us to any dealer, and the proposed selling price to the public.

We have agreed to indemnify the selling stockholderindemnification by us against certain civil liabilities, including certain liabilities under the Securities Act.Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

WeIf so indicated in the applicable prospectus supplement, we will authorize underwriters or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in the prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in the prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

Certain agents, underwriters and dealers, and their associates and affiliates may be customers of, have borrowing relationships with, engage in other transactions with, and/or perform services, including investment banking services, for us or one or more of our respective affiliates in the ordinary course of business.

In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may overallot in connection with the selling stockholderoffering, creating a short position for their own accounts. In addition, to keepcover overallotments or to stabilize the Registration Statement of which this prospectus constitutes a part effective until the earlier of (i) such time as allprice of the shares covered by this prospectus have been disposedsecurities or of pursuant toany such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in accordance with the Registration Statement, (ii) such time as allopen market. Finally, in any offering of the shares covered by this prospectus are sold under circumstancessecurities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in which allthe offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the applicable conditionssecurities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

Under Rule 144 promulgated under the Securities Act (or any similar provisions then in force) under the Securities Act are met, (iii) such time as all15c6-1 of the shares covered by thisExchange Act, trades in the secondary market generally are required to settle in three business days, unless the parties to any such trade expressly agree otherwise. The applicable prospectus are otherwise transferred and such sharessupplement may provide that the original issue date for your securities may be resold without subsequent registration undermore than three scheduled business

days after the Securities Act or (iv)trade date for your securities. Accordingly, in such time as alla case, if you wish to trade securities on any date prior to the third business day before the original issue date for your securities, you will be required, by virtue of the shares covered by this prospectus shallfact that your securities initially are expected to settle more than three scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

The securities may be new issues of securities and may have ceasedno established trading market. The securities may or may not be listed on a national securities exchange. We can make no assurance as to be outstanding.the liquidity of or the existence of trading markets for any of the securities.

LEGAL MATTERS

TheUnless the applicable prospectus supplement indicates otherwise, the validity of the shares offered bysecurities in respect of which this prospectus has beenis being delivered will be passed upon by Wilmer Cutler Pickering Hale and Dorr LLP, Boston, Massachusetts.LLP.

EXPERTS

The consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control overOver Financial Reporting) incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2014, have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and we are not soliciting offers to buy these securities in any jurisdiction where the offer or sale is not permitted.

Subject to completion, dated July 2, 2015

Up to $30,000,000

PROSPECTUS

Common Stock

We have entered into a sales agreement with Cowen and Company, LLC, or Cowen, relating to shares of our common stock, $0.01 par value per share, offered by this prospectus. In accordance with the terms of the sales agreement, we may offer and sell from time to time shares of our common stock having an aggregate offering price of up to $30,000,000.

Our common stock trades on the NASDAQ Global Market, or Nasdaq, under the symbol “CRIS.” On June 30, 2015, the last reported sale price for our common stock on Nasdaq was $3.31 per share.

Upon our delivery of a placement notice and subject to the terms and conditions of the sales agreement, Cowen may sell the common stock by methods deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, or the Securities Act, including sales made directly on Nasdaq, on any other existing trading market for the common stock or to or through a market maker. In addition, with our prior written approval, Cowen may also sell the common stock in negotiated transactions. Cowen will act as sales agent using its commercially reasonable efforts consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of the NASDAQ Stock Market, LLC.

We will pay Cowen a commission for its services in acting as agent and/or principal in the sale of common stock, of 3% of the gross sales price per share of all shares sold through it as agent under the sales agreement.

Investing in our common stock involves a high degree of risk. See “Risk Factors” beginning onPage SA-7 of this prospectus, as well as the section captioned “Item 1A—Risk Factors” in our most recently filed annual report onForm 10-K or quarterly report onForm 10-Q which is incorporated by reference into this prospectus, for certain risks you should consider. You should read the entire prospectus carefully before you make your investment decision.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Cowen and Company

Prospectus dated                     , 2015.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, utilizing a shelf registration process. Under the shelf registration process, we may offer shares of our common stock having an aggregate offering price of up to $30,000,000 from time to time under this prospectus at prices and on terms to be determined by market conditions at the time of offering.

This prospectus describes the specific terms of the common stock we are offering and also adds to, and updates information contained in the documents incorporated by reference into this prospectus. To the extent there is a conflict between the information contained in this prospectus, on the one hand, and the information contained in any document incorporated by reference into this prospectus that was filed with the SEC before the date of this prospectus, on the other hand, you should rely on the information in this prospectus. If any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference into this prospectus — the statement in the document having the later date modifies or supersedes the earlier statement.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference herein were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreement, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

You should rely only on the information contained in or incorporated by reference in this prospectus and in any free writing prospectus we have authorized for use in connection with this offering. We have not, and Cowen has not, authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. We and Cowen take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We are not, and Cowen is not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus, the documents incorporated by reference in this prospectus, and in any free writing prospectus prepared by or on behalf of us that we have authorized for use in connection with this offering is accurate only as of the date of those respective documents. Our business, financial condition, results of operations and prospects may have changed since those dates. You should read this prospectus, the documents incorporated by reference in this prospectus, and any free writing prospectus prepared by or on behalf of us that we have authorized for use in connection with this offering, in their entirety before making an investment decision. You should also read and consider the information in the documents we have referred you to in the sections of this prospectus entitled “Where You Can Find More Information” and “Incorporation by Reference.”

