Key clinical point: Palbociclib+endocrine therapy (ET) did not yield superior progression-free survival (PFS) vs. capecitabine in patients with aromatase inhibitor-resistant metastatic breast cancer (AIR-MBC) but was well tolerated and improved quality of life (QoL).
Major finding: Median PFS with palbociclib+fulvestrant vs. capecitabine was 7.5 vs. 10.0 months (adjusted hazard ratio [aHR], 1.13; P = .398). Palbociclib+ET did not show PFS superiority vs. capecitabine in patients with wild-type estrogen receptor-1 AIR-MBC (8.0 vs. 10.6 months; aHR, 1.11; P = .404). Palbociclib+ET was better tolerated and improved QoL (aHR, 0.67; P = .001).
Study details : Phase 3 PEARL trial randomly allocated postmenopausal women with AIR-MBC to receive either palbociclib+exemestane or capecitabine (n=296) or palbociclib+fulvestrant or capecitabine (n=305).
Disclosures: This study was supported by Pfizer and AstraZeneca and sponsored by GEICAM Spanish Breast Cancer Group. The lead author reported ties with AstraZeneca, Pfizer, Amgen, Taiho Oncology, Roche/Genentech, Novartis, PharmaMar, Eli Lilly, PUMA, and Daiichi-Sankyo. Other investigators reported owning stocks, being an employee, receiving support, and/or consulting for various pharmaceutical companies including Pfizer and AstraZeneca.
Source: Martin M et al. Ann Oncol. 2020 Dec 29. doi: 10.1016/j.annonc.2020.12.013 .