Exhibit 4.1

CURIS, INC.

WARRANT

Curis, Inc., a Delaware corporation (the “Company”), hereby certifies that, for value received,             or its registered assigns (the “Holder”), is entitled to purchase from the Company up to a total of [            ] shares of common stock, par value $0.01 per share (the “Common Stock”), of the Company (each such share, a “Warrant Share” and all such shares, the “Warrant Shares”) at an exercise price equal to $3.55 per share (as adjusted from time to time as provided in Section 9, the “Exercise Price”), at any time and from time to time from and after the date hereof and through and including January 27, 2015 (the “Expiration Date”), and subject to the following terms and conditions:

1. Definitions. In addition to the terms defined elsewhere in this Warrant, capitalized terms that are not otherwise defined herein shall have the meanings given to such terms in the Subscription Agreement dated January 22, 2010 to which the Company and the original Holder are parties (the “Subscription Agreement”).

2. Registration of Warrant. The Company shall register this Warrant, upon records to be maintained by the Company for that purpose (the “Warrant Register”), in the name of the record Holder hereof from time to time. The Company may deem and treat the registered Holder of this Warrant as the absolute owner hereof for the purpose of any exercise hereof or any distribution to the Holder, and for all other purposes, absent actual notice to the contrary.

3. Registration of Transfers. The Company shall register the transfer of any portion of this Warrant in the Warrant Register, upon surrender of this Warrant, with the Form of Assignment attached hereto duly completed and signed, to the Company at its address specified herein. Upon any such registration or transfer, a new Warrant to purchase Common Stock, in substantially the form of this Warrant (any such new Warrant, a “New Warrant”), evidencing the portion of this Warrant so transferred shall be issued to the transferee and a New Warrant evidencing the remaining portion of this Warrant not so transferred, if any, shall be issued to the transferring Holder. The acceptance of the New Warrant by the transferee thereof shall be deemed the acceptance by such transferee of all of the rights and obligations of a holder of a Warrant.

4. Exercise and Duration of Warrants. This Warrant shall be exercisable by the registered Holder at any time and from time to time on or after the date hereof to and including the Expiration Date. At 5:00 p.m., New York City time on the Expiration Date, the portion of this Warrant not exercised prior thereto shall be and become void and of no value. The Company may not call or redeem all or any portion of this Warrant without the prior written consent of the Holder.

5. Delivery of Warrant Shares.

(a) To effect exercises hereunder, the Holder shall not be required to physically surrender this Warrant unless the aggregate Warrant Shares represented by this Warrant is being exercised. Upon delivery of the Exercise Notice to the Company (with the attached Warrant Shares Exercise Log) at its address for notice set forth herein and upon payment of the Exercise Price multiplied by the number of Warrant Shares that the Holder intends to purchase hereunder, the Company shall promptly (but in no event later than three business days after the Date of Exercise (as defined herein)) issue and deliver to the Holder, a certificate for the Warrant Shares issuable upon such exercise, which, unless otherwise required by the Subscription Agreement, shall be free of restrictive legends. The Company shall, upon request of the Holder, use its best efforts to deliver Warrant Shares hereunder electronically through the Depository Trust Corporation or another established clearing corporation performing similar functions, if available, provided, that, the Company may, but will not be required to change its transfer agent if its current transfer agent cannot deliver Warrant Shares electronically through the Depository Trust Corporation. A “Date of Exercise” means the date on which the Holder shall have delivered to Company: (i) the Exercise Notice (with the Warrant Exercise Log attached to it), appropriately completed and duly signed and (ii) if such Holder is not utilizing the cashless exercise provisions set forth in this Warrant, payment of the Exercise Price for the number of Warrant Shares so indicated by the Holder to be purchased.

(b) In addition to any other rights available to the Holder, if by the close of the third trading day after delivery of an Exercise Notice and the payment of the aggregate exercise price in any manner permitted by this Warrant, the Company fails to deliver to the Holder the required number of Warrant Shares in the manner required pursuant to Section 5(a), and if after such third trading day and prior to the receipt of such Warrant Shares, the Holder or the Holder’s brokerage firm purchases (in an open market transaction or otherwise) shares of Common Stock to deliver in satisfaction of a sale by the Holder of the Warrant Shares which the Holder anticipated receiving upon such exercise (a “Buy-In”), then the Company shall, within three (3) trading days after the Holder’s request and in the Holder’s sole discretion, either (1) pay in cash to the Holder an amount equal to the Holder’s total purchase price (including brokerage commissions, if any) for the shares of Common Stock so purchased (the “Buy-In Price”), at which point the Company’s obligation to deliver such Warrant Shares shall terminate or (2) promptly honor its obligation to deliver to the Holder such Warrant Shares and pay cash to the Holder in an amount equal to the excess (if any) of Holder’s total purchase price (including brokerage commissions, if any) for the shares of Common Stock so purchased in the Buy-In over the product of (A) the number of shares of Common Stock purchased in the Buy-In, times (B) the closing bid price of a share of Common Stock on the Date of Exercise.

