Examination of the relationship between oncology drug labeling revision frequency and FDA product categorization

Objectives. I examined the relationship between the Food and Drug Administration's (FDA's) use of special regulatory designations and the frequency with which labels of oncology drugs are revised to explore how the FDA's designation of products relates to product development and refinement. Methods. One hundred oncology drugs, designated by the FDA as accelerated approval, priority review, orphan drug, or traditional review, were identified from publicly available information. Drug information for each product was evaluated to assess the rate at which manufacturers revised product labeling. Rates were compared between specially categorized products and traditional review products (e.g., orphan vs nonorphan drugs) to produce revision rate ratios for each special category. Results. Labeling for accelerated approval and priority review products are revised significantly more frequently than are labels for traditional products. Conclusions. Accelerated approval products are approved based on surrogate endpoints; this approval process anticipates subsequent labeling refinement. Priority review products, however, are approved through a process that is ostensibly as rigorous as traditional review. Their higher than expected label revision rate may suggest deficiencies in the FDA's current priority review evaluation processes.