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 extension (surrogate) we could end the trial earlier. Then quicker we know if the drug/treatment worked by extending life over the current standard of care the quicker we could begin to use it.
The problem is that currently a drug company has no incentive to develop surrogates as they could not get a return on their investment. It seems to me that the NCI, the DOD or some similar type of governmental body should be encouraging the development of surrogates. This would be an excellent investment of my tax dollars.
Joel T Nowak MA, MSW