EXHIBIT 2

3/21, 2012

Merrill Lynch, Pierce, Fenner & Smith

 Incorporated,

Credit Suisse Securities (USA) LLC

as Representatives of the several

Underwriters to be named in the

within-mentioned Underwriting Agreement

c/o Merrill Lynch, Pierce, Fenner & Smith  Incorporated One Bryant Park New York, New York 10036

c/o Credit Suisse Securities (USA) LLC Eleven Madison Avenue New York, NY 10010-3629

Re: Proposed Public Offering by Durata Therapeutics, Inc.

Dear Sirs:

The undersigned, a stockholder and/or an officer and/or director of Durata Therapeutics, Inc., a Delaware corporation (the “Company”), understands that Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill Lynch”) and Credit Suisse Securities (USA) LLC (“Credit Suisse,” and together with Merrill Lynch, the “Representatives”) propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) with the Company providing for the public offering (the “Offering”) of shares (the “Securities”) of the Company’s common stock, par value $0.01 per share (the “Common Stock”).  In recognition of the benefit that such an offering will confer upon the undersigned as a stockholder and/or an officer and/or director of the Company, as applicable, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned agrees with each underwriter to be named in the Underwriting Agreement that, during the period beginning on the date hereof and ending on the date that is 180 days from the date of the Underwriting Agreement (subject to extensions as discussed below), the undersigned will not, without the prior written consent of the Representatives, directly or indirectly, (i) 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 for the sale of, or otherwise dispose of or transfer any shares of the Company’s Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, whether now owned or hereafter acquired by the undersigned or with respect to which the undersigned has or hereafter acquires the power of disposition (collectively, the “Lock-Up Securities”), or exercise any right with respect to the registration of any of the Lock-up Securities, or the filing of any registration statement in connection therewith, under the Securities Act of 1933, as amended, or (ii) enter into any swap or any other agreement or any transaction that

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transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Lock-Up Securities, whether any such swap or transaction is to be settled by delivery of Common Stock or other securities, in cash or otherwise.  If the undersigned is an officer or director of the Company, the undersigned further agrees that the foregoing provisions shall be equally applicable to any issuer-directed Securities the undersigned may purchase in the Offering.

If the undersigned is an officer or director of the Company, (1) the Representatives agree that, at least three business days before the effective date of any release or waiver of the foregoing restrictions in connection with a transfer of shares of the Common Stock, the Representatives will notify the Company of the impending release or waiver, and (2) the Company has agreed in the Underwriting Agreement to announce the impending release or waiver by press release through a major news service at least two business days before the effective date of the release or waiver.  Any release or waiver granted by the Representatives hereunder to any such officer or director shall only be effective two business days after the publication date of such press release.  The provisions of this paragraph will not apply if (i) the release or waiver is effected solely to permit a transfer not for consideration and (ii) the transferee has agreed in writing to be bound by the same terms described in this letter to the extent and for the duration that such terms remain in effect at the time of the transfer.

Notwithstanding the foregoing, and subject to the conditions below, the undersigned may transfer the Lock-Up Securities without the prior written consent of the Representatives, provided that (1) the Representatives each receive a signed lock-up agreement for the balance of the lock-up period from each donee, trustee, distributee, or transferee, as the case may be, (2) any such transfer shall not involve a disposition for value, (3) in the case of clauses (i) – (iv) below, such transfers are not required to be reported with the Securities and Exchange Commission (the “Commission”) on Form 4 in accordance with Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and (4) in the case of clauses (i) – (iv) below, the undersigned does not otherwise voluntarily effect any public filing or report regarding such transfers:

(i) as a bona fide gift or gifts; or

(ii) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned (for purposes of this lock-up agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin); or

(iii) as a distribution to limited partners, members or stockholders of the undersigned; or

(iv) to the undersigned’s affiliates or to any investment fund or other entity controlled or managed by the undersigned; or

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(v) by will, other testamentary document or intestate succession to the legal representative, heir, beneficiary or a member of the immediate family of the undersigned.

In addition, the restrictions on transfer and disposition of Lock-Up Securities shall not apply to (a) the exercise of an option to purchase shares of Common Stock outstanding as of the date hereof, or granted under any stock incentive plan as described in the General Disclosure Package (as defined in the Underwriting Agreement) of the Company, provided that the underlying shares of Common Stock continue to be subject to the restrictions on transfer set forth in this lock-up agreement, (b) the repurchase of Lock-Up Securities by the Company in connection with the termination of the undersigned’s employment with the Company, (c) the establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of Common Stock, provided that such plan does not provide for any transfers of Common Stock during the 180-day lock-up period or any extension thereof pursuant to this lock-up agreement, or (d) the transfer or disposition of shares of Common Stock purchased in the Offering from the Underwriters (other than any issuer-directed Securities purchased in the Offering by an officer or director of the Company) or on the open market following the Offering.

Notwithstanding the foregoing, if:

(1)           during the last 17 days of the 180-day lock-up period, the Company issues an earnings release or material news or a material event relating to the Company occurs; or

(2)           prior to the expiration of the 180-day lock-up period, the Company announces that it will release earnings results or becomes aware that material news or a material event will occur during the 16-day period beginning on the last day of the 180-day lock-up period,

the restrictions imposed by this lock-up agreement shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event, as applicable, unless the Representatives waive, in writing, such extension.

The undersigned agrees that, prior to engaging in any transaction or taking any other action that is subject to the terms of this lock-up agreement during the period from the date of this lock-up agreement to and including the 34th day following the expiration of the initial 180-day lock-up period, it will give notice thereof to the Company and will not consummate such transaction or take any such action unless it has received written confirmation from the Company that the 180-day lock-up period (as may have been extended pursuant to the previous paragraph) has expired.

The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the Lock-Up Securities except in compliance with the foregoing restrictions.

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If (i) the Company notifies you in writing that it does not intend to proceed with the Offering, (ii) the Underwriting Agreement is not executed on or prior to December 31, 2012 or (iii) for any reason the Underwriting Agreement shall be terminated prior to payment for and delivery of the Securities thereunder, this lock-up agreement shall terminate and the undersigned shall be released from its obligations hereunder.

Very truly yours,
Signature:	/s/ Lloyd Appel
Print Name:	Lloyd Appel, CFO
	Aisling Capital III, LP

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