Ben Samelson-Jones, MD, PhD: Validating Long-Term Safety of Hemophilia AAV Gene Therapy

In new data from the largest dataset with the longest follow-up for a hemophilia B gene therapy, fidanacogene elaparvovec (Beqvez; Pfizer) has demonstrated favorable safety.

These findings, from a phase 1/2 trial, a long-term follow-up, and the pivotal BENEGENE-2 trial (NCT03861273), were presented at the 66th American Society of Hematology (ASH) Annual Meeting and Exposition, held December 7-10, 2024, in San Diego, California, by Ben Samelson-Jones, MD, PhD, assistant professor pediatric hematology, Perelman School of Medicine, University of Pennsylvania and Associate Director, Clinical In Vivo Gene Therapy, Children’s Hospital of Philadelphia.

“It should be very reassuring that there's nothing unexpected. I think the story of AAV-based gene therapy for hemophilia over the last three decades has been surprises. And I think what this is should be reassuring, that there's nothing has popped up that it that is of concern,” Samelson-Jones told HCPLive® during the meeting.

Samelson-Jones gave an overview of the safety findings, noting 5 serious adverse events (SAEs) that occurred in 2 participants of gastrointestinal (GI) ulcers and associated bleeding and anemia. He noted that these SAEs were probably secondary to steroids that were prescribed without gastric protection and emphasized the importance of GI protection during steroid use after gene therapy.

“I think there's been a potential misconception that, using a metric of other new drugs, how rapidly the uptake is, and I don't think it's a good comparison, just because of the logistics of getting everything in place to do this totally new type of medication,” Samelson-Jones said, commenting on the relatively slow uptake of gene therapy fpr hemophilia in general.

REFERENCE

Samelson-Jones B, Frenzel L, Kavakli K, et al. Use of Fidanacogene Elaparvovec, a Gene Therapy Vector, to Deliver a Stable, Fully Functional Human Factor IX Transgene for the Treatment of Hemophilia B: A Combined Analysis of Safety. Presented at: ASH Annual meeting; December 7-10; San Diego, California. Abstract 3577