Combination therapy with experimental drug improves outlook for breast cancer patients

A combination therapy using an experimental new drug shows significant promise for women with a common type of breast cancer in which estrogen causes their tumors to grow, researchers with the Revlon/UCLA Women's Cancer Research Program at UCLA's Jonsson Comprehensive Cancer Center report. The treatment, which incorporates the standard anti-estrogen therapy letrozole and the experimental drug PD 0332991, developed by pharmaceutical company Pfizer Inc., was found to increase progression-free survival time — the length of time a patient is on treatment without tumor growth — in women with estrogen receptor-positive, HER2-negative cancer, compared with letrozole alone. The results of a two-part, phase 2 clinical trial testing the new combination therapy were announced Dec. 5 at the 2012 CTRC-AACR San Antonio Breast Cancer Symposium in San Antonio, Texas, by Richard S. Finn, an associate professor of medicine at UCLA and a member of the Jonsson Cancer Center, who led the trial. The clinical study built on pre-clinical work from the Translational Oncology Research Laboratory directed by Dennis Slamon, a professor of medicine at the Jonsson Cancer Center and director of the Revlon/UCLA Women's Cancer Research Program. For the first part of the study, in which 66 patients were enrolled, preliminary results showed significant improvement in median progression-free survival for individuals who were given the new drug combination. The second part of the study enrolled 99 more patients — but only those whose tumors revealed selected biomarkers known as CCND1 amplification and p16 loss.