Applied Genetic Technologies Corporation (Nasdaq: AGTC), a biotechnology company conducting human clinical trials of adeno-associated virus (AAV)-based gene therapies for the treatment of rare diseases, has announced next steps in the clinical development of the Company’s potential treatment of X-linked retinitis pigmentosa (XLRP) caused by mutations in the RPGR gene following receipt of written feedback from the FDA. The revised development plan, which includes immediate expansion of the current trial in parallel with the planned Phase 2/3 trial, will be designed to evaluate sustained efficacy across multiple measures of potential benefit in patients with XLRP.
In lieu of an in-person meeting likely due to limitations imposed by COVID-19, the FDA provided comprehensive written feedback regarding the design and execution of a registration trial and future regulatory submissions. The Company continues to move forward as planned with manufacturing, clinical site preparation and other activities to enable initiation of the studies as quickly as possible.
“We are pleased with the productive feedback from the FDA and are modifying our development program based on their recommendations to advance our XLRP gene therapy candidate,” said Sue Washer, President and CEO of AGTC. “Based on data available to date, we believe we have the potential for a best-in-class product when important factors such as visual sensitivity improvements, BCVA and safety are considered, which could provide meaningful benefit to patients with XLRP who today have no treatment options.”
AGTC is expanding its ongoing Phase 1/2 trial immediately and plans to dose approximately 20 patients in two masked dosing arms to collect additional functional data, including a mobility test added as a supplemental endpoint. The Company expects to begin dosing in Q4 2020.
For late stage studies, the FDA has indicated in its written feedback, which is consistent with how others in the XLRP gene therapy space are analyzing data, that a change in visual sensitivity of 7 decibels or greater in at least 5 loci would be clinically meaningful. AGTC has previously reported visual sensitivity as a mean over an entire treated area, but believes multiple patients already evaluated in the ongoing Phase 1/2 trial would meet the FDA’s definition. The Company’s revised Phase 2/3 trial design is also expected to include two masked active arms in addition to a control group, with visual sensitivity as the primary endpoint and several supplemental endpoints such as the mobility test. AGTC expects to begin this trial in Q1 2021.
Further information on the protocols for these trials including patient numbers, timelines and corporate cash guidance will be provided in the Company’s 10K filing for the fiscal year ending June 30, 2020. In addition, AGTC remains on track to provide multiple data readouts for both its XLRP and ACHM clinical programs in the second half of 2020. These readouts will include data from the two higher dose groups in the XLRP Phase 1/2 trial.