Nature of Business and Basis of Presentation	6 Months Ended
Jun. 30, 2021
Accounting Policies [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Nature of Business Altimmune, Inc., headquartered in Gaithersburg, Maryland, United States, together with its subsidiaries (collectively, the “Company” or “Altimmune”) is a clinical stage biopharmaceutical company incorporated under the laws of the State of Delaware. The Company is focused on developing treatments for obesity and liver diseases. The Company’s pipeline includes next generation peptide therapeutics for obesity, NASH (ALT-801) and chronic hepatitis B (HepTcell); proprietary intranasal vaccines; and an intranasal immune modulating therapeutic for the coronavirus disease (“COVID 19”) (T-COVID). Since its inception, the Company has devoted substantially all of its efforts to business planning, research and development, recruiting management and technical staff, and raising capital, and has financed its operations through the issuance of common and preferred stock, long-term debt, and proceeds from research grants and government contracts. The Company has not generated any revenues from the sale of any products to date, and there is no assurance of any future revenues from product sales. On June 29, 2021, the Company announced the discontinuation of the development program for the COVID-19 vaccine candidate, AdCOVID following the Company’s review of findings from the Phase 1 clinical trial, and in view of the highly competitive COVID-19 landscape. The Company is currently evaluating options for the future development of T-COVID as a result of enrollment challenges due to the effective rollout in the United States of authorized COVID-19 vaccines and decreasing incidence of the disease. Basis of Presentation The accompanying unaudited consolidated financial statements are prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Accordingly, they do not include all of the information and disclosures required by accounting principles generally accepted in the United States (“U.S. GAAP”) for complete consolidated financial statements and should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2020 included in the Annual Report on Form 10-K which was filed with the SEC on February 25, 2021. In the opinion of management, the Company has prepared the accompanying unaudited consolidated financial statements on the same basis as the audited consolidated financial statements, and these consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the results of the interim periods presented. The operating results for the interim periods presented are not necessarily indicative of the results expected for the full year 2021 or any future years or periods. The accompanying unaudited consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. The accompanying unaudited consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets, and the satisfaction of liabilities in the ordinary course of business. The financial statements do not include any adjustments relating to the recoverability and classification of recorded assets and liabilities that might be necessary should we be unable to continue as a going concern.

Nature of Business and Basis of Presentation

6 Months Ended

Jun. 30, 2021

Nature of Business and Basis of Presentation

1. Nature of Business and Basis of Presentation

Nature of Business

Altimmune, Inc., headquartered in Gaithersburg, Maryland, United States, together with its subsidiaries (collectively, the “Company” or “Altimmune”) is a clinical stage biopharmaceutical company incorporated under the laws of the State of Delaware.

The Company is focused on developing treatments for obesity and liver diseases. The Company’s pipeline includes next generation peptide therapeutics for obesity, NASH (ALT-801) and chronic hepatitis B (HepTcell); proprietary intranasal vaccines; and an intranasal immune modulating therapeutic for the coronavirus disease (“COVID 19”) (T-COVID). Since its inception, the Company has devoted substantially all of its efforts to business planning, research and development, recruiting management and technical staff, and raising capital, and has financed its operations through the issuance of common and preferred stock, long-term debt, and proceeds from research grants and government contracts. The Company has not generated any revenues from the sale of any products to date, and there is no assurance of any future revenues from product sales.

On June 29, 2021, the Company announced the discontinuation of the development program for the COVID-19 vaccine candidate, AdCOVID following the Company’s review of findings from the Phase 1 clinical trial, and in view of the highly competitive COVID-19 landscape. The Company is currently evaluating options for the future development of T-COVID as a result of enrollment challenges due to the effective rollout in the United States of authorized COVID-19 vaccines and decreasing incidence of the disease.

Basis of Presentation

The accompanying unaudited consolidated financial statements are prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Accordingly, they do not include all of the information and disclosures required by accounting principles generally accepted in the United States (“U.S. GAAP”) for complete consolidated financial statements and should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2020 included in the Annual Report on Form 10-K which was filed with the SEC on February 25, 2021. In the opinion of management, the Company has prepared the accompanying unaudited consolidated financial statements on the same basis as the audited consolidated financial statements, and these consolidated financial statements include all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the results of the interim periods presented. The operating results for the interim periods presented are not necessarily indicative of the results expected for the full year 2021 or any future years or periods.

The accompanying unaudited consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.

The accompanying unaudited consolidated financial statements have been prepared on the basis of continuity of operations, realization of assets, and the satisfaction of liabilities in the ordinary course of business. The financial statements do not include any adjustments relating to the recoverability and classification of recorded assets and liabilities that might be necessary should we be unable to continue as a going concern.