Abraxane seen more effective than Taxotere
LOS ANGELES (Reuters) - A mid-stage study showed that a dose of Abraxis BioScience Inc.'s Abraxane given weekly was more effective for patients with advanced breast cancer than Sanofi-Aventis SA's Taxotere given every three weeks, Abraxis said on Sunday.
Abraxis said interim data from the head-to-head trial showed that a weekly injection of Abraxane increased tumor response rate by more than 60 percent, and resulted in fewer side effects, compared with the Taxotere regimen.
The company said it plans to launch a phase III trial comparing the two chemotherapy drugs in the first half of next year. The drugs are forms of paclitaxel, a class of drugs called antineoplastics and used with the aim of interfering with cancer cell growth.
Interim analysis of the 300-patient phase II trial showed that 58 percent to 62 percent of patients treated weekly with a low dose and high dose, respectively, of Abraxane responded to the drug, compared with 36 percent given Taxotere every three weeks, the company said.
A dose of Abraxane give once every three weeks resulted in a response rate of just 33 percent.
Officials at Sanofi-Aventis were not immediately available for comment.
The trial, presented at the San Antonio Breast Cancer Symposium, also showed fewer adverse side effects, including low white blood cell counts and mouth sores, in patients treated with Abraxane, said Dr. William Gradishar, director of breast medical oncology at Northwestern University and a lead investigator in the study.
Abraxis plans to present final progression-free survival data from the trial next year, but said the interim analysis showed longer progression-free survival with all three Abraxane regimens than Taxotere dosed every three weeks.
"Our general experience was higher response rates, and increase in progression-free survival and less toxicity," Gradishar said.
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Abraxane seen more effective than Taxotere
In the study reviewed here, advanced (metastatic) breast cancers treated with Abraxane (chemical name: paclitaxel), a different form of paclitaxel than Taxol (chemical name: paclitaxel), responded 60 percent better than those treated with Taxotere (chemical name: docetaxel).
Abraxane was given as an injection once a week. Taxotere injections were given every three weeks, the current standard schedule for both medicines. Despite receiving Abraxane more often, the women who received it had fewer side effects than women receiving Taxotere.
In January 2005, the U.S. Food and Drug Administration (FDA) approved Abraxane for treatment of advanced breast cancer. This approval was for second-line therapy—which means the drug should be used after another chemotherapy regimen has been used and has stopped working.
Abraxane, Taxotere, and Taxol are taxanes, a powerful type of chemotherapy medicines that can stop cancer cells from repairing themselves and making new cells. Studies have shown them to be effective in treating women with advanced breast cancer that does not respond to other forms of chemotherapy.
Taxanes can cause serious side effects, including low white blood cell counts (neutropenia), weakness, and infection.
The two older taxanes, Taxol and Taxotere, use solvents to dissolve their main ingredients so the medicines can enter the bloodstream. These solvents make Taxol and Taxotere harder to tolerate while being given. Usually, women take pre-medications to minimize reactions to the solvents in Taxol and Taxotere. Abraxane doesn't use a solvent, which may make it easier to take without the need for pre-medication.
In this study, Abraxane's lack of solvent might be why the women who got Abraxane had fewer side effects than women receiving Taxotere, even though the Abraxane treatment was given more often. And Abraxane being given more often might be why the advanced breast cancer responded better to it.
