NightStar Therapeutics

The company's primary business was the clinical development of adeno-associated virus (AAV) based gene therapies delivered via subretinal injection. This approach aimed to provide a functional copy of a mutated gene to halt or slow disease progression. Its client base consisted of patients with rare, genetic ophthalmology disorders for which there were no approved treatments. Nightstar's pipeline included candidates for several conditions. Its lead asset, NSR-REP1 (timrepigene emparvovec), was in Phase 3 development for choroideremia (CHM), a rare X-linked disorder causing progressive blindness. The second clinical program, NSR-RPGR (cotoretigene toliparvovec), was in development for X-linked retinitis pigmentosa (XLRP). Its preclinical pipeline included NSR-ABCA4 for Stargardt disease and programs for other conditions like Best vitelliform macular dystrophy.

After its founding, Nightstar raised $99.9 million over three funding rounds and launched an initial public offering (IPO) on NASDAQ in September 2017, raising $75 million. In March 2019, Biogen announced an agreement to acquire Nightstar Therapeutics for approximately $800 million ($25.50 per share). The acquisition was completed in June 2019, and Nightstar's stock was delisted from NASDAQ. The deal was intended to accelerate Biogen's entry into the ophthalmology gene therapy space. However, by June 2021, both of the main acquired drug candidates from Nightstar, for choroideremia and XLRP, had failed in their late-stage clinical trials. Subsequently, in 2023, Biogen announced it was exiting research into eye diseases.