Altimmune, Inc. — Director's Dealing 2017

May 9, 2017

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Altimmune, Inc. (NASDAQ:ALT)
CIK: 0001326190
Period of Report: 2017-05-04

Reporting Person: Roberts M Scot (Chief Scientific Officer)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2017-05-04	Stock Option (option to buy)	$0.08	A	55120	Acquired	2022-12-05	Common Stock, par value $0.0001 (55120)	Direct
2017-05-04	Stock Option (option to buy)	$0.59	A	8956	Acquired	2023-12-04	Common Stock, par value $0.0001 (8956)	Direct
2017-05-04	Stock Option (option to buy)	$2.59	A	8956	Acquired	2024-12-02	Common Stock, par value $0.0001 (8956)	Direct
2017-05-04	Stock Option (option to buy)	$13.38	A	11235	Acquired	2026-04-07	Common Stock, par value $0.0001 (11235)	Direct

Footnotes

F1: Acquired pursuant to the Agreement and Plan of Merger, dated as of January 18, 2017 (as amended on March 29, 2017, the "Merger Agreement"), pursuant to which a wholly-owned subsidiary of the Issuer merged with and into Altimmune, Inc. ("Altimmune"). Pursuant to the Merger Agreement the Issuer assumed all outstanding options to purchase shares of Altimmune capital stock on a 0.749106:1 basis upon closing of the merger.

F2: The option is currently exercisable to purchase 6,716 shares of the Issuer's common stock, par value $0.0001 ("Common Stock"). The remaining portion of the option will vest on 12/4/2017.

F3: The option is currently exercisable to purchase 4,477 shares of Common Stock. An additional 25% of the option will vest on each of 12/3/2017 and 12/3/2018.

F4: The option is currently exercisable to purchase 2,809 shares of Common Stock. An additional 25% of the option will vest on each of 3/2/2018, 3/2/2019, and 3/2/2020.