(c) The Company’s obligations to issue and deliver Warrant Shares in accordance with the terms hereof are absolute and unconditional, irrespective of any action or inaction by the Holder to enforce the same, any waiver or consent with respect to any provision hereof, the recovery of any judgment against any Person or any action to enforce the same, or any setoff, counterclaim, recoupment, limitation or termination, or any breach or alleged breach by the Holder or any other Person of any obligation to the Company or any violation or alleged violation of law by the Holder or any other Person, and irrespective of any other circumstance which might otherwise limit such obligation of the Company to the Holder in connection with

the issuance of Warrant Shares. Nothing herein shall limit a Holder’s right to pursue any other remedies available to it hereunder, at law or in equity including, without limitation, a decree of specific performance and/or injunctive relief with respect to the Company’s failure to timely deliver certificates representing shares of Common Stock upon exercise of the Warrant as required pursuant to the terms hereof.

6. Charges, Taxes and Expenses. Issuance and delivery of certificates for shares of Common Stock upon exercise of this Warrant shall be made without charge to the Holder for any issue or transfer tax, withholding tax, transfer agent fee or other incidental tax or expense in respect of the issuance of such certificates, all of which taxes and expenses shall be paid by the Company; provided, however, that the Company shall not be required to pay any tax which may be payable in respect of any transfer involved in the registration of any certificates for Warrant Shares or Warrants in a name other than that of the Holder. The Holder shall be responsible for all other tax liability that may arise as a result of holding or transferring this Warrant or receiving Warrant Shares upon exercise hereof.

7. Replacement of Warrant. If this Warrant is mutilated, lost, stolen or destroyed, the Company shall issue or cause to be issued in exchange and substitution for and upon cancellation hereof, or in lieu of and substitution for this Warrant, a New Warrant, but only upon receipt of evidence reasonably satisfactory to the Company of such loss, theft or destruction and customary and reasonable indemnity (which shall not include a surety bond), if requested. Applicants for a New Warrant under such circumstances shall also comply with such other reasonable regulations and procedures and pay such other reasonable third-party costs as the Company may prescribe. If a New Warrant is requested as a result of a mutilation of this Warrant, then the Holder shall deliver such mutilated Warrant to the Company as a condition precedent to the Company’s obligation to issue the New Warrant.

8. Reservation of Warrant Shares. The Company covenants that it will at all times reserve and keep available out of the aggregate of its authorized but unissued and otherwise unreserved Common Stock, solely for the purpose of enabling it to issue Warrant Shares upon exercise of this Warrant as herein provided, the number of Warrant Shares which are then issuable and deliverable upon the exercise of this entire Warrant, free from preemptive rights or any other contingent purchase rights of persons other than the Holder (taking into account the adjustments and restrictions of Section 9). The Company covenants that all Warrant Shares so issuable and deliverable shall, upon issuance and the payment of the applicable Exercise Price in accordance with the terms hereof, be duly and validly authorized, issued and fully paid and nonassessable.

9. Certain Adjustments. The Exercise Price and number of Warrant Shares issuable upon exercise of this Warrant are subject to adjustment from time to time as set forth in this Section 9.

(a) Stock Dividends and Splits. If the Company, at any time while this Warrant is outstanding, (i) pays a stock dividend on its Common Stock or otherwise makes a distribution on any class of capital stock that is payable in shares of Common Stock, (ii) subdivides outstanding shares of Common Stock into a larger number of shares, or (iii) combines outstanding shares of Common Stock into a smaller number of shares, then in each such case the

Exercise Price shall be multiplied by a fraction of which the numerator shall be the number of shares of Common Stock outstanding immediately before such event and of which the denominator shall be the number of shares of Common Stock outstanding immediately after such event. Any adjustment made pursuant to clause (i) of this paragraph shall become effective immediately after the record date for the determination of stockholders entitled to receive such dividend or distribution, and any adjustment pursuant to clause (ii) or (iii) of this paragraph shall become effective immediately after the effective date of such subdivision or combination. If any event requiring an adjustment under this paragraph occurs during the period that an Exercise Price is calculated hereunder, then the calculation of such Exercise Price shall be adjusted appropriately to reflect such event.

