The FDA has handed a boost to Astellas Pharma’s stuttering push into gene therapy by lifting the clinical hold on a phase 1/2 study in late-onset Pompe disease (LOPD). Astellas was forced to pump the brakes on the AT845 program last year after a participant developed peripheral sensory neuropathy.
AT845 is one of the assets that originated at Audentes Therapeutics, the gene therapy developer Astellas bought in an ill-fated $3 billion takeover three years ago. Astellas’ woes initially centered on AT132, an investigational treatment for another neuromuscular disease that was linked to deaths, but the trouble spread to the adeno-associated virus gene replacement therapy AT845 last summer.
Now, seven months after imposing a clinical hold on the FORTIS study of AT845, the FDA has removed the restriction on Astellas’ activities. The Japanese drugmaker needs to complete “clinical and regulatory activities” before it can resume dosing in the study.
Astellas is yet to share a timeline for the resumption of dosing or a new schedule for the rest of the trial. ClinicalTrials.gov lists the estimated primary completion target as December 2022, but that forecast dates back to when the study got underway in 2020 and therefore predates the clinical hold. In October, the company told (PDF) investors “an updated timeline for proof-of-concept judgment is under discussion.”
Ha Tran, executive medical director for Astellas, gave no indication that the serious adverse event and subsequent clinical hold have dented confidence in AT845, calling the prospect an “important potential new treatment for adults living with LOPD” in a statement to disclose the FDA’s action.
AT845 is designed to deliver a functional copy of the acid alpha-glucosidase gene to the muscles and thereby enable patients to express the enzyme that is at the root of Pompe disease. Patients with the disease currently undergo enzyme replacement therapy. Sanofi has built a blockbuster franchise in Pompe, across both LOPD and infantile-onset disease, with Myozyme, Lumizyme and Nexviazyme.