Beacon Therapeutics announces treatment of first patient in VISTA registrational trial for AGTC-501

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Beacon Therapeutics Holdings Limited announced the treatment of the first patient in its registrational VISTA clinical trial (NCT04850118) with its lead asset, AGTC-501 (laruparetigene zovaparvovec).

According to a news release, VISTA is a global randomly assigned, controlled, masked, multi-center pivotal study evaluating the efficacy, safety, and tolerability of 2 dose levels of AGTC-501 for the treatment of X-linked retinitis pigmentosa (XLRP) compared to an untreated control group.¹

According to the news release, the company will use the data generated from the VISTA trial, in combination with data from the Phase 1/2 HORIZON and Phase 2 SKYLINE studies, including all available long-term data, to support a BLA in the US and a MAA in Europe for the treatment of patients with XLRP.

AGTC-501 has received Fast Track in the United States, an Innovative Medicine Designation (ILAP) in the UK, Priority Medicine (PRIME) in the EU for the treatment of XLRP caused by mutations in the RPGR gene.

Darin Curtiss, PharmD, global vice president of Clinical Development at Beacon Therapeutics, noted that the company looks forward to progressing AGTC-501.

“This is an important milestone for the continued clinical development of AGTC-501, which offers the potential to transform the prognosis of patients with XLRP by enabling them to see better or maintain their current vision,” he said in the news release.

David Birch, PhD, scientific director at Retina Foundation of the Southwest, pointed out this step is key in the progress of the development of AGTC-501.

“We are delighted to start the final phase of this important trial of gene therapy for X-linked retinitis pigmentosa,” he said in the news release. “It will bring hope to thousands of young men affected by this disease. The results so far have been very encouraging.”

XLRP, an orphan disease affecting approximately 17,000 patients in the US and EU5, is a severe, aggressive, inherited retinal disease that often leads to blindness by middle age with no treatment options available. The disease is primarily caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene.¹

According to the news release, AGTC-501 expresses the full length RPGR protein and researchers believe it is likely to rescue function of both rod and cone photoreceptors, making it uniquely well-suited as a potential treatment to improve the lives of patients with XLRP.

Earlier this year, 12-month interim safety and efficacy results for the Phase 2 SKYLINE trial in patients with X-linked retinitis pigmentosa (XLRP) at the 47th Annual Macula Society Meeting in Palm Springs, California.

According to the company’s news release,² 12-month data from males with XLRP demonstrated a response rate (defined as an improvement in retinal sensitivity, as assessed by microperimetry, of at least 7 decibels (dB) in at least 5 loci) of 63% in study eyes treated with a high dose (6.8 E+11 vg/eye) of AGTC-501.

Moreover, Mark Pennesi, MD, PhD, FARVO, director of Ophthalmic Genetics at the Retina Foundation in Dallas, Texas; and professor of Ophthalmology and Professor of Molecular and Medical Genetics, Paul H. Casey Ophthalmic Genetics Division at the Casey Eye Institute, Oregon Health and Science University, noted in the presentation that response rates in study eyes treated with a low dose (7.5 E+10 vg/eye) of AGTC-501 were similar to the untreated fellow eyes in the high dose cohort (0% for both). In addition, patients in the high-dose cohort also demonstrated a robust improvement in visual function, including mean retinal sensitivity. AGTC-501 was well-tolerated and there were no clinically significant safety events associated with treatment, and any treatment-related adverse events were mostly nonserious and mild to moderate in severity.²

References

1. philip.withers. Beacon Therapeutics Treats First Patient in VISTA Registrational Trial for AGTC-501. Beacon Therapeutics. Published June 11, 2024. Accessed June 12, 2024. https://www.beacontx.com/news-and-events/beacon-therapeutics-treats-first-patient-in-vista-registrational-trial-for-agtc-501/

2. Beacon Therapeutics Announces Positive 12-Month Data from Phase 2 SKYLINE Trial of AGTC-501 in Patients with X-Linked Retinitis Pigmentosa. BioSpace. Accessed February 8, 2024. https://www.biospace.com/article/releases/beacon-therapeutics-announces-positive-12-month-data-from-phase-2-skyline-trial-of-agtc-501-in-patients-with-x-linked-retinitis-pigmentosa/