Amicus’ Gene Therapy for CLN6 Batten Given PRIME Status in Europe

The European Medicines Agency (EMA) has given priority medicines (PRIME) status to AT-GTX-501, Amicus Therapeutics‘ investigational gene therapy for CLN6 Batten disease, otherwise known as variant late infantile neuronal ceroid lipofuscinosis 6 (vLINCL6) disease.

PRIME designation helps speed the development and regulatory review of promising medicines that target unmet medical needs. The program’s goal is to help these medicines reach patients sooner.

“We are very pleased that the EMA has recognized the potential of our CLN6 gene therapy,” John F. Crowley, chairman and CEO of Amicus, said in a press release.

AT-GTX-501 uses an inactive adeno-associated virus as a vehicle to provide cells with a functional copy of the CLN6 gene. Fourteen different genes — CLN1 to CLN14 — can cause Batten disease, by enabling toxic deposits called lipofuscins to accumulate, especially within cells of the central nervous system.

“Based on our preliminary clinical data, we believe AT-GTX-501 could potentially be a transformative treatment option for children living with CLN6 Batten disease, an ultra-rare, debilitating condition that presents in early childhood and is often associated with childhood death,” Crowley added.

This early data comes from an ongoing Phase 1/2 clinical trial (NCT02725580) evaluating a single dose of the therapy in 13 CLN6 Batten patients, ages 1 year and older, who are ambulatory or able to walk with assistance.

Each received one dose of AT-GTX-501 into their spinal canal (an intrathecal injection) on day zero, then returned for follow-up visits on days seven, 14, 21, and 30. After this initial period, follow-ups occur every three months through month 24. Those who complete this study may participate in a long-term follow up study (NCT04273243) that opened in January runs until 2035.

Amicus intends to present additional trial data at the virtual Child Neurology Society Annual Meeting, set for Oct. 12–23, and then to provide an update on regulatory proceedings in early 2021.

Past interim results showed signs that AT-GTX-501 might halt disease progression, as tracked by changes in patients’ Hamburg Motor & Language Scale scores, which measure mobility and speech disability.

Results also demonstrated that patients tolerated the therapy well, with mild side effects thought to be unrelated to the treatment itself.

The PRIME designation in the EU complements the orphan drug designation and rare pediatric disease designation given AT-GTX-501 in the U.S. Similar to PRIME, these designations provide resources and incentives to accelerate the development of promising therapies that address conditions with few treatment options.