Trastuzumab deruxtecan

A phase III, multicenter, open-label, randomized trial (DESTINY-Breast03 [NCT03529110]) compared the efficacy and safety of trastuzumab deruxtecan with trastuzumab emtansine. The study included 524 patients with HER2-positive metastatic breast cancer previously treated with a taxane and trastuzumab. PFS was the primary end point.[79] This trial led to a change in the standard of care for patients with HER2-positive metastatic breast cancer, such that patients with prior taxane/trastuzumab therapy proceed to trastuzumab deruxtecan, rather than trastuzumab emtansine, for second-line therapy.

A phase III, multicenter, open-label, randomized trial (DESTINY-Breast03 [NCT03529110]) compared the efficacy and safety of trastuzumab deruxtecan with trastuzumab emtansine. The study included 524 patients with HER2-positive metastatic breast cancer previously treated with a taxane and trastuzumab. PFS was the primary end point.[79] This trial led to a change in the standard of care for patients with HER2-positive metastatic breast cancer, such that patients with prior taxane/trastuzumab therapy proceed to trastuzumab deruxtecan, rather than trastuzumab emtansine, for second-line therapy.

At 12 months, 75.8% of patients who received trastuzumab deruxtecan were alive without disease progression, compared with 34.1% of patients who received trastuzumab emtansine (HR, 0.28; 95% CI, 0.22–0.37; P < .001).

A phase III, multicenter, open-label, randomized trial (DESTINY-Breast03 [NCT03529110]) compared the efficacy and safety of trastuzumab deruxtecan with trastuzumab emtansine. The study included 524 patients with HER2-positive metastatic breast cancer previously treated with a taxane and trastuzumab. PFS was the primary end point.[79] This trial led to a change in the standard of care for patients with HER2-positive metastatic breast cancer, such that patients with prior taxane/trastuzumab therapy proceed to trastuzumab deruxtecan, rather than trastuzumab emtansine, for second-line therapy.

Secondary end points were OS, overall response rate, and safety. A total of 94.1% of patients who received trastuzumab deruxtecan were alive at 12 months, compared with 85.9% of patients who received trastuzumab emtansine (HRdeath, 0.55; 95% CI, 0.36–0.86). The overall response rate was 79.7% versus 34.2%, favoring trastuzumab deruxtecan. Grade 3 to 4 drug-related adverse events occurred in 45.1% of patients who received trastuzumab deruxtecan and 38.9% of patients who received trastuzumab emtansine. Interstitial lung disease and pneumonitis occurred in 10.5% of patients who received trastuzumab deruxtecan and 1.9% of patients who received trastuzumab emtansine; none of these events were grade 4 to 5.