Patient-reported outcomes of palbociclib plus exemestane with GnRH agonist versus capecitabine in premenopausal women with hormone receptor-positive metastatic breast cancer from the YoungPearl phase ll trial (KCSG-BR 15-10, NCT02592746)

Background Recently, palbociclib plus exemestane with GnRH agonist demonstrated a statistically significant improvement in progression-free survival (PFS) compared with that of the capecitabine for premenopausal women with hormone receptor-positive metastatic breast cancer (median PFS 20·1 vs. 14·4 months, p = 0·0235 ; HR 0·659 [95% C.I. 0·437–0·994])(Park YH et al, J Clin Oncol 37, 2019 [suppl; abstr 1007]). We evaluated PROs in YoungPEARL phase ll trial. Methods Pts (N = 189) were randomized 1:1 to receive palbociclib plus exemestane with GnRH agonist or capecitabine. PROs were assessed at day 1 (baseline), every 6 weeks, and at the end of treatment, using European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-30). Repeated-measures mixed-effect analyses were carried out to compare on-treatment overall scores and changes from baseline between the treatment groups while controlling for baseline. Results Questionnaire completion rates were 100% at baseline and during treatment from baseline to 84 weeks in each group. Global health status/QoL scores were maintained from baseline to the end of treatment across all time points within each cohort. Between-treatment comparison in the change from baseline functioning scale scores showed trends favoring palbociclib arm for physical functioning (0.12 vs -3.66, p = 0.1201) while favoring capecitabine arm for emotional (0.87 vs 2.61, p = 0.5963) and social functioning (2.63 vs 5.97, p = 0.3234). There was a trend to improve appetite loss (-5.27 vs 0.72, p = 0.1484) and insomnia tended to get worse (3.81 vs -2.65, p = 0.0736) in palbociclib arm while capecitabine arm showed the greater improvement in pain (-2.80 vs -5.83, p = 0.3200) but worsening in diarrhea (1.17 vs 7.37, p = 0.0598) without statistical significance. Conclusions These findings show that palbociclib plus endocrine therapy maintained high PRO scores with some different function and symptom profiles compared with capecitabine arm. Clinical trial identification NCT02592746. Legal entity responsible for the study Korea Cancer Study Group. Funding Pfizer. Disclosure All authors have declared no conflicts of interest.