Any new drug that you see released to the market probably started in a lab some 8 – 15 years ago….For every FDA-approved drug that makes it to market, 5000 to 10000 compounds were explored during the drug discovery phase. This is expected, what most companies optimize for is to have the failure occur as early in the pipeline as possible. The later down the pipeline a drug fails, the more costly development becomes.
A visual depiction from Quora is below.
