Breast Cancer Coverage From Every Angle

Ado-trastuzumab Emtansine as First-Line Therapy for Metastatic Breast Cancer in MARIANNE Trial

By: Cordi Craig
Posted: Friday, August 4, 2017

The final results of the phase III MARIANNE trial support earlier findings with ado-trastuzumab emtansine (formerly known as T-DM1), suggesting it remains an “effective and tolerable alternative first-line treatment for patients with HER2-positive metastatic breast cancer,” according to Edith A. Perez, MD, Professor of Medicine at Mayo Clinic, Jacksonville, Florida, and colleagues. Dr. Perez presented these final safety and efficacy data at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 1003).

In this study, patients with untreated advanced HER2-positive breast cancer were randomized to receive one of three first-line treatments: (1) trastuzumab plus docetaxel or paclitaxel (HT; n=365); (2) ado-trastuzumab emtansine plus placebo (T-DM1; n=367); or (3) ado-trastuzumab emtansine plus pertuzumab (T-DM1+P; n=363).

After a median follow-up of 54 months, 512 patient deaths were reported. Overall survival rates were similar across the 3 groups receiving HT, T-DM1, and T-DM1+P (50.9, 53.7, and 51.8 months, respectively). Numerically fewer grade 3 or higher adverse events were reported in the group of patients receiving ado-trastuzumab emtansine treatment (47.1% vs. 55.8% in the HT arm and 48.6% in the T-DM1+P arm).