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Randomly allocating animals to treatment groups could help improve preclinical research. (Andre Penner/Associated Press)

Few new potential drugs tested in animals are ever successfully approved for use, perhaps because the early stage research is so flawed, say Canadian researchers who offer suggestions.

Recognizing that only 11 per cent of agents such as investigational drugs that start clinical tests ever become licensed, researchers reviewed studies for ways to better weed out unsuccessful options.

"This high rate of failure in drug development drives high pharmaceutical prices," said Prof. Jonathan Kimmelman of McGill University in Montreal, who led the study in Tuesday's issue of PLOS Medicine, published by the Public Library of Science.

"It also exposes many patients in trials to unsafe and/or useless drugs, and consumes scarce resources available for medical research. Our paper was motivated by a desire to find better, less burdensome ways of developing new drugs," he added in an email.

Kimmelman and his co-authors identified experimental practices that were commonly recommended in 26 guidelines on the topic, which they suggest should be properly implemented.

Experimental cancer drug failures

"Poor study design and execution is a waste of the talent and resources we have available for medical research," he said.

The authors said that some fields such as neurological drug development already address preclinical bias. But other fields such as cancer — which has the highest rate of drug development attrition — do not.

Some of the most common recommendations the team identified were:

  • Use power calculations to ensure sample sizes are large enough to provide statistically meaningful results.
  • Randomly allocate animals to treatment groups.
  • Ensure researchers who assess outcomes to treatment, such as those handling the animals, are blinded (unaware of which data points were produced by the treatment).

Kimmelman said that currently there is "a peculiar acquiescence to shoddy technique." He suggested that preclinical researchers could do a better job so the evidence of a drug's promise is revealed before clinical development has began instead of after.

The authors also suggested that investigators, review boards at hospitals and universities, journals and funding agencies consider the recommendations when designing, evaluating and sponsoring research.

They acknowledged that it's unclear whether failure to implement the suggestions explains why so many drugs ultimately fail to be safe and effective for use in patients. Kimmelman called the findings a starting point to devise core practices in preclinical research that will need to be refined.

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

With files from CBC's Amina Zafar