Shares of Pfizer Inc. gained 0.2% in premarket trading on Thursday after the company said peer-reviewed research shows that Ibrance improved survival among about 1,400 breast-cancer patients when used as a first-line therapy in combination with aromatase inhibitor letrozole. Patients who had taken the combination therapy reported 20 months of real-world progression-free survival compared to the roughly 12 months reported by patients taking only letrozole. Ibrance, which received regulatory approval in the U.S. as a first-line treatment in 2017, generated $5.4 billion in revenue in 2020. Pfizer’s stock is up 26.3% over the past 12 months, while the broader S&P 500 has gained 58.9%.

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