As rival Phase III gene therapy trials get underway, Sarepta’s product could have the edge in safety and efficacy over its rival from Pfizer, but the chance of failure remains high.

The day before an FDA advisory committee meeting about the safety of AAV vector-based gene therapies, Astellas reported liver damage in a patient in its trial of AT132.

Advisory committee will discuss five types of toxicity risks with adeno-associated virus vector-based gene therapy products at a two-day meeting in September, which follows some recent high-profile instances of adverse events that have delayed development programs.

Recent adverse events are ‘speed bumps’ that need to be worked around, biologics center head Peter Marks says; Morgan Stanley’s Peter Hwang asserts high-profile safety issues have added to unpredictability of gene therapy development, dampening investor enthusiasm for the field.