Cancer Therapy Center

Reuters notes that Abraxis (maker of Abraxane) published interim data showing tumors were more responsive to Abraxane and patients showed fewer side effects than with competing drug Taxotere.

Interim analysis of the 300-patient Phase II trial showed that 61 percent to 72 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.

A Phase III trial is scheduled for the first half of 2007. Both drugs are forms of pacilataxel, developed with the goal of interfering with cancer cell growth.

Abraxane does not help patients live longer than an older treatment (Taxol), though it does shrink tumors in more patients, according to clinical trials. And the old and new medicines have similar side effects. An independent review of Abraxane published in December in a cancer research journal concluded that the drug was “old wine in a new bottle.”

Still, Abraxis BioScience, has promoted Abraxane as a major advance in treating late-stage breast cancer:

“We have a breakthrough,” he said. “Look at the data.”

The NY Times article describes the general formula:

ABRAXANE is a reformulated version of paclitaxel, a chemical found in the Pacific yew tree that destroys cancer cells. But paclitaxel, which is given intravenously, is difficult to use. Because it does not dissolve in water, the drug must be mixed in Cremophor, a combination of castor oil and alcohol that can cause severe allergic reactions. To reduce that risk, patients who receive Cremophor first receive a steroid and an antihystamine.

Working with University of Illinoisresearchers in the 1990’s, Dr. Soon-Shiong found a way to give Taxol without Cremophor by coating paclitaxel in fragments of albumin, a protein found in human blood. He named the new treatment Abraxane.

Abraxane patients do not need antihistamines or steroids. The drug can also be given at slightly higher doses and injected more quickly than traditional paclitaxel, which requires a three hour-infusion.

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