Sec Form 4 Filing - GADICKE ANSBERT @ Harpoon Therapeutics, Inc. - 2019-02-12

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 GADICKE ANSBERT 2. Issuer Name and Ticker or Trading Symbol Harpoon Therapeutics, Inc. [ HARP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O MPM CAPITAL, 450 KENDALL STREET 3. Date of Earliest Transaction (MM/DD/YY) 02/12/2019 (Street) CAMBRIDGE, MA02142 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 02/12/2019 C 3,050,329 A 3,372,392 I See Footnote ( 2 ) ( 3 ) Common Stock 02/12/2019 C 3,157,506 A 6,529,898 I See Footnote ( 3 ) ( 4 ) Common Stock 02/12/2019 C 835,705 A 7,365,603 I See Footnote ( 3 ) ( 5 ) Common Stock 02/12/2019 X( 6 ) 559,215 A $ 0.0492 7,924,818 I See Footnote ( 3 ) ( 7 ) Common Stock 02/12/2019 S( 6 ) 1,971 D $ 14 7,922,847 I See Footnote ( 3 ) ( 8 ) Common Stock 02/12/2019 P 500,000 A $ 14 8,422,847 I See Footnote ( 3 ) ( 9 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivat ive 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 Series A Preferred Stock ( 1 ) 02/12/2019 C 3,050,329 ( 1 ) ( 1 ) Common Stock 3,050,329 $ 0 0 I See Footnote ( 10 ) Series B Preferred Stock ( 1 ) 02/12/2019 C 3,157,506 ( 1 ) ( 1 ) Common Stock 3,157,506 $ 0 0 I See Footnote ( 10 ) Series C Preferred Stock ( 1 ) 02/12/2019 C 835,705 ( 1 ) ( 1 ) Common Stock 835,705 $ 0 0 I See Footnote ( 10 ) Common Stock Warrant (Right to Buy) $ 0.0492 02/12/2019 X( 6 ) 25,418 03/23/2015 03/24/2025 Common Stock 25,418 $ 0 0 I See Footnote ( 10 ) Common Stock Warrant (Right to Buy) $ 0.0492 02/12/2019 X( 6 ) 57,192 07/23/2015 07/23/2025 Common Stock 57,192 $ 0 0 I See Footnote ( 10 ) Common Stock Warrant (Right to Buy) $ 0.0492 02/12/2019 X( 6 ) 171,579 08/19/2015 08/19/2025 Common Stock 171,579 $ 0 0 I See Footnote ( 10 ) Common Stock Warrant (Right to Buy) $ 0.0492 02/12/2019 X( 6 ) 50,837 12/16/2015 12/16/2025 Common Stock 50,837 $ 0 0 I See Footnote ( 10 ) Common Stock Warrant (Right to Buy) $ 0.0492 02/12/2019 X( 6 ) 152,514 11/01/2016 11/01/2026 Common Stock 152,514 $ 0 0 I See Footnote ( 10 ) Common Stock Warrant (Right to Buy) $ 0.0492 02/12/2019 X( 6 ) 101,675 01/10/2017 01/10/2027 Common Stock 101,675 $ 0 0 I See Footnote ( 10 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other GADICKE ANSBERT C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE, MA02142 X Signatures /s/ Ansbert Gadicke 02/14/2019 Signature of Reporting Person Date

Explanation of Responses:

( 1 )All series of convertible preferred stock will automatically convert into the number of shares of the Issuer's common stock on a 1-for-1 basis, for no additional consideration, immediately prior to the closing of the Issuer'sinitial public offering and have no expiration date. ( 2 )The shares are held as follows: 1,382,777 by MPM BioVentures 2014, L.P. ("BV 2014"), 92,229 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 50,158 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"), 1,525,165 by UBS Oncology Impact Fund L.P. ("UBS Oncology") and 322,063 by MPM Asset Management LLC ("AM LLC"). MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). Ansbert Gadicke is a member of BV LLC. MPM Oncology Impact Management GP LLC ("Oncology GP LLC) is the General Partner of MPM Oncology Impact Management LP, the General Partner of Oncology Impact Fund (Cayman) Management L.P., the General Partner of UBS Oncology Impact Fund, L.P. Ansbert Gadicke is the Managing Director of Oncology GP LLC and a member of AM LLC. ( 3 )The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein. ( 4 )The shares are held as follows: 2,814,142 by BV 2014, 187,696 by BV 2014(B), 102,077 AM BV2014, 3,103,920 by UBS Oncology and 322,063 by AM LLC. ( 5 )The shares are held as follows: 3,192,985 by BV 2014, 212,964 by BV 2014(B), 115,818 AM BV2014, 3,521,773 by UBS Oncology and 322,063 by AM LLC. ( 6 )On February 12, 2019, BV 2014, BV 2014(B), AM BV2014 and UBS Oncology exercised warrants to purchase an aggregate of 559,215 shares of the Issuer's common stock for $0.0492 per share. The warrants were exercised as follows: 391,784 by BV 2014, 26,129 by BV 2014(B), 14,206 by AM BV2014 and 127,096 by UBS Oncology. The exercise price was paid on a cashless basis, resulting in the Issuer's withholding of an aggregate of 1,971 of the warrant shares to pay the exercise price and issuing to the Reporting Persons the remaining 557,244shares. ( 7 )The shares are held as follows: 3,584,769 by BV 2014, 239,093 by BV 2014(B), 130,024 AM BV2014, 3,648,869 by UBS Oncology and 322,063 by AM LLC. ( 8 )The shares are held as follows: 3,583,391 by BV 2014, 238,998 by BV 2014(B), 129,973 AM BV2014, 3,648,422 by UBS Oncology and 322,063 by AM LLC. ( 9 )The shares are held as follows: 3,810,051 by BV 2014, 254,116 by BV 2014(B), 138,195 AM BV2014, 3,898,422 by UBS Oncology and 322,063 AM LLC. ( 10 )No securities held by the Reporting Person.

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