Sec Form 4 Filing - Venrock Healthcare Capital Partners III, L.P. @ Altimmune, Inc. - 2021-02-25

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 Venrock Healthcare Capital Partners III, L.P. 2. Issuer Name and Ticker or Trading Symbol Altimmune, Inc. [ ALT] 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 VENROCK, 7 BRYANT PARK, 23RD FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 02/25/2021 (Street) NEW YORK, NY10018 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 02/25/2021 J( 1 ) 1,000,000 D $ 0 ( 1 ) 3,500,000 ( 2 ) I By Funds ( 3 )

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 Warrant $ 0.0001 02/25/2021 J( 1 ) 1,000,000 ( 4 ) ( 5 ) Common Stock 1,000,000 $ 0 1,000,000 ( 6 ) I By Funds ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Venrock Healthcare Capital Partners III, L.P. C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X VHCP Co-Investment Holdings III, LLC C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X VHCP Management III, LLC C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X Venrock Healthcare Capital Partners II, L.P. C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X VHCP Co-Investment Holdings II, LLC C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X VHCP Management II, LLC C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X Koh Bong Y C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X Shah Nimish P C/O VENROCK 7 BRYANT PARK, 23RD FLOOR NEW YORK, NY10018 X Signatures /s/ David L. Stepp, Authorized Signatory 03/01/2021 Signature of Reporting Person Date David L. Stepp, Authorized Signatory 03/01/2021 Signature of Reporting Person Date David L. Stepp, Authorized Signatory 03/01/2021 Signature of Reporting Person Date David L. Stepp, Authorized Signatory 03/01/2021 Signature of Reporting Person Date David L. Stepp, Authorized Signatory 03/01/2021 Signature of Reporting Person Date David L. Stepp, Authorized Signatory 03/01/2021 Signature of Reporting Person Date David L. Stepp, Attorney-in-fact 03/01/2021 Signature of Reporting Person Date David L. Stepp, Attorney-in-fact 03/01/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On February 25, 2021, the Issuer entered into an exchange agreement with the Reporting Persons pursuant to which the Issuer exchanged an aggregate of 1,000,000 shares of common stock owned by the Reporting Persons for pre-funded warrants (the "Exchange Warrants") to purchase an aggregate of 1,000,000 shares of common stock (subject to adjustment in the event of stock splits, recapitalizations and other similar events affecting common stock), with an exercise price of $0.0001 per share. ( 2 )Consists of 925,050 shares held by Venrock Healthcare Capital Partners II, L.P. ("VHCP II"), 374,849 shares held by VHCP Co-Investment Holdings II, LLC ("VHCP II Co"), 2,000,252 shares held by Venrock Healthcare Capital Partners III, L.P. ("VHCP III") and 199,849 shares held by VHCP Co-Investment Holdings III, LLC ("VHCP III Co"). ( 3 )VHCP Management II, LLC ("VHCPM II") is the sole general partner of VHCP II and the sole manager of VHCP II Co. VHCP Management III, LLC ("VHCPM III") is the sole general partner of VHCP III and the sole manager of VHCP III Co. Dr. Bong Koh and Nimish Shah are the voting members of VHCPM II and VHCPM III. Dr. Koh, Mr. Shah, VHCPM II and VHCPM III disclaim beneficial ownership over all shares held by VHCP II, VHCP II Co, VHCP III and VHCP III Co, except to the extent of their respective indirect pecuniary interests therein. ( 4 )The Exchange Warrants are exercisable at any time, except that the Exchange Warrants will not be exercised by the Reporting Persons if, upon giving effect or immediately prior thereto, the Reporting Persons would beneficially own more than 9.99% of the total number of the Issuer's issued and outstanding common stock, which percentage may change at the holders' election to any other number less than or equal to 19.99% upon 61 days' notice to the Issuer. ( 5 )The Exchange Warrants have no expiration date. ( 6 )Consists of 264,300 shares underlying Exchange Warrants held by VHCP II, 107,100 shares underlying Exchange Warrants held by VHCP II Co, 571,500 shares underlying Exchange Warrants held by VHCP III and 57,100 shares underlying Exchange Warrants held by VHCP III Co.

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