Roche’s Genentech reported positive progression-free survival (PFS) and one- and two-year survival data from the Phase III Emilia trial evaluating the antibody drug conjugate trastuzumab emtansine (T-DM1) in the treatment of patients with Her2-positive metastatic breast cancer (mBC). The firm says regulatory applications in this indication are now expected to be submitted to FDA and EMA later this year.
Trastuzumab emtansine comprises trastuzumab (Herceptin®) and ImmunoGen’s DM1 cancer-killing agent, joined using ImmunoGen linker technology. The Emilia study showed that in comparison with treatment using lapatinib plus Xeloda® (capecitabine), therapy with trastuzumab emtansine was associated with a 35% reduction in the risk of disease worsening or death. Progression-free survival was 9.6 months for patients treated using trastuzumab emtansine, compared with 6.4 months for those given lapatinib plus capecitabine.
One-year survival for trastuzumab emtansine patients was 84.7% and two-year survival 65.4%. In comparison, one-year and two-year survival rates for patients receiving lapatinib plus capecitabine were 77.0% and 47.5%, respectively.
Overall survival for the lapatinib plus capecitabine treatment group was 23.3 months. However, Genentech states, overall survival data for the trastuzumab emtansine cohort aren’t yet available as longer follow up is needed before a sufficient number of events have occurred in this patient cohort.
Genentech says Emilia represents the first randomized Phase III trial evaluating trastuzumab emtansine in patients with Her2-positive mBC who had previously received trastuzumab and a taxane chemotherapy.
Two additional Phase III studies evaluating transtuzumab emtansine are ongoing. Marianne is comparing trastuzumab emtansine monotherapy with trastuzumab emtansine plus pertuzumab and trastuzumab plus a taxane therapy in patients with Her2-positive mBC who haven’t previously been treated for metastatic disease. Th3resa is comparing trastuzumab emtansine with physician’s choice of therapy in people with Her2-positive mBC who have previously received both Herceptin and lapatinib.