Quality of Life Maintained With Abemaciclib Plus Trastuzumab With or Without Fulvestrant in Patients with HR-Positive, HER2-Negative Breast Cancer

Quality of life was maintained for patient-reported pain, global health, functioning, and most symptoms when abemaciblib was added to a trastuzumab and fulvestrant combination compared with the standard of care chemotherapy in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2-positive) advanced breast cancer (ABC).

The results were published as a poster session during the San Antonio Breast Cancer Symposium in San Antonio, TX. In the randomized, 3-arm, phase 2 study monarcHER study for HR-positive, HER2-positive ABC, abemaciclib in combination with trastuzumab and fulvestrant significantly improved investigator-assessed progression-free survival versus trastuzumab plus chemotherapy.

In the study, 237 postmenopausal (surgical, natural, or chemical ovarian suppression) women with ABC prior to HER2-positive directed therapies in the advanced setting were randomized 1:1:1 to 150 mg abemaciclib + trastuzumab (intravenous infusion every 21 days) with 500 mg fulvestrant or without fulvestrant vs trastuzumab plus physician’s choice of chemotherapy. Patient-reported outcomes were measured at baseline and at every cycle using the modified Brief Pain inventory-short form and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30.

Abemacilib is an oral selective inhibitor of cyclin-dependent kinases 4 and 6 approved for HR-positive, HER2-negative metastatic breast cancer.

Patient-reported outcome compliance rates were 90% through cycle 15. The range for median duration of each treatment component of each group was 7.5-10.0 cycles. No statistically significantly differences or clinically meaningful changes from baseline differences were observed between treatment groups for global health score, function scales, or for symptoms of fatigue, dyspnea, appetite loss, or financial difficulties. Worsening adverse events (AEs), including nausea/vomiting and diarrhea, showed statistically significant improvements with the fulvestrant plus trastuzumab group versus chemotherapy.

Overall, quality of life was maintained for patient-reported pain, global health, functioning, and most symptoms when abemaciclib was added to fulvestrant plus trastuzumab compared with physician’s choice of chemotherapy in patients with HR-positive, HER2-positive ABC. Furthermore, gastrointestinal-related adverse events were transient and consistent with the manageable, reversible AE profile.

REFERENCE

Health-related quality of life (HRQoL) in monarcHER: Abemaciclib plus trastuzumab with or without fulvestrant versus trastuzumab plus standard-of-care chemotherapy in HR+, HER2+ advanced breast cancer. Accessed December 2, 2019. https://plan.core-apps.com/sabcs2019/abstract/a25f48e96f590da9de0d7c903eddc944.