Safety and efficacy of ribociclib plus letrozole in patients with HR+, HER2– advanced breast cancer: Results from the Spanish sub-population of the phase 3b CompLEEment-1 trial

• Published in: Breast (Edinburgh) Vol. 66; pp. 77 - 84
• Main Authors: Salvador Bofill, Javier, Moreno Anton, Fernando, Rodriguez Sanchez, Cesar Augusto, Galve Calvo, Elena, Hernando Melia, Cristina, Ciruelos Gil, Eva Maria, Vidal, Maria, Jiménez-Rodriguez, Begoña, De la Cruz Merino, Luis, Martínez Jañez, Noelia, Villanueva Vazquez, Rafael, de Toro Salas, Ruben, Anton Torres, Antonio, Alvarez Lopez, Isabel Manuela, Gavila Gregori, Joaquin, Quiroga Garcia, Vanesa, Vicente Rubio, Elena, De la Haba-Rodriguez, Juan, Gonzalez-Santiago, Santiago, Diaz Fernandez, Nieves, Barnadas Molins, Agusti, Cantos Sanchez de Ibargüen, Blanca, Delgado Mingorance, Juan Ignacio, Bellet Ezquerra, Meritxell, de Casa, Sonia, Gimeno, Asuncion, Martin, Miguel
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.12.2022; Elsevier
• Subjects: Advanced breast cancer; Aminopyridines - adverse effects; Antineoplastic Combined Chemotherapy Protocols - adverse effects; Aromatase Inhibitors - therapeutic use; Breast Neoplasms - pathology; CDK4/6 inhibitor; Female; Humans; Letrozole; Middle Aged; Neutropenia - etiology; Original; Postmenopausal; Premenopausal; Protein Kinase Inhibitors - therapeutic use; Receptor, ErbB-2 - metabolism; Ribociclib; Postmenopausal; QTcF; ABC; PR; Advanced breast cancer; FACT-B; Ribociclib; ALT; CNS; HR; PRO; ORR; CDK4/6 inhibitor; SD; TTP; CBR; ECOG; Premenopausal; HRQoL; PFS; SS; AST; RECIST; AE; AESI; CDK4/6; OS; CI; LPLV; CR; ET; SAE; LPFV; NE; FAS; FPFV; HER2
• ISSN: 0960-9776; 1532-3080
• DOI: 10.1016/j.breast.2022.09.006

Breast cancer is the most common malignancy and the second leading cause of cancer-related mortality in Spanish women. Ribociclib in combination with endocrine therapy (ET) has shown superiority in prolonging survival in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) advanced breast cancer (ABC) vs. ET alone. CompLEEment-1 is a single-arm, open-label phase 3b trial evaluating ribociclib plus letrozole in a broad population of patients with HR+, HER2– ABC. The primary endpoints were safety and tolerability. Here we report data for Spanish patients enrolled in CompLEEment-1. A total of 526 patients were evaluated (median follow-up: 26.97 months). Baseline characteristics showed a diverse population with a median age of 54 years. At study entry, 56.5% of patients had visceral metastases and 8.7% had received prior chemotherapy for advanced disease. Rates of all-grade and Grade ≥3 adverse events (AEs) were 99.0% and 76.2%, respectively; 21.3% of patients experienced a serious AE, and 15.8% of AEs led to treatment discontinuation. AEs of special interest of neutropenia, increased alanine aminotransferase, increased aspartate aminotransferase and QTcF prolongation occurred in 77.8%, 14.8%, 11.4% and 4.0% of patients, respectively. Patients aged >70 years experienced increased rates of all-grade and Grade ≥3 neutropenia and anemia. Efficacy results were consistent with the global study. Results from Spanish patients enrolled in CompLEEment-1 are consistent with global data showing efficacy and a manageable safety profile for ribociclib plus letrozole treatment in patients with HR+, HER2− ABC, including populations of interest (NCT02941926). ClinicalTrials.gov NCT02941926 •Results from the CompLEEment-1 Spanish population are comparable to the global results.•Manageable safety was shown in elderly patients and those with visceral disease.•Efficacy data were comparable to those of the global study in a younger population.•Efficacy and safety of ribociclib are confirmed in a broader patient population.•Results confirm a robust response to treatment in a local setting.