Similar, but not the same
The disparate Phase II results seen with two histone deacetylase inhibitors last week are a reminder that good or bad results with one compound can't automatically be extrapolated to a class. This may be especially true of HDAC inhibitors because of the many isoforms of HDAC and the multiple chemical classes of inhibitors in development.
Titan Pharmaceuticals Inc. halted three Phase II trials of its Pivanex HDAC inhibitor after seeing "significant" undisclosed safety issues in a Phase IIb trial of the short chain fatty acid in combination with docetaxel in non-small cell lung cancer (NSCLC). However, Gloucester Pharmaceuticals Inc. reported positive data from a Phase II trial of its FK228 depsipeptide in T cell lymphoma. The key to the disparity may be the chemical differences in the various classes of HDAC inhibitors. ...