RE:Rare and Orphan diseases approved w smaller pt trial numbersAccording to ClinicalTrials.gov a trial can report either actual or expected numbers recruited but not both. The anticipated number of patients to be recruited in rare trials is less than that of non-rare disease trials (median, 41[IQR 24–74] vs. 76[40–182]). Similarly, the actual number of patients recruited is less for rare disease trials than in non-rare trials (29[12–60] vs. 62[27–175]).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4255432/