FDA last updated their page on trial success rates
Post# of 72440
https://www.fda.gov/forpatients/approvals/dru...405622.htm
Quote:
Phase 3
Study Participants: 300 to 3,000 volunteers who have the disease or condition
Length of Study: 1 to 4 years
Purpose: Efficacy and monitoring of adverse reactions
Approximately 25-30% of drugs move to the next phase
So I'll assume 100% of NDA applications are approved and use 25% as my floor. If 85% of NDA applications are approved, my 22% looks like it is still very relevant. Either way, close enough for napkin math.