Other than in the United States, no action has been taken by us or Cowen that would permit a public offering of the securities offered by this prospectus in any jurisdiction where action for that purpose is required. The securities offered by this prospectus may not be offered or sold, directly or indirectly, nor may this prospectus or any other offering material or advertisements in connection with the offer and sale of any such securities be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus comes are advised to inform themselves about and to observe any restrictions relating to the offering and the distribution of this prospectus. This prospectus does not constitute an offer to sell or a solicitation of an offer to buy any securities offered by this prospectus in any jurisdiction in which such an offer or a solicitation is unlawful.

Unless the context requires otherwise, all references in this prospectus to “we,” “us,” “our,” “Curis,” the “Company” and similar designations refer to Curis, Inc. and its consolidated subsidiaries. The Curis logo is a trademark of Curis in the United States and in other select countries. We may indicate U.S. trademark registrations and U.S. trademarks with the symbols “^®” and “™”, respectively. Other third-party logos and product/trade names are registered trademarks or trade names of their respective owners.

SA-1

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at http://www.curis.com. Our website is not a part of this prospectus and is not incorporated by reference in this prospectus. You may also read and copy any document we file at the SEC’s Public Reference Room, 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the operation of the Public Reference Room.

This prospectus is part of a registration statement that we filed with the SEC. TheThis prospectus omits some information contained in the registration statement contains morein accordance with SEC rules and regulations. You should review the information than this prospectus regardingand exhibits in the registration statement for further information on us and our common stock, including certain exhibitsconsolidated subsidiaries and schedules. You can obtain a copy ofthe securities we are offering. Statements in this prospectus concerning any document we filed as an exhibit to the registration statement fromor that we otherwise filed with the SEC atare not intended to be comprehensive and are qualified by reference to these filings. You should review the address listed above or from the SEC’s Internet site.complete document to evaluate these statements.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate” into this prospectusincorporate by reference much of the information that we file with the SEC, in other documents. Thiswhich means that we can disclose important information to you by referring you to other documents that contain that information.those publicly available documents. The information incorporatedthat we incorporate by reference in this prospectus is considered to be part of this prospectus. Information containedBecause we are incorporating by reference future filings with the SEC, this prospectus is continually updated and those future filings may modify or supersede some of the information included or incorporated in this prospectus. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus and information that we file with the SECor in the future and incorporateany document previously incorporated by reference in thishave been modified or superseded.

This prospectus automatically updates and supersedes previously filed information. We incorporateincorporates by reference the documents listed below (File No. 000-30347) and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act afterof 1934, as amended, or the date of this prospectusExchange Act (in each case, other than those documents or the portions of those documents not deemed to be filed) until allbetween the date of the common stock to which this prospectus relates has been sold orinitial registration statement and the effectiveness of the registration statement and following the effectiveness of the registration statement until the offering of the securities under the registration statement is otherwise terminated.terminated or completed:

A statement contained in a document

You may request a copy of these documentsfilings, at no cost, by writing or telephoning us usingat the following contact information:address or phone number:

Curis, Inc.

4 Maguire Road

Lexington, MA 02421

Attention:Attn: Chief Financial Officer

Telephone: (617) 503-6500

SA-2

NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents we incorporate by reference herein include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, which we refer to as the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, which we refer to as the Exchange Act. For purposes of these statutes, any statement contained in this prospectus or in the documents we incorporate by reference herein other than a statement of historical fact, may be a forward-looking statement, including statements regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans and objectives of management. In some cases, you can identify forward-looking statements by such terms as “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “project,” “should,” “will,” “would” or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. Forward-looking statements may include, but are not limited to, statements about:

Our actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including the factors referred to under the heading “Risk Factors” onpage SA-7 of this prospectus supplement and in the “Risk Factors” section of our Annual Report on Form 10-K for the year ended December 31, 2014. If one or more of these factors materialize, or if any underlying assumptions prove incorrect, our actual results, performance or achievements may vary materially from any future results, performance or achievements expressed or implied by these forward-looking statements.

SA-3

You should consider these factors and the other cautionary statements made in this prospectus supplement, the accompanying prospectus and the documents we incorporate by reference herein and therein as being applicable to all related forward-looking statements wherever they appear in this prospectus supplement, the accompanying prospectus, or the documents incorporated by reference. While we may elect to update forward-looking statements wherever they appear in this prospectus supplement, the accompanying prospectus, or the documents incorporated by reference herein and therein, we do not assume, and specifically disclaim, any obligation to do so, whether as a result of new information, future events or otherwise.

SA-4

CURIS, INC.

We are a biotechnology company seeking to develop and commercialize innovative drug candidates for the treatment of human cancers. Our most advanced drug candidate is CUDC-907, an orally-available, small molecule inhibitor of histone deacetylase, or HDAC, and phosphatidylinositol-3-kinase, or PI3K enzymes. In addition, we recently entered into an exclusive collaboration agreement focused on immuno-oncology and selected precision oncology targets with Aurigene. Our proprietary pipeline also includes CUDC-427, an orally-available, small molecule antagonist of inhibitor of apoptosis, or IAP proteins, and CUDC-305, a Heat Shock Protein 90, or HSP90, inhibitor. Our collaborators F. Hoffmann-La Roche Ltd, or Roche, and Genentech Inc., or Genentech, a member of the Roche Group, are commercializing Erivedge^® (vismodegib), a first-in-class orally-administered small molecule Hedgehog pathway inhibitor, in advanced basal cell carcinoma, or BCC.

