Exhibit (a)(1)(E)

This announcement is neither an offer to purchase nor a solicitation of an offer to sell Shares (as defined below). The Offer (as defined below) is being made only by the Offer to Purchase, dated April 22, 2024 (the “Offer to Purchase”) and the related Letter of Transmittal, as each may be amended or supplemented from time to time, and is being made to all holders of Shares. THE OFFER IS NOT BEING MADE TO (NOR WILL TENDERS BE ACCEPTED FROM OR ON BEHALF OF) THE HOLDERS OF SHARES IN ANY JURISDICTION IN WHICH THE MAKING OF THE OFFER OR ACCEPTANCE THEREOF WOULD NOT BE IN COMPLIANCE WITH THE LAWS OF SUCH JURISDICTION. IN THOSE JURISDICTIONS WHERE APPLICABLE LAWS OR REGULATIONS REQUIRE THE OFFER TO BE MADE BY A LICENSED BROKER OR DEALER, THE OFFER SHALL BE DEEMED TO BE MADE ON BEHALF OF PURCHASER (AS DEFINED BELOW) BY ONE OR MORE REGISTERED BROKERS OR DEALERS LICENSED UNDER THE LAWS OF SUCH JURISDICTION TO BE DESIGNATED BY PURCHASER.

Notice of Offer to Purchase

All Outstanding Shares of Common Stock

of

Alpine Immune Sciences, Inc.

at

$65.00 per share, net to the seller in cash, without interest thereon and subject to any applicable tax withholding

by

Adams Merger Sub, Inc.

a wholly owned subsidiary

of

Vertex Pharmaceuticals Incorporated

Adams Merger Sub, Inc., a Delaware corporation (“Purchaser”) and a wholly owned subsidiary of Vertex Pharmaceuticals Incorporated, a Massachusetts corporation (“Vertex”), is offering to purchase all of the issued and outstanding shares of common stock, par value $0.001 per share (the “Shares”), of Alpine Immune Sciences, Inc., a Delaware corporation (“Alpine”), at a purchase price of $65.00 per Share (the “Offer Price”), net to the seller in cash, without interest thereon and subject to any applicable tax withholding, upon the terms and subject to the conditions set forth in the Offer to Purchase and in the related Letter of Transmittal (which, together with the Offer to Purchase, as each may be amended or supplemented from time to time, collectively constitute the “Offer”).

Tendering stockholders who are holders of record of their Shares and who tender directly to Broadridge Corporate Issuer Solutions, LLC, the depositary and paying agent for the Offer (the “Depositary”), will not be obligated to pay brokerage fees or commissions or, except as otherwise provided in Instruction 6 of the Letter of Transmittal, stock transfer taxes with respect to the purchase of Shares by Purchaser pursuant to the Offer. Stockholders who hold their Shares through a broker, dealer, commercial bank, trust company or other nominee should consult such broker, dealer, commercial bank, trust company or other nominee as to whether it charges any service fees or commissions.

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT ONE MINUTE PAST 11:59 P.M., EASTERN TIME, ON MAY 17, 2024, UNLESS THE OFFER IS EXTENDED OR EARLIER TERMINATED.

The Offer is being made pursuant to an Agreement and Plan of Merger, dated April 10, 2024 (as it may be amended from time to time, the “Merger Agreement”), by and among Alpine, Vertex and Purchaser, pursuant to which, after consummation of the Offer and subject to the satisfaction or waiver of certain conditions, Purchaser will merge with and into Alpine pursuant to Section 251(h) of the General Corporation Law of the State of Delaware, as amended (the “DGCL”), upon the terms and subject to the conditions set forth in the Merger Agreement, with Alpine continuing as the surviving corporation (the “Surviving Corporation”) and becoming a wholly owned subsidiary of Vertex (the “Merger”). At the effective time of the Merger (the “Effective Time”), each Share issued and outstanding immediately prior to the Effective Time (other than (i) Shares owned by Alpine or any wholly owned subsidiary of Alpine immediately prior to the Effective Time, (ii) Shares owned by Vertex, Purchaser or any other subsidiary of Vertex or Purchaser at the commencement of the Offer and owned by Vertex, Purchaser or any other subsidiary of Vertex immediately prior to the Effective Time, (iii) Shares irrevocably accepted for purchase by Purchaser in the Offer, or (iv) Shares that are held by stockholders who are entitled to demand and properly demand appraisal for such Shares pursuant to and in compliance in all respects with Section 262 of the DGCL and do not fail to perfect or otherwise waive, withdraw or lose their rights to such appraisal with respect to such shares under the DGCL) will be converted into the right to receive the Offer Price in cash, without interest thereon, subject to any applicable tax withholding.

