Skyline Therapeutics recently announced the FDA granted orphan drug designation for its novel gene therapy, SKG1108, aimed at treating retinitis pigmentosa.

The orphan drug designation (ODD) indicates recognition from the FDA of SKG1108’s potential as a treatment option for retinitis pigmentosa (RP), a genetic condition that leads to progressive vision loss. According to a press release from Skyline Therapeutics, “SKG1108 is a recombinant adeno-associated virus (rAAV) vector with innovative design, utilizing the novel intravitreal capsid AAV.0106 to deliver single-stranded DNA encoding light-activatable proteins directly to the retina. The protein, regulated by specific genetic elements, aims to improve or restore visual function by generating new photo-sensing cells, thereby compensating for the loss of rod and cone photoreceptors in patients with late-stage RP.”

Often resulting in blindness by the age of 40, RP is linked to more than 100 genes. RP progresses with degeneration of photoreceptors, and there are currently no effective treatments that can stop or reverse this process. While some existing therapies target specific mutant genes, these approaches are suited to only a limited number of RP patients. As a gene-agnostic therapy, SKG1108 does not need to target the specific gene or genetic mutation responsible for a patient's RP.

The ODD provides incentives—including tax credits, exemption from prescription drug user fees, and potentially seven years of market exclusivity following FDA approval—for SKG1108’s development.