Yesterday Amgen (AMGN) announced that an FDA panel backed its vaccine T-VEC for use in patients with melanoma. There were a lot of FDA staff who were opposed to the vaccine prior to the panel meeting, but ultimately the panel voted 22 to 1 in favor of backing T-VEC for approval. This doesn't mean that the drug is already approved, as the final decision has to come from the FDA itself. The FDA doesn't have to always follow the panels' findings, but it seems that they probably will as the vote was almost unanimous. 

T-VEC is a cancer immunotherapy that attempts to utilize a patient's immune system to fight cancerous cells. T-VEC is a different version of the herpes simplex virus that is injected directly into the melanoma tumor. The T-VEC vaccine has been genetically modified to only replicate in cancerous cells, thus avoiding the ability to destroy healthy tissue cells. T-VEC also has another function, in which it uses a protein -- GM-CSF -- that calls for immune boosting cells to come to attack the tumor cells. 

In a phase 3 trial T-VEC met the primary endpoint of achieving a Median OS -- overall survival rate -- of 4.4 months in addition to a 16% durable response rate compared to a placebo compound. However, the company  fell short of the secondary endpoint of achieving statistical significance in Overall Survival. Despite this there was a subset of patients who responded well with a durable response.

FDA notes that came out this past Monday were skeptical about approving this drug, but it seems like the FDA panel thought the results were good enough to merit the panel's backing.In addition, many analysts interpreted the miss on the secondary endpoint of Overall Survival as being very close - i.e., that it barely missed the stat significance by a small margin. We think that the FDA should approve the drug because of the FDA panel vote outcome, but how well it does in the market against other competitors that treat melanoma with immunotherapy treatments, companies like Merck (MRK) and Bristol-Meyers Squibb (BMY), is still a question.