Our principal executive offices are located at 4 Maguire Road, Lexington, Massachusetts 02421, and our telephone number is (617) 503-6500. Our website is located at www.curis.com. The information on our website or any other website is not incorporated by reference into this prospectus or any accompanying prospectus supplement. Our website address is included as an inactive textual reference only.

The Offering

SA-5

The number of shares of our common stock that will be outstanding immediately after this offering as shown above is based on 128,337,695 shares outstanding as of March 31, 2015. The number of shares outstanding as of March 31, 2015, as used throughout this prospectus, unless otherwise indicated, excludes the following:

SA-6

RISK FACTORS

An investment in our common stock involves a high degree of risk. Before deciding whether to invest in our common stock, you should consider carefully the risks described below and discussed under the section captioned “Risk Factors” contained in Part I—Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2014, which is incorporated by reference herein in its entirety, together with other information in this prospectus, and the information and documents incorporated by reference in this prospectus, and in any free writing prospectus that we have authorized for use in connection with this offering. We expect to update these Risk Factors from time to time in the periodic and current reports that we file with the SEC after the date of this prospectus. These updated Risk Factors will be incorporated by reference in this prospectus. If any of these risks actually occurs, our business, financial condition, results of operations or cash flow could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment.

Additional Risks Related to This Offering

We have broad discretion in how we use the net proceeds of this offering, and we may not use these proceeds effectively or in ways with which you agree.

Our management will have broad discretion as to the application of the net proceeds of this offering and could use them for purposes other than those contemplated at the time of this offering. Our stockholders may not agree with the manner in which our management chooses to allocate and spend the net proceeds. Moreover, our management may use the net proceeds for corporate purposes that may not increase the market price of our common stock.

You may experience immediate and substantial dilution.

The offering prices per share in this offering may exceed the net tangible book value per share of our common stock. Assuming that an aggregate of 9,063,444 shares of our common stock are sold at a price of $3.31 per share pursuant to this prospectus, which was the last reported sale price of our common stock on The NASDAQ Global Market on June 30, 2015, for aggregate gross proceeds of $30.0 million, after deducting commissions and estimated aggregate offering expenses payable by us, you would experience immediate dilution of $2.53 per share, representing the difference between our as adjusted net tangible book value per share as of March 31, 2015 after giving effect to this offering and the assumed offering price. The exercise of outstanding stock options and warrants may result in further dilution of your investment. See the section entitled “Dilution” below for a more detailed illustration of the dilution you would incur if you participate in this offering.

You may experience future dilution as a result of future equity offerings.

In order to raise additional capital, we may in the future offer additional shares of our common stock or other securities convertible into or exchangeable for our common stock at prices that may not be the same as the price per share in this offering. We may sell shares or other securities in any other offering at a price per share that is less than the price per share paid by any investors in this offering, and investors purchasing shares or other securities in the future could have rights superior to existing stockholders. The price per share at which we sell additional shares of our common stock, or securities convertible or exchangeable into common stock, in future transactions may be higher or lower than the price per share paid by any investors in this offering.

Because we do not anticipate paying any cash dividends on our capital stock in the foreseeable future, capital appreciation, if any, will be your sole source of gain.

We have never declared or paid cash dividends on our capital stock. We anticipate that we will retain our earnings, if any, for future growth and therefore do not anticipate paying cash dividends in the future. As a result, only appreciation of the price of our common stock will provide a return to stockholders.

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DESCRIPTION OF COMMON STOCK

The following description of our common stock is intended as a summary only. This description is based upon, and is qualified by reference to, our restated certificate of incorporation, as amended, or our certificate of incorporation, our amended and restated by-laws, as amended, or our by-laws, and applicable provisions of Delaware corporate law. This summary is not complete. You should read our certificate of incorporation and by-laws, which are filed as exhibits to the registration statement of which this prospectus forms a part, for the provisions that are important to you.

As of March 31, 2015, 128,337,695 shares of common stock were outstanding.

Common Stock

Annual Meeting.Annual meetings of our stockholders are held on the date designated in accordance with our by-laws. Written notice must be mailed to each stockholder entitled to vote not less than ten nor more than 60 days before the date of the meeting. The presence in person or by proxy of the holders of record of a majority of our issued and outstanding shares entitled to vote at such meeting constitutes a quorum for the transaction of business at meetings of the stockholders. Special meetings of the stockholders may be called for any purpose or purposes by the chairman of the board of directors, the chief executive officer (or if there is no chief executive officer, the president) or the board of directors. Except as may be otherwise provided by applicable law, our certificate of incorporation or our by-laws, all elections shall be decided by a plurality, and all other questions shall be decided by a majority, of the votes cast by stockholders entitled to vote thereon at a duly held meeting of stockholders at which a quorum is present.

