Abraxane (chemical name: albumin-bound or nab-paclitaxel) is a different form of paclitaxel than Taxol (chemical name: paclitaxel). Both medicines are taxanes, a powerful type of chemotherapy medicine that can stop cancer cells from repairing themselves and making new cells.
Taxol uses a solvent to dissolve its main ingredients so the medicine can enter the bloodstream. These solvents can make Taxol harder to tolerate while being given. Usually women take medicine before receiving Taxol to minimize any reactions to the solvents. Abraxane doesn’t use a solvent, which can make it easier to tolerate and also means that women don’t need to take medicine before receiving it.
Earlier research has shown that Abraxane offers more benefits than a solvent-based taxane when treating metastatic breast cancer. Another study found that treating early-stage breast cancer before surgery with chemotherapy consisting of a taxane followed by an anthracycline offered better pathologic complete response rates than an anthracycline followed by a taxane.
Treatment given to weaken and destroy breast cancer before surgery is called neoadjuvant treatment. Neoadjuvant chemotherapy isn’t routinely used to treat early-stage breast cancer, but may be used if the cancer is large or aggressive.
One way for doctors to judge the effectiveness of neoadjuvant treatment is to look at the tissue removed during surgery to see if any active cancer cells are present. If no active cancer cells are present, doctors call it a “pathologic complete response.”
Anthracycline chemotherapy medicines are:
- Adriamycin (chemical name: doxorubicin)
- Ellence (chemical name: epirubicin)
- Doxil (chemical name: doxorubicin)
- daunorubicin (brand names: Cerubidine, DaunoXome)
- mitoxantrone (brand name: Novantrone)
Anthracyclines work by damaging cancer cells’ genes and interfering with their reproduction.
Because of the earlier studies, the researchers who did this study, called the GeparSepto study, wondered if using Abraxane as the taxane in a taxane-anthracycline neoadjuvant chemotherapy regimen for early-stage breast cancer would have higher pathologic complete response rates than using Taxol as the taxane.
The study was published online on Feb. 8, 2016 by the journal The Lancet Oncology. Read the abstract of “Nab-paclitaxel versus solvent-based paclitaxel in neoadjuvant chemotherapy for early breast cancer (GeparSepto-GBG 69): a randomized, phase 3 trial.”
In the study, the researchers randomly assigned 1,206 women diagnosed with early-stage breast cancer that had not been treated to receive one of two chemotherapy regimens before surgery:
- 606 women received Abraxane once a week for 12 weeks, followed by 12 weeks of Ellence plus Cytoxan (chemical name: cyclophosphamide)
- 600 women received Taxol once a week for 12 weeks, followed by 12 weeks of Ellence plus Cytoxan
The results showed that Abraxane offered a 38% pathologic complete response rate (233 women) compared to Taxol’s 29% pathologic complete response rate (174 women).
This difference in pathologic complete response rates was statistically significant, which means that it was likely due to the difference in taxane medicines rather than just because of chance.
Like all chemotherapy medicines, taxanes and anthracyclines may cause side effects, some of them serious. Anthracyclines may cause heart damage, which can lead to heart failure. Taxanes may cause low white blood cell counts (neutropenia), weakness, peripheral neuropathy (nerve damage in the hands and feet), and infection.
Women in the Abraxane treatment group had higher rates of two side effects:
- 2% (13 women) treated with Abraxane had severe anemia (low red blood cell counts) compared to 1% (4 women) treated with Taxol
- 10% (63 women) treated with Abraxane had severe peripheral neuropathy compared to 3% (16 women) treated with Taxol
Overall, 23% (283 women) in the study had at least one serious side effect:
- 26% (156 women) in the Abraxane group
- 21% (127 women) in the Taxol group
If you’ve been diagnosed with early-stage breast cancer and your doctor recommends that you have chemotherapy before surgery with a regimen that includes a taxane, you may want to talk to your doctor about this study and ask if using Abraxane instead of Taxol makes sense for you. Together, you and your doctor will make the best decision for your unique situation.
For more information, including what to expect when receiving chemotherapy, visit the Breastcancer.org Chemotherapy section.