Data, analyzed using standard methodology for prostate cancer research, demonstrate an effect on circulating tumor cells (CTC). For patients who at baseline have favorable circulating tumor cell counts (< 5), the majority remains favorable at 4 weeks (86.2%) and for those with CTC enumeration at 12 weeks (84.2%). Furthermore, for those patients with unfavorable CTC (greater than or equal to 5), 26% become favorable at 4 weeks and for those with counts at 12 weeks 62.5% become favorable. CTC enumerations below 5 are associated with increased survival.

One patient at the highest dose group (700 mg) experienced a drug-to-drug interaction with simvastatin that resolved after cessation of both drugs and had not been observed at lower doses. Because anti-tumor activity has been seen at all dose levels, and a qualitative difference in this biological activity at even higher doses is not expected, the company concluded that further dose escalation represents a safety concern and that the trial has provided sufficient information to proceed to a Phase IIb study with a suitable partner. Additional clinical trials will also be conducted by CIPI in China and Hong Kong; and with a suitable partner(s) elsewhere, Harbor BioSciences will use CIPI's data to support these further development efforts. 

SOURCE Harbor BioSciences, Inc.