(b) Fundamental Transactions. If, at any time while this Warrant is outstanding, (1) the Company effects any merger or consolidation of the Company with or into another Person, (2) the Company effects any sale of all or substantially all of its assets in one or a series of related transactions, (3) any tender offer or exchange offer (whether by the Company or another Person) is completed pursuant to which holders of Common Stock are permitted to tender or exchange their shares for other securities, cash or property, or (4) the Company effects any reclassification of the Common Stock or any compulsory share exchange pursuant to which the Common Stock is effectively converted into or exchanged for other securities, cash or property (in any such case, a “Fundamental Transaction”), then the Holder shall have the right thereafter to receive, upon exercise of this Warrant, the same amount and kind of securities, cash or property as it would have been entitled to receive upon the occurrence of such Fundamental Transaction if it had been, immediately prior to such Fundamental Transaction, the holder of the number of Warrant Shares then issuable upon exercise in full of this Warrant (the “Alternate Consideration”). For purposes of any such exercise, the determination of the Exercise Price shall be appropriately adjusted to apply to such Alternate Consideration based on the amount of Alternate Consideration issuable in respect of one share of Common Stock in such Fundamental Transaction, and the Company shall apportion the Exercise Price among the Alternate Consideration in a reasonable manner reflecting the relative value of any different components of the Alternate Consideration. If holders of Common Stock are given any choice as to the securities, cash or property to be received in a Fundamental Transaction, then the Holder shall be given the same choice as to the Alternate Consideration it receives upon any exercise of this Warrant following such Fundamental Transaction. The terms of any agreement pursuant to which a Fundamental Transaction is effected shall include terms requiring any such successor or surviving entity to comply with the provisions of this paragraph (b) and insuring that the Warrant (or any such replacement security) will be similarly adjusted upon any subsequent transaction analogous to a Fundamental Transaction. Notwithstanding the foregoing, until the later to occur of (i) two years from the date of original issuance of this Warrant and (ii) the date upon which Genentech (Roche Holdings Ltd.) submits a New Drug Application (NDA) for GDC-0449 (Hedgehog Pathway Inhibitor), in the event of a Change of Control, at the option of the Holder exercisable at any time concurrently with or within 90 days after such Change of Control, the Company (or the successor entity) shall purchase this Warrant from the Holder by paying to the Holder, within five trading days after such request (or, if later, on the effective date of the Change of Control), cash in an amount equal to the Black Scholes Value of the remaining unexercised portion of this Warrant on the date of the consummation of such Change of Control. The Company shall cause any successor entity in a Fundamental Transaction in which the Company is not the survivor (the “Successor Entity”) to assume in writing all of the obligations

of the Company under this Warrant in accordance with the provisions of this Section 9(b) pursuant to written agreements prior to such Fundamental Transaction and shall, at the option of the holder of this Warrant, deliver to the Holder in exchange for this Warrant a security of the Successor Entity evidenced by a written instrument substantially similar in form and substance to this Warrant which is exercisable for a corresponding number of shares of capital stock of such Successor Entity (or its parent entity) equivalent to the shares of Common Stock acquirable and receivable upon exercise of this Warrant (without regard to any limitations on the exercise of this Warrant) prior to such Fundamental Transaction, and with an exercise price which applies the exercise price hereunder to such shares of capital stock (but taking into account the relative value of the shares of Common Stock pursuant to such Fundamental Transaction and the value of such shares of capital stock, such number of shares of capital stock and such exercise price being for the purpose of protecting the economic value of this Warrant immediately prior to the consummation of such Fundamental Transaction). Upon the occurrence of any such Fundamental Transaction, the Successor Entity shall succeed to, and be substituted for (so that from and after the date of such Fundamental Transaction, the provisions of this Warrant referring to the “Company” shall refer instead to the Successor Entity), and may exercise every right and power of the Company and shall assume all of the obligations of the Company under this Warrant with the same effect as if such Successor Entity had been named as the Company herein.

As used herein, the following capitalized terms shall have the meanings set forth below:

“Black Scholes Value” means the value of this Warrant based on the Black and Scholes Option Pricing Model obtained from the “OV” function on Bloomberg L.P. (“Bloomberg”) determined as of the day of consummation of the applicable Change of Control for pricing purposes and reflecting: (i) a risk-free interest rate corresponding to the U.S. Treasury rate for a period equal to the time between the date of the public announcement of the applicable Change of Control and the Expiration Date, (ii) an expected volatility equal to the greater of eighty percent (80%) and the one-year volatility obtained from the “HVT” function on Bloomberg determined as of the trading day immediately following the public announcement of the applicable Fundamental Transaction, (iii) the underlying price per share used in such calculation shall be the sum of the price per share to be received in cash, if any, plus the value of any non-cash consideration to be received, if any, by the holders of Common Stock upon the consummation of the applicable Change of Control, and (iv) a remaining option time equal to the time between the date of the public announcement of the applicable Change of Control and the Expiration Date.

“Change of Control” means any Fundamental Transaction other than (i) any reorganization, recapitalization or reclassification of the Common Stock in which holders of the Company’s voting power immediately prior to such reorganization, recapitalization or reclassification continue after such reorganization, recapitalization or reclassification to hold the investment power (which includes the direct ownership of and power to dispose of such securities) and voting power with respect to publicly traded securities and, directly have the voting power of the surviving entity or entities necessary to elect a majority of the members of the board of directors (or their equivalent if other than a corporation) of such entity or entities, or (ii) pursuant to a migratory merger effected solely for the purpose of changing the jurisdiction of incorporation of the Company.

(c) Pro Rata Distributions. If the Company, at any time while this Warrant is outstanding, distributes to all holders of Common Stock for no consideration (i) evidences of its indebtedness, (ii) any security (other than a distribution of Common Stock covered by the preceding paragraph) or (iii) rights, options or warrants to subscribe for or purchase any security, or (iv) any other asset (including cash or cash dividends) (in each case, “Distributed Property”), then, upon any exercise of this Warrant that occurs after the record date fixed for determination of stockholders entitled to receive such distribution, the Holder shall be entitled to receive, in addition to the Warrant Shares otherwise issuable upon such exercise (if applicable), the Distributed Property that such Holder would have been entitled to receive in respect of such number of Warrant Shares had the Holder been the record holder of such Warrant Shares immediately prior to such record date without regard to any limitation on exercise contained therein.

