Interim results from CompLEEment-1 (A phase IIIb study of ribociclib and letrozole as first-line therapy for advanced breast cancer in an expanded population): Spanish cohort results

Abstract

Background: In Spain luminal metastatic Breast Cancer accounts for more than 3000 deaths yearly. Ribociclib+letrozole has shown efficacy on prolonging progression free survival (PFS) vs placebo+letrozol in two phase 3 trials. However, data on efficacy and tolerability is lacking for a broader population. We present interim data from CompLEEment-1, an ongoing, open-label, phase 3b trial evaluating ribociclib+letrozole as first-line endocrine therapy in an expanded population of patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). Method(s): Patients treated with = 3 treatment-related adverse events (AEs) was 98.5% and 70.0%, respectively. Treatment-related serious AEs occurred in 12.2% of patients. All-grade and grade >= 3 AEs leading to ribociclib discontinuation occurred in 13.7% and 8.2% of patients, respectively. Rates of >= 3 AEs of special interest (AESI) were 59.5% for neutropenia, 6.8% for increased alanine aminotransferase, 4.8% for increased aspartate aminotransferase, and 0.6% for QTcF prolongation. Patient health-related quality of life was maintained versus baseline. Conclusion(s): Initial results from the Spanish cohort in CompLEEment-1 are consistent with previous data showing efficacy and a manageable safety profile of ribociclib plus letrozole as a first-line treatment option in a diverse group of patients with HR+, HER2- ABC. Acknowledgement: Dr. J. Gavila-Gregori, Dr. M.J. Martinez-Serrano and Dr. M. Perello contributed equally to this study. Clinical trial identification: NCT02941926. Legal entity responsible for the study: Novartis Pharmaceuticals Corporation. Funding(s): Novartis Pharmaceuticals Corporation. Disclosure: E.M. Ciruelos: Advisory / Consultancy, Speaker Bureau / Expert testimony, Speaker and ad.board honoraria: Novartis; Advisory / Consultancy, Speaker Bureau / Expert testimony, Speaker and ad.board honoraria: Lilly; Advisory / Consultancy, Speaker Bureau / Expert testimony, Speaker and ad.board honoraria: Roche; Advisory / Consultancy, Speaker Bureau / Expert testimony, Speaker and ad.board honoraria: Pfizer. R. Villanueva Vazquez: Advisory / Consultancy: Novartis; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Roche. F. Moreno: Advisory / Consultancy, Travel / Accommodation / Expenses: Novartis; Advisory / Consultancy, Travel / Accommodation / Expenses: Pfizer; Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: Eisai; Advisory / Consultancy: MSD. I. Alvarez: Research grant / Funding (institution): Novartis; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche. S. Gonzalez-Santiago: Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Roche; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): AstraZeneca. A. Barnadas: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Novartis; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Pfizer; Research grant / Funding (institution): Bristol-Myers Squibb; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZeneca; Research grant / Funding (institution): Lilly; Advisory / Consultancy, Travel / Accommodation / Expenses: Eisai; Advisory / Consultancy, Travel / Accommodation / Expenses: Genomic Health; Advisory / Consultancy, Travel / Accommodation / Expenses: Pierre Fabre. B. Cantos: Research grant / Funding (institution), Study enrollment: Fundacion para la Investigacion del Hospital Puerta de Hierro de Majadahonda; Advisory / Consultancy: Novartis; Advisory / Consultancy: Roche; Advisory / Consultancy: Celgene; Advisory / Consultancy: AstraZeneca. M. Bellet Ezquerra: Advisory / Consultancy: Novartis; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Lilly. M. Martin: Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy, Research grant / Funding (institution): Roche; Advisory / Consultancy: Lilly; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Pharmamar; Advisory / Consultancy: Taiho Oncology; Advisory / Consultancy: Amgen; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution): Puma. N. Martinez: Research grant / Funding (institution): Roche; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): AstraZeneca. All other authors have declared no conflicts of interest.Copyright © 2019 European Society for Medical Oncology