On Wednesday, the first formal late-stage trial of Pfizer Inc’s treatment for advanced breast cancer was stopped early after the medicine met its goal of delaying progression of the disease in previously treated patients.
The Phase 3 study, called Paloma 3, was stopped after an independent data monitoring board determined that the breast cancer drug, Imbrance, had proven its effectiveness among patients with advanced disease who were previously treated with anti-estrogen drugs.
The entire study will be presented at an upcoming medical meeting.
The trial followed patients whose breast cancer was classified as estrogen-receptor positive, human epidermal growth factor receptor 2-negative (ER+/HER2-).
The successful trial results should boost demands for the recently approved treatment. This treatment works differently than approved medicines and ha blockbuster sales potential.
Some analysts have predicted that the drug could eventually generate annual sales of more than $5 billion.
Ibrance was approved by the U.S. Food and Drug Administration in February for patients with ER+/HER2-, but only patients who had not previously been treated for advanced disease.
The accelerated approval was based on a study that demonstrated that Ibrance delayed the progression of disease significantly longer than Novartis AG’s Femara. Novartis Ag’s Femara is a member of another class of breast cancer treatments called aromatase inhibitors.
Patients taking Ibrance in combination with AstraZeneca Plc’s Faslodex were deemed to have fared better in terms of disease progression than those taking Faslodex alone. Faslodex is a widely used treatment to block estrogen.
Pfizer is conducting a large trial called Paloma-2, which hopefully will confirm the benefit of Ibrance as a first-line treatment, in combination with Femara.
Other drugmakers are testing drugs that block the same or similar enzymes as potential treatments for a variety of cancers.
Pfizer shares went up .9% at $35.34 on the New York Stok Exchange.