Because of how difficult it is to find participants for rare neurodegenerative disease trials, the FDA says in a recent draft guidance that phase 1 trials of gene therapies (GT) for such diseases may be sufficient to produce evidence for regulatory submissions.

The agency said eligibility for first-in-human GT trials should, in general, consider disease severity or stage as part of the benefit-risk profile and, where feasible, should be initiated in adult patients who understand the risks and are able to provide informed consent.

The guidance also encourages the use of innovative clinical trial designs, such as adaptive trials, and recommends that trials with a placebo arm should consider giving an already-proven treatment to all participants before randomizing them. Crossover trial designs, in which two randomized arms alternate treatments to give all participants a chance to receive the investigational product, also could be used.

Read the FDA’s draft guidance here: https://bit.ly/3mzyc5x.