The Offer and the Merger are not subject to any financing condition. The obligation of Purchaser to accept for payment and pay for Shares validly tendered (and not properly withdrawn) pursuant to the Offer is subject to the satisfaction of the conditions set forth in Section 15 of the Offer to Purchase (collectively, the “Offer Conditions”), including the Minimum Tender Condition (as defined below) and the Regulatory Condition (as defined below).

The “Regulatory Condition” means that the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, applicable to the purchase of Shares pursuant to the Offer and the consummation of the Merger has either expired or been terminated, and the waiting periods, approvals, clearances and consents required from the Springing Regulatory Conditions, if triggered, have been terminated, expired or been obtained, as applicable. The “Springing Regulatory Conditions” mean the following foreign regulatory conditions: (1) The United Kingdom Competition and Markets Authority (the “CMA”) shall have confirmed to Parent that either: (a) it has no further questions in respect of the Transactions; (b) it will not make a reference of the Transactions (or any matter arising therefrom) under section 33 of the Enterprise Act 2002 (a “Reference”); or, if such a Reference takes place, the CMA shall have either: (x) concluded that the Transactions (and any matter therefrom) may not be expected to result in a substantial lessening of competition within any market or markets in the UK, or (y) accepted undertakings to remedy, mitigate or prevent any substantial lessening of competition within a market or markets in the UK that may be expected to arise from the Transactions (or any matter therefrom); provided that the foregoing condition in this clause (1) shall only be required to be satisfied if, prior to the then-scheduled expiration of the Offer, (i) the CMA has issued a request for information to any party in respect of the Transactions or (ii) the CMA has commenced, or given notice to any party that it intends to commence, a merger investigation in respect of the Transactions; and (2) The European Commission shall have issued a decision under Article 6(1)(b), 6(2), 8(1) or 8(2) of Council Regulation (EC) No. 139/2004 (the “Merger Regulation”) (or being deemed to have done so under Article 10(6) of the Merger Regulation); provided that the foregoing condition in this clause (2) shall only be required to be satisfied if, prior to the then-scheduled expiration of the Offer, (i) the Transactions are referred in whole or in part to the European Commission under Article 22 of Council Regulation (EC) No. 139/2004, or (ii) any party receives legal notice from the European Commission barring consummation of the Transactions.

The “Minimum Tender Condition” means that there have been validly tendered in the Offer and not properly withdrawn prior to the Expiration Time (as defined below) that number of Shares that, when added to the Shares, if any, then owned by Vertex, Purchaser or any subsidiary of Vertex, would represent at least a majority of the Shares outstanding as of immediately following the consummation of the Offer (including, the Shares issued upon the automatic exercise of any then-outstanding Other Company Warrants (as defined in the Offer to Purchase) upon the Offer Closing Time (as defined below)).

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The term “Expiration Time” means one minute past 11:59 P.M., Eastern Time, on May 17, 2024, unless the expiration of the Offer is extended to a subsequent date in accordance with the terms of the Merger Agreement, in which case the term “Expiration Time” means such subsequent time on such subsequent date. A subsequent offering period for the Offer is not contemplated.

The term “Offer Closing Time” means the time at which Purchaser first irrevocably accepts for purchase the Shares tendered in the Offer.

The board of directors of Alpine (the “Alpine Board”) unanimously (i) determined that the Offer, the Merger and the other transactions contemplated pursuant to the Merger Agreement (collectively, the “Transactions”) are fair to and in the best interest of Alpine and its stockholders, (ii) approved and declared advisable the Merger and the execution, delivery and performance by Alpine of the Merger Agreement and the consummation of the Transactions, (iii) resolved that the Merger Agreement and the Merger will be governed by and effected under Section 251(h) of the DGCL and that the Merger will be consummated as soon as practicable following the Offer Closing Time and (iv) subject to the other terms and conditions of the Merger Agreement, resolved to recommend that all holders of the Shares accept the Offer and tender their Shares pursuant to the Offer.

