Take-home message: In a phase IIa study of patients with neovascular age-related macular degeneration, a single subretinal injection of rAAV.sFlt-1 gene therapy demonstrated acceptable safety, but not a complete or durable anti-VEGF response. Additional preclinical research is under way.
Reviewed by Jeffrey S. Heier, MD
Boston—In a phase IIa study, rAAV.sFlt-1 gene therapy (AVA-101, Avalanche Biotechnologies) for neovascular age-related macular degeneration (AMD) demonstrated acceptable safety.
However, the therapy failed to provide a complete or durable anti-vascular endothelial growth factor (VEGF) response.
The results are disappointing, but the outcomes of the trial do not necessarily spell the end of the investigational product’s development, according to Jeffrey S. Heier, MD.
“I still believe gene therapy is well-suited for the management of retinal disease—it has a proven track record in humans, and for a variety of reasons, the retina is ideally suited for developing gene-based therapies,” said Dr. Heier, director, vitreoretinal service, Ophthalmic Consultants of Boston. “Furthermore, there is a strong rationale for developing a sustained delivery product that could help with the ongoing treatment burden.
“Now, numerous factors are being studied in an effort to fully understand the responses observed in the phase IIa study of AVA-101, and more preclinical research is under way that will hopefully provide insight into variables that can improve outcomes,” he said.
AVA-101 uses an adeno-associated viral vector to deliver a gene that produces naturally occurring sFlt-1 (soluble VEGF receptor-1).