Adding anastrozole to trastuzumab is beneficial in breast cancer
Adding hormonal therapy with anastrozole (Arimidex) to the HER2-receptor blocker trastuzumab (Herceptin) doubles progression-free survival in women with metastatic breast cancer positive for both hormone and HER2 receptors, according to the first study to look at blocking both types of receptors.
The study, presented this week at the European
Society for Medical Oncology congress in Istanbul, Turkey, included 208 postmenopausal women with
HER2-positive advanced breast cancer that was also hormone receptor positive.
They were randomised to receive anastrozole (1 mg daily), alone or in
combination with trastuzumab 2mg/kg weekly doses, until disease progression.
Bella Kaufman, Sheva Medical Centre, Telhashomer, Israel, reported that
median progression-free survival, the primary endpoint of the trial,
was 4. 8 months for patients who received the combination, compared with
2.4 months for patients who received hormonal therapy alone (P=0.0016).
Patients in the combination arm also responded significantly better to
treatment (overall response rate was 20.3 per cent versus 6.8 per cent;
P=0.018). Clinical benefit (complete or partial response, or stable disease
lasting more than six months) was achieved in 42.7 per cent of women
treated with trastuzumab plus anastrozole compared with 27.9 per cent
of those on anastrozole alone.
Dr Kaufman said few trials in breast cancer had previously shown a doubling
of progression-free survival. “In these very poor prognosis patients,
adding Herceptin to anastrozole increased clinical benefit by more than
50 per cent. More than 15 per cent of women on the combination did not
progress for at least two years.”
Around two-thirds of women who develop breast cancer have hormone receptor-positive
tumours and up to a quarter of these breast cancers are also HER2-positive. |
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Pharmaceutical Journal
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