Descriptions of the reasons for the Alpine Board’s recommendation and approval of the Offer are set forth in Alpine’s Solicitation/Recommendation Statement on Schedule 14D-9 (the “Schedule 14D-9”), which is being mailed to Alpine stockholders together with the Offer materials (including the Offer to Purchase and the related Letter of Transmittal). Stockholders should carefully read the information set forth in the Schedule 14D-9, including the information set forth in Item 4 thereof under the sub-headings “Recommendation of the Board” and “Background of the Merger Agreement; Reasons for the Recommendation.”

The Merger Agreement contains provisions that govern the circumstances under which Purchaser is required or permitted to extend the Offer. Specifically, the Merger Agreement provides that: (i) if, at the scheduled Expiration Time, any Offer Condition, other than the Minimum Tender Condition, has not been satisfied or waived, Purchaser will, and Vertex will cause Purchaser to, extend the Offer for one or more consecutive increments of not more than 10 business days each (or such longer period as Vertex and Alpine may agree), until such time as such conditions have been satisfied or waived (irrespective of whether the Minimum Tender Condition has been satisfied); (ii) Purchaser will, and Vertex will cause Purchaser to, extend the Offer for the minimum period required by any rule, regulation, interpretation or position of the SEC or the staff thereof or Nasdaq, in each case, that are applicable to the Offer; and (iii) if, at the scheduled Expiration Time, each Offer Condition (other than the Minimum Tender Condition) has been satisfied or waived and the Minimum Tender Condition has not been satisfied, Purchaser may (and if so requested by Alpine, Purchaser will, and Vertex will cause Purchaser to), extend the Offer for one or more consecutive increments of such duration as requested by Alpine (or if not so requested by Alpine, as determined by Vertex) but not more than 10 business days each (or for such longer period as may be agreed between Alpine and Vertex); provided that Alpine may not request Purchaser to, and Vertex will not be required to cause Purchaser to, extend the Offer on more than five occasions. In each case, Purchaser is not required to extend the Offer beyond the Outside Date and may only do so with Alpine’s consent. The “Outside Date” means April 10, 2025.

If the Offer is consummated, Purchaser will not seek the approval of Alpine’s remaining stockholders before effecting the Merger. Vertex, Purchaser and Alpine have agreed to take all necessary and appropriate action to cause the Merger to become effective as soon as practicable following the consummation (within the meaning of Section 251(h)(6) of the DGCL) of the Offer without a vote of the holders of the Shares in accordance with Section 251(h) of the DGCL.

Purchaser expressly reserves the right to waive, in its sole discretion, in whole or in part, any Offer Condition or modify the terms of the Offer in any manner not inconsistent with the Merger Agreement, except that Alpine’s prior written approval is required for Purchaser to, and for Vertex to permit Purchaser to: (i) reduce the number of Shares subject to the Offer; (ii) reduce the Offer Price; (iii) waive, amend or modify either of the Minimum Tender Condition or the Termination Condition (as defined in the Offer to Purchase); (iv) add to the Offer Conditions or impose any other conditions on the Offer or amend, modify or supplement any Offer Condition in any manner adverse to the holders of Shares; (v) except as otherwise provided in the Merger Agreement, terminate, extend or otherwise amend or modify the scheduled Expiration Time; (vi) change the form or terms of consideration payable in the Offer; (vii) otherwise amend, modify or supplement any of the terms of the Offer in any manner adverse to holders of Shares; or (viii) provide for any “subsequent offering period” in accordance with Rule 14d-11 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

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Any extension, delay, termination or amendment of the Offer will be followed as promptly as practicable by a public announcement thereof, and such announcement in the case of an extension will be made no later than 9:00 a.m., Eastern Time, on the business day after the previously scheduled Expiration Time. Without limiting the manner in which Purchaser may choose to make any public announcement, Purchaser intends to make announcements regarding the Offer by issuing a press release and making any appropriate filing with the SEC.

Purchaser is not providing for guaranteed delivery procedures. Therefore, Alpine stockholders must allow sufficient time for the necessary tender procedures to be completed during normal business hours of The Depository Trust Company (“DTC”), which end earlier than the Expiration Time. Normal business hours of DTC are between 8:00 a.m. and 5:00 p.m., Eastern Time, Monday through Friday. Alpine stockholders must tender their Shares in accordance with the procedures set forth in the Offer to Purchase and the related Letter of Transmittal prior to the Expiration Time. Tenders received by the Depositary after the Expiration Time will be disregarded and of no effect.

