Merck reports Phase II data for Keytruda in breast cancer

Merck & Co. Inc. (NYSE:MRK) reported data from 40 evaluable patients with trastuzumab-resistant, HER2- and PD-L1-positive metastatic breast cancer in the Phase II portion of the Phase Ib/II KEYNOTE-014 (PANACEA) trial showing that 200 mg IV Keytruda pembrolizumab (MK-3475) every three weeks plus Herceptin trastuzumab led to an objective response rate (ORR) of 15%, including one complete response and five partial responses, plus seven cases of stable disease. Median progression-free survival (PFS) was 2.7 months and median overall survival (OS) was 16.1 months. The 12-month PFS and OS rates were 13% and 65%, respectively. Data were presented at the San Antonio Breast Cancer Symposium in December. The trial was sponsored by the International Breast Cancer Study Group in collaboration with the Breast International Group.

The open-label, international trial evaluated safety and ORR as primary endpoints. Secondary endpoints include PFS, disease control rate (DCR), duration of response, duration of disease control and OS...