Voting Rights. For all matters submitted to a vote of stockholders, each holder of common stock is entitled to one vote for each share registered in his or her name on our books. Our common stock does not have cumulative voting rights. As a result, holders of a majority of our outstanding common stock can elect all of the directors who are up for election in a particular year.

Dividends. If our board of directors declares a dividend, holders of common stock will receive payments from our funds that are legally available to pay dividends. However, this dividend right is subject to any preferential dividend rights we may grant to the persons who hold preferred stock, if any is outstanding.

Liquidation and Dissolution. If we are liquidated or dissolve, the holders of our common stock will be entitled to share ratably in all the assets that remain after we pay our liabilities and any amounts we may owe to the persons who hold preferred stock, if any is outstanding.

Other Rights. Holders of the common stock have no right to:

Holders of shares of the common stock are not required to make additional capital contributions.

Transfer Agent and Registrar. Computershare Trust Company, N.A. is transfer agent and registrar for the common stock.

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Provisions of Our Certificate of Incorporation and By-laws and Delaware Law That May Have Anti-Takeover Effects

Board of Directors. Our by-laws provide for a board of directors divided as nearly equally as possible into three classes. Each class is elected to a term expiring at the annual meeting of stockholders held in the third year following the year of such election. The number of directors comprising our board of directors is fixed from time to time by the board of directors.

Removal of Directors by Stockholders. Our by-laws provide that directors may be removed only for cause by the affirmative vote of the holders of 75% of the shares of our capital stock issued, outstanding and entitled to vote. Our by-laws require the affirmative vote of the holders of at least 75% of our outstanding voting securities to amend or repeal the provision relating to the division of our board of directors into three classes.

Stockholder Nomination of Directors. Our by-laws provide that a stockholder must notify us in writing of any stockholder nomination of a director not earlier than the 90^th day and not later than the 60^th day prior to such meeting; provided, if less than 70 days’ notice or prior public disclosure of the date of the meeting is given to stockholders, such nomination shall have been mailed or delivered to the Secretary not later than the close of business on the 10^th day following the date on which the notice of the meeting was mailed or such public disclosure was made, whichever occurs first.

No Action By Written Consent. Our certificate of incorporation provides that our stockholders may not act by written consent and may only act at duly called meetings of stockholders.

Delaware Business Combination Statute. Section 203 of the General Corporation Law of the State of Delaware, which we refer to as the DGCL, is applicable to us. Section 203 of the DGCL restricts some types of transactions and business combinations between a corporation and a 15% stockholder. A 15% stockholder is generally considered by Section 203 to be a person owning 15% or more of the corporation’s outstanding voting stock. Section 203 refers to a 15% stockholder as an “interested stockholder.” Section 203 restricts these transactions for a period of three years from the date the stockholder acquires 15% or more of our outstanding voting stock. With some exceptions, unless the transaction is approved by the board of directors and the holders of at least two-thirds of the outstanding voting stock of the corporation, Section 203 prohibits significant business transactions such as:

The shares held by the interested stockholder are not counted as outstanding when calculating the two-thirds of the outstanding voting stock needed for approval.

The prohibition against these transactions does not apply if:

Directors’ Liability

Our certificate of incorporation provides that a member of the board of directors will not be personally liable to us or our stockholders for monetary damages for breaches of their legal duties to us or our stockholders as a director, except for liability:

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Our certificate of incorporation also allows us to indemnify directors and officers to the fullest extent authorized by Delaware law, and we have entered into indemnification agreements with our directors.

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USE OF PROCEEDS

We intend to use the net proceeds from the sale of any securities offered under this prospectus for general corporate purposes unless otherwise indicated in any applicable prospectus supplement. General corporate purposes may include to conduct further preclinical testing and clinical studies of our product candidates, to fund other research and development expenses, the in-licensing of individual drug candidates or drug programs, the acquisition of companies or businesses that complement our business, repayment and refinancing of debt, working capital and capital expenditures.

The amounts and timing of our use of the net proceeds from the sale of securities in this offering will depend on a number of factors, such as the timing and progress of our and our strategic partners’ clinical trials of our product candidates and our development efforts, the timing and progress of any partnering efforts, technological advances and the competitive environment for our product candidates. As of the date of this prospectus, we cannot specify with certainty all of the particular uses for the net proceeds to us from this offering. Accordingly, our management will have broad discretion in the timing and application of these proceeds. Pending application of the net proceeds as described above, we intend to temporarily invest the proceeds in short-term, interest-bearing instruments.

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DILUTION

If you invest in this offering, your ownership interest will be diluted immediately to the extent of the difference between the public offering price per share and the adjusted net tangible book value per share of our common stock after this offering. We calculate net tangible book value per share by dividing the new tangible book value, which is tangible assets less total liabilities, by the number of outstanding shares of our common stock. Dilution represents the difference between the portion of the amount per share paid by purchasers of shares in this offering and the as adjusted net tangible book value per share of our common stock immediately after giving effect to this offering.

Our net tangible book value on March 31, 2015 was approximately $78.6 million, or $0.61 per share.