For purposes of the Offer, Purchaser will be deemed to have accepted for payment, and thereby purchased, Shares validly tendered to Purchaser and not properly withdrawn as, if and when Purchaser gives oral or written notice to the Depositary of Purchaser’s acceptance for payment of such Shares pursuant to the Offer. Upon the terms and subject to the conditions of the Offer, payment for Shares accepted for payment pursuant to the Offer will be made by deposit of the purchase price for such Shares with the Depositary, which will act as agent for tendering stockholders for the purpose of receiving payments from Purchaser and transmitting such payments to tendering stockholders whose Shares have been accepted for payment. If Purchaser extends the Offer, is delayed in its acceptance of Shares for payment or is unable to accept Shares for payment pursuant to the Offer for any reason, then, without prejudice to Purchaser’s rights under the Offer, the Depositary may retain tendered Shares on Purchaser’s behalf, and such Shares may not be withdrawn except to the extent that tendering stockholders are entitled to withdrawal rights as described in Section 4 of the Offer to Purchase. However, Purchaser’s ability to delay the payment for Shares that it has accepted for payment is limited by Rule 14e-1(c) under the Exchange Act, which requires Purchaser to pay the consideration offered or return the securities deposited by or on behalf of stockholders promptly after the termination or withdrawal of the Offer. Under no circumstances will Purchaser pay interest on the Offer Price for Shares accepted for payment in the Offer, including by reason of any extension of the Offer or any delay in making such payment.

In all cases, Purchaser will pay for Shares validly tendered and accepted for payment pursuant to the Offer only after timely receipt by the Depositary of (i) the certificates evidencing such Shares (the “Share Certificates”) or confirmation of a book-entry transfer of such Shares into the Depositary’s account at DTC (such a confirmation, a “Book-Entry Confirmation”) pursuant to the procedures set forth in Section 3 of the Offer to Purchase, (ii) the Letter of Transmittal, properly completed and duly executed, with any required signature guarantees (or, in the case of a book-entry transfer or a tender through DTC’s Automated Tender Offer Program, an Agent’s Message (as defined in the Offer to Purchase) in lieu of the Letter of Transmittal) and (iii) any other documents required by the Letter of Transmittal or the Depositary, in each case prior to the Expiration Time. Accordingly, tendering stockholders may be paid at different times depending upon when the Share Certificates and Letter of Transmittal, or Book-Entry Confirmations and Agent’s Message, in each case, with respect to Shares that are actually received by the Depositary.

Shares tendered pursuant to the Offer may be withdrawn at any time prior to the Expiration Time. Thereafter, tenders are irrevocable, except that if Purchaser has not accepted your Shares for payment within 60 days of commencement of the Offer, you may withdraw them at any time after June 20, 2024, the 60th day after commencement of the Offer, until Purchaser accepts your Shares for payment.

For a withdrawal of Shares to be effective, the Depositary must timely receive a written notice of withdrawal at one of its addresses set forth on the back cover of the Offer to Purchase. Any notice of withdrawal must specify the name of the person who tendered the Shares to be withdrawn, the number of Shares to be withdrawn and the names in which the Share Certificates are registered, if different from the person who tendered such Shares. The signature(s) on the notice of withdrawal must be guaranteed by an Eligible Institution (as defined in the Offer to Purchase), unless such Shares have been tendered for the account of an Eligible Institution. If Shares have been tendered pursuant to the procedures for book-entry transfer as set forth in Section 3 of the Offer to Purchase, any notice of withdrawal must

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specify the name and number of the account at DTC to be credited with the withdrawn Shares. If Share Certificates representing the Shares to be withdrawn have been delivered or otherwise identified to the Depositary, then, prior to the physical release of such Share Certificates, the name of the holder(s) of record and the serial numbers shown on such Share Certificates must also be furnished to the Depositary.

Withdrawals of tenders of Shares may not be rescinded and any Shares properly withdrawn will be deemed not validly tendered for purposes of the Offer. Withdrawn Shares may, however, be retendered by following one of the procedures for tendering Shares described in Section 3 of the Offer to Purchase at any time prior to the Expiration Time.

