NEW YORKPaclitaxel (Taxol) given as a weekly one-hour infusion has
significant activity in metastatic breast cancer and is well tolerated
at a dose of 100 mg/m²/wk or less, researchers from Memorial Sloan-Kettering
Cancer Center reported at a poster session of the San Antonio Breast Cancer
In this phase II trial headed by Andrew Seidman, MD, eligible patients
had received up to two prior chemotherapy regimens, but no previous taxane.
The dose was modified every two to four weeks depending on toxicity. Since
the researchers were also interested in paclitaxel pharmacology, assays
were done at 0.5, 1, 3, 6, 25, and 26 hours.
A lack of cumulative neutropenia allowed paclitaxel dose escalation
to 110 to 120 mg/m². However, since grade 3 peripheral neuropathy
was seen in five of nine patients at these doses, no further escalations
above 100 mg/m²/wk were done.
To date, one complete and five partial responses have been seen in 15
evaluable patients, for an objective response rate of 40%. Pharmacokinetic
data in 14 patients revealed paclitaxel levels adequate for cytotoxicity.