Sec Form 4 Filing - EASTLAND JULIA MARIE @ Harpoon Therapeutics, Inc. - 2024-03-11

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person EASTLAND JULIA MARIE 2. Issuer Name and Ticker or Trading Symbol Harpoon Therapeutics, Inc. [ HARP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) President and CEO (Last) (First) (Middle) C/O HARPOON THERAPEUTICS, INC., 611 GATEWAY BOULEVARD, SUITE 400 3. Date of Earliest Transaction (MM/DD/YY) 03/11/2024 (Street) SOUTH SAN FRANCISCO, CA94080 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/11/2024 A( 1 ) 31,250 A $ 0 269,381 ( 2 ) D Common Stock 03/11/2024 D( 3 ) 269,381 ( 4 ) D ( 3 ) 0 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Employee Stock Option (Right to Buy) $ 21.1453 03/11/2024 D( 3 ) 2,765 ( 7 )( 8 ) ( 7 )( 8 ) Common Stock 2,765 ( 7 ) ( 8 ) 0 D Employee Stock Option (Right to Buy) $ 8.9 03/11/2024 D( 3 ) 40,759 ( 7 )( 8 ) ( 7 )( 8 ) Common Stock 40,759 ( 7 ) ( 8 ) 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other EASTLAND JULIA MARIE C/O HARPOON THERAPEUTICS, INC. 611 GATEWAY BOULEVARD, SUITE 400 SOUTH SAN FRANCISCO, CA94080 X President and CEO Signatures /s/ Frank J. Lanza, Attorney-in-Fact 03/11/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Reflects the number of restricted stock units ("RSUs") vested upon the achievement of certain performance-related metrics. Each RSU represents a contingent right to receive one share of the Issuer's common stock, par value $0.0001 per share ("Common Stock"), issuable upon the vesting of RSUs. ( 2 )Includes 6,128 shares of Common Stock acquired under the Issuer's employee stock purchase plan on February 29, 2024. ( 3 )This Form 4 reports securities disposed of pursuant to the terms of the Agreement and Plan of Merger (the "Merger Agreement"), dated as of January 7, 2024, by and among the Issuer, Merck Sharp & Dohme LLC, a New Jersey limited liability company ("Parent"), and Hawaii Merger Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent ("Merger Sub"), pursuant to which Merger Sub merged with and into the Issuer on March 11, 2024, with the Issuer surviving the merger as a wholly owned subsidiary of Parent (the "Merger"). ( 4 )Includes 259,750 RSUs. ( 5 )Pursuant to the terms of the Merger Agreement, at the effective time of the Merger (the "Effective Time"), each outstanding RSU was cancelled and automatically converted into the right to receive an amount in cash (without interest and subject to any applicable withholding or other taxes) equal to the product of (i) the Common Stock Merger Consideration (as defined below) payable with respect to such RSU multiplied by (ii) the total number of shares of Common Stock subject to such RSU immediately prior to the Effective Time, with the number of shares of Company Common Stock subject to any such Company RSU that vests based on the achievement of performance goals determined in accordance with the applicable award agreement. ( 6 )Pursuant to the terms of the Merger Agreement, at the Effective Time, each outstanding share of Common Stock was cancelled and automatically converted into the right to receive $23.00 in cash, without interest (the "Common Stock Merger Consideration"). ( 7 )Pursuant to the terms of the Merger Agreement, immediately prior to the Effective Time, each outstanding option to purchase shares of Common Stock granted under an Issuer equity plan (each, a "Stock Option"), to the extent unvested, became fully vested and exercisable effective immediately prior to, and contingent upon, the Effective Time. Pursuant to the terms of the Merger Agreement, at the Effective Time, (i) each Stock Option that was outstanding and unexercised immediately prior to the Effective Time and that had a per share exercise price that is less than the Common Stock Merger Consideration (each, an "In the Money Option") was cancelled in exchange for the right to receive an amount in cash (without interest and subject to any applicable withholding or other taxes) equal to the product of (1) the total number of shares of Common Stock subject to such Stock Option immediately prior to the Effective Time and (2) the excess of the ( 8 )(Continued from footnote 7) Common Stock Merger Consideration over the per share exercise price payable for such Stock Option immediately prior to the Effective Time and (ii) each Stock Option other than an In the Money Option then outstanding and unexercised was cancelled with no consideration payable in respect thereof.

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