Dr. Nagourney's Blog

For Advanced Breast Cancer, Taxol is Still Best of its Class

By Robert A. Nagourney, MD

An important trial result was reported for patients with advanced breast cancer.

A total of 783 patients with stage IIIC/IV disease, received one of 3 drugs that were all combined with Bevacizumab (Avastin).

The trial compared Taxol (Paclitaxel) with micro-albuminated nab-Paclitaxel (Abraxane) or Ixabepilone (Ixempra). The investigators found that the Taxol combination was superior to the two experimental groups. 

Using weekly schedules of each drug given 3 weeks in a row with a one week rest, all agents were combined with an every other week dose of Avastin.

The Taxol group provided superior progression free survival, median time to treatment failure and median overall survival. Toxic side effects were also reduced in the Taxol group.

This CALGB (Cancer & Leukemia Group B) report by Dr Hope Rugo from UCSF, http://bit.ly/1KUumM5 does a service to breast cancer patients all over the world. It is highly revealing that the patients receiving the simplest treatment, namely, Taxol did the best.

What is most important is that Taxol the oldest (and cheapest) member of this class, a drug that has been used in breast cancer for decades, bested the two newer agents.

Taxol discovered in the 1960s targets structures in the cell known as microtubules.

After it established activity in advanced breast cancer, other related agents moved into the clinical arena.

The first was Taxotere (Docetaxel), then the epothilones (Ixempra) and then most recently, the micro-albuminated formulation of Abraxane. 

What is most gratifying is that the cheapest, easiest drug was the best.

In fact, a simple calculation using a 3 week dose schedule for the average patient (excluding Avastin) reveals the stark difference, with 3 weeks of Taxol coming in at $300, compared with Ixempra at about $6100 and Abraxane at over $8000. These recurring drug costs are demonstrably greater than the one-time fee for our laboratory analyses that are capable of selecting amongst these alternatives. In an era of “value-oncology” these results should be of more than passing interest to physicians and insurers. 

Over the years our laboratory has frequently compared Ixempra to Paclitaxel and Docetaxel, finding similar degrees of activity for most patients.

Indeed, when we do not have enough tissue in breast cancer patients to study all of the drugs, we simply use Taxol to gauge the likelihood of benefit from the entire class of microtubule agents. 

The findings from this CALGB study provide clinical confirmation that drugs with similar modes of action generally provide similar benefits. Our functional profiling analyses have often been able to recommend Taxol as the cheaper alternative.

We now have clinical proof in breast cancer that the “me-too” drugs are indeed more alike than different.  Dr. Rugo is to be applauded for conducting this trial.

We all benefit from these important findings.