Kadcyla® (ado-trastuzumab emtansine; Roche) significantly extends progression-free survival (PFS) in patients with advanced HER2-positive breast cancer, according to results of the phase 3 TH3RESA trial presented this week at the 2013 European Cancer Congress (ECC) in Amsterdam.
The TH3RESA study evaluated Kadcyla, an HER2-targeted antibody-drug conjugate that contains Roche’s trastuzumab antibody and ImmunoGen’s DM1 cytotoxic agent, for the treatment of advanced HER2-positive breast cancer that progressed despite previous treatment with at least two HER2-targeted medicines.
Approximately 600 patients were randomized two-to-one to receive Kadcyla or their physician’s choice. A majority (80%) of patients treated with physician’s choice received trastuzumab (Herceptin®; Genentech) plus a second agent.
Compared with physician’s choice, Kadcyla significantly extended the duration of PFS (median 6.2 vs. 3.3 months) and reduced the risk of disease progression or death by 47% (hazard ratio=0.528; P<0.0001).
In addition, overall survival (OS) in the planned interim analyses favored Kadcyla, although the data are not yet complete. The co-primary endpoints of the trial are PFS and OS. No new safety concerns were observed with Kadcyla.
Based on results of the previous EMILIA phase 3 trial, Kadcyla is currently approved for marketing in the United States, Japan, Switzerland, Canada, and Australia. EMILIA evaluated Kadcyla in patients with HER2-positive metastatic breast cancer who had been treated with Herceptin and taxane chemotherapy. Patients who also received treatment with lapatinib (Tykerb®) were eligible for the TH3RESA trial.
Roche is currently investigating a number of potential additional uses for Kadcyla, including for first-line treatment of HER2-positive metastatic breast cancer, for early-stage HER2-positive breast cancer, and for advanced HER2-positive gastric cancer.