June 25 (Reuters) - Pfizer Inc said on Monday a combination of its breast cancer drug, Ibrance, and another drug was not statistically significant in extending overall survival in certain patients, the secondary goal of a late-stage trial.
Ibrance is Pfizer's blockbuster treatment and is already approved as a combination with endocrine therapy for use in breast cancer patients. The treatment brought in sales of $933 million in the first quarter of 2018.
Pfizer said on Monday the results demonstrated a positive trend in a ratio that helps determine to what extent a treatment can shorten the duration of an illness, but failed to reach statistical significance.
An interim analysis of the trial in 2015 showed that the Ibrance combo had met its main goal of progression-free survival, or extending the length of time a patient lives without the disease worsening.
The company would present detailed data on the trial at an upcoming meeting.
Reporting by Manas Mishra in Bengaluru; Editing by Sriraj Kalluvila