Collaboration and License Agreements	3 Months Ended
Mar. 31, 2021
Collaboration and License Agreements [Abstract]
Collaborative Arrangement Disclosure	Collaboration and License Agreements Lexicon has derived substantially all of its revenues from drug discovery and development alliances, target validation collaborations for the development and, in some cases, analysis of the physiological effects of genes altered in knockout mice, product sales, government grants and contracts, technology licenses, subscriptions to its databases and compound library sales. Ipsen. In October 2014, Lexicon entered into a License and Collaboration Agreement, which was subsequently amended in March 2015 (collectively, the “Ipsen Agreement”), with Ipsen for the development and commercialization of XERMELO outside of the United States and Japan (the “Licensed Territory”). The Ipsen Agreement was assigned to TerSera in September 2020 in connection with the XERMELO sale. Prior to the XERMELO sale, Lexicon had earned certain milestone payments and royalties from Ipsen. Revenue, including royalty revenue, recognized under the Ipsen Agreement was $0.1 million for the three months ended March 31, 2020. Sanofi. In November 2015, Lexicon entered into a Collaboration and License Agreement, which was subsequently amended in July 2017 (collectively, the “Sanofi Agreement”), with Sanofi for the worldwide development of Lexicon’s diabetes drug candidate sotagliflozin. In December 2016, Sanofi terminated its rights under the Sanofi Agreement with respect to Japan. Effective as of September 9, 2019 (the “Settlement Date”), Lexicon entered into the Termination Agreement with Sanofi, pursuant to which the Sanofi Agreement was terminated and certain associated disputes between Lexicon and Sanofi were settled. Under the terms of the Termination Agreement, Lexicon regained all rights to sotagliflozin and assumed full responsibility for the worldwide development and commercialization of sotagliflozin in all indications. Sanofi paid Lexicon $208 million in September 2019 and $26 million in each of March and September 2020 (less amounts withheld by Sanofi offsetting certain third party costs and internal costs incurred by Sanofi and asserted by Sanofi to be payable by Lexicon under the terms of the Termination Agreement), and neither party will owe any additional payments pursuant to the Sanofi Agreement. The parties have cooperated in the transition of responsibility for ongoing clinical studies and other activities, and each party is responsible for its own expenses associated with such transition, subject to certain exceptions. See Note 6, Commitments and Contingencies, for additional information. Beginning in March 2020, Lexicon closed out early the clinical studies related to the Phase 3 development program for sotagliflozin in type 2 diabetes, heart failure and chronic kidney disease. Subsequent to the Termination Agreement, Lexicon has no remaining performance obligations to Sanofi.

Collaboration and License Agreements

3 Months Ended

Mar. 31, 2021

Collaboration and License Agreements [Abstract]

Collaboration and License Agreements

Lexicon has derived substantially all of its revenues from drug discovery and development alliances, target validation collaborations for the development and, in some cases, analysis of the physiological effects of genes altered in knockout mice, product sales, government grants and contracts, technology licenses, subscriptions to its databases and compound library sales.

Ipsen. In October 2014, Lexicon entered into a License and Collaboration Agreement, which was subsequently amended in March 2015 (collectively, the “Ipsen Agreement”), with Ipsen for the development and commercialization of XERMELO outside of the United States and Japan (the “Licensed Territory”). The Ipsen Agreement was assigned to TerSera in September 2020 in connection with the XERMELO sale.

Prior to the XERMELO sale, Lexicon had earned certain milestone payments and royalties from Ipsen. Revenue, including royalty revenue, recognized under the Ipsen Agreement was $0.1 million for the three months ended March 31, 2020.

Sanofi. In November 2015, Lexicon entered into a Collaboration and License Agreement, which was subsequently amended in July 2017 (collectively, the “Sanofi Agreement”), with Sanofi for the worldwide development of Lexicon’s diabetes drug candidate sotagliflozin. In December 2016, Sanofi terminated its rights under the Sanofi Agreement with respect to Japan.

Effective as of September 9, 2019 (the “Settlement Date”), Lexicon entered into the Termination Agreement with Sanofi, pursuant to which the Sanofi Agreement was terminated and certain associated disputes between Lexicon and Sanofi were settled.

Under the terms of the Termination Agreement, Lexicon regained all rights to sotagliflozin and assumed full responsibility for the worldwide development and commercialization of sotagliflozin in all indications. Sanofi paid Lexicon $208 million in September 2019 and $26 million in each of March and September 2020 (less amounts withheld by Sanofi offsetting certain third party costs and internal costs incurred by Sanofi and asserted by Sanofi to be payable by Lexicon under the terms of the Termination Agreement), and neither party will owe any additional payments pursuant to the Sanofi Agreement. The parties have cooperated in the transition of responsibility for ongoing clinical studies and other activities, and each party is responsible for its own expenses associated with such transition, subject to certain exceptions. See Note 6, Commitments and Contingencies, for additional information. Beginning in March 2020, Lexicon closed out early the clinical studies related to the Phase 3 development program for sotagliflozin in type 2 diabetes, heart failure and chronic kidney disease. Subsequent to the Termination Agreement, Lexicon has no remaining performance obligations to Sanofi.