Beacon Therapeutics initiated the final leg of the race for its lead asset, AGTC-501 (laruparetigene zovaparvovec), announcing recently that the company has treated its first patient in the pivotal trial, VISTA. Currently, the only retinitis pigmentosa therapy on the market is Spark Therapeutics’ Luxturna (voretigene neparvovec), a retinoid isomerohydrolase activator, indicated for patients with confirmed biallelic RPE65 mutation-associated retinal dystrophy. AGTC-501 is highly anticipated as having the potential to become the first gene therapy specifically indicated for X-linked retinitis pigmentosa (XLRP), says GlobalData.
AGTC-501 is an XLRP GTPase regulator (retinitis pigmentosa 15 or retinitis pigmentosa 3 GTPase regulator [RPGR]) activator that expresses the full length RGPR protein. It thereby targets the full complement of photoreceptor damage that XLRP causes and is consequently anticipated to restore the function of rod and cone receptors.
Sara Reci, MSc, Managing Pharma Analyst at GlobalData, states, “Should AGTC-501 affirm its potential in restoring rod and cone receptor function, AGTC-501 will establish itself as the first promising and life-changing treatment option for long-waiting XLRP patients.”
AGTC-501 is currently in Phase II/III of development for retinitis in the VISTA trial, a randomised, masked, controlled, multi-center pivotal trial that is set to investigate the impact that AGTC-501 has on vision and other symptoms in additional patients with XLRP, particularly studying its efficacy, safety, and tolerability at two dose levels. The trial will enrol patients in the U.S. and is then set to expand globally.
Results from AGTC-501’s Phase II SKYLINE trial (NCT03316560) revealed that at 12 months, 63 per cent of eyes treated with high-dose AGTC-501 (6.8E + 11 vg/eye) experienced retinal sensitivity improvement of at least seven decibels (dB) in at least five loci.
Furthermore, patients in this study arm also demonstrated a strong improvement in visual function and in mean retinal sensitivity. Beacon Therapeutics reported that AGTC-501 was well-tolerated; there were no clinically significant safety events related to treatment.
Beacon Therapeutics announced that data from VISTA, SKYLINE, and HORIZON, as well as long-term data, will collectively support the Biologics License Application (BLA) filing in the US, and the Marketing Authorisation Application (MAA) in Europe.
Key opinion leaders (KOLs) interviewed by GlobalData noted that AGTC-501 has some very good initial data, with Phase I–II trials showing that an improvement in microperimetry was observed in patients, and furthermore, optical coherence tomography (OCT) unveiled structural changes. KOLs added that in the subsequent Phase II trial for AGTC-501, patients randomised to the higher dose had a pretty good improvement in microperimetry, and consequently, pivotal trial results are highly anticipated.
“It is evident that AGTC-501 has tremendous potential to be popular among XLRP patients and clinicians alike, given the promising results from its SKYLINE trial. Should VISTA further promote the efficacy and safety of this drug, AGTC-501 may be set on a trajectory,” Reci concludes.