- At the end of April, FDA experts raised heavy questions about Amgen's talimogene laherparepvec (T-Vec), a virus therapy for metastatic melanoma, based on safety concerns and what they said were flaws in a phase III trial.
- However, a full-throated defense of the drug by the Amgen team led the panel to vote 22-1 that T-vec has a favorable risk/benefit profile, boding well for an eventual FDA approval.
- But it should be noted that many panel members felt that T-Vec should only be used in certain patient populations.
When T-Vec is injected directly into metastatic melanoma tumors, it is supposed to replicate and then rupture the tumor cells, which is then supposed to lead to the release of antigens that catalyze an immune response. Amgen's regulatory team had to make the case to the FDA that T-Vec has a systemic effects and that there was some consistency to response rates.
There were concerns that the response rates were widely varied, as well as concerns about viral shedding in which healthcare workers could be infected by the live herpes simplex virus used as a vector in T-Vec.
Despite these concerns, the regulatory team was able to use a huge volume of phase III data to make the case. There is also the added factor that there is still an unmet medical need around the treatment of metastatic melanoma, which kills 10,000 people per year in the U.S.