Beacon Therapeutics Reports Encouraging Interim Results from Phase 2 Clinical Trial for XLRP Gene Therapy
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The company plans to begin a Phase 2/3 clinical trial for the treatment during the first half of 2024.
Beacon Therapeutics has reported vision improvements for five of eight patients receiving the high dose of its X-linked retinitis pigmentosa (XLRP) gene therapy in the Phase 2 SKYLINE clinical trial. Known as AGTC-501, the emerging gene therapy is for patients with mutations in RPGR, the gene most frequently associated with XLRP. Interim, 12-month results for SKYLINE were reported on February 7, 2024, by Mark Pennesi, MD, PhD, director, Ophthalmic Genetics at the Retina Foundation of the Southwest, at the 47th Macula Society Meeting.
Vision improvements were measured using microperimetry, a test that measures light sensitivity at several loci (points) in the central retina. The test also captures retinal images. The five of eight patients responding to the high dose of AGTC-501 had improvements in retinal sensitivity of at least 7 decibels in 5 or more loci. Responses of the six patients receiving the low dose of the therapy were similar to untreated eyes in the high dose group.
AGTC-501 was well-tolerated and no clinically significant safety events were associated with treatment.
The XLRP gene therapy was delivered by a one-time subretinal injection. AGTC-501 uses a human-engineered adeno-associated virus (AAV), which works like a vast container system, to deliver healthy copies of the RPGR gene to cells in the retina.
Beacon plans to launch its Phase 2/3 VISTA clinical trial for AGTC-501 during the first half of 2024.
The Foundation Fighting Blindness funded successful canine studies of XLRP gene therapy at the University of Pennsylvania School of Veterinary Medicine that helped make the XLRP gene therapy clinical trial possible.
XLRP affects approximately 20,000 people in the US and EU. As an X-linked condition, XLRP usually affects males. Though females are usually unaffected carriers of XLRP, they sometimes have vision loss, as well. The condition causes constriction of vision, reduced vision in dark settings, and central vision loss, especially in later stages. Most males with XLRP are legally blind by the age of 45.