Time to inclusion in clinical guidance documents for non-oncological orphan drugs and biologics with expedited FDA designations: a retrospective survival analysis

OBJECTIVES: Drug and biological products that treat rare, serious or life-threatening conditions can receive US Food and Drug Administration (FDA) orphan designation and expedited programme designations (accelerated approval, breakthrough therapy, fast track or priority review) meant to incentivise development. Timely recommendations from guidance documents may encourage more rapid and appropriate use and access to these medicines for serious conditions. We sought to determine time between FDA approval and inclusion in guidance documents for non-oncological orphan products overall and by number and type of expedited programme designations. DESIGN AND SETTING: Retrospective survival analysis of non-oncological orphan products with ≥1 expedited designation approved since 1992. In June 2020, PubMed, Turning Research into Practice and Guideline Central databases were searched to identify guidance documents influencing US practice that included each product. MAIN OUTCOMES AND MEASURES: The primary outcome was time to guidance inclusion, defined as any recommendation on use provided within the recommendation framework used by the guidance document. RESULTS: Among 135 included non-oncological orphan products, 97.0% (n=131) were designated with priority review, 49.6% (n=67) fast track, 16.3% (n=22) breakthrough therapy and 14.1% (n=19) accelerated approval. Sixty per cent of products (n=81) received ≥2 designations. Overall, 74.1% (n=100) were included in a guidance document. The median time to inclusion was 2.87 years (IQR 2.21–4.18) for the entire cohort. In survival analyses, guidance inclusion was more likely to occur earlier for products with ≥2 designations (HR, 1.84; 95% CI 1.21 to 2.79) and for those with fast-track designation compared with priority review (HR 1.40; 95% CI 1.02 to 2.0). Of 35 products not included in a guidance document, 54.3% (n=19) were approved in 2018 or later. CONCLUSIONS: Among non-oncological orphan products with priority designations, nearly 3 years had passed between FDA approval and inclusion in any guidance document. These findings suggest that despite efforts to expedite availability, appropriate access to these treatments may be delayed because of the lack of timely guidance on their use in clinical practice.