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.
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.