Gene Therapy for Rare Blinding Disease Achieves First Late-Stage Trial Success; Regulatory Filing Planned This Year

A gene therapy for the rare blinding disease X-linked retinitis pigmentosa (XLRP) has achieved its goal in a late-stage clinical trial for the first time.

According to BiopharmaDive on the 21st (local time), Beacon Therapeutics said its gene therapy, laruparetigene zovaparvovec (laru-zova), met the primary endpoint in a late-stage trial involving patients with XLRP.

The company said the results represent the first case in which an XLRP therapy has achieved its goal in a pivotal clinical trial.

XLRP is a disease in which the light-sensing cells in the retina gradually degenerate, leading to vision loss. It primarily affects men and accounts for approximately 14% of all patients with retinitis pigmentosa.

Laru-zova delivers a normal copy of the RPGR gene, which is mutated in XLRP. The therapy was tested at two dose levels, low and high, in 85 male patients.

In the clinical trial, the proportions of patients who read at least 15 additional letters on a low-luminance visual acuity test were 24% in the low-dose group and 31% in the high-dose group. No patients in the control group met that criterion.

The company said it also observed positive trends on certain secondary endpoints, although some results were not statistically significant.

Most treatment-related adverse events were mild to moderate. The company determined that two serious adverse events resulted from the surgical procedure used to administer the therapy.

Robert Sisk, a professor of ophthalmology at the University of Cincinnati, said, "Beacon selected endpoints that best capture meaningful improvements for patients, particularly improvements in low-luminance vision."

Lance Baldo, Beacon's chief executive officer, said the results were "statistically significant and clinically meaningful" and "demonstrate the potential of a one-time treatment to alter the course of inherited retinal disease."

Beacon plans to present detailed data at a medical conference in October. The company plans to begin "sequential" regulatory filings, submitted in stages, by the end of the year.