License Agreements	12 Months Ended
Dec. 31, 2017
License Agreements.
License Agreements	Note 10. License Agreements In 2012, the Company entered into three exclusive license agreements with Antecip Bioventures II LLC, or Antecip, an entity owned by Axsome’s Chief Executive Officer and Chairman of the Board, Herriot Tabuteau, M.D., in which it was granted exclusive licenses to develop, manufacture, and commercialize Antecip’s patents and applications related to the development of AXS‑02, AXS‑05, and AXS‑04, a product candidate that is currently in early stage development, anywhere in the world for veterinary and human therapeutic and diagnostic use. Pursuant to the agreements, the Company is required to use commercially reasonable efforts to develop, obtain regulatory approval for and commercialize AXS‑02, AXS‑05, and AXS‑04. Under the terms of the agreements, the Company is required to pay to Antecip a royalty equal to 4.5% for AXS‑02, 3.0% for AXS‑05, and 1.5% for AXS‑04, of net sales of products containing the licensed technology by the Company, its affiliates, or permitted sublicensees. These royalty payments are subject to reduction by an amount up to 50.0% of any required payments to third parties. Unless earlier terminated by a party for cause or by the Company for convenience, the agreements shall remain in effect on a product‑by‑product and country‑by‑country basis until the later to occur of (i) the applicable product is no longer covered by a valid claim in that country or (ii) 10 years from the first commercial sale of the applicable product in that country. Upon expiration of the agreements with respect to a product in a country, the Company’s license grant for that product in that country will become a fully paid‑up, royalty‑free, perpetual non‑exclusive license. If Antecip terminates any of the agreements for cause, or if the Company exercises its right to terminate any of the agreements for convenience, the rights granted to the Company under such terminated agreement will revert to Antecip. To date, the Company has not been required to make any payments to Antecip under any of the license agreements.

Note 10. License Agreements

In 2012, the Company entered into three exclusive license agreements with Antecip Bioventures II LLC, or Antecip, an entity owned by Axsome’s Chief Executive Officer and Chairman of the Board, Herriot Tabuteau, M.D., in which it was granted exclusive licenses to develop, manufacture, and commercialize Antecip’s patents and applications related to the development of AXS‑02, AXS‑05, and AXS‑04, a product candidate that is currently in early stage development, anywhere in the world for veterinary and human therapeutic and diagnostic use. Pursuant to the agreements, the Company is required to use commercially reasonable efforts to develop, obtain regulatory approval for and commercialize AXS‑02, AXS‑05, and AXS‑04. Under the terms of the agreements, the Company is required to pay to Antecip a royalty equal to 4.5% for AXS‑02, 3.0% for AXS‑05, and 1.5% for AXS‑04, of net sales of products containing the licensed technology by the Company, its affiliates, or permitted sublicensees. These royalty payments are subject to reduction by an amount up to 50.0% of any required payments to third parties. Unless earlier terminated by a party for cause or by the Company for convenience, the agreements shall remain in effect on a product‑by‑product and country‑by‑country basis until the later to occur of (i) the applicable product is no longer covered by a valid claim in that country or (ii) 10 years from the first commercial sale of the applicable product in that country. Upon expiration of the agreements with respect to a product in a country, the Company’s license grant for that product in that country will become a fully paid‑up, royalty‑free, perpetual non‑exclusive license. If Antecip terminates any of the agreements for cause, or if the Company exercises its right to terminate any of the agreements for convenience, the rights granted to the Company under such terminated agreement will revert to Antecip. To date, the Company has not been required to make any payments to Antecip under any of the license agreements.