Novartis has won approval for its Afinitor drug as a treatment for advanced breast cancer in the EU, just days after getting the go-ahead from the US Food and Drug Administration (FDA) for the new indication.
Afinitor (everolimus) has been approved by the European Medicines Agency (EMA) for use in combination with Pfizer's Aromasin (exemestane) with hormone receptor-positive/HER2-negative advanced breast cancer who have progressed despite earlier treatment with aromatase inhibitors such as Novartis' Femara (letrozole) or AstraZeneca's Arimidex (anastrozole).
The approval marks the first new treatment for this most common form of breast cancer since the aromatase inhibitors were introduced 15 years ago, said Novartis.
Around 220,000 women are diagnosed with hormone receptor-positive advanced breast cancer each year, and while aromatase inhibitors are a useful first-line therapy many patients go on to develop resistance.
The approval was based on the results of the BOLERO-2 trial, which found that treatment with Afinitor plus Aromasin more than doubled median progression-free survival (PFS) to 7.8 months, compared to 3.2 months with Aromasin alone.
One of the principal investigators in BOLERO-2, Jose Baselga of Massachusetts General Hospital in the US, said: "By boosting the effectiveness of endocrine therapy, Afinitor significantly extends the time women with hormone receptor-positive advanced breast cancer live without tumour progression."
Typically, women with metastatic breast cancer have a life expectancy of approximately 18-36 months after diagnosis and median survival for women with stage III disease is less than five years.
Afinitor is the first drug in the mTOR inhibitor class to be approved for this indication, which could add another $1bn a year to the drug's peak sales potential, according to analysts.
The drug is thought to be effective in resistant hormone receptor-positive breast cancer because it blocks a molecular escape mechanism commonly employed by tumour cells.
Afinitor is already approved to treat four other types of malignant and non-malignant tumour, including advanced renal cell carcinoma and neuroendocrine tumours of pancreatic origin, and pulled in $318m in sales in the first half of the year.
Novartis is also testing Afinitor in two phase III trials involving HER2-positive breast cancer patients, as well as earlier-stage studies in gastric cancer, hepatocellular carcinoma and lymphoma.