Nightstar Therapeutics plc, a clinical-stage gene therapy company, focuses on developing and commercializing novel one-time treatments for patients suffering from rare inherited retinal diseases in the United Kingdom. The company's lead product candidate is NSR-REP1, a candidate that is in phase 3 clinical development for the treatment of patients with choroideremia. It is also developing NSR-RPGR, a candidate that is in Phase 2/3 clinical trials for the treatment of patients with X-linked retinitis pigmentosa, an inherited X-linked recessive retinal disease; and NSR-BEST1. In addition, the company is developing NSR-ABCA4, a candidate that is in preclinical development stage for the treatment of Stargardt disease. The company was incorporated in 2017 and is headquartered in London, the United Kingdom.