Trastuzumab emtansine (T-DM1)

In a phase III trial (KATHERINE [NCT01772472]), 1,486 women with HER2-positive disease who received a preoperative taxane-containing chemotherapy (with or without an anthracycline) along with trastuzumab with or without a second HER2 targeted agent, but who had residual disease after surgery, were randomly assigned to receive 14 cycles of adjuvant trastuzumab or T-DM1. The primary end point was IDFS.[141][Level of evidence B1]

In a phase III trial (KATHERINE [NCT01772472]), 1,486 women with HER2-positive disease who received a preoperative taxane-containing chemotherapy (with or without an anthracycline) along with trastuzumab with or without a second HER2 targeted agent, but who had residual disease after surgery, were randomly assigned to receive 14 cycles of adjuvant trastuzumab or T-DM1. The primary end point was IDFS.[141][Level of evidence B1]

At the time of a planned interim analysis, IDFS was significantly higher in the T-DM1 group than in the trastuzumab group (HRinvasive disease or death, 0.50; 95% CI, 0.39–0.64; P < .001; IDFS at 3 years, 88.3% vs. 77%).

In a phase III trial (KATHERINE [NCT01772472]), 1,486 women with HER2-positive disease who received a preoperative taxane-containing chemotherapy (with or without an anthracycline) along with trastuzumab with or without a second HER2 targeted agent, but who had residual disease after surgery, were randomly assigned to receive 14 cycles of adjuvant trastuzumab or T-DM1. The primary end point was IDFS.[141][Level of evidence B1]

Data on OS are immature and not significant (HR, 0.70; 95% CI, 0.47–1.05).

In a phase III trial (KATHERINE [NCT01772472]), 1,486 women with HER2-positive disease who received a preoperative taxane-containing chemotherapy (with or without an anthracycline) along with trastuzumab with or without a second HER2 targeted agent, but who had residual disease after surgery, were randomly assigned to receive 14 cycles of adjuvant trastuzumab or T-DM1. The primary end point was IDFS.[141][Level of evidence B1]

Patients receiving T-DM1 were more likely to discontinue treatment because of an adverse event (18% vs. 2.1%) and had a higher frequency of sensory neuropathy (18.6% vs. 6.9%), most cases of which had resolved at the time of the analysis.

In a phase III trial (KATHERINE [NCT01772472]), 1,486 women with HER2-positive disease who received a preoperative taxane-containing chemotherapy (with or without an anthracycline) along with trastuzumab with or without a second HER2 targeted agent, but who had residual disease after surgery, were randomly assigned to receive 14 cycles of adjuvant trastuzumab or T-DM1. The primary end point was IDFS.[141][Level of evidence B1]

On subgroup analysis, the benefit of T-DM1 was observed in all subgroups, including participants who received dual HER2-targeted therapy in the preoperative setting.