In some cancer conditions people are living for many years with cancer before they eventually succumb. Biochemically recurrent prostate cancer can be like that. There’s evidence the cancer has spread but it’s not obvious where. Another case is in CLL where people with less aggressive subtypes may have had treatment but then be in remission for several years. So here’s the regulatory problem: if people are going to live several or many years with a cancer, how can you early on a measure the effectiveness of a proposed new drug that might help them live longer? In prostate cancer and CLL, to name two examples, that’s the dilemma. There may be a “survival advantage,” for example for one of these promising new “small molecule” pills now in trials, or even a new drug that’s been approved, as in prostate cancer. But you need a test the FDA and other regulatory bodies will accept as a “surrogate” for how long someone lives.
In an interview with Dr. Celestia Higano, a prostate cancer expert, she tells me about just that. And in another interview, with Dr. Peter Hillmen, a CLL expert, he said he is going before the FDA to ask that sensitive tests for MRD (minimal residual disease) be acceptable measures. The idea is new tests, or ones that should be developed, can be an acceptable measure of whether a potential new drug will extend life.
My view is the FDA, and other agencies around the world, should work collaboratively with industry and scientists to expeditiously assess if a potential new drug is worth approval. If new tests can speed things up then let’s agree on them and use them.
As some cancers are now becoming more like chronic conditions where you live with them rather than dying fairly quickly from them, we need a new system to measure how lasting “chronic” is.