An experimental drug treatment may help keep a certain kind of aggressive breast cancer at bay, offering new hope for individual therapies against difficult tumours, said research.
The phase III trial comparing trastuzumab emtansine (T-DM1) to standard therapy for human epidermal growth factor receptor 2 (HER2 positive) breast cancer was presented at the American Society of Clinical Oncology conference in Chicago.
The international study randomised nearly 1 000 patients to receive either T-DM1 or standard therapy every three weeks. The subjects all had metastatic cancer that had spread to other parts of the body.
Little dose limiting toxicity
The trial found that progression-free survival in the T-DM1 group was 9.6 months, compared to 6.4 months in the standard therapy group, which study authors described as "clinically meaningful improvement."
"The drug worked. It was significantly better than a very effective approved therapy for HER2 over expressing metastatic breast cancer," said lead study author Kimberly Blackwell, professor of medicine at Duke University.
"Also, as a clinician who takes care of a lot of breast cancer patients, I'm pleased that this drug has very little dose-limiting toxicity. Patients don't lose their hair from this drug.
"For patients facing metastatic breast cancer, this is a breakthrough."
The data on overall survival time showed 65% of T-DM1 patients were alive after two years, compared to 47.5% of the standard therapy patients, a threshold that fell short of the trial's predetermined limits for judging statistical significance.
More analysis of survival times is planned for later in the ongoing study.
(Sapa, June 2012)
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