Eva M. Ciruelos, MD, PhD, on HER2-Positive and PAM50 Luminal Breast Cancer: Primary Results From the PATRICIA Trial

We presented the first primary results of the PATRICIA cohort C trial. This is an open level, phase two randomized trial that recruited HER2-positive advanced breast cancer patients who received an experimental combination consisted on palbociclib, trastuzumab and endocrine therapy versus treatment of physician choice with T-DM1 or the combination of trastuzumab chemotherapy or endocrine treatment. These patients were pre-treated patients, at least two prior lines of treatment, and all of them were selected based on the intrinsic subtyping. Just luminal A and luminal B tumors were included in this trial. Primary result was achieved and progression for survival was significantly improved with combination of palbociclib trastuzumab endocrine treatment over treatment of physician's choice, with a reduction in the risk of progression of about 48%, which is statistically significant. These results are unique as we try to select patients based on a new biomarker, which is intrinsic subtype, and offering this non-chemotherapy combination for these patients that harbored about 50% within the HER-positive HER2-positive disease. Regarding tolerability, no dose reductions were done differently from these two arms and no dose discontinuations were needed in the experimental arm. That is why our conclusions says that this is a new way to classify in patients within the HER2-positive disease. This is a non-chemo alternative for these patients that will translate, for sure, into quality of life. But still we should validate our results as our trial had some limitations due to a small sample size, so maybe new prospective randomized designs will be needed to confirm our [inaudible 00:02:21] results.