Older drug for advanced breast cancer beat newer, pricier meds

That may be the case for patients with advanced breast cancer, who appeared to fare better in a new study when they took an older drug, Taxol (paclitaxel), instead of two newer and more expensive rivals.

Both of those newer medications, Abraxane and Ixempra, failed to outperform Taxol in terms of either survival without progression of disease or the level of the most noxious side effects, the study of almost 800 breast cancer patients found.

"These data suggest that similar patients may be appropriately treated with weekly paclitaxel [Taxol]," said study author Dr. Hope Rugo, director of breast oncology and clinical trials at the Helen Diller Family Comprehensive Cancer Center at the University of California, San Francisco.

She spoke at a news briefing Sunday at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago. The study, which was funded by the U.S. National Cancer Institute, is to be formally presented on Monday.

Taxol has been used for years to help fight advanced, metastatic breast cancers. But, not every woman fares equally well on Taxol, and newer drugs have emerged, including a variant of paclitaxel called Abraxane (nanoparticle albumin bound paclitaxel) and a drug called Ixempra (ixabepilone).

However, these newer, patented drugs also carry heftier price tags than Taxol, which went off patent years ago. While calculating the exact price difference for any one patient is "enormously complicated," Rugo said that "a generic drug like paclitaxel is going to be significantly less expensive than newer agents."

So, are the newer medicines worth the extra money?

In the new study, Rugo and her team tracked outcomes for 799 patients with either locally advanced or metastatic breast cancers. Patients were randomly assigned to received either Taxol, Abraxane or Ixempra weekly, with each cycle involving three weeks of treatment followed by a one-week break. Almost all of the patients in the trial were also receiving the cancer drug Avastin (bevacizumab) at some point, since it was standard therapy at the time. Last fall, the U.S. Food and Drug Administration withdrew its approval of Avastin for the treatment of advanced breast cancer because of the potential for dangerous cardiac side effects.

Taxol seemed to outperform the newer drugs, Rugo and her team reported. For example, the average time at which women survived without further progression of their cancer was 10.6 months for those taking Taxol, 9.2 months for those on Abraxane and 7.6 months for those taking Ixempra.

Women taking the newer medications also seemed to suffer more side effects. For example, just 16 percent of women taking Taxol experienced the debilitating tingling and numbness of chemotherapy-induced neuropathy, compared to 25 percent of women taking either Abraxane or Ixempra.

Blood-linked toxicities were lowest for women taking Ixempra (12 percent), rose to 21 percent for those on Taxol and climbed to 51 percent for women taking Abraxane, the study found.

Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City, said the findings "remind us that a hypothesis must always be proven. These randomized trials show us that what is newest and latest is not always best."

So, with this new data, should any woman with metastatic breast cancer receive Abraxane or Ixempra instead of Taxol? Rugo said that most women will probably do fine on Taxol, but she noted that a minority typically are allergic to the drug and may prefer to take Abraxane instead.

ASCO spokesman Dr. Nicholas Vogelzang, who moderated the news briefing, said that more is always better when it comes to the number of drugs patients have on hand.

"All of these agents are clearly active -- I want all three of these on my team when I treat breast cancer," said Vogelzang, who is medical director of the developmental therapeutics committee at the Comprehensive Cancer Care Centers of Nevada.

Findings presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.

More information: There's more on the treatment of breast cancer at the American Cancer Society.

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