Exhibit 4.5

Nestle Health Science US Holdings, Inc.

900 Long Ridge Road, Building 2

Stamford, CT 06902

November 23, 2016

Aimmune Therapeutics, Inc.

8000 Marine Blvd., Suite 300

Brisbane, California 94005

Attention: Chief Executive Officer

Re:  Standstill Agreement

Gentlemen:

In connection with the acquisition of Common Stock, par value $0.0001 per share (the “Common Stock”), of Aimmune Therapeutics, Inc., a Delaware corporation (the “Company”), by Nestle Health Science US Holdings, Inc., a Delaware corporation (the “Purchaser”), pursuant to the Securities Purchase Agreement, dated as of November 3, 2016, between the Company and the Purchaser (the “Purchase Agreement”), the Purchaser hereby delivers this letter agreement (this “Standstill Agreement”) to the Company in accordance with the terms Purchase Agreement. Capitalized terms used but not otherwise defined herein shall have the meaning ascribed to it in the Purchase Agreement.

In consideration of the mutual covenants contained in the Purchase Agreement and this Standstill Agreement, and for other good and valuable consideration the receipt and adequacy of which are hereby acknowledged, the Company and the Purchaser agrees as follows:

1.Standstill.  Until the later of (i) the end of the Term (as such term is defined in that certain Collaboration Agreement, dated the date hereof, by and among the Company and Nestec Ltd. (the “Collaboration Agreement”)) and (ii) November 23, 2018 (the “Market Standoff Termination Date”), neither the Purchaser nor any of its Affiliates (as defined below) shall, directly or indirectly, without the prior written consent of a majority of the members of the Board of Directors of the Company (the “Board”) who are not affiliated with the Purchaser:

provided that, the foregoing restrictions shall not apply after (A) a public announcement by the Company of the initiation of any merger, consolidation, acquisition, scheme, business combination or other extraordinary transaction in which the Company or any of its subsidiaries is a constituent corporation or party (a “Business Combination”) or (B) the submission of any bona

fide offer or attempt by any third party to acquire all or a substantial portion of the securities or assets of the Company through any means, process or structure, and: provided, further, that nothing in this Section 1 is intended to (X) restrict the Purchaser’s right to vote its shares of Common Stock purchased pursuant to the Purchase Agreement or otherwise in its discretion on matters brought to a vote of the stockholders of the Company, (Y) restrict the activities of the Purchaser or the discussions among the representatives of the Company and the Purchaser, in each case, as contemplated by the Collaboration Agreement or (Z) restrict the Purchaser’s or any

of its Affiliates’ right to acquire any rights, title or interest in any options or other securities of

the Company granted to members of the Board who are affiliated with the Purchaser.

For purposes of this letter agreement,  (i) “Affiliates” shall mean (1) any person, corporation, partnership, trust, limited liability company or other entity, whether existing now or in the future, that, directly or indirectly, controls, is controlled by or is under common control with, the Purchaser and (ii) “Beneficially Owns” (including the terms “Beneficial Ownership”, “Beneficially Owned” or “Beneficially Owning”) shall mean beneficial ownership within the meaning of Rule 13d-3 under the Exchange Act.

2.No Effect.  Notwithstanding any of the foregoing, the provisions set forth in Section 1 shall in no way limit (i) the ability of any individual who is serving as a director of the Company to take any actions (or to refrain from taking any actions) in his/her capacity as a director of the Company or (ii) the ability of the Purchaser or its Affiliates to initiate and engage in confidential discussions with the Board regarding the transactions referred to in clauses (a)(i)-(iii) of Section 1.

3. Market Standoff. During the period beginning on the date hereof and ending at 11:59 pm Pacific Time on the Market Standoff Termination Date, neither the Purchaser nor any of its Affiliates shall, directly or indirectly, without the prior written consent of a majority of the members of the Board who are not affiliated with the Purchaser:

4.Representations.  Each party represents to the other that: (a) this Letter Agreement has been duly authorized by all necessary corporate or partnership action, as the case may be;

and (b) this letter agreement is a valid and binding agreement of such party, enforceable against it in accordance with its terms, subject to the Enforceability Limitations.  The Company represents that this Letter Agreement was approved by the vote a majority of the members of the Board who are not affiliated with the Purchaser.

5.Specific Enforcement; Legal Effect.  The parties hereto agree that any breach of this Letter Agreement would result in irreparable injury to other party and that money damages would not be an adequate remedy for such breach.  Accordingly, without prejudice to the rights and remedies otherwise available under applicable law, either party shall be entitled to specific performance and equitable relief by way of injunction or otherwise if the other party breaches or threatens to breach any of the provisions of this letter agreement.  It is further understood and agreed that no failure or delay by either party in exercising any right, power or privilege hereunder shall operate as a waiver thereof, nor shall any single or partial exercise thereof preclude any other or further exercise thereof or the exercise of any right, power or privilege hereunder.  This Letter Agreement contains the entire agreement between the parties hereto concerning the matters addressed herein.  No modification of this Letter Agreement or waiver of the terms and conditions hereof shall be binding upon either party hereto, unless approved in writing by each such party; provided, however, that no waiver or amendment shall be effective as against the Company unless such waiver or amendment is approved in writing by the vote a majority of the members of the Board who are not affiliated with the Purchaser.  This Letter Agreement shall be governed by and construed in accordance with the law of the State of New York without regard to principles of conflicts of law that would cause the application of the laws of any jurisdiction other than the State of New York. Any dispute arise under or in connection with this Agreement shall be resolved in accordance with the dispute resolution procedures set out in Section 13.6 of the Purchase Agreement, which procedures are incorporated herein by this reference.

6.Counterparts.  This Standstill Agreement may be executed and delivered (including by facsimile or portable document format (“pdf”) in two or more counterparts, each of which shall constitute an original, but all of which, when taken together, shall constitute but one instrument, and shall become effective when one or more counterparts have been signed by each party hereto and delivered to the other parties.

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IN WITNESS WHEREOF, the parties hereto have executed this Standstill Agreement effective as of the Closing.