(d) Number of Warrant Shares. Simultaneously with any adjustment to the Exercise Price pursuant to paragraph (a) or (e) of this Section, the number of Warrant Shares that may be purchased upon exercise of this Warrant shall be increased or decreased proportionately, so that after such adjustment the aggregate Exercise Price payable hereunder for the adjusted number of Warrant Shares shall be the same as the aggregate Exercise Price in effect immediately prior to such adjustment.

(e) Subsequent Equity Sales.

(i) Except as provided in paragraph (e)(iii) of this Section 9, if and whenever the Company shall issue or sell, or is, in accordance with any of paragraphs (e)(ii)(l) through (e)(ii)(7) of this Section 9, deemed to have issued or sold, any shares of Common Stock or Common Stock Equivalents entitling any Person to acquire shares of Common Stock for no consideration or for a consideration per share less than the Exercise Price in effect immediately prior to the time of such issue or sale, then and in each such case (a “Trigger Issuance”) the then-existing Exercise Price shall be reduced as of the close of business on the effective date of the Trigger Issuance, to a price determined as follows:

where

“A” equals the number of shares of Common Stock outstanding immediately preceding such Trigger Issuance;

“B” equals the Exercise Price in effect immediately preceding such Trigger Issuance;

“C” equals the number of Additional Shares of Common Stock issued or deemed issued hereunder as a result of the Trigger Issuance; and

“D” equals the aggregate consideration, if any, received or deemed to be received by the Company upon such Trigger Issuance;

provided, however, that in no event shall the Exercise Price after giving effect to such Trigger Issuance be greater than the Exercise Price immediately prior to such Trigger Issuance.

As used in this Warrant, the term “Additional Shares of Common Stock” shall mean all shares of Common Stock or Common Stock Equivalents issued by the Company or deemed to be issued pursuant to this paragraph (e), other than Excluded Issuances (as defined in paragraph (e)(iii) of this Section 9).

As used in this Warrant, the term “Common Stock Equivalents” means any securities of the Company which would entitle the holder thereof to acquire at any time Common Stock, including, without limitation, any debt, preferred stock, rights, options, warrants or other instrument that is at any time convertible into or exchangeable for, or otherwise entitles the holder thereof to receive, Common Stock or other securities that entitle the holder to receive, directly or indirectly, Common Stock.

(ii) For purposes of this paragraph (e), the following paragraphs (e)(ii)(l) to (e)(ii)(7) shall also be applicable:

(1) Issuance of Rights or Options. In case at any time the Company shall in any manner grant (directly and not by assumption in a merger or otherwise) any warrants or other rights to subscribe for or to purchase, or any options for the purchase of, Common Stock or any stock or security convertible into or exchangeable for Common Stock (such warrants, rights or options being called “Options” and such convertible or exchangeable stock or securities being called “Convertible Securities”), whether or not such Options or the right to convert or exchange any such Convertible Securities are immediately exercisable, and the price per share for which Common Stock is issuable upon the exercise of such Options or upon the conversion or exchange of such Convertible Securities (determined by dividing (i) the sum (which sum shall constitute the applicable consideration) of (x) the total amount, if any, received or receivable by the Company as consideration for the granting of such Options, plus (y) the aggregate amount of additional consideration payable to the Company upon the exercise of all such Options, plus (z), in the case of such Options that relate to Convertible Securities, the aggregate amount of additional consideration, if any, payable upon the issue or sale of such Convertible Securities and upon the conversion or exchange thereof, by (ii) the total maximum number of shares of Common Stock issuable upon the exercise of such Options or upon the conversion or exchange of all such Convertible Securities issuable upon the exercise of such Options) shall be less than the Exercise Price in effect immediately prior to the time of the granting of such Options, then the total number of shares of Common Stock issuable upon the exercise of such Options or upon conversion or exchange of the total amount of such Convertible Securities issuable upon the exercise of such Options shall be deemed to have been issued for such price per share as of the date of granting of such Options or the issuance of such Convertible Securities and thereafter shall be deemed to be outstanding for purposes of adjusting the Exercise Price. Except as otherwise provided in paragraph (e)(ii)(3), no adjustment of the Exercise Price shall be made upon the actual issue of such Common Stock or of such Convertible Securities upon exercise of such Options or upon the actual issue of such Common Stock upon conversion or exchange of such Convertible Securities.

