Retinitis pigmentosa (RP) is a class of diseases involving...

Retinitis pigmentosa (RP) is a class of diseases involving progressive degeneration of the retina. There are multiple types of RP (see table below) and over 40 different genes associated with the disease.



PYC’s lead candidate drug, VP-001, is specifically targeting one of the autosomal dominant types of Retinitis Pigmentosa – RP11, in which a mutation occurs in the gene, PRPF31. According to PYC, RP11 accounts for just 1.5 -3% of all cases of Retinitis Pigmentosa. Hence its rare disease status.

While there are no other known drug development programs targeting RP11, there are multiple other drug development programs targeting other types of RP or attempting to broadly address RP.

The failed Phase 2/3 Biogen gene therapy trial was in a different type of RP – X-linked RP caused by a mutation to the RPGR gene. The trial failed to meet a primary endpoint which measured improvement in retinal function.

The drug being tested by Biogen was one of two clinical-stage gene therapies acquired in 2019 from Nightstar Therapeutics in a US$800m buyout.

PYC has demonstrated in pre-clinical, patient-derived models that VP-001 can rescue RPE function, a goal that has eluded AAV-based gene therapies to date.