Fragment-based drug discovery: what has it achieved so far?

Fragment-based drug discovery has proved to be a very useful approach particularly in the hit-to-lead process, providing a complementary tool to traditional high-throughput screening. Although often synonymous with fragment screening, fragment-based drug discovery is a far wider area covering high-throughput screening, fragment screening and virtual screening efforts. The unifying feature of fragment-based drug discovery is the low molecular weight of the hit rather than the approach it originates from. Over the last ten years, fragment-based drug discovery has provided in excess of 50 examples of small molecule hits that have been successfully advanced to leads and therefore resulted in useful substrate for drug discovery programs. To our knowledge, there are currently no marketed drugs that can be attributed to these efforts. However, due to the time scales of drug discovery and development it is likely that over the next few years the number of such examples will increase significantly.