On the Prostate Problems Mailing List there has been some recent discussion and a large amount of confusion expressed about the need for and importance of surrogate end points for drug and treatment approval. I attempted to make a very simple clarification and recommendation about surrogates. Here it is, but slightly modified …….
Maybe I can clarify for those who are still confused why surrogates are important. Currently, the FDA requires statistical proof of the effectiveness of a drug or treatment prior to its approval. The “gold standard” is survival.
We now need to wait for our clinical trials to have certain numbers of people die to be able to perform a valid statistical analysis. Waiting for these deaths can add years to the length of the trial which translates into more deaths of patients and more expense for the drug company.
Developing acceptable surrogate endpoints for survival (or measures that we could say would accurately predict survival time) would allow us to draw conclusions about drug efficacy in a shorter period of time. The problem is that PSA is not an accurate measure of survival. Surprisingly, neither is disease progression.
A good prostate cancer example demonstrating the need for surrogates is the current status of Provenge. The FDA sent Provenge back for additional study to determine if it was effective, or if it extended survival. Without an approved surrogate, we need to continue the clinical trial and wait for more deaths in the sample population. (This also means that we will allow more deaths in men not receiving treatment while we wait for the results of the trial.)
If we had an alternative measure of life ex