After giving effect to the sale of shares of our common stock in the aggregate amount of $30.0 million in this offering at an assumed offering price of $3.31 per share, which was the last reported sale price of our common stock on the NASDAQ Global Market on June 30, 2015, and after deducting estimated offering commissions and expenses payable by us, our net tangible book value as of March 31, 2015 would have been approximately $107.6 million, or $0.78 per share of common stock. This represents an immediate increase in net tangible book value of $0.17 per share to our existing stockholders and an immediate dilution in net tangible book value of $2.53 per share to investors participating in this offering. The following table illustrates this dilution per share to investors participating in this offering:

The table above assumes, for illustrative purposes, that an aggregate of 9,063,444 shares of our common stock are sold at a price of $3.31 per share, the last reported sale price of our common stock on the NASDAQ Global Market on June 30, 2015, for aggregate gross proceeds of $30.0 million. The shares sold in this offering, if any, will be sold from time to time at various prices. An increase of $0.50 per share in the price at which the shares are sold from the assumed offering price of $3.31 per share shown in the table above, assuming all of our common stock in the aggregate amount of $30.0 million is sold at that price, would increase our as adjusted net tangible book value per share after the offering to $0.79 per share and would increase the dilution in net tangible book value per share to new investors to $3.02 per share, after deducting commissions and estimated aggregate offering expenses payable by us. A decrease of $0.50 per share in the price at which the shares are sold from the assumed offering price of $3.31 per share shown in the table above, assuming all of our common stock in the aggregate amount of $30.0 million is sold at that price, would decrease our as adjusted net tangible book value per share after the offering to $0.77 per share and would decrease the dilution in net tangible book value per share to new investors to $2.04 per share, after deducting commissions and estimated aggregate offering expenses payable by us. This information is supplied for illustrative purposes only.

To the extent that any options or warrants are exercised, new options are issued under our equity incentive plans or we otherwise issue additional shares of common stock in the future, there will be further dilution to new investors.

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PRICE RANGE OF COMMON STOCK

Our common stock is listed on the NASDAQ Global Market under the symbol “CRIS.” The following table shows the high and low per share sale prices of our common stock for the periods indicated.

On June 30, 2015, the last sale price reported on the NASDAQ Global Market for our common stock was $3.31 per share.

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DIVIDEND POLICY

We have never declared or paid any cash dividends on our common stock. We currently intend to retain earnings, if any, to support our business strategy and do not anticipate paying cash dividends in the foreseeable future. Payment of future dividends, if any, will be at the sole discretion of our board of directors after taking into account various factors, including our financial condition, operating results, capital requirements and any plans for expansion.

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PLAN OF DISTRIBUTION

We have entered into a sales agreement with Cowen and Company, LLC, or Cowen, under which we may issue and sell from time to time up to $30,000,000 of our common stock through Cowen as our sales agent. Sales of the common stock, if any, will be made at market prices by any method that is deemed to be an “at the market offering” as defined in Rule 415 under the Securities Act, including sales made directly on the NASDAQ Global Market and any other trading market for the common stock, and sales to or through a market maker other than on an exchange. In addition, with our prior written consent, Cowen may also sell our common stock in negotiated transactions.

Cowen will offer the common stock subject to the terms and conditions of the sales agreement on a daily basis or as otherwise agreed upon by us and Cowen. We will designate the maximum amount of common stock to be sold through Cowen on a daily basis or otherwise determine such maximum amount together with Cowen. Subject to the terms and conditions of the sales agreement, Cowen will use its commercially reasonable efforts to sell on our behalf all of the shares of common stock requested to be sold by us. We may instruct Cowen not to sell common stock if the sales cannot be effected at or above the price designated by us in any such instruction. We or Cowen may suspend the offering of the common stock being made through Cowen under the sales agreement upon proper notice to the other party. We and Cowen each have the right, by giving written notice as specified in the sales agreement, to terminate the sales agreement in each party’s sole discretion at any time.

The aggregate compensation payable to Cowen as sales agent shall be 3% of the gross sales price of the shares sold through it pursuant to the sales agreement.

The remaining sales proceeds, after deducting any expenses payable by us and any transaction fees imposed by any governmental, regulatory or self-regulatory organization in connection with the sales, will equal our net proceeds for the sale of such common stock.

Cowen will provide written confirmation to us following the close of trading on the NASDAQ Global Market, each day in which common stock is sold through it as sales agent under the sales agreement. Each confirmation will include the number of shares of common stock sold through it as sales agent on that day, the gross sales price per share, the net proceeds to us and the compensation payable by us to Cowen.

We will report at least quarterly the number of shares of common stock sold through Cowen under the sales agreement, the net proceeds to us and the compensation paid by us to Cowen in connection with the sales of common stock.

Settlement for sales of common stock will occur, unless the parties agree otherwise, on the third business day that is also a trading day following the date on which any sales were made in return for payment of the net proceeds to us. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

In connection with the sales of the common stock on our behalf, Cowen may be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation paid to Cowen may be deemed to be underwriting commissions or discounts. We have agreed in the sales agreement to provide indemnification and contribution to Cowen against certain liabilities, including liabilities under the Securities Act. As sales agent, Cowen will not engage in any transactions that stabilize our common stock. In addition, we have agreed to reimburse a portion of the expenses of Cowen in connection with this offering up to a maximum of $30,000.

We estimate that the total expenses of the offering payable by us, excluding commissions payable to Cowen under the sales agreement, will be approximately $100,000.

