Roche has reported positive topline results from its first randomised trial of trastuzumab emtansine (T-DM1), an antibody-drug conjugate, in HER2-positive metastatic breast cancer.

The randomised, multicentre international, two-arm and open-label clinical trial was designed to compare T-DM1 single agent to the combination of Herceptin (trastuzumab) and chemotherapy (docetaxel) in previously untreated patients.

The trial enrolled 137 patients with first-line HER2-positive metastatic breast cancer from approximately 64 sites, who were randomised to receive either T-DM1 or Herceptin and chemotherapy.

The study results revealed that patients receiving T-DM1 lived significantly longer with their disease under control and experienced fewer side effects typical of chemotherapy.

The primary endpoints of the study were progression-free survival and safety, while secondary endpoints were objective response, duration of objective response, and clinical benefit rate.

Genentech, a member of the Roche Group, has licensed technology for T-DM1 under an agreement with ImmunoGen.