TCG Crossover GP II, LLC Reports 5.0% Stake in Altimmune, Inc. Following Underwritten Offering

On May 1, 2026, TCG Crossover GP II, LLC and associated entities filed a Schedule 13G reporting a new significant ownership stake in Altimmune, Inc. (ALT). The filing indicates that TCG Crossover GP II, LLC beneficially owns 10,000,000 shares of Common Stock, representing 5.0% of the class. This position consists of 5,000,000 shares of Common Stock held of record and an additional 5,000,000 shares issuable upon the exercise of Common Warrants acquired in an underwritten offering that closed on April 24, 2026. Chen Yu, as the sole managing member of the general partner entities, reported an aggregate beneficial ownership of 20,000,000 shares (9.8%) when combining holdings from TCG Crossover II and TCG Crossover III. The warrants include a beneficial ownership limitation of 9.99%. The reporting persons certified that the acquisition was not made for the purpose of changing or influencing the control of the issuer.