{"url_path":"/sec/alt/10-q/2026/item-6","section_key":"item-6","section_title":"Item 6 Exhibits","topic":"sec","document":{"doc_type":"10-Q","doc_date":"2026-05-13","source_url":"https://www.sec.gov/Archives/edgar/data/1326190/0001326190-26-000040-index.html","accession_number":"0001326190-26-000040","cik":"0001326190","ticker":"ALT","issuer_name":"Altimmune, Inc.","edgar_url":"https://www.sec.gov/Archives/edgar/data/1326190/0001326190-26-000040-index.html","primary_entity_key":"0001326190","primary_entity_name":"Altimmune, Inc."},"word_count":741,"has_tables":true,"body_markdown":"Item 6. Exhibits\n\n​\n\n​\n\n​\n\n​\n\n​\n\n**Exhibit Index**\n\n​\n\n​\n\n​\n\nExhibit No.\n\n  ​ ​ ​\n\nDescription\n\n​\n\n​\n\n​\n\n1.1\n\n  ​\n\n[Underwriting Agreement, dated April 22, 2026, by and between by and between the Company, Leerink Partners LLC and Barclays Capital Inc., as representatives of the several underwriters named therein (incorporated by reference to Exhibit 1.1 to the Registrant’s Form 8-K filed on April 24, 2026)](https://www.sec.gov/Archives/edgar/data/1326190/000110465926048552/tm2612493d2_ex1-1.htm)\n\n​\n\n​\n\n​\n\n3.1\n\n  ​\n\n[Amended and Restated Certificate of Incorporation, dated October 17, 2017 (incorporated by reference to Exhibit 3.1 to the Registrant’s Form 8-K filed on October 18, 2017)](https://www.sec.gov/Archives/edgar/data/1326190/000119312517312751/d470504dex31.htm)\n\n​\n\n​\n\n​\n\n3.2\n\n  ​\n\n[Certificate of Amendment to Amended and Restated Certificate of Incorporation regarding a reverse stock split (incorporated by reference to Exhibit 3.1 to the Registrant’s Form 8-K filed on September 13, 2018)](https://www.sec.gov/Archives/edgar/data/1326190/000119312518272896/d621454dex31.htm)\n\n​\n\n​\n\n​\n\n3.3\n\n  ​\n\n[Certificate of Amendment to Amended and Restated Certificate of Incorporation regarding an increase in authorized shares (incorporated by reference to Exhibit 3.2 to the Registrant’s Form 8-K filed on September 13, 2018)](https://www.sec.gov/Archives/edgar/data/1326190/000119312518272896/d621454dex32.htm)\n\n​\n\n​\n\n​\n\n3.4\n\n  ​\n\n[Certificate of Amendment to Amended and Restated Certificate of Incorporation regarding an increase in authorized shares (incorporated by reference to Exhibit 3.1 to the Registrant’s Form 8-K filed on April 16, 2026)](https://www.sec.gov/Archives/edgar/data/1326190/000132619026000027/alt-20260416xex3d1.htm)\n\n​\n\n​\n\n​\n\n3.5\n\n  ​\n\n[Amended and Restated Bylaws of Altimmune, Inc. (incorporated by reference to Exhibit 3.2 to the Registrant’s Form 8-K filed on October 18, 2017)](https://www.sec.gov/Archives/edgar/data/1326190/000119312517312751/d470504dex32.htm)\n\n​\n\n​\n\n​\n\n4.1\n\n  ​\n\n[Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 to the Registrant’s Form 8-K filed on January 28, 2026)](https://www.sec.gov/Archives/edgar/data/1326190/000132619026000006/alt-20260127xex4d1.htm)\n\n​\n\n​\n\n​\n\n4.2\n\n  ​\n\n[Form of Common Stock Warrant (incorporated by reference to Exhibit 4.1 to the Registrant’s Form 8-K filed on April 24, 2026)](https://www.sec.gov/Archives/edgar/data/1326190/000110465926048552/tm2612493d2_ex4-1.htm)\n\n​\n\n​\n\n​\n\n4.3\n\n  ​\n\n[Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.2 to the Registrant’s Form 8-K filed on April 24, 2026)](https://www.sec.gov/Archives/edgar/data/1326190/000110465926048552/tm2612493d2_ex4-2.htm)\n\n​\n\n​\n\n​\n\n10.1\n\n  ​\n\n[Form of Securities Purchase Agreement, dated January 27, 2026 (incorporated by (reference to Exhibit 10.1 to the Registrant’s Form 8-K filed on January 28, 2026)](https://www.sec.gov/Archives/edgar/data/1326190/000132619026000006/alt-20260127xex10d1.htm)\n\n​\n\n​\n\n​\n\n10.2\n\n  ​\n\n[Placement Agency Agreement, dated January 27, 2026 (incorporated by (reference to Exhibit 10.2 to the Registrant’s Form 8-K filed on January 28, 2026)](https://www.sec.gov/Archives/edgar/data/1326190/000132619026000006/alt-20260127xex10d2.htm)\n\n​\n\n​\n\n​\n\n31.1 †\n\n  ​\n\n[Certification of Principal Executive Officer Pursuant to SEC Rule 13a-14(a)/15d-14(a)](alt-20260331xex31d1.htm)\n\n​\n\n​\n\n31.2 †\n\n  ​\n\n[Certification of Principal Financial Officer Pursuant to SEC Rule 13a-14(a)/15d-14(a)](alt-20260331xex31d2.htm)\n\n​\n\n​\n\n32.1 †\n\n  ​\n\n[Certification Pursuant to Section 1350 of Chapter 63 of Title 18 of the United States Code](alt-20260331xex32d1.htm)\n\n​\n\n​\n\n32.2 †\n\n  ​\n\n[Certification Pursuant to Section 1350 of Chapter 63 of Title 18 of the United States Code](alt-20260331xex32d2.htm)\n\n​\n\n​\n\n101.INS\n\n  ​\n\nInline XBRL Instance Document (the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document)\n\n​\n\n​\n\n101.SCH\n\n  ​\n\nInline XBRL Taxonomy Extension Schema Document\n\n​\n\n​\n\n101.CAL\n\n  ​\n\nInline XBRL Taxonomy Extension Calculation Linkbase Document\n\n​\n\n​\n\n101.DEF\n\n  ​\n\nInline XBRL Taxonomy Extension Definition Linkbase Document\n\n​\n\n​\n\n101.LAB\n\n  ​\n\nInline XBRL Taxonomy Extension Label Linkbase Document\n\n​\n\n​\n\n101.PRE\n\n  ​\n\nInline XBRL Taxonomy Extension Presentation Linkbase Document\n\n​\n\n​\n\n​\n\n104\n\n​\n\nCover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101)\n\n​\n\n25\n\n[Table of Contents](#TOC)\n\n*\n\nFiled herewith.\n\n†\n\nThis certification will not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section. Such certification will not be deemed to be incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except to the extent specifically incorporated by reference into such filing.\n\n§\n\nCertain portions of this exhibit have been omitted in accordance with Item 601(b)(10)(iv) of Regulation S-K.\n\n​\n\n26\n\n[Table of Contents](#TOC)\n\nSIGNATURES\n\nPursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused the report to be signed on its behalf by the undersigned, thereunto duly authorized.\n\n​\n\n​\n\n​\n\n​\n\nALTIMMUNE, INC.\n\n​\n\n​\n\n​\n\nDated: May 13, 2026\n\nBy:\n\n/s/ Jerome Durso\n\n​\n\nName:\n\nJerome Durso\n\n​\n\nTitle:\n\nPresident and Chief Executive Officer (Principal Executive Officer)\n\n​\n\n​\n\n​\n\nDated: May 13, 2026\n\nBy:\n\n/s/ Gregory Weaver\n\n​\n\nName:\n\nGregory Weaver\n\n​\n\nTitle:\n\nChief Financial Officer (Principal Financial and Accounting Officer)\n\n​\n\n​\n\n​\n\n​\n\n​\n\n27"}