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MATERIAL FEDERAL U.S. TAX CONSIDERATIONS FOR NON-U.S. HOLDERS OF COMMON STOCK

The following is a general discussion of material U.S. federal income and estate tax considerations relating to ownership and disposition of our common stock by a non-U.S. holder. For purposes of this discussion, the term “non-U.S. holder” means a beneficial owner (other than a partnership or other pass-through entity) of our common stock that is not, for U.S. federal income tax purposes:

This discussion is based on current provisions of the Code, existing and proposed U.S. Treasury Regulations promulgated thereunder, current administrative rulings, and judicial decisions, all publicly available and as in effect as of the date of this prospectus and all of which are subject to change or to differing interpretation, possibly with retroactive effect. Any change or differing interpretation could alter the tax consequences to non-U.S. holders described in this prospectus. In addition, the IRS could challenge one or more of the tax consequences described in this prospectus and we have not obtained nor do we intend to obtain an opinion of counsel with respect to the U.S. federal income or estate tax consequences to a non-U.S. holder of acquiring, holding, and disposing of our common stock.

This discussion addresses only non-U.S. holders that hold shares of our common stock as a capital asset (generally, property held for investment). This discussion does not address all aspects of U.S. federal income and estate taxation that may be relevant to a particular non-U.S. holder in light of that non-U.S. holder’s individual circumstances nor does it address the alternative minimum tax, the Medicare tax on net investment income or any aspects of U.S. state, local, or non-U.S. taxes. This discussion also does not consider any specific facts or circumstances that may apply to a non-U.S. holder and does not address the special tax rules applicable to particular non-U.S. holders, such as:

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In addition, this discussion does not address the tax treatment of partnerships or persons who hold their common stock through partnerships or other entities that are pass-through entities for U.S. federal income tax purposes. A partner in a partnership or other pass-through entity that will hold our common stock should consult his, her, or its own tax advisor regarding the tax consequences of the purchase, ownership, and disposition of our common stock through a partnership or other pass-through entity, as applicable.

Prospective investors should consult their own tax advisors regarding the U.S. federal, state, local, and non-U.S. income and other tax considerations of acquiring, holding, and disposing of our common stock.

Dividends

If we pay distributions on our common stock, those distributions generally will constitute dividends for U.S. federal income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. If a distribution exceeds our current and accumulated earnings and profits, the excess will be treated as a tax-free return of the non-U.S. holder’s investment, up to such holder’s tax basis in the common stock. Any remaining excess will be treated as capital gain, subject to the tax treatment described below under the heading “—Gain on Disposition of Common Stock.”

Dividends paid to a non-U.S. holder generally will be subject to withholding of U.S. federal income tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the United States and such holder’s country of residence. A non-U.S. holder of our common stock who claims the benefit of an applicable income tax treaty between the United States and such holder’s country of residence generally will be required to provide a properly executed IRS Form W-8BEN or W-8BEN-E (or successor form) and satisfy applicable certification and other requirements. A non-U.S. holder that is eligible for a reduced rate of U.S. withholding tax under an income tax treaty may obtain a refund or credit of any excess amounts withheld by timely filing an appropriate claim with the IRS. Non-U.S. holders are urged to consult their own tax advisors regarding their entitlement to benefits under a relevant income tax treaty.

Dividends that are treated as effectively connected with a trade or business conducted by a non-U.S. holder within the United States and, if an applicable income tax treaty so provides, that are attributable to a permanent establishment or a fixed base maintained by the non-U.S. holder within the United States are generally exempt from the 30% withholding tax if the non-U.S. holder satisfies applicable certification and disclosure requirements. However, such U.S. effectively connected income is taxed on a net income basis at the same graduated U.S. federal income tax rates applicable to United States persons (as defined in the Code). Any U.S. effectively connected income received by a non-U.S. holder that is a corporation may also, under certain circumstances, be subject to an additional “branch profits tax” at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the United States and such holder’s country of residence.

Gain on Disposition of Common Stock

A non-U.S. holder generally will not be subject to U.S. federal income tax on gain recognized on a disposition of our common stock unless:

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Information Reporting and Backup Withholding

We must report annually to the IRS and to each non-U.S. holder the gross amount of the distributions on our common stock paid to such holder and the tax withheld, if any, with respect to such distributions. Non-U.S. holders may have to comply with specific certification procedures to establish that the holder is not a U.S. person (as defined in the Code) in order to avoid backup withholding at the applicable rate, currently 28%, with respect to dividends on our common stock. Generally, a non-U.S. holder will comply with such procedures if it provides a properly executed IRS Form W-8BEN or W-8BEN-E (or other applicable Form W-8) or otherwise meets documentary evidence requirements for establishing that it is a non-U.S. holder, or otherwise establishes an exemption. Dividends paid to non-U.S. holders subject to withholding of U.S. federal income tax, as described above under the heading “—Dividends,” will generally be exempt from U.S. backup withholding.

Information reporting and backup withholding generally will apply to the proceeds of a disposition of our common stock by a non-U.S. holder effected by or through the U.S. office of any broker, U.S. or foreign, unless the holder certifies its status as a non-U.S. holder and satisfies certain other requirements, or otherwise establishes an exemption. Generally, information reporting and backup withholding will not apply to a payment of disposition proceeds to a non-U.S. holder where the transaction is effected outside the United States through a non-U.S. office of a broker. However, for information reporting purposes, dispositions effected through a non-U.S. office of a broker with substantial U.S. ownership or operations generally will be treated in a manner similar to dispositions effected through a U.S. office of a broker. Non-U.S. holders should consult their own tax advisors regarding the application of the information reporting and backup withholding rules to them.

