Multicenter phase 3 trial of first-line dalpiciclib plus endocrine therapy for HR-positive, HER2-negative advanced breast cancer

The phase 3 DAWNA-2 trial, at 42 centers in China, evaluated addition of the CDK4/6 inhibitor dalpiciclib versus placebo to first-line endocrine therapy (letrozole or anastrozole) for HR-positive, HER2-negative advanced breast cancer. The median progression-free survival was 30.6 months in the dalpiciclib group versus 18.2 months in the placebo group (sHR 0.51; p<0.0001). Adverse events of grade 3 or 4 were reported in 90% of patients in the dalpiciclib group and 12% of patients in the placebo group. Two patients in the dalpiciclib group died from unknown causes. The authors conclude that dalpiciclib plus letrozole or anastrozole could be a novel standard first-line treatment for patients with HR-positive, HER2-negative advanced breast cancer.