Researchers argue that the pattern among researchers to announce the discovery of a new drug that eradicates a disease in animals, only to see the same drug bomb in human trials, may be related to the way researchers predict outcomes of their work in early stages of drug development.
“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 and director of the Center for Ethnics and Policy at Carnegie Mellon University. “But when it comes to the leap from animal studies to the first trials in humans, there are serious problems.”
In the journal PLoS Medicine, ethics experts London and Jonathan Kimmelman, associate professor in the biomedical ethnics and social studies of medicine departments at McGill University, suggest that the interpretation of preclinical results may suffer from a kind of myopia, in which a narrow focus on the data about the performance of a new drug in preclinical studies produces overly optimistic predictions.
“Clearly we need to look at the pre-clinical evidence about a new intervention when estimating its likely benefits and burdens of people,” says London. “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.”
Kimmelman and London also question whether researchers are doing enough to minimize any factors that interfere with measuring a drug’s true effects. They suggest that some of the techniques such as randomization and blind testing that are common in clinical trials involving human subjects should also be used at the preclinical stage.
“Medical researchers do a lot to control bias in drug trials with humans. We think if these measures were taken up by researchers who test drugs in animals, we would have a better basis for designing human trials,” say Kimmelman.
Kimmelman adds, “Pre-clinical studies provide a useful starting place for determining whether a new drug is clinically promising. We think we can—and should—be doing more to ensure predictions about clinical activity rest on a more complete and sound evidence base.”
Source: McGill University