Copies of information returns may be made available to the tax authorities of the country in which the non-U.S. holder resides or is incorporated under the provisions of a specific treaty or agreement.

Backup withholding is not an additional tax. Rather, any amounts withheld under the backup withholding rules from a payment to a non-U.S. holder can be refunded or credited against the non-U.S. holder’s U.S. federal income tax liability, if any, provided that an appropriate claim is timely filed with the IRS.

FATCA

Sections 1471 through 1474 of the Code (commonly referred to as the “Foreign Account Tax Compliance Act” or “FATCA”) generally impose a 30% withholding tax on dividends on, and gross proceeds from the sale or other disposition of, our common stock if paid to a foreign entity unless (i) if the foreign entity is a “foreign financial institution,” the foreign entity undertakes certain due diligence, reporting, withholding, and certification obligations, (ii) if the foreign entity is not a “foreign financial institution,” the foreign entity identifies certain of its U.S. investors, or (iii) the foreign entity is otherwise excepted under FATCA.

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Under applicable U.S. Treasury regulations, withholding under FATCA generally applies currently to payments of dividends on our common stock and will apply to payments of gross proceeds from a sale or other disposition of our common stock made after December 31, 2016. If withholding under FATCA is required on any payment related to our common stock, investors not otherwise subject to withholding (or that otherwise would be entitled to a reduced rate of withholding) on such payment may be required to seek a refund or credit from the IRS. An intergovernmental agreement between the United States and an applicable foreign country may modify the requirements described in this section. Non-U.S. holders should consult their own tax advisors regarding the possible implications of FATCA on their investment in our common stock and the entities through which they hold our common stock, including, without limitation, the process and deadlines for meeting the applicable requirements to prevent the imposition of the 30% withholding tax under FATCA.

Federal Estate Tax

Common stock owned or treated as owned by an individual who is a non-U.S. holder (as specially defined for U.S. federal estate tax purposes) at the time of death will be included in the individual’s gross estate for U.S. federal estate tax purposes and, therefore, may be subject to U.S. federal estate tax, unless an applicable estate tax or other treaty provides otherwise.

The preceding discussion of material U.S. federal tax considerations is for general information only. It is not tax advice. Prospective investors should consult their own tax advisors regarding the particular U.S. federal, state, local, and non-U.S. tax consequences of purchasing, holding, and disposing of our common stock, including the consequences of any proposed changes in applicable laws.

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LEGAL MATTERS

The validity of the issuance of the common stock offered by this prospectus will be passed upon for us by Wilmer Cutler Pickering Hale and Dorr LLP, Boston, Massachusetts. Cowen is being represented in connection with this offering by LeClairRyan, A Professional Corporation, Newark, New Jersey.

EXPERTS

The consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control Over Financial Reporting) incorporated in this Prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2014, have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

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Up to $30,000,000

Common Stock

PROSPECTUS

Cowen and Company

                    , 2015

PART IIII.

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.

The following table setsSet forth below are estimates (except in the variouscase of the SEC registration fee) of the amount of fees and expenses to be incurred in connection with the saleissuance and distribution of the offered securities, being registered hereby, all of which will be borne by Curis, Inc. (except anyother than underwriting discounts and commissions and expenses incurred by the selling stockholder for brokerage, accounting, tax or legal services or any other expenses incurred by the selling stockholder in disposing of the shares). All amounts shown are estimates except the SEC registration fee.commissions.

Item 15. Indemnification of Directors and Officers.

Section 102 of the DGCL allows a corporation to eliminate the personal liability of directors of a corporation to the corporation or its stockholders for monetary damages for a breach of fiduciary duty as a director, except where the director breached his duty of loyalty, failed to act in good faith, engaged in intentional misconduct or knowingly violated a law, authorized the payment of a dividend or approved a stock repurchase in violation of the DGCL or obtained an improper personal benefit. We have included such a provision in our restated certificate of incorporation, as amended.

Section 145 of the DGCLGeneral Corporation Law of the State of Delaware (“DGCL”) provides, generally, that a corporation hasshall have the power to indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding (except actions by or in the right of the corporation) by reason of the fact that such person is or was a director, officer, employee or agent of the corporation against all expenses, judgments, fines and certain other persons serving at the request of the corporation in related capacities against amounts paid in settlement actually and expensesreasonably incurred by such person in connection with ansuch action, suit or proceeding to which he is or is threatened to be made a party by reason of such position, if such person shall have acted in good faith and in a manner such person reasonably believed to be in or not opposed to the best interests of the corporation and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful. A corporation may similarly indemnify such person for expenses actually and reasonably incurred by such person in connection with the defense or settlement of any action or suit by or in the right of the corporation,provided that such person acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, and, in any criminal proceeding, if such person had no reasonable cause to believe his conduct was unlawful; provided that, in the case of actions brought by or in the right of the corporation, no indemnification shall be made with respect to any matterclaims, issues and matters as to which such person shall have been adjudged to be liable to the corporation, unlessprovided that a court shall have determined, upon application, that, despite the adjudication of liability but in view of all of the circumstances of the case, such person is fairly and onlyreasonably entitled to indemnity for such expenses which such court shall deem proper.

