Paclitaxel as Weekly One Hour Infusion Is Active in Metastatic Breast Cancer

NEW YORK—Paclitaxel (Taxol) given as a weekly one-hour infusion hassignificant activity in metastatic breast cancer and is well toleratedat a dose of 100 mg/m²/wk or less, researchers from Memorial Sloan-KetteringCancer Center reported at a poster session of the San Antonio Breast CancerSymposium.

In this phase II trial headed by Andrew Seidman, MD, eligible patientshad received up to two prior chemotherapy regimens, but no previous taxane.The dose was modified every two to four weeks depending on toxicity. Sincethe researchers were also interested in paclitaxel pharmacology, assayswere done at 0.5, 1, 3, 6, 25, and 26 hours.

A lack of cumulative neutropenia allowed paclitaxel dose escalationto 110 to 120 mg/m². However, since grade 3 peripheral neuropathywas seen in five of nine patients at these doses, no further escalationsabove 100 mg/m²/wk were done.

To date, one complete and five partial responses have been seen in 15evaluable patients, for an objective response rate of 40%. Pharmacokineticdata in 14 patients revealed paclitaxel levels adequate for cytotoxicity.