Key clinical point: Dalpiciclib, a cyclin-dependent kinase 4/6 inhibitor, plus letrozole or anastrozole demonstrated progression-free survival (PFS) benefits and a manageable safety profile in untreated patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) advanced breast cancer (BC).
Major finding: A 12.4-month improvement in PFS was observed with dalpiciclib vs placebo, with both letrozole and anastrozole (stratified hazard ratio 0.51; P < .0001). Dalpiciclib plus letrozole or anastrozole demonstrated a manageable safety profile, with similar proportions of patients in the dalpiciclib and placebo groups (4% and 2%, respectively) discontinuing the treatment.
Study details: Findings are from the phase 3 DAWNA-2 study including 456 patients with HR+/HER2− advanced BC who were randomly assigned to receive either letrozole or anastrozole with dalpiciclib or placebo.
Disclosures: This study was funded by Jiangsu Hengrui Pharmaceuticals and partly by the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences. Three authors declared being employees of Hengrui, and Binghe Xu declared receiving research grants and fees from some sources.
Source: Zhang P et al. Dalpiciclib plus letrozole or anastrozole versus placebo plus letrozole or anastrozole as first-line treatment in patients with hormone receptor-positive, HER2-negative advanced breast cancer (DAWNA-2): A multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol. 2023;24:646-657 (May 11). doi: 10.1016/S1470-2045(23)00172-9