New Cancer Drug Approvals: Less Than Half Of Important Clinical Trial Uncertainties Reported By The FDA To Clinicians, 2019–22

Uncertainties about the benefits and harms of new drugs are common at the time of drugs' approval. It is unclear to what extent the Food and Drug Administration (FDA) communicates these uncertainties in the FDA-approved prescribing information (the drug label), which is the primary channel of communication between the FDA and physicians. Although physicians might not regularly consult the drug label for prescribing decisions, other information sources used by physicians either index or incorporate information from the label. We searched FDA review documents for uncertainties identified by FDA reviewers with new cancer drugs. We considered the subset of uncertainties highlighted in the FDA's Benefit-Risk Framework as important to the FDA's approval decision. During the period 2019-22, the FDA approved fifty-two new cancer drugs. In review documents, FDA reviewers identified a total of 213 clinical trial uncertainties with new cancer drugs, 50 percent of which were considered to be important uncertainties to the FDA's approval decision. Labels for physicians reported information on 26 percent of all uncertainties and 48 percent of uncertainties that were important to the FDA's approval decision. Communicating uncertainties about the evidence of drugs in the label is essential for informing physicians about drugs' safe and effective use.