(2) Issuance of Convertible Securities. In case the Company shall in any manner issue (directly and not by assumption in a merger or otherwise) or sell any Convertible Securities, whether or not the rights to exchange or convert any such Convertible Securities are immediately exercisable, and the price per share for which Common Stock is issuable upon such conversion or exchange (determined by dividing (i) the sum (which sum shall constitute the applicable consideration) of (x) the total amount received or receivable by the Company as consideration for the issue or sale of such Convertible Securities, plus (y) the aggregate amount of additional consideration, if any, payable to the Company upon the conversion or exchange thereof, by (ii) the total number of shares of Common Stock issuable upon the conversion or exchange of all such Convertible Securities) shall be less than the Exercise Price in effect immediately prior to the time of such issue or sale, then the total maximum number of shares of Common Stock issuable upon conversion or exchange of all such Convertible Securities shall be deemed to have been issued for such price per share as of the date of the issue or sale of such Convertible Securities and thereafter shall be deemed to be outstanding for purposes of adjusting the Exercise Price, provided that (a) except as otherwise provided in paragraph (e)(ii)(3), no adjustment of the Exercise Price shall be made upon the actual issuance of such Common Stock upon conversion or exchange of such Convertible Securities and (b) no further adjustment of the Exercise Price shall be made by reason of the issue or sale of Convertible Securities upon exercise of any Options to purchase any such Convertible Securities for which adjustments of the Exercise Price have been made pursuant to the other provisions of paragraph (e). No adjustment pursuant to this Section 9 shall be made if such adjustment would result in an increase of the Exercise Price then in effect.

(3) Change in Option Price or Conversion Rate. Upon the happening of any of the following events, namely, if the purchase price provided for in any Option referred to in paragraph (e)(ii)(l) of this Section 9, the additional consideration, if any, payable upon the conversion or exchange of any Convertible Securities referred to in paragraphs (e)(ii)(l) or (e)(ii)(2), or the rate at which Convertible Securities referred to in paragraphs (e)(ii)(l) or (e)(ii)(2) are convertible into or exchangeable for Common Stock shall change at any time (including, but not limited to, changes under or by reason of provisions designed to protect against dilution), the Exercise Price in effect at the time of such event shall forthwith be reduced to the Exercise Price that would have been in effect at such time had such Options or Convertible Securities still outstanding provided for such changed purchase price, additional consideration or conversion rate, as the case may be, at the time initially granted, issued or sold.

(4) Stock Dividends. Subject to the provisions of this paragraph (e), in case the Company shall declare a dividend or make any other distribution upon any stock of the Company (other than the Common Stock) payable in Common Stock, Options or Convertible Securities, then any Common Stock, Options or Convertible Securities, as the case may be, issuable in payment of such dividend or distribution shall be deemed to have been issued or sold without consideration.

(5) Consideration for Stock. In case any shares of Common Stock, Options or Convertible Securities shall be issued or sold for cash, the consideration received therefor shall be deemed to be the gross amount received by the Company therefor. In case any shares of Common Stock, Options or Convertible Securities shall be issued or sold for a consideration other than cash, the amount of the consideration other than cash received by the Company shall be deemed to be the fair value of such consideration as determined in good faith by the Board of Directors of the Company. In case any Options or Convertible Securities (the “Additional Rights”) are issued in connection with the issue or sale of other securities of the Company, together comprising one integrated transaction, (x) such Options or Convertible Securities will be deemed to have been issued for the fair value as determined in good faith by the Board of Directors of the Company (the “Option Value”) and (y) the other securities issued or sold in such integrated transaction shall be deemed to have been issued for the difference of (I) the aggregate consideration received by the Company, less (II) the Option Value. The Board of Directors of the Company shall respond promptly, in writing, to an inquiry by the Holder as to the fair market value of the Additional Rights. In the event that the Board of Directors of the Company and the Holder are unable to agree upon the fair market value of the Additional Rights, the Company and the Holder shall jointly select an appraiser who is experienced in such matters. The decision of such appraiser shall be final and conclusive, and the cost of such appraiser shall be borne evenly by the Company and the Holder.

(6) Record Date. In case the Company shall take a record of the holders of its Common Stock for the purpose of entitling them (i) to receive a dividend or other distribution payable in Common Stock, Options or Convertible Securities, or (ii) to subscribe for or purchase Common Stock, Options or Convertible Securities, then such record date shall be deemed to be the date of the issue or sale of the shares of Common Stock deemed to have been issued or sold upon the declaration of such dividend or the making of such other distribution or the date of the granting of such right of subscription or purchase, as the case may be.

(7) Treasury Shares. The number of shares of Common Stock outstanding at any given time shall not include shares owned or held by or for the account of the Company or any of its wholly-owned subsidiaries, and the disposition of any such shares (other than the cancellation or retirement thereof) shall be considered an issue or sale of Common Stock for the purpose of this paragraph (e).

(iii) Notwithstanding the foregoing, no adjustment will be made under this paragraph (e) in respect of: (i) the issuance of securities upon the exercise or conversion of any Common Stock or Common Stock Equivalents issued by the Company prior to the date hereof provided that the terms of such Common Stock or Common Stock Equivalents are not amended, modified or changed on or after the date hereof, (ii) the grant of options, warrants, Common Stock or other Common Stock Equivalents (but not including any amendments to such instruments) under any duly authorized Company stock option, restricted stock plan or stock purchase plan whether now existing or hereafter approved by the Company and its stockholders in the future, and the issuance of Common Stock in respect thereof, (iii) the issuance of securities in connection with a Strategic Transaction, or (iv) the issuance of securities in a transaction described in Section 9(a) or 9(c) (collectively, “Excluded Issuances”). For purposes of this paragraph, a “Strategic Transaction” means a transaction or relationship in which (1) the

Company issues shares of Common Stock to a Person that the Board of Directors of the Company determined in good faith is, itself or through its Subsidiaries, an operating company in a business synergistic with the business of the Company (or a shareholder thereof) and (2) the Company expects to receive benefits in addition to the investment of funds, but shall not include (x) a transaction in which the Company is issuing securities primarily for the purpose of raising capital or to a Person whose primary business is investing in securities or (y) issuances to lenders.

