LACK OF THERMAL ENHANCEMENT FOR TAXANES IN-VITRO

The taxanes represent a new class of clinical chemotherapeutic agents. A series of in vitro studies were independently of each other initiat ed in two different institutes (Amsterdam and Madison) to test the hyp othesis that hyperthermia might enhance the cytotoxicity of taxanes. C lonogenic capacity experiments (Amsterdam) included the exposure of R1 - and SW 1573-cells to 1, 4, or 24 h of paclitaxel with heat 43 degree s C x 60 min in the last hour of drug treatment or at 24, 48 as well a s 72 h post drug treatment. Survival assay experiments (Madison) inclu ded the exposure of L-929-cells to paclitaxel and docetaxel for 24 h w ith heat 41.8 degrees C x 60 min the first or last hour of drug treatm ent as well as 24 and 48 h post treatment. No thermal enhancement of c ytotoxicity for the taxanes was observed in these human and murine cel l lines, with congruent data in both institutes. In addition, high per formance liquid chromatography studies at 41.8 degrees C and 43 degree s C demonstrated paclitaxel and docetaxel were heat stable.