HAYWARD, Calif., April 16 /PRNewswire/ -- Kosan Biosciences Incorporated (Nasdaq: KOSN - News) today presented safety data from preclinical and clinical studies of its lead Hsp90 inhibitor, tanespimycin (KOS-953). Serial electrocardiogram (ECG) monitoring of patients was conducted in four Phase 1 trials of tanespimycin. Cardiac monitoring analyses were conducted in more than 85 patients. Tanespimycin was found to have no effect on QTc interval (a measure of the heart’s electrical cycle) in these patients based on data analyses from manually read ECGs in a central laboratory or by site cardiologists.