Real-World Outcomes of Ribociclib Treatment in Patients With Metastatic Breast Cancer at a Tertiary Care Hospital

Background  Ribociclib is an important treatment option in patients with hormone receptor-positive (HR+) HER2-negative (HER2-) advanced/metastatic breast cancer (ABC/MBC); however, there are limited data on its efficacy and safety in the South Asian population. This study aims to evaