But it's 42% of 19%. So out of 1,000 drugs, you're looking at 805 being ruled out before you even get to that "most expensive phase", which is my point. At Phase 3, you're looking at 113 succeeding, so you're "only" eating the really expensive[1] costs of Phase 3 for 82[2] of 1,000 attempts.

[1] Which isn't to say there's zero cost for Phase 1 or Phase 2, but it's a lot lot less than Phase 3 trials.

[2] 1,000 drugs, 63%, 630 of which make it through Phase 1. In Phase 2, 195 drugs, 31% of 630 succeed and make it through to Phase 3, and then 82 drugs (58% of 195) make it to regulatory approval.