At the Tri-Conference last week, Maria M. Flocco of Pfizer stated that a search of the IDDB3/Prous databases yielded 30 examples of compounds that had made it into the clinic from fragment-based approaches, of which 23 are still active, and 4 are in Phase II testing.
And not just in the clinic. According to her, tipranavir, an HIV protease inhibitor approved by the FDA in 2005, was derived from a 30 micromolar hydroxycoumarin fragment, back before people really thought in terms of fragments. This leads to the question, how many approved drugs could be considered the result of fragment-based drug discovery? I have argued that sorafenib fits the bill, having started from a relatively weak (17 micromolar) fragment-like screening hit. Any others?
BTW: Readers of Practical Fragments had previously identified 17 clinical compounds discovered through fragment-based methods. You can read that discussion here.