(iv) Nasdaq Limitation. Notwithstanding any other provisions in this Section 9 to the contrary, if a reduction in the Exercise Price pursuant to Section 9(e)(i) would require the Company to obtain stockholder approval of the transactions contemplated by the Subscription Agreement pursuant to Nasdaq Marketplace Rule 5635(d) and such stockholder approval has not been obtained, (i) the Exercise Price shall be reduced to the maximum extent that would not require stockholder approval under such Rule, and (ii) the Company shall use its reasonable best efforts to obtain such stockholder approval (including causing the Board of Directors of the Company to recommend to the stockholders that they grant such approval) as soon as reasonably practicable, including by calling a special meeting of stockholders to vote on such Exercise Price adjustment. If, despite the Company’s reasonable best efforts, stockholder approval is not obtained at such special meeting, the Company shall cause an additional special meeting to be held each calendar quarter thereafter until such stockholder approval is obtained.

(f) Calculations. All calculations under this Section 9 shall be made to the nearest cent or the nearest 1/100^th of a share, as applicable. The number of shares of Common Stock outstanding at any given time shall not include shares owned or held by or for the account of the Company, and the disposition of any such shares shall be considered an issue or sale of Common Stock.

(g) Notice of Adjustments. Upon the occurrence of each adjustment pursuant to this Section 9, the Company at its expense will promptly compute such adjustment in accordance with the terms of this Warrant and prepare a certificate setting forth such adjustment, including a statement of the adjusted Exercise Price and adjusted number or type of Warrant Shares or other securities issuable upon exercise of this Warrant (as applicable), describing the transactions giving rise to such adjustments and showing in detail the facts upon which such adjustment is based. Upon written request, the Company will promptly deliver a copy of each such certificate to the Holder and to the Company’s transfer agent.

(h) Notice of Corporate Events. If the Company (i) declares a dividend or any other distribution of cash, securities or other property in respect of its Common Stock, including without limitation any granting of rights or warrants to subscribe for or purchase any capital stock of the Company or any Subsidiary, (ii) enters into any agreement contemplating or solicits stockholder approval for any Fundamental Transaction or (iii) authorizes the voluntary dissolution, liquidation or winding up of the affairs of the Company, then the Company shall deliver to the Holder a notice describing the material terms and conditions of such transaction, at least 20 calendar days prior to the applicable record or effective date on which a Person would need to hold Common Stock in order to participate in or vote with respect to such transaction, and the Company will take all steps reasonably necessary in order to insure that the Holder is given the practical opportunity to exercise this Warrant prior to such time so as to participate in

or vote with respect to such transaction; provided, however, that the failure to deliver such notice or any defect therein shall not affect the validity of the corporate action required to be described in such notice.

10. Payment of Exercise Price. The Holder may pay the Exercise Price in one of the following manners:

(a) Cash Exercise. The Holder may deliver immediately available funds; or

(b) Cashless Exercise. In the case of a Restrictive Legend Event (as defined below), the Holder may notify the Company in an Exercise Notice of its election to utilize a “cashless exercise,” in which event the Company shall issue to the Holder the number of Warrant Shares determined as follows:

X = Y [(A-B)/A]

where:

X = the number of Warrant Shares to be issued to the Holder.

Y = the total number of Warrant Shares with respect to which this Warrant is being exercised.

A = the average of the Closing Sale Prices of the shares of Common Stock (as reported by Bloomberg Financial Markets) for the five (5) consecutive trading days ending on the date immediately preceding the Exercise Date (the “Average Price”).

B = the Exercise Price then in effect for the applicable Warrant Shares at the time of such exercise.

For purposes of this Warrant, “Closing Sale Price” means, for any security as of any date, the last trade price for such security on the principal securities exchange or trading market for such security, as reported by Bloomberg Financial Markets, or, if such exchange or trading market begins to operate on an extended hours basis and does not designate the last trade price, then the last trade price of such security prior to 4:00 P.M., New York City time, as reported by Bloomberg Financial Markets, or if the foregoing do not apply, the last trade price of such security in the over-the-counter market on the electronic bulletin board for such security as reported by Bloomberg Financial Markets, or, if no last trade price is reported for such security by Bloomberg Financial Markets, the average of the bid prices, or the ask prices, respectively, of any market makers for such security as reported in the “pink sheets” by Pink Sheets LLC. If the Closing Sale Price cannot be calculated for a security on a particular date on any of the foregoing bases, the Closing Sale Price of such security on such date shall be the fair market value as mutually determined by the Company and the Holder. If the Company and the Holder are unable to agree upon the fair market value of such security, then the Board of Directors of the Company shall use its good faith judgment to determine the fair market value. The Board of Directors’

determination shall be binding upon all parties absent demonstrable error. All such determinations shall be appropriately adjusted for any stock dividend, stock split, stock combination or other similar transaction during the applicable calculation period.

