Swiss drugmaker Roche and U.S. group Merck & Co are to present data on their rival immunotherapy drugs in breast cancer in December, extending the novel approach to fighting tumors to another cancer type. Early clinical results with Roche's drug, known as MPDL3280A, in so-called triple negative breast cancer will be revealed at the Dec. 9-13 San Antonio Breast Cancer Symposium, the firm said after announcing third-quarter results.