Retaspimycin: Development discontinued

Infinity discontinued development of IPI-504 to treat breast cancer after an interim review of data from 26 HER2-positive metastatic breast cancer patients enrolled in the first cohort of an open-label Phase II trial showed that once-weekly 300 mg/m 2 IV IPI-504 plus Herceptin trastuzumab displayed clinical activity that was insufficient to continue the study. The company said it believes the insufficient activity was a result of the compound being administered at a less than optimal dose. The combination was well tolerated.

Last year, Infinity temporarily halted enrollment in the trial in order to amend the protocol, which the company said may include evaluating a different dose and/or the institution of additional pharmacokinetic and pharmacodynamic monitoring. The move followed the company's termination of the Phase III RING trial to treat refractory gastrointestinal stromal tumors (GIST) after a review of safety data from the trial showed a higher than anticipated mortality rate among patients receiving IPI-504 (see BioCentury, April 20, 2009 & May 11, 2009). In 2008, Infinity reacquired full rights to IPI-504 from AstraZeneca plc (LSE:AZN; NYSE:AZN, London, U.K.) (see BioCentury, Dec. 15, 2008). ...