Altimmune Inc

8. Common Stock

The Amended and Restated Certificate of Incorporation, as amended (“Charter”), authorized the Company to issue 200,000,000 shares of common stock, par value $0.0001 per share. As of December 31, 2023, the Company had 70,677,400 shares of common stock issued andoutstanding.

The Charter also authorized the Company to issue 1,000,000 shares of preferred stock, par value $0.0001 per share. As of December 31, 2023, the Company hadno shares of preferred stock issued andoutstanding.

At-the-Market Offerings

On February 28, 2023, the Company entered into an Equity Distribution Agreement (the “2023 Agreement”) with Evercore Group L.L.C., JMP Securities LLC and B. Riley Securities, Inc., serving as sales agents (the “Sales Agents”), with respect to an at-the-market offerings program under which the Company may offer and sell, from time to time at its sole discretion, shares of its common stock, having an aggregate offering price of up to $150.0 million (the “Shares”) through the Sales Agents (the “2023 Offering”). All Shares offered and sold in the 2023 Offering will be issued pursuant to the Company’s Registration Statement on Form S-3ASR filed with the SEC on February 28, 2023, which was declared effective immediately, the prospectus supplement relating to the 2023 Offering filed with the SEC on February 28, 2023 and any applicable additional prospectus supplements related to the 2023 Offering that form a part of the Registration Statement. The Company capitalized approximately $0.2 million of other offering costs which will offset the proceeds received from the shares sold under the 2023 Agreement. During the year ended December 31, 2023, the Company sold 20,454,516 shares of common stock under the 2023 Agreement resulting in approximately $86.6 million in proceeds, net of $2.8 million commission and other offering costs, with, $60.6 million remaining available to be sold under the 2023 Agreement. As of December 31, 2023, there was $0.1 million in deferred offering costs included in prepaid expenses and other current assets on the accompanying Consolidated Balance Sheets.

On February 25, 2021, the Company entered into an Equity Distribution Agreement (the “2021 Agreement”) with Piper Sandler & Co., Evercore Group L.L.C. and B. Riley Securities, Inc., serving as sales agents (the “2021 Sales Agents”), with respect to an at-the-market offerings program under which the Company offered and sold shares of its common stock, having an aggregate offering price of up to $125.0 million (the “2021 Shares”) through the 2021 Sales Agents (the “2021 Offering”). All 2021 Shares offered and sold in the 2021 Offering were issued pursuant to the Company’s Registration Statement on Form S-3 filed with the SEC on December 31, 2020, which was declared effective on January 11, 2021, the prospectus supplement relating to the 2021 Offering filed with the SEC on February 25, 2021 and any applicable additional prospectus supplements related to the 2021 Offering that form a part of the Registration Statement. Under the 2021 Agreement, the Company sold 10,004,869 shares of common stock resulting in approximately $121.0 million in proceeds, net of $4.0 million commission and other offering costs. As of December 31, 2023, there wereno remaining shares available under the 2021 Agreement.

Public Offering

On July 16, 2020, the Company offered and sold (i)3,369,564 shares of common stock, at a price to the public of $23.00 per share, and (ii) pre-funded warrants of the Company to purchase 1,630,436 shares of common stock at an exercise price equal to $0.0001 per share (the “Pre-Funded Warrants”), at a price to the public of $22.9999 per share of common stock underlying the Pre-Funded Warrants (equal to the public offering price per share of Common Stock, minus the exercise price of each Pre-Funded Warrant). The Pre-Funded Warrants were classified as equity and were accounted for as a component of additional paid-in capital at the time of issuance. In January 2022,760,870 of the Pre-Funded Warrants were exercised, resulting in the issuance of 760,870 shares of common stock. Furthermore, on October 18, 2023, warrant holders exercised the remaining 869,566 Pre-Funded Warrants in a net cashless exercise and were issued 869,530 shares of common stock (see Note 9).