Saturday, May 17, 2008

Pleural Mesothelioma Trial Shows No Benefit for Chemo

Adding chemotherapy to active symptom control in cases of malignant pleural mesothelioma appeared to have little effect in a large randomized trial, researchers said here.

Neither of two chemotherapy regimens -- analyzed together or singly -- extended life significantly nor was there a significant effect on quality of life, according to Richard Stephens of the Medical Research Council Clinical Trials Unit, and colleagues.


But an exploratory analysis suggested that one of the chemotherapy agents used -- vinorelbine (Navelbine) -- might have a benefit and should be studied further, the researchers reported in the May 17 issue of The Lancet.

On the other hand, the trial might have been overtaken by events, the researchers said.

The study was designed in the 1990s and was intended to compare active symptom control to symptom control plus vinorelbine and symptom control plus mitomycin (Mutamycin), vinblastine (Velban), and cisplatin (Platinol).

But in 2002, a large randomized trial showed a modest survival improvement for cisplatin and pemetrexed (Alimta), which had the effect of slowing patient recruitment for the trial reported here.

Efforts to include the cisplatin and pemetrexed regimen were unsuccessful, the researchers said. Instead, given the slow accrual, they changed the study design to combine the two chemotherapy arms, although the three-arm randomization was kept to allow for exploratory analyses of each regimen.

Subsequently, a second large randomized trial found a survival benefit for cisplatin and ralitrexed (Tomudex).

The upshot of those two studies is that doublet chemotherapy appears to have a survival benefit of about 2.5 months, according to Nicholas Vogelzang, M.D., of the Nevada Cancer Institute in Las Vegas.

Dr. Vogelzang, who led the cisplatin/pemetrexed study, said the standard of care now is cisplatin and pemetrexed. It is also possible that cisplatin and gemcitabine (Gemzar) will be beneficial, he said, although that has not been well tested. Ralitrexed is no longer available, Dr. Vogelzang noted.

Writing in an accompanying comment article, he dismissed the notion of vinorelbine as a possible therapy.

"I believe that single-agent chemotherapy offers little to patients in the way of palliation or survival, since [active symptom control] plus vinorelbine was statistically indistinguishable from [symptom control] alone," he argued.

Indeed, in the current study, the researchers found:

  • Compared with active symptom control alone, there was a small and non-significant survival benefit for added chemotherapy. The hazard ratio was 0.89, with a 95% confidence interval from 0.72 to 1.10.
  • Median survival was 7.6 months for symptom control alone and 8.5 months when chemotherapy was added.
  • Exploratory analyses suggested active symptom control plus vinorelbine might have an advantage, although it was also non-significant. The hazard ratio was 0.80 with a median survival of 9.5 months.
  • There was no evidence of a survival benefit in the cisplatin arm, which had a hazard ratio of 0.99 compared with symptom control alone.

Medpagetoday Medical News

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