RE:IND misteryHey Georgie you should have gone further down in the wiki definition ... are you scared now!
Approximately two thirds of both INDs and new drug applications (NDAs) are small-molecule drugs. The rest are biopharmaceuticals. About half of the INDs fail in preclinical and clinical phases of drug development.
although it doesn't say in the wiki explanation should FDA ask for clarification that also resets the clock ... 30 days starts after the last communication