Pfizer breast cancer drug succeeds in mid-stage trial

The Pfizer logo is seen outside their world headquarters in New York November 5, 2013. REUTERS/Adam Hunger

(Reuters) - Pfizer Inc said its experimental breast cancer drug, in a mid-stage trial, showed a statistically significant improvement in patients' survival rates without their disease worsening.

The drug palbociclib was tested in post-menopausal patients in combination with the hormonal therapy letrozole, and results were compared with patients receiving only letrozole.

(Reporting by Esha Dey in Bangalore; Editing by Ted Kerr)