Failure of drugs during development is due to many reasons, such as Poor biopharmaceutical properties =40%, Lack of efficacy =30% and Toxicity =45%. So what is the percentage of drugs that fail

Question

Failure of drugs during development is due to many reasons, such as Poor biopharmaceutical properties =40%, Lack of efficacy =30% and Toxicity =45%. So what is the percentage of drugs that fail

Answer 1

You can find a range of failure or the probability of failing assuming independence.

Assuming independence, P(failing) = 1 - P(passing all 3) = 1 - (1 - .4)(1 - .3)(1 - .45) = .769

For the range, if all that have bad biopharmaceutical properties or lack efficacy are toxic, P(failing) = .45

If .15 have lack of efficacy and toxicity, .4 only have bad biopharmaceutical properties, .15 only lack efficacy, and .3 only have toxicity, P(failing) = 1