The Company shall provide to the Holder prompt written notice of any time that the Company is unable to issue the Warrant Shares via DTC transfer (or otherwise without restrictive legend), because (A) the Securities and Exchange Commission (the “Commission”) has issued a stop order with respect to the Registration Statement on Form S-3 (File No. 333-152612) (the “Registration Statement”), (B) the Commission otherwise has suspended or withdrawn the effectiveness of the Registration Statement, either temporarily or permanently, (C) the Company has suspended or withdrawn the effectiveness of the Registration Statement, either temporarily or permanently, or (D) the Registration Statement is otherwise not then effective (each a “Restrictive Legend Event”). To the extent that a Restrictive Legend Event occurs after the Holder has exercised this Warrant but prior to the delivery of the Warrant Shares, the Company shall (i) if the Average Price of the Warrant Shares is greater than the Exercise Price, provide written notice to the Holder that the Company will deliver that number of Warrant Shares to the Holder as should be delivered in a cashless exercise in accordance with this Section 10, and return to the Holder all consideration paid to the Company in connection with the Holder’s attempted exercise of this Warrant (a “Company-Elected Conversion”), or (ii) at the election of the Holder to be given within five (5) days of receipt of notice of a Company-Elected Conversion, the Holder shall be entitled to rescind the previously submitted Notice of Exercise and the Company shall return all consideration paid by Holder for such shares upon such rescission. The Company shall provide to the Holder prompt written notice of the termination of the Restrictive Legend Event. If a Restricted Legend Event is occurring as of the Expiration Date, the term of this Warrant shall be extended until the fifth (5^th) business day after the termination of such Restricted Legend Event.

Notwithstanding anything herein to the contrary, in the case of a Restrictive Legend Event on the Expiration Date, this Warrant shall be automatically exercised via cashless exercise on the Expiration Date pursuant to this Section 10.

11. Limitations on Exercise.

(a) Notwithstanding anything to the contrary contained herein, the number of Warrant Shares that may be acquired by the Holder upon any exercise of this Warrant (or otherwise in respect hereof) shall be limited to the extent necessary to ensure that, following such exercise (or other issuance), the total number of shares of Common Stock then beneficially owned by the Holder and its affiliates and any other persons whose beneficial ownership of Common Stock would be aggregated with the Holder’s for purposes of Section 13(d) of the Exchange Act, does not exceed 4.99% of the total number of issued and outstanding shares of Common Stock (including for such purpose the shares of Common Stock issuable upon such exercise). For such purposes, beneficial ownership shall be determined in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder. For purposes of this Section 11(a), in determining the number of outstanding shares of Common Stock, a Holder may rely on the number of outstanding shares of Common Stock as reflected in (A) the Company’s most recent periodic or annual report filed with the Commission, as the case

may be, (B) a more recent public announcement by the Company or (C) a more recent written notice by the Company or its transfer agent setting forth the number of shares of Common Stock outstanding. Upon the written or oral request of a Holder, the Company shall within two trading days confirm orally and in writing to the Holder the number of shares of Common Stock then outstanding. In any case, the number of outstanding shares of Common Stock shall be determined after giving effect to the conversion or exercise of securities of the Company, including this Warrant, by the Holder or its affiliates since the date as of which such number of outstanding shares of Common Stock was reported. The Company’s obligation to issue shares of Common Stock in excess of the limitation referred to in this Section shall be suspended (and, except as provided below, shall not terminate or expire notwithstanding any contrary provisions hereof) until such time, if any, as such shares of Common Stock may be issued in compliance with such limitation; provided that if, as of 5:30 P.M., New York City time, on the Expiration Date, the Company has not received written notice that the shares of Common Stock may be issued in compliance with such limitation, the Company’s obligation to issue such shares shall terminate. This provision shall not restrict the number of shares of Common Stock which a Holder may receive or beneficially own in order to determine the amount of securities or other consideration that such Holder may receive in the event of a Fundamental Transaction as contemplated in this Warrant. By written notice to the Company, the Holder may waive the provisions of this Section but any such waiver will not be effective until the 61st day after such notice is delivered to the Company, nor will any such waiver affect any other Holder.

(b) Notwithstanding anything to the contrary contained herein, the number of Warrant Shares that may be acquired by the Holder upon any exercise of this Warrant (or otherwise in respect hereof) shall be limited to the extent necessary to ensure that, following such exercise (or other issuance), the total number of shares of Common Stock then beneficially owned by such Holder and its affiliates and any other persons whose beneficial ownership of Common Stock would be aggregated with the Holder’s for purposes of Section 13(d) of the Exchange Act, does not exceed 9.99% of the total number of issued and outstanding shares of Common Stock (including for such purpose the shares of Common Stock issuable upon such exercise). For such purposes, beneficial ownership shall be determined in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder. The Company’s obligation to issue shares of Common Stock in excess of the limitation referred to in this Section shall be suspended (and, except as provided below, shall not terminate or expire notwithstanding any contrary provisions hereof) until such time, if any, as such shares of Common Stock may be issued in compliance with such limitation; provided that if, as of 5:30 P.M., New York City time, on the Expiration Date, the Company has not received written notice that the shares of Common Stock may be issued in compliance with such limitation, the Company’s obligation to issue such shares shall terminate. This provision shall not restrict the number of shares of Common Stock which a Holder may receive or beneficially own in order to determine the amount of securities or other consideration that such Holder may receive in the event of a Fundamental Transaction as contemplated in this Warrant. This restriction may not be waived.

