Palbociclib plus letrozole significantly improved progression free survival (PFS) compared to letrozole alone in the phase III PALOMA-2 trial. QOL is a critical consideration when adding targeted agents to hormone therapy in metastatic breast cancer (MBC). We compared patient reported HRQOL in treatment naïve postmenopausal patients with ER + , HER2- MBC in PALOMA-2 (Pfizer: NCT01740427).
PALOMA-2 randomized patients 2:1 to palbociclib + letrozole (N= 444) or placebo + letrozole (N= 222). Patient reported outcomes were assessed at baseline, day 1 of cycle 2, 3 and day 1 of every other cycle from cycle 5 until end of treatment using the Functional Assessment of Cancer Therapy – Breast (FACT-B) questionnaire. FACT-B includes FACT-General (FACT-G) and BC-specific subscale (BCS). FACT-B produces five subscale scores: physical well-being (PWB), social/family well-being (SWB), emotional well-being (EWB), functional wellbeing (FWB), and a BC subscale (BCS), used to derive overall FACT-B, FACT-G, and Trial Outcome Index (TOI) scores. A higher score indicates a better QOL. Repeated measures mixed-effects analyses were performed to compare between treatments change from baseline in each subscale and FACT-B scores, controlling for baseline.
Baseline scores were comparable between the two treatment arms for FACT-B (102 vs 103), FACT- G, TOI and each of the subscale scores. There were no significant differences between the treatment groups in change from baseline scores for PWB (-0.5 vs. -0.3; p= 0.414), SWB (-0.6 vs -0.7; p = 0.762), EWB (0.7 vs 0.5;p = 0.538) and FWB (0.2 vs 0.3;p = 0.707). Overall change from baseline scores was comparable for the BCS (0.19 vs 0.83; p =0.055), Trial Outcome Index (-0.1 vs 0.71; p= 0.325), FACT- G (-0.39 vs -0.53; p = 0.882) and FACT-B (-0.11 vs 0.22; p = 0.782) scores.
The addition of palbociclib to letrozole maintains HRQOL in treatment naïve postmenopausal patients with ER+ HER2- MBC and showed no significant difference compared to letrozole alone. This data adds favorably to the significant improvement in PFS seen in PALOMA-2.
Clinical trial identification
Legal entity responsible for the study
H. Rugo: Institution receives research funding from Pfizer, Novartis, Lilly. V. Dieras: Consultant/Advisory role -Roche, Pfizer, Novartis Speaker's Bureau-Roche, Pfizer, Novartis. R. Finn: Consultant/Advisory role -Pfizer, Bayer, Novartis, Bristol Myers Squibb Institution receives research funding from Pfizer.
D. Slamon: Stock Ownership; Travel Accommodations or Expenses -PFizer Leadership; Stock Ownership; Travel Accommodations or Expenses- BioMarin. M. Miguel: Honraria - Amgen, Novartis Consultant/Advisory Role -Celgene; Novartis; Pfizer; Roche Pharma AG Research funding – Novartis.
J. Ettl: Consulting or Advisory Role; Travel Accommodations or Expenses - Pfizer, Roche, GSK, Teva, Novartis. A. Mori, D.R. Lu, H. Bhattacharyya, C.H. Bartlett, S. Iyer: Pfizer employee and stockholder
S. Johnston: Research Funding - Pfizer Consultant/Advisory Board - Astra Zeneca, Roche/Genetech, Novartis, Puma. N. Harbeck: Honararia-Amgen; Celgene, NanoString Technologies, Novartis; Pfizer, Roche.Consultant/Advisory Role -AstraZeneca, Celgene, Genomic Health, Novartis, Roche/Genentech, Sandoz, Wilex.Research Funding -Boehringer Ingelheim, Novartis, Pfizer, Roche/Genentech. All other authors have declared no conflicts of interest.