
BLA vs NDA: the differences, plus ANDA, 505(b)(2) and biosimilars, and the inspection each one triggers
A comparison of the five FDA marketing application pathways (NDA, 505(b)(2), ANDA, BLA and 351(k) biosimilar) by statute, reviewing center, data required, exclusivity, user fee program and review goal, followed by the part most explainers skip: the pre-approval or pre-license inspection each pathway triggers. Includes Atlas counts of complete response letters by application type (65 in 2024, 48 in 2025, 17 in early 2026), drug vs biologic inspection outcomes from January 2025 to October 2026, and a June 2026 Form 483 at a licensed vaccine maker.


