12. No Fractional Shares. No fractional shares of Warrant Shares will be issued in connection with any exercise of this Warrant. In lieu of any fractional shares which would, otherwise be issuable, the Company shall pay cash equal to the product of such fraction

multiplied by the closing price of one Warrant Share as reported by the Nasdaq Stock Market or such other national exchange on which the Common Stock is then traded.

13. Notices. Any and all notices or other communications or deliveries hereunder (including, without limitation, any Exercise Notice) shall be in writing and shall be deemed given and effective on the earliest of (i) the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number specified in this Section prior to 6:30 p.m. (New York City time) on a business day, (ii) the next business day after the date of transmission, if such notice or communication is delivered via facsimile at the facsimile number specified in this Section on a day that is not a business day or later than 5:00 p.m. (New York City time) on any business day, (iii) the business day following the date of mailing, if sent by nationally recognized overnight courier service, or (iv) upon actual receipt by the party to whom such notice is required to be given. The addresses for such communications shall be: (i) if to the Company, to Curis, Inc., Attn: Chief Executive Officer, Facsimile No.: (617) 492-8287, or (ii) if to the Holder, to the address or facsimile number appearing on the Warrant Register or such other address or facsimile number as the Holder may provide to the Company in accordance with this Section.

14. Warrant Agent. The Company shall serve as warrant agent under this Warrant. Upon 30 days’ notice to the Holder, the Company may appoint a new warrant agent. Any corporation into which the Company or any new warrant agent may be merged or any corporation resulting from any consolidation to which the Company or any new warrant agent shall be a party or any corporation to which the Company or any new warrant agent transfers substantially all of its corporate trust or shareholders services business shall be a successor warrant agent under this Warrant without any further act. Any such successor warrant agent shall promptly cause notice of its succession as warrant agent to be mailed (by first class mail, postage prepaid) to the Holder at the Holder’s last address as shown on the Warrant Register.

15. Miscellaneous.

(a) This Warrant shall be binding on and inure to the benefit of the parties hereto and their respective successors and assigns. Subject to the preceding sentence, nothing in this Warrant shall be construed to give to any Person other than the Company and the Holder any legal or equitable right, remedy or cause of action under this Warrant. This Warrant may be amended only in writing signed by the Company and the Holder and their successors and assigns.

(b) All questions concerning the construction, validity, enforcement and interpretation of this Warrant shall be governed by and construed and enforced in accordance with the internal laws of the State of New York, without regard to the principles of conflicts of law thereof.

(c) The headings herein are for convenience only, do not constitute a part of this Warrant and shall not be deemed to limit or affect any of the provisions hereof.

(d) In case any one or more of the provisions of this Warrant shall be invalid or unenforceable in any respect, the validity and enforceability of the remaining terms and

provisions of this Warrant shall not in any way be affected or impaired thereby and the parties will attempt in good faith to agree upon a valid and enforceable provision which shall be a commercially reasonable substitute therefor, and upon so agreeing, shall incorporate such substitute provision in this Warrant.

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK,

SIGNATURE PAGE FOLLOWS]

IN WITNESS WHEREOF, the Company has caused this Warrant to be duly executed by its authorized officer as of the date first indicated above.

CURIS, INC.

WARRANT ORIGINALLY ISSUED JANUARY 27, 2010

WARRANT NO. 2010-[    ]

EXERCISE NOTICE

To CURIS, INC.:

The undersigned hereby irrevocably elects to purchase              shares of Common Stock pursuant to the above captioned Warrant, and, if such Holder is not utilizing the cashless exercise provisions set forth in the Warrant, encloses herewith $             in cash, certified or official bank check or checks or other immediately available funds, which sum represents the aggregate Exercise Price (as defined in the Warrant) for the number of shares of Common Stock to which this Exercise Notice relates, together with any applicable taxes payable by the undersigned pursuant to the Warrant.

The undersigned requests that certificates for the shares of Common Stock issuable upon this exercise be issued in the name of

(Please print name and address)

Warrant Shares Exercise Log

CURIS, INC.

WARRANT ORIGINALLY ISSUED JANUARY 27, 2010

WARRANT NO. 2010-[    ]

FORM OF ASSIGNMENT

[To be completed and signed only upon transfer of Warrant]

FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers unto                              the right represented by the above-captioned Warrant to purchase              shares of Common Stock to which such Warrant relates and appoints                      attorney to transfer said right on the books of the Company with full power of substitution in the premises.

Dated:             ,