With the arrival of two revolutionary treatment strategies, immunotherapy and personalized medicine, cancer researchers have found new hope — and a problem that is perhaps unprecedented in medical research.
There are too many experimental cancer drugs in too many clinical trials, and not enough patients to test them on.
The logjam is caused partly by companies hoping to rush profitable new cancer drugs to market, and partly by the nature of these therapies, which can be spectacularly effective but only in select patients.
In July, an expert panel of the Food and Drug Administration approved a groundbreaking new leukemia treatment, a type of immunotherapy. Companies are scrambling to develop other drugs based on using the immune system itself to attack cancers.
Many of these experimental candidates in trials are quite similar. Yet each drug company wants to have its own proprietary version, seeing a potential windfall if it receives F.D.A. approval.
As a result, there are more than 1,000 immunotherapy trials underway, and the number keeps growing. “It’s hard to imagine we can support more than 1,000 studies,” said Dr. Daniel Chen, a vice president at Genentech, a biotechnology company.
In a commentary in the journal Nature, he and Ira Mellman, also a vice president at the company, wrote that the proliferating trials “have outstripped our progress in understanding the basic underlying science.”
“I think there is a lot of exuberant rush to market,” said Dr. Peter Bach, director of the Center for Health Policy and Outcomes at Memorial Sloan Kettering Cancer Center. “And we are squandering our most precious resource — patients.”
Take melanoma: There are more than 85,000 cases a year in the United States, according to Dr. Norman Sharpless, director of the Lineberger Comprehensive Cancer Center at the University of North Carolina, who was recently named director of the National Cancer Institute.
Most melanomas are cured by surgery, leaving about 10,000 patients who have had relapses and could be candidates for an experimental treatment. But nearly all will be treated by doctors outside of academic medical centers, who are not part of the clinical trials network and so do not offer patients experimental treatments.
Companies therefore must compete for the few patients with relapsed melanoma who are at centers offering clinical trials. Many end up struggling to find enough subjects to determine whether a treatment actually works — and if so, for whom.
And these drugs often are not so different from one another.
Immunotherapy drugs that attack a protein known as PD-1 are approved for treatment of lung cancer, renal cell cancer, bladder cancer and Hodgkin’s disease, noted Dr. Richard Pazdur, director of the F.D.A.’s Oncology Center of Excellence.
Yet many pharmaceutical companies want their own anti-PD-1. Companies are hoping to combine immunotherapy drugs with other cancer drugs for added effect, and many do not want to have to rely on a competitor’s anti-PD-1 drug along with their own secondary drugs.
So in new trials, additional anti-PD-1 drugs are being tested…