PF-04929113

PF-04929113 is a small-molecule Hsp90 inhibitor based on the 6,7-dihydro-indazol-4-one scaffold. PF-04929113 also inhibits Her-2 degradation with IC50 of 37 nM. PF-04929113 inhibited tumor growth and prolonged survival compared with controls. Surprisingly, PF-04929113 did not reduce serum prostate-specific antigen (PSA) levels in vivo; in parallel, these decrease in tumor volume. PF-04929113 administered orally twice a week is well tolerated and inhibits its intended target Hsp90. PF-04929113 is currently under the Phase I clinical trial.