A new nanotech-enabled drug recently approved by the US Food and Drug Administration promises to make life a little easier for patients with breast cancer. The drug, Abraxane, is the first of a new class of so-called protein-bound particle drugs, which use naturally occurring proteins to facilitate drug delivery.
Marketed by American Pharmaceutical Partners, Abraxane is the anticancer drug paclitaxel (Taxol), reengineered and reborn into a nanoparticle that hitches a ride on albumin, a protein already found in the body. Patrick Soon-Shiong, American Pharmaceutical's executive chair, says this is the first example of a nanoparticle-coupled human protein.
The albumin molecule allows paclitaxel to cross blood-vessel walls to deliver the drug to where it's needed. From the patient's point of view, it's easier to swallow than Cremophor, the polyethoxylated castor oil used to ensure that Taxol is absorbed properly. Patients often require additional medications to counteract Cremophor's toxicity. In contrast, Abraxane accomplishes one of the goals of nanotechnology in pharmaceuticals: targeted drug delivery without negative side effects.
But the drug is also not a traditional nanotech product. Nanotech expert and oncologist Uri Sagman, executive director of the Canadian NanoBusiness Alliance and a pioneer in the use of buckminsterfullerenes in medicine, says Abraxane is in a kind of "gray zone." It's not a drug attached to nanotubes or fullerenes or any other nanoscale delivery devices making headlines these days; rather, it is a nanoengineered drug coated with a protein to make it easy for the body to absorb. Not quite so sexy, perhaps, but Sagman says it really doesn't matter: Nano or not, it should improve the lives of patients with breast cancer.