Section 102(b)(7) of the DGCL provides, generally, that our certificate of incorporation may contain a provision eliminating or limiting the personal liability of a director to the extent that the adjudicating court determinescorporation or its shareholders for monetary damages for breach of fiduciary duty as a director,provided that such indemnification is properprovision may not eliminate or limit the liability of a director (i) for any breach of the director’s duty of loyalty to the corporation or its shareholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) under section 174 of the circumstances.DGCL, or (iv) for any transaction from which the director derived an improper personal benefit. No such provision may eliminate or limit the liability of a director for any act or omission occurring prior to the date when such provision became effective.

Article Sixth of our restated certificate of incorporation as amended, provides that no director shall be personally liable to us or any of our stockholders for any monetary damages for any breach of fiduciary duty as a director of Curis, except to the extent that the DGCL prohibits the elimination or limitation of liability of directors for breach of fiduciary duty.

Article Eighth of our restated certificate of incorporation as amended, provides, in general, that we shall indemnify each person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of Curis),

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by reason of the fact that such person is or was, or has agreed to become, a director or officer of Curis, or is or was serving or has agreed to serve, at the request of Curis, as a director, officer or trustee of, or in a similar capacity with, another corporation (including any partially or wholly owned subsidiary of the Registrant), partnership, joint venture, trust or other enterprise (including any employee benefit plan), against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred in connection with any such action, suit or proceeding to the maximum extent permitted by the DGCL. The foregoing right of indemnification is in no way exclusive of any other rights of indemnification to which any such director or officer may be entitled, under any by-law, agreement, vote of directors or stockholders or otherwise.

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In addition to the indemnification provided by our restated certificate of incorporation as amended, and under the DGCL, we have entered into indemnification agreements with our executive officers and directors. The indemnification agreements provide that each such person:

Notwithstanding the foregoing, to the extent that an officer or director has been successful, on the merits or otherwise, he or she is required to be indemnified by us against all expenses (including attorneys’ fees) incurred in connection with defending any proceeding to the extent that we do not assume the defense of such proceeding. Expenses shall be advanced to an officer or director, provided that he or she undertakes to repay the amount advanced if it is ultimately determined that he or she is not entitled to indemnification for such expenses.

Indemnification is required to be made unless we determine that the applicable standard of conduct required for indemnification has not been met. As a condition precedent to the right of indemnification, the officer or director must give us notice of the action for which indemnity is sought and we have the right to participate in such action or assume the defense thereof.

We maintain a general liability insurance policy which covers certain liabilities of directors and officers of Curis arising out of claims based on acts or omissions in their capacities as directors or officers.

Item 16. ExhibitsExhibits.

The exhibits to this Registration Statement are listed in the exhibit index, which appears elsewhere herein and is incorporated herein by reference.

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Item 17. Undertakings.

Item 512(a) of Regulation S-K. The undersigned Registrant hereby undertakes:

(a)(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933, as amended (the “Securities Act”);

(ii) To reflect in the prospectus any facts or events arising after the effective date of this Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this Registration Statement. Notwithstanding the foregoing, any increase or decrease in the volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective Registration Statement; andII-2

(iii) To include any material information with respect to the plan of distribution not previously disclosed in this Registration Statement or any material change to such information in this Registration Statement;

provided,however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(ii)(iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that are incorporated by reference in this Registration Statement.registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of this registration statement.

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(2) That, for the purposes of determining any liability under the Securities Act, each post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at the time shall be deemed to be the initialbona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

Item 512(b) of Regulation S-K.

(c) The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the Registrant’s annual report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in this Registration Statementregistration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initialbona fide offering thereof.

Item 512(h)(d) The undersigned Registrant hereby undertakes to file an application for the purpose of Regulation S-K.determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Trust Indenture Act.

(e) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the Registrant pursuant to the indemnification provisions described herein, or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrantRegistrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statementRegistration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the CityTown of Lexington, Commonwealth of Massachusetts, on April 17,July 2, 2015.

SIGNATURES AND POWER OF ATTORNEY

We, the undersigned officers and directors of Curis, Inc., hereby severally constitute and appoint Ali Fattaey and Michael P. Gray, and each of them singly, our true and lawful attorneys with full power to any of them, and to each of them singly, to sign for us and in our names in the capacities indicated below the Registration Statement onForm S-3 filed herewith and any and all pre-effective andamendments (including post-effective amendmentsamendments) to said Registration Statement, and any registration statement filed pursuant to Rule 462 under the Securities Act of 1933, as amended, in connection with said Registration Statement, and to file or cause to be filed the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, and generally to do all such things in our name and on our behalf in our capacities as officers and directors to enable Curis, Inc. to comply with the provisions of the Securities Act of 1933, as amended, and all requirements of the Securities and Exchange Commission, hereby ratifying and confirming our signatures as they may be signed by ourall that said attorneys, or anyand each of them, or their substitute or substitutes, shall do or cause to said Registration Statement and any and all amendments thereto.be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

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EXHIBIT INDEX

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