In today's Wall Street Journal, Mark Thornton, M.D., Ph.D. deplores the FDA's decision on Dendreon's sipuleucal-T immunotherapy (Provenge vaccine). Dr. Thornton says "May 9, 2007, should be cited in the annals of cancer immunotherapy as Black Wednesday. Within an eight-hour period that day, the FDA succeeded in killing not one but two safe, promising therapies designed and developed to act by stimulating a patient's immune system against cancer. The FDA's hubris will affect the lives and possibly the life spans of cancer patients from nearly every demographic, from elderly men with prostate cancer to young children with the rarest of bone cancers."
Thornton is referring to Dendreon's Provenge and IDM's Junovan for children with osteosarcoma. He says: "In the span of eight hours, the dawn of a new era in cancer immunotherapy was driven back into the night. It will be years before we know the full impact of these decisions and how many cancer patients, young and old, have had their lives cut short as a result. For now, however, one thing is clear: While our lawmakers obsess over FDA "safety reforms," no one is holding this government agency accountable for its complicity in stalling therapies for life-threatening diseases."
In his WSJ piece Dr. Thornton writes:
Progress and investment, however, have been unsteady as tumor shrinkages following treatment never quite translated into "hard," clinically relevant outcomes such as prolongation of the survival of the patient. Still, this type of approach remains the Holy Grail of cancer treatment....
Thus it was remarkable that in the last several months two different biotech companies, with products utilizing two completely different cancer immune approaches, came before the FDA's Advisory Committee Meeting for judgment. The first product, Provenge, made by the Dendreon company, is a cellular therapy that tackles prostate cancer. The results of the Provenge clinical trial in men with prostate cancer who had failed all other therapies appeared before the committee that advises on cell-based cancer products for the FDA Center for Biologics. This committee was comprised of immunology and oncology experts. The second product, Junovan, made by the IDM company, was tested in children with osteosarcoma, a rare bone cancer that affects just 900 children per year. The results of the Junovan clinical trial appeared before a different committee -- one that judges protein cancer agents and was comprised solely of oncologists with no immunology experts.
Both the Provenge and Junovan clinical trials provided evidence that patients lived longer compared to control groups. But according to the FDA, these "survival advantages" that statisticians talk about had "issues." When the issues were discussed in the Provenge public meeting the majority of the committee (in a 13-4 vote) thought the issues, while relevant and important, were superseded by the solid immunology science behind the product.
However, those voting in the minority, very powerful members of the oncology community, launched an unprecedented PR campaign accusing those in the majority of incompetence and naivetÃƒÂ© in matters relating to cancer products. The arrogance of this campaign overlooked the notion that survival data from immune-based products may be qualitatively different from, and may need to be judged by different criteria than, survival data from chemotherapy drugs.
But such intriguing academic discussions never had a chance to take root. Instead -- just a few weeks after the favorable ruling on Provenge -- the Junovan product came before the FDA's Advisory Committee for approval. Incredibly, the improvement in the survival rate of children with bone cancer who received Junovan was summarily dismissed as irrelevant by the committee. Why? The statistical data showing the odds of efficacy were 94% surety instead of the usual goal of 95% surety. This 1% difference was all the committee needed to justify a 12-2 "No" vote.
The Junovan meeting was chaired by the very physician [Dr. Maha Hussain, M.D.] who launched the PR campaign against Provenge. Unlike the meeting on Provenge, however, all discussion time on Junovan was spent kneeling before the altar of statistics -- not a single comment was made about the immunology science supporting the efficacy of Junovan. Remarkably, as the Junovan vote was taking place, the FDA folded under the pressure and announced that it would not abide by the favorable vote on Provenge. Instead, the FDA called for more testing that -- if the product is not killed outright by its maker Dendreon -- will take at least three years to complete.
Mark Thornton, MD, PhD, a former medical officer in the FDA Office of Oncology Products, serves as Senior Vice President of Product Development for GENVEC. GENVEC is a biopharmaceutical company developing novel gene-based therapeutic drugs and vaccines.
Dr. Thornton volunteers as president of the Sarcoma Foundation of America. In a previous article in WSJ he spoke of his Ã¢â‚¬Å“eight-year experience as a cancer patient advocateÃ¢â‚¬Â on behalf of his son. Dr. Thornton is the Abigail Alliance Rare Cancers Advisor. Mark represented the Abigail Alliance at the ASCO (American Society of Clinical Oncologists) conference in Orlando, FL.
At the FDA Dr. Thornton served on the clinical review team for Erbitux®for its initial colon cancer indication, and Pegasys® for its Hepatitis C indication. At the FDA he also led the initial efforts to establish the FDA Gene Therapy Patient Tracking System and published on the topic of optimizing regulatory pathways for cancer vaccines. In industry, Dr. Thornton has performed Phase I-III clinical trials in both oncology and infectious disease settings, and successfully submitted PLAs for Certiva™ while at North American Vaccine and WinRho® while at Univax Biologics.