Key clinical point: Palbociclib plus endocrine therapy (ET) improved progression-free survival (PFS) across all subgroups of patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2−) advanced breast cancer (BC).
Major finding: Median PFS was longer in patients receiving palbociclib+letrozole vs placebo+letrozole (hazard ratio [HR] 0.56; 95% CI 0.46-0.69) or palbociclib+fulvestrant vs placebo+fulvestrant (HR 0.50; 95% CI 0.40-0.62), with similar outcomes observed in subgroups of patients reporting a disease-free interval of ≤12 months, visceral disease, or ET resistance.
Study details : Findings are from a post hoc analysis of two phase 3 trials including women with HR+/HER2− advanced BC who were randomly assigned to receive letrozole with palbociclib or placebo (n = 666; PALOMA-2) or fulvestrant with palbociclib or placebo (n = 521; PALOMA-3).
Disclosures: This study was funded by Pfizer Inc. Four authors declared being employees and stockholders of Pfizer, and the other authors reported ties with several sources, including Pfizer.
Source: Rugo HS et al. Effect of palbociclib plus endocrine therapy on time to chemotherapy across subgroups of patients with hormone receptor‒positive/human epidermal growth factor receptor 2‒negative advanced breast cancer: Post hoc analyses from PALOMA-2 and PALOMA-3. Breast. 2022;66:324-331 (Nov 15). Doi: 10.1016/j.breast.2022.11.005