Novartis' ($NVS) hopes for Afinitor just got closer to reality. The drug more than doubled progression-free survival when added to standard hormonal therapy in post-menopausal women with estrogen-receptor-positive breast cancer. The drug, which targets the mTOR protein in cancer cells, also cut the risk of disease progression by 57% compared with Pfizer's Aromasin hormone therapy alone.
The authors of the study said the Afinitor data, which were presented at a European cancer conference in Stockholm, could be a "game-changer" for treating ER+HER2 breast disease. "I don't recall a study in this patient population that had this magnitude of an effect," lead author Jose Baselga, who also heads up hematology and oncology at Massachusetts General Hospital, told Bloomberg. Baselga called the new study the "strongest data ever seen in ER+ breast cancer," Medscape Medical News reports.
Most women with metastatic cancer treated with hormonal therapy develop resistance over time, and that resistance has been associated with mTOR, the very protein that Afinitor targets, Novartis said. The mTOR protein also is implicated in tumor-cell division, blood-vessel growth and cell metabolism. The company plans to ask regulators on both sides of the Atlantic to approve this new indication for Afinitor--aiming for an application by year's end.
"Everolimus is the first drug to show significant efficacy when combined with hormonal therapy in women with ER+HER2-advanced breast cancer, where there continues to be a critical unmet need," Novartis Oncology President Hervé Hoppenot said in a statement. "The magnitude of benefit seen in these patients, despite their resistance to previous hormonal therapies, shows everolimus represents a potentially important new treatment approach."
The new data prompted Bank Vontobel analyst Andrew Weiss to upgrade his peak sales forecast for Afinitor to $3.5 billion, Bloomberg said. Weiss now projects Afinitor in breast cancer will account for $1.8 billion in sales--up from $1.5 billion. And one of Baselga's colleagues at the Harvard Medical School is calling for a study of Afinitor in women with early-stage breast cancer to see if it prevents disease from returning. "It works," Richard Gelber told the news service. "Let's move it forward and see if it can help other patients at an earlier phase."