Experimental cancer drug may not affect heart

Kosan Biosciences Inc. said new safety data from preclinical and early-stage clinical trials of tanespimycin show that the experimental cancer drug does not affect heart rhythms.

The drug is designed to block a protein that cancer cells need to proliferate and grow.

Kosan said on Sunday electrocardiogram monitoring of patients was conducted in four phase I trials of tanespimycin and the results for 85 patients have been analyzed.
Tanespimycin was found to have no effect on QTc interval -- the time it takes the heart to electrically recharge itself -- based on analyses of the results by outside cardiologists, the company said.

Chief Executive Robert Johnson said the analyses show that two previously reported incidents of possible QTc interval effects in studies conducted by the
National Cancer Institute were due to misreading of automated computer printouts.

Kosan said the drug has so far been tested in more than 600 patients and it plans to launch in the first half of this year a phase III trial of tanespimycin in patients with multiple myeloma.

Johnson said the company is currently talking to potential partners about co-development of the drug.

The data from the cardiac monitoring analyses were presented here at the annual meeting of the American Association for Cancer Research.