Why do drug trials boom and bust?

CARNEGIE MELLON (US)/MCGILL (CAN) — The up and down success of drug trials may be due to a kind of myopia in which overly optimistic predictions result from narrowly focusing on a new drug’s performance in pre-clinical studies.

“We do a fairly good job of predicting the success of interventions that make it to later stages of clinical research, says Alex John London, associate professor of philosophy at Carnegie Mellon University.

“But when it comes to the leap from animal studies to the first trials in humans, there are serious problems.

“Clearly we need to look at the pre-clinical evidence about a new intervention when estimating its likely benefits and burdens in people.

“But we also need to look at how similar interventions have fared in the past. If drugs that work on the same principle have failed development, there may be good grounds for tempering our expectations.”

Details of the research are published in the journal PLoS Medicine.

London and Jonathan Kimmelman, associate professor of biomedical ethics at McGill University, also question whether enough is being done to minimize any factors that interfere with measuring a drug’s true effects, suggesting that some of the techniques, such as randomization and blind testing that are common in clinical tests involving human subjects, should also be used at the pre-clinical stage.

“Medical researchers do a lot to control bias in drug trials with humans. If these measures were taken up by researchers who test drugs in animals, we would have a better basis for designing human trials,” Kimmelman says.

Improving the ways that outcomes from pre-clinical trials are predicted will help participants, drug developers, and funding agencies make informed decisions about clinical drug testing.

“Pre-clinical studies provide a useful starting place for determining whether a new drug is clinically promising,” Kimmelman says.

“We think we can—and should—be doing more to ensure predictions about clinical activity rest on a more complete and sound evidence base.”

The study was funded by the Canadian Institutes of Health Research.

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