Gene Therapy: Bluebird’s Eli-Cel Efficacy Uncertain, Malignancy Risk Concerning, US FDA Says

 
• By Sue Sutter

Interpretation of efficacy from single-arm studies in patients with cerebral adrenoleukodsytrophy complicated by comparability with external controls and limited follow-up, FDA says in advisory committee briefing documents which also cite three cases of myelodysplastic syndrome and raise broader questions about lentiviral vector safety.

Apples and oranges
Differences in the characteristics of clinical trial subjects and external controls complicate interpretation of eli-cel's efficacy, the FDA said. • Source: Shutterstock

Differences between individuals in external control groups and patients who received bluebird bio’s elivaldogene autotemcel (eli-cel) in single-arm trials make it difficult to assess efficacy of the lentiviral vector gene therapy for pediatric patients with early cerebral adrenoleukodystrophy, the US Food and Drug Administration said.

In a briefing

In addition, although there appeared to be little difference between eli-cel and HSCT on a survival endpoint, there were few clinical events within the 24-month timeframe assessed, and longer-term observation is needed to better gauge

More from US FDA Performance Tracker

More from Regulatory Trackers