Roche Registration Ltd.

To provide trastuzumab emtansine monotherapy or in combination with other drugs to patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic cancer who have benefited from the Genentech/Roche-sponsored trastuzumab emtansine parent study; to collect safety data of long-term administration of trastuzumab emtansine monotherapy or trastuzumab emtansine in combination with other drugs.

Efficacy objective: To evaluate the efficacy of tocilizumab monotherapy and in combination with methotrexate compared with methotrexate alone. Safety objective: To evaluate the safety of subcutaneous (SC) tocilizumab monotherapy and in combination with methotrexate compared with methotrexate alone.

The primary objective of this study is to describe the pharmacokinetic characteristics of trastuzumab emtansine (including trastuzumab emtansine, total trastuzumab, and DM1) in Chinese patients with HER2-positive locally advanced or metastatic breast cancer who have previously received trastuzumab and taxane treatment; the secondary objective is to investigate the safety and tolerability of trastuzumab emtansine in Chinese patients with HER2-positive locally advanced or metastatic breast cancer.