BioMarin Delays Hemophilia A Therapy Valoctocogene Roxaparvovec Filing as FDA Calls for More Data
BioMarin HQ/courtesy of BioMarin
The U.S. Food and Drug Administration has requested additional data for BioMarin Pharmaceutical’s Biologics License Application (BLA) for its hemophilia A therapy, valoctocogene roxaparvovec.
In its announcement, BioMarin stated the FDA wants to see more data on the durability of the therapy's effect and its safety profile. These protocols are typical for new therapies, especially investigational new therapies like this one.
BioMarin plans to resubmit its application to the FDA by the end of September, instead of in June, as it had originally planned. In the meantime, the company is working on collecting additional data from ongoing trials.
Currently, the European Medicines Agency (EMA) is still assessing BioMarin's Marketing Authorization Application (MAA) for valoctocogene roxaparvovec, and the company believes a Committee for Medicinal Products for Human Use (CHMP) decision will be issued this year. Following the GENEr8-1 study, BioMarin submitted two-year follow-up safety and efficacy data to the EMA.
Scope of Valoctocogene Roxaparvovec
If approved, valoctocogene roxaparvovec has the potential to provide hemophilia A patients with sustained protection from bleeds. Currently, there is no cure for hemophilia A, and people with the condition often require frequent factor VIII infusions to prevent bleeds. These infusions can be costly and inconvenient, and are associated with serious complications.
In the past, efforts to develop gene therapies for hemophilia A have been hampered due to the fact that the factor VIII protein is too large to fit into existing viral vectors. However, valoctocogene roxaparvovec uses a new generation of adeno-associated virus (AAV) vector, which is able to deliver the factor VIII gene to cells in the liver.
Overall, the valoctocogene roxaparvovec safety profile in Phase I/II was comparable to that seen in previously reported data. No treatment-related adverse events have been reported thus far, and no participants withdrew from the study due to a factor VIII inhibitor. Although one patient did experience a serious adverse event of a parotid acinic cell carcinoma after being treated five years ago, it was determined to be unrelated to the treatment.
There have been no events where the formation of a blood clot blocked a blood vessel. The most frequent adverse effects linked to valoctocogene roxaparvovec occurred early after a single infusion and included brief-lived infusion-related reactions and fleeting, asymptomatic, and mild to moderate increases in liver function test markers, without any long-term consequences.