Published in Pipeline

Beacon Therapeutics releases positive 12-month data from phase 2 XLRP trial

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Beacon Therapeutics Holdings Limited presented 12-month interim safety and efficacy results from the phase 2 SKYLINE trial for X-linked retinitis pigmentosa (XLRP).

This is a new company, isn’t it?

Indeed it is. Founded in 2023, the ophthalmic gene therapy company was established by London-based Syncona Limited, a life sciences investment company, following its November 2022 acquisition of AGTC, a publicly-treated biotechnology company developing genetic therapies for rare inherited conditions.

Its purpose: restoring and improving vision in patients with prevalent and rare retinal diseases that lead to blindness through its XLRP candidate and two preclinical programs (dry age-related macular degeneration [AMD] and cone-rod dystrophy [CRD]).

Gotcha. Now talk about its XLRP candidate.

AGTC-501 is a late-stage and lead development candidate for XLRP, which is primarily a result of mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene.

Per Beacon, it works by expressing “the full length RPGR protein, thereby addressing the full complement of photoreceptor damage caused by XLRP, including both rod and cone loss.

Now this study.

Launched as an expansion (follow-up) of the company’s ongoing phase 1/2 HORIZON trial (n = 29; males), the SKYLINE phase 2 trial is a randomized, masked, multicenter study comparing two doses of AGTC-501:

  • High: 6.8 E+11 vg/eye
  • Low: 7.5 E+10 vg/eye

A total of 14 participants (aged 8-50; male) have been enrolled, with each being administered gene therapy (AGTC-501) in one eye to further assess its safety and potential efficacy.

And the data?

AGTC-501 demonstrated a 63% response rate in study eyes with a high dose of AGTC-501; that cohort also demonstrated “a robust improvement in visual function, including mean retinal sensitivity.”

For low dose-treated eyes, the response rate was similar to the untreated fellow eye in the high dose cohort (0% for both), according to Beacon.

How about overall?

The company reported that AGTC-501 was well tolerated with no clinically significant safety events associated with treatment.

As for treatment-related adverse events, most were nonserious and mild to moderate in severity.

The data, “demonstrate a favorable safety profile and notable improvement in visual function,” stated Nadia Waheed, MD, MPH, Beacon’s chief medical officer (CMO).

So … what’s next?

With promising data from the SKYLINE trial, Beacon expects to initiate its pivotal 2/3 VISTA trial for AGTC-501 in XLRP in H1 (first six months of) 2024.

VISTA is being conducted as a randomized, controlled, masked, multicenter pivotal study that will assess the safety, efficacy, and tolerability of two AGTC-501 in two doses (low/high) in male participants (aged 13-50) vs an untreated control group.

See all clinical trial info here.

And the goal?

The company intends to use data from the VISTA trial, HORIZON trial, and SKYLINE trial (complete with all available long-term results) to support an eventual Biologics License Application (BLA) submission in the U.S.