AstraZeneca says ENHERTU achieved 61.6% progression-free survival rate in study

Results from the DESTINY-Breast12 Phase IIIb/IV trial showed that ENHERTU demonstrated substantial overall and intracranial clinical activity in a large cohort of patients with HER2-positive metastatic breast cancer who have brain metastases and received no more than two prior lines of therapy in the metastatic setting, announced AstraZeneca (AZN) and Daiichi Sankyo (DSNKY). Results will be presented today as a late-breaking presentation at the European Society for Medical Oncology and simultaneously published in Nature Medicine. ENHERTU is a specifically engineered HER2-directed DXd antibody drug conjugate discovered by Daiichi Sankyo and being jointly developed and commercialized by AstraZeneca and Daiichi Sankyo. In patients with brain metastases at baseline, the primary endpoint of progression-free survival (PFS) by independent central review showed a 12-month PFS rate of 61.6%. Additionally, patients with brain metastases showed a central nervous system 12-month PFS rate of 58.9%. Results were consistent in patients with stable and active brain metastases. Patients with stable brain metastases had a 12-month PFS rate of 62.9% and a 12-month CNS PFS rate of 57.8%. Patients with active brain metastases had a 12-month PFS rate of 59.6% and a 12-month CNS PFS rate of 60.1%. In patients without brain metastases at baseline, the primary endpoint of confirmed objective response rate, or ORR, by independent central review showed an ORR of 62.7% with 23 complete responses, or CR, and 128 partial responses, or PR.