To print: Select File and then Print from your browser's menu

Title: Albumin-bound Paclitaxel Nanoparticles Effective in Metastatic Breast Cancer: Presented at LSBCS

"Albumin-bound Paclitaxel Nanoparticles Effective in Metastatic Breast Cancer: Presented at LSBCS"

W. A. Thomasson, PhD CHICAGO, IL -- November 4, 2004 -- Results of phase 3 clinical trials indicate that an albumin-bound paclitaxel formulation (Abraxane) is more effective than unbound paclitaxel in taxane-naive patients with metastatic breast cancer and have some activity in patients with taxane-resistant tumors. William Gradishar, MD, of Northwestern University in Chicago, Illinois, presented data from these trials here on November 1[^st at the Lynn Sage Breast Cancer Symposium.

With colleagues from American Bioscience, Inc, Santa Monica, California, and Baylor-Charles A. Sammons Cancer Center, Dallas, Texas, Dr. Gradishar compared a regimen for taxane-naive patients including 175 mg/m² unbound paclitaxel or an ABX dose of 260 mg/m² paclitaxel. Both drugs were delivered every 3 weeks as intravenous infusions, the unbound paclitaxel over 3 hours with standard dexamethasone and antihistamine premedication, the ABX over 30 minutes with no premedication.

Two hundred twenty-nine patients received ABX and 225 the unbound paclitaxel. In the overall group, 179 patients were receiving the trial medication as first-line therapy while 275 had previously received non-taxane chemotherapy.

Albumin-bound paclitaxel produced a higher total (complete plus partial) response rate both in the overall group (33.2% versus 18.7%, p = 0.001) and in patients receiving first-line therapy (42.3% versus 27.0%, p = 0.029). Time to tumor progression was also longer in the albumin-bound paclitaxel group, again both for the entire patient group (21.9 versus 16.1 weeks, P =.03) and for those receiving first-line therapy (28.4 versus 21.2 weeks, P =.056).

Toxicity was generally similar between the two regimens, although the ABX group had significantly less grade 4 neutropenia (9% versus 22%, p < 0.001). On the other hand, this group had significantly more grade 3 sensory neuropathy (10% versus 2%, p < 0.001).

Following discontinuation of the albumin bound paclitaxel formulation, however, grade 3 neuropathy improved to grade 1 or 2 in a median of 22 days.

In a second study, 105 patients who either had experienced tumor progression while on a taxane (88%) or who had experienced relapse within 12 months of taxane therapy (12%) were treated with albumin-bound paclitaxel at a weekly dose equivalent to 100 mg/m² paclitaxel for 3 out of 4 weeks.

Ninety-one percent of these patients had visceral disease and 65% had more than three metastatic sites.

Of the treated patients, 15% experienced a partial response and another 15% had stable disease for at least 16 weeks. Thirteen percent of patients remained progression-free at 12 months and 38% were alive at that time.

Toxicity was moderate, with two patients who experienced grade 4 toxicities (leukopenia and febrile neutropenia). Grade 3 toxicities other than leukopenia and neutropenia were likewise uncommon.

Albumin-bound paclitaxel appears to be a promising new agent for treatment of metastatic breast cancer. A New Drug Application for the agent was filed in March 2004.

[Presentation title: "Enhanced Activity of Abraxane^TM in Metastatic Breast Cancer."

Copyright © 2009 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content.