All questions as to the validity, form, eligibility (including time of receipt) and acceptance for payment of any tender of Shares will be determined by Purchaser in its sole discretion, which determination will be final and binding on all parties, subject to the rights of holders of Shares to challenge such determination with respect to their Shares in a court of competent jurisdiction and any subsequent judgment of any such court. Purchaser reserves the absolute right to reject any and all tenders determined by the Purchaser not to be in proper form or the acceptance for payment of which may, in Purchaser’s opinion, be unlawful. Purchaser also reserves the absolute right to waive any defect or irregularity in the tender of any Shares of any particular stockholder, whether or not similar defects or irregularities are waived in the case of other stockholders. No tender of Shares will be deemed to have been validly made until all defects and irregularities have been cured or waived to Purchaser’s satisfaction. None of Purchaser, Vertex or any of their respective affiliates or assigns, the Depositary, Morrow Sodali LLC (the “Information Agent”) or any other person will be under any duty to give any notification of any defects or irregularities in tenders or incur any liability for failure to give any such notification. Subject to the terms of the Merger Agreement and the rights of holders of Shares to challenge any interpretation with respect to their Shares in a court of competent jurisdiction and any subsequent judgment of any such court, Purchaser’s interpretation of the terms and conditions of the Offer (including the Letter of Transmittal and the instructions thereto) will be final and binding.

The information required to be disclosed by paragraph (d)(1) of Rule 14d-6 of the General Rules and Regulations under the Exchange Act is contained in the Offer to Purchase and is incorporated herein by reference.

Alpine has provided Purchaser with its stockholder list and security position listings for the purpose of disseminating the Offer to Purchase, the related Letter of Transmittal and other materials related to the Offer to holders of Shares. The Offer to Purchase, the related Letter of Transmittal and other materials related to the Offer, including the Schedule 14D-9, will be mailed to record holders of Shares whose names appear on Alpine’s stockholder list and will be furnished for subsequent transmittal to beneficial owners of Shares to brokers, dealers, commercial banks, trust companies and other nominees whose names, or the names of whose nominees, appear on Alpine’s stockholder list or, if applicable, who are listed as participants in a clearing agency’s security position listing.

The exchange of Shares for cash pursuant to the Offer or the Merger will generally be a taxable transaction for U.S. federal income tax purposes. A U.S. Holder (as defined in the Offer to Purchase) who sells Shares pursuant to the Offer or receives cash in exchange for Shares pursuant to the Merger generally will recognize capital gain or loss for U.S. federal income tax purposes in an amount equal to the difference, if any, between (i) the amount of cash received (determined before deduction of any applicable withholding taxes) and (ii) the U.S. Holder’s adjusted tax basis in the Shares sold pursuant to the Offer or converted pursuant to the Merger. See Section 5 — “U.S. Federal Income Tax Considerations” of the Offer to Purchase for a more detailed discussion of the U.S. federal income tax considerations generally applicable to the Offer and the Merger. You are urged to consult with your tax advisor as to the particular tax consequences to you of the Offer and the Merger in light of your particular circumstances (including the application and effect of any U.S. federal, state, local or non-U.S. income and other tax laws).

The Offer to Purchase and the related Letter of Transmittal contain important information, and Alpine’s stockholders should read both carefully and in their entirety before making a decision with respect to the Offer.

Questions or requests for assistance may be directed to the Information Agent at the address and telephone numbers set forth below. Copies of the Offer to Purchase, the related Letter of Transmittal and other materials related to the Offer may be obtained at no cost to Alpine’s stockholders from the Information Agent. Additionally, copies of

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the Offer to Purchase, the related Letter of Transmittal and any other materials related to the Offer are available free of charge at www.sec.gov. Stockholders may also contact their brokers, dealers, commercial banks, trust companies or other nominees for assistance. Neither Vertex nor Purchaser will pay any fees or commissions to any broker, dealer, commercial bank, trust company or to any other person (other than to the Depositary and the Information Agent) in connection with the solicitation of tenders of Shares pursuant to the Offer.

The Information Agent for the Offer is:

430 Park Avenue

14th Floor

New York, NY 10022

Banks and Brokers Call: (203) 658-9400

Stockholders Call Toll Free: (800) 662-5200

E-mail: ALPN@info.morrowsodali.com

April 22, 2024

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