Health-Related Quality of Life in MONARCH 3: Abemaciclib plus an Aromatase Inhibitor as Initial Therapy in HR+, HER2- Advanced Breast Cancer.

BACKGROUND: MONARCH 3, a phase III trial (NCT02246621) of postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC), previously demonstrated significantly improved progression-free survival in patients receiving abemaciclib plus a nonsteroidal aromatase inhibitor (NSAI). This study evaluated patient-reported outcomes, including global health-related quality of life (HRQoL), functioning, and symptoms. METHODS: Patients were randomly assigned 2:1 to receive abemaciclib (150 mg twice daily; n = 328) or placebo (n = 165), plus 1 mg anastrozole or 2.5 mg letrozole daily. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and Breast Cancer-Specific Quality of Life Questionnaire HRQoL instruments were administered at baseline, every two cycles during cycles 2 through 19 (each cycle being 28 days), every three cycles thereafter, and once at a short-term posttherapy follow-up visit (approximately 30 days after discontinuation). Longitudinal mixed regression and Cox proportional hazards models evaluated postbaseline change and time to sustained deterioration (TTSD), respectively. RESULTS: Baseline scores were similar between treatment arms. Although select scores statistically favored the placebo arm, global HRQoL, most symptoms, and functioning scales did not meet the threshold for clinically meaningful differences between treatment arms. Only diarrhea favored the placebo arm with statistically and clinically meaningful differences. There were no TTSD differences between treatment arms for global HRQoL, most symptoms (except diarrhea), or functioning. CONCLUSION: Over a 2-year period, there were no clinically meaningful differences in global HRQoL, functioning, and most symptoms for patients receiving abemaciclib plus NSAI compared with NSAI alone. Only diarrhea favored the placebo arm, consistent with prior safety data, which has been shown to be manageable and reversible. Combined with clinical efficacy, results support treatment with abemaciclib plus NSAI for postmenopausal women with HR+, HER2- ABC. IMPLICATIONS FOR PRACTICE: The addition of abemaciclib to a nonsteroidal aromatase inhibitor (NSAI) was not associated with a clinically meaningful detriment in patient-reported global health-related quality of life, functioning, and most symptoms in postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). Prior studies have also demonstrated clinical efficacy of abemaciclib plus NSAI compared with NSAI alone, including improved progression-free survival and objective response rate. These results also complement previously reported toxicity data, as measured by investigator-assessed adverse events. Taken together, these results support treatment with abemaciclib plus NSAI for postmenopausal women with HR+, HER2- ABC.

Health-Related Quality of Life in MONARCH 2: Abemaciclib plus Fulvestrant in Hormone Receptor-Positive, HER2-Negative Advanced Breast Cancer After Endocrine Therapy.

BACKGROUND: In the phase III MONARCH 2 study (NCT02107703), abemaciclib plus fulvestrant significantly improved progression-free survival (PFS) versus placebo plus fulvestrant in patients with hormone receptor-positive (HR+), HER2-negative advanced breast cancer (ABC). This study assessed patient-reported pain, global health-related quality of life (HRQoL), functioning, and symptoms. MATERIALS AND METHODS: Abemaciclib or placebo (150 p.o. mg twice daily) plus fulvestrant (500 mg, per label) were randomly assigned (2:1). The modified Brief Pain Inventory, Short Form (mBPI-sf); European Organization for Research and Treatment of Cancer (EORTC) QoL Core 30 (QLQ-C30); and Breast Cancer Questionnaire (QLQ-BR23) assessed outcomes. Data were collected at baseline, cycle 2, every two cycles 3-13, thereafter at every three cycles, and 30 days postdiscontinuation. Longitudinal mixed regression and Cox proportional hazards models assessed postbaseline change and time to sustained deterioration (TTSD) by study arm. RESULTS: On-treatment HRQoL scores were consistently maintained from baseline and similar between arms. Patients in the abemaciclib arm (n = 446) experienced a 4.9-month delay in pain deterioration (mBPI-sf), compared with the control arm (n = 223), and significantly greater TTSD on the mBPI-sf and analgesic use (hazard ratio, 0.76; 95% CI, 0.59-0.98) and QLQ-C30 pain item (hazard ratio, 0.62; 95% CI, 0.48-0.79). TTSD for functioning and most symptoms significantly favored the abemaciclib arm, including fatigue, nausea and vomiting, and cognitive and social functioning. Only diarrhea significantly favored the control arm (hazard ratio, 1.60; 95% CI, 1.20-2.10). CONCLUSION: HRQoL was maintained on abemaciclib plus fulvestrant. Alongside superior PFS and manageable safety profile, results support treatment with abemaciclib plus fulvestrant in a population of patients with endocrine-resistant HR+, HER2-negative ABC. IMPLICATIONS FOR PRACTICE: In MONARCH 2, abemaciclib plus fulvestrant demonstrated superior efficacy and a manageable safety profile for patients with in hormone receptor-positive (HR+), HER2-negative (-) advanced breast cancer (ABC). Impact on health-related quality of life (HRQoL) is important to consider, given the palliative nature of ABC treatment. In this study, abemaciclib plus fulvestrant, compared with placebo plus fulvestrant, significantly delayed sustained deterioration of pain and other patient-reported symptoms (including fatigue, nausea, vomiting), and social and cognitive functioning. Combined with demonstrated clinical benefit and tolerability, the stabilization of patient-reported symptoms and HRQoL further supports abemaciclib plus fulvestrant as a desirable treatment option in endocrine resistant, HR+, HER2- ABC.