X0306 4 2017-05-04 0 0001326190 Altimmune, Inc. NASDAQ:ALT 0001705564 Enright William 19 FIRSTFIELD ROAD, SUITE 200 GAITHERSBURG MD 20878 1 1 0 0 See Remarks Common Stock, par value $0.0001 2017-05-04 4 A 0 17787 A 17787 D Stock Options (option to buy) 2.59 2017-05-04 4 A 0 125887 A 2017-05-04 2018-05-31 Common Stock, par value $0.0001 125887 125887 D Stock Options (option to buy) 0.08 2017-05-04 4 A 0 71644 A 2017-05-04 2019-12-31 Common Stock, par value $0.0001 71644 71644 D Stock Options (option to buy) 0.08 2017-05-04 4 A 0 91733 A 2017-05-04 2021-12-03 Common Stock, par value $0.0001 91733 91733 D Stock Options (option to buy) 0.08 2017-05-04 4 A 0 183347 A 2017-05-04 2021-12-03 Common Stock, par value $0.0001 183347 183347 D Stock Options (option to buy) 6.50 2017-05-04 4 A 0 99927 A 2027-05-04 Common Stock, par value $0.0001 99927 99927 D 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 then outstanding shares of Altimmune's capital stock was converted into the right to receive a number of shares of the Issuer's common stock, par value $0.0001 on a 0.749106:1 basis upon the closing of the merger. Pursuant to the terms of 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. On the first anniversary of the date of grant, 25% of the unvested portion of the option will become vested and exercisable, and the aggregate remaining unvested portion will vest and become exercisable in equal monthly installments over the 36-month period following such anniversary date. However, the agreement also provides that, if the compensation committee of the Issuer's board of directors, in its sole discretion, determines that the consummation of the mergers was successful, then 50% of the unvested portion of the option shall become immediately vested and exercisable. Granted under the terms of the Altimmune 2017 Omnibus Incentive Plan. President and Chief Executive Officer /s/ Ori Solomon, Attorney in fact for William Enright 2017-05-08