Abraxane: A Better Delivery System for Paclitaxel?
Like many other people, I had Taxol (paclitaxel) as part of my chemo. Both Taxol and its cousin Taxotere (docetaxel) need to be dissolved in a solvent before they are administered. My doctor explained to me that many patients are allergic to the solvent, so I would need premedication with steroids and antihistamines.
Fortunately for me, the premedications worked, and I had no problems. True, a Taxol infusion took a long time over three hours because slow administration of the drug reduces the risk of allergic reactions and side effects. However, some patients have not been so lucky as I and have had to stop treatment with taxanes because of allergic reactions.
Abraxane (nab-paclitaxel) is the same active ingredient as Taxol, but scientists have found a new way to deliver it. The "nab" part of Abraxane's generic name stands for "nanoparticle albumin bound." Using albumin, a human protein, to mix the paclitaxel has proved to be a safe and less toxic way to deliver the drug.
The big advantages of Abraxane are no premedications, fewer allergic reactions, and a faster infusion time. As a layperson reading the promotional materials put out by the drug manufacturer and the clinical studies, I confess that I am confused about whether Abraxane is actually better than Taxol at prolonging survival significantly.
A study led by Dr. William Gradishar found higher response rates and a delay in tumor progression comparing Abraxane with Taxol. Gradishar's study found higher rates of sensory neuropathy 10 percent with Abraxane versus 2 percent with Taxol. The study, funded by the drug's manufacturer, notes the neuropathy was "easily managed and improved rapidly." As a person who is still coping with neuropathy 13 years after taking Taxol, I personally would want to see more evidence about long-term neuropathy rates with the two drugs.
Most non-metastatic breast cancer patients will not have a choice between Taxol and Abraxane. Taxol is now available generically, and Abraxane is still very expensive. Insurance companies are understandably hesitant to approve a more expensive version of the identical active ingredient without a good reason.
Abraxane has also only been approved so far for metastatic or recurring breast cancer. I am seeing anecdotal evidence that doctors will prescribe Abraxane for earlier stage patients if they have allergic reactions to Taxol. Studies underway are finding that Abraxane may also be effective with other types of cancer such as lung and pancreatic cancer.