Biogen has announced it will acquire Nightstar Therapeutics for around $800m, providing the pharma giant with a pipeline of gene therapy candidates for ophthalmology. The deal is set to be complete by the middle of 2019.

The acquisition of Nightstar gives Biogen the small company’s lead asset, NSR-REP1, a treatment for treatment of rare and degenerative, X-linked inherited retinal disorder choroideremia (CHM). Currently there are no treatments for CHM. NSR-REP1 is comprised of an AAV vector administered by subretinal injection, and provides a functioning CHM gene and expression of the REP-1 protein to restore membrane trafficking.

Nightstar additionally has in its pipeline an AAV-based treatment for X-linked retinitis pigmentosa (XLRP), another rare inherited retinal disease which affects males and currently has no approved treatments.