Choroideremia is a rare X-linked recessive retinal disease which eventually leads to blindness. A series B funding round has landed the NightstaRx (‘Nightstar’) biotech in Oxford an additional $35M for their vision-improving gene therapy.
Since the mutation causing Choroideremia is sex-linked, sufferers are almost always males, with the onset of symptoms in childhood often starting with night-blindness. The CHM gene is responsible for encoding the Rab-escort protein 1 in retinal cells, a mutant version of which is responsible for vision deterioration. You can read more about this rare disease through the Choroideremia Research Foundation.
Developed at Oxford’s Nuffield Lab of Ophthalmology in the UK by Robert MacLaren, Nightstar has a gene therapy which uses an adeno-associated retroviral vector (AAV). This vector delivers a wild-type of the defective gene (CHM) into the retinal cells of the patient, to produce functional REP proteins and partially restore vision.