From about 10,000 promising compounds, how many typically reach clinical trials and how many are eventually approved?

From about 10,000 promising compounds, how many typically reach clinical trials and how many are eventually approved?

• A. Fewer than 10 reach clinical trials and about 2 are approved.
• B. About 100 reach trials and 20 approved.
• C. About 1,000 reach trials and 100 approved.
• D. All reach trials and 50 approved.

Answer: (D)

The main idea here is that drug development has a very steep attrition rate. From a large pool of promising compounds, only a small fraction actually makes it into clinical testing, and even fewer ultimately receive approval. A common, rough rule of thumb is that about one-tenth of promising compounds progress to clinical trials, and about one-tenth of those entering trials are approved. So, starting with 10,000 candidates, you’d expect around 1,000 to reach clinical trials and roughly 100 to become approved drugs. This reflects the many hurdles—efficacy, safety, pharmacokinetics, manufacturing, and regulatory considerations—that weed out most candidates long before approval.

The main idea here is that drug development has a very steep attrition rate. From a large pool of promising compounds, only a small fraction actually makes it into clinical testing, and even fewer ultimately receive approval. A common, rough rule of thumb is that about one-tenth of promising compounds progress to clinical trials, and about one-tenth of those entering trials are approved. So, starting with 10,000 candidates, you’d expect around 1,000 to reach clinical trials and roughly 100 to become approved drugs. This reflects the many hurdles—efficacy, safety, pharmacokinetics, manufacturing, and regulatory considerations—that weed out most candidates long before approval.