KEY TAKEAWAYS
- CompLEEment-1 tested ribociclib and letrozole in HR+/HER2- ABC patients.
- Men and women of any menopausal status received oral ribociclib 600mg and letrozole 2.5mg daily, with premenopausal women also getting a GnRH-agonist.
- Treatment-related AEs caused dose adjustments/interruptions in 63.1% of patients, with 10.6% quitting treatment.
- The SERCE subgroup’s safety outcomes matched the pivotal ribociclib-endocrine treatment trials.
- Ribociclib appears safe and tolerated in a wide spectrum of HR+/HER2- ABC patients, more reflective of real-world clinical practice.
The CDK4/6 inhibitor ribociclib, when used in conjunction with endocrine therapy, showed superior overall survival in premenopausal patients with HR+/HER2-advanced breast cancer (ABC) and significantly improved progression-free survival in the first-line setting in postmenopausal patients with HR+/HER2-ABC (MONALEESA-7). The largest phase 3 clinical trial (MONALEESA-2) to date to evaluate the safety and efficacy of a CDK4/6 inhibitor was the multinational, phase 3b, CompLEEment-1 trial, which evaluated the safety and efficacy of ribociclib plus letrozole in a broader population of patients who have not received prior endocrine therapy for advanced disease. Researchers present a subanalysis of patients recruited in the SERCE (Southern Europe, RUC, Central Europe) cluster of CompLEEment-1 (N = 339). Oral ribociclib 600 mg once daily (3 weeks on/1 week off) plus continuous letrozole 2.5 mg was given to men and women of any menopausal status with HR+/HER2- ABC. Moreover, a GnRH-agonist was given to males and premenopausal females.
The primary endpoint was the number of patients who experienced adverse events (AEs) during 36 months. Researchers also tracked how quickly patients improved, how many people responded, and how many patients saw clinical benefits. Ribociclib, in combination with endocrine therapy, showed similar safety data in the SERCE subgroup as in the preliminary clinical trials. Dose reductions or interruptions due to treatment-related adverse events occurred in 63.1% of patients, while only 10.6% ultimately decided to stop therapy altogether. Neutropenia and transaminase increases were the most common adverse events (AEs) of grade ≥ 3 caused by the medication. No patients died from complications during treatment. These data from the SERCE subgroup suggest that ribociclib is safe and well tolerated by many patients with HR+/HER2- ABC, more reflective of patients seen in routine clinical practice.
Source: https://pubmed.ncbi.nlm.nih.gov/35575587/
Clinical Trial: https://clinicaltrials.gov/ct2/show/NCT02941926
Borstnar S, Palacova M, Łacko A, Timcheva C, Gal-Yam EN, Papazisis K, Beniak J, Kudela P, Rubovszky G. Ribociclib plus letrozole in patients with hormone receptor-positive, HER2-negative advanced breast cancer with no prior endocrine therapy: subgroup safety analysis from the phase 3b CompLEEment-1 trial. Radiol Oncol. 2022 May 17;56(2):238-247. doi: 10.2478/raon-2022-0020. PMID: 35575587; PMCID: PMC9122294.
