Newswise — As the growing wave of excitement over immunotherapies has swept through the cancer field, a concern has followed in its wake: Are there now too many clinical trials for these novel treatments, which enlist the immune system to battle tumors? One recent tally found more than 1100 studies combining a popular new class called checkpoint inhibitor drugs, which unleash suppressed immune cells, with other treatments. That's up from about 100 trials testing these combos through 2014.

Some academic researchers, pharma executives, and other cancer experts have decried this explosion of trials as a counter-productive glut motivated more by the race for money than by good science. They worry that many of these efforts may not finish because of a lack of participants. Even if these trials do meet enrollment targets, many duplicate other trials and are diverting resources that could go to novel drugs, Richard Pazdur, director of the U.S. Food and Drug Administration's (FDA's) Oncology Center of Excellence in Silver Spring, Maryland, has warned.

“The trials have to be smarter,” says Yale University lung cancer researcher Roy Herbst.

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