The FDA approved ImClone’s Erbitux and Amgen’s Vectibix in 2004 and 2006 respectively for the treatment of colorectal cancer.
Then, research findings published last year revealed the 2 monoclonal antibodies only work in 60% of the population whose tumors do not have a mutation in the so-called K-RAS gene.
So in a meeting last month with the FDA’s Oncology Drugs Advisory Committee, the drug companies pressed the agency to alter their drugs’ labels so as to warn physicians not to treat patients with the mutant K-RAS gene.
The research prompting the request was a large, multinational trial presented at the American Society of Clinical Oncology meetings by Eric Van Cutsem of University Hosptial, Leuven, Belgium.
At the meeting, ImClone’s Sr. VP Hagop Youssoufian described the findings as “nothing less than transformational.”
In fact, the trial results compelled the European Medicines Agency to recommend that physicians establish patients’ K-RAS status before prescribing the drugs, and just yesterday the American Society of Clinical Oncologists made a similar recommendation.
Meanwhile, Amgen had cut a deal with UK-based DxS to provide its K-RAS mutation screening kit in conjunction with Vectibix in the US. The deal could translate to more revenue for Amgen if the FDA changes the drug label.
More than $600 million dollars per year in completely worthless treatments, if the above study is right, would be saved if the drugs were not given to patients having the mutation.
The Advisory Committee’s response was the scientific version of “whoa Nelly!”
It wants more data before it recommends companion diagnostics for targeted cancer drugs in general, and claims to have issues with retrospectively identified biomarkers.
Such studies can introduce bias, the Committee asserted.