Why Does the FDA Overrule Its Expert Committees’ Recommendations?

To evaluate some complex drugs, the Food and Drug Administration (FDA) creates committees of experts who recommend whether the drugs should be approved or rejected. The popular press and earlier studies commonly report that the FDA almost never overrules these recommendations. Some say this is because both the FDA and the experts have financial ties to drug companies, leading them to approve too many drugs. Others claim the FDA and experts are both risk averse, leading them to reject too many drugs when they fear approval could draw criticism from the press and Congress. We show that FDA overrules are fairly common (16 percent of cases), and that financial ties to drug companies do not explain them. We find that in a majority of overrules, experts recommend rejection, but the FDA approves the drug anyway, suggesting that the experts could be more risk averse than the FDA. This is consistent with our finding that committees with top experts reject more drugs, perhaps to protect their reputations from being associated with drugs that later might be judged unsafe.