Satraplatin is an oral platinum drug that is believed to bind the DNA of the cancer cell, which then prevents the cancer from being able to reproduce. Satraplatin had been tested in a phase III trial in men with metastatic castrate-resistant prostate cancer (mCRPC) who have failed chemotherapy with docetaxel. It failed because it did not show a median survival benefit and was not approved by the FDA.
Despite the lack of a demonstrable survival advantage additional analysis of the data showed Satraplatin was a drug that did show objective evidence that it works and inhibits tumor growth, but did not work in enough men to change the statistical balance demonstrating a survival advantage. The question remains as to whether it’s possible to identify those men who will respond to satraplatin?
In a biomarker development trial being conducted by Mathew D. Galsky, MD, Associate Professor of Medicine, Hematology and Medical Oncology and Assistant Professor of Urology at The Mount Sinai Hospital, New York, about half of the subject men saw benefit with satraplatin, consistent with the original phase III results. Galsky is now looking at tumor samples (from biopsies) to see if tissue biomarkers can be identified to allow us to know which men would benefit from the drug.
This biomarker study is a great example of how we will be developing personalized medicine, even from data generated by what traditional science would call a failed clinical trial. In this particular study if we identify biomarkers we will then have to re-do the clinical phase 3 trial sorting out and including only those men having the biomarker. Good science and follow through actions we might be able to raise phoenixes from the ash.
This type of study would also greatly benefit all the drugs we currently use to treat prostate cancer, even those that have shown a statistical survival benefit and been FDA approved. None of our drugs work on every person; in reality many of them will not do anything to help as much as 40% of us. It would be great for us to be able to look at out own biomarkers and know if a treatment would benefit us without our having to spend the absorbent cost of a drug which will not work for us while also allowing our cancer to progress.
Joel T. Nowak, M.A., M.S.W.