Beacon Therapeutics has reported positive Phase II/III results for its adeno-associated virus (AAV) gene therapy laru-zova in patients with the rare eye disease X-linked retinitis pigmentosa caused by RPGR gene mutations.
The VISTA study met it’s primary endpoint a greater than or equal to 15-letter improvement in low-luminance visual acuity, essentially, better reading vision in dim light, with 31% of high dose, and 24% of low dose patients achieving this goal, as opposed to none in the control group.
X-linked retinitis pigmentosa is a severe inherited retinal degeneration, usually affecting boys and young men due to being largely recessive and carried on the X chromosome. It is estimated to affect around 6800 men and boys in the U.S. and usually begins with night blindness, progressing to peripheral-field loss and eventually blindness.
While therapies for other forms of retinitis pigmentosa have been approved, such as Luxturna for treatment for the rare subgroup with biallelic RPE65-mediated inherited retinal dystrophy, there is currently no approved disease-modifying treatment for RPGR-associated X-linked retinitis pigmentosa.
The VISTA study tested a one-time subretinal gene therapy, laruparetigene zovaparvovec (laru-zova), in 85 males aged 12–48 years with X-linked retinitis pigmentosa caused by RPGR mutations. Over 12 months, two dose groups were compared with an untreated control group.
In addition to meeting it’s primary endpoint, the secondary results from the study were also encouraging. For example, 48.3% of the high dose and 58.6% of the low dose group had an improvement of greater than or equal to 10-letter improvement in low-luminance visual acuity, versus 3.7% of controls.
The treatment also modestly improved the sensitivity of the central part of the retina, which is needed for detailed vision. Both doses performed better than no treatment, but only the improvement with the lower dose was statistically significant.
Beacon was launched in 2023 in the U.K. by life-science investor Syncona. Since then the company has expanded and now also has a base in Cambridge, Massachusetts. Syncona acquired struggling U.S. retinal-gene-therapy company Applied Genetic Technologies Corporation in November 2022. One of their assets, laru-zova, then called AGTC-501, became Beacon’s lead candidate.
Beacon is focused on eye diseases and also has two preclinical candidates in its pipeline that it’s developing for treatment of geographic atrophy secondary to dry age-related macular degeneration and cone rod dystrophy.
“These results represent a landmark moment for the hundreds of thousands of patients worldwide living with X-linked retinitis pigmentosa who currently have no treatment options and no way to slow the loss of their sight,” said Lance Baldo, MD, CEO of Beacon in a press statement. “We now look forward to working closely with regulatory authorities to bring laru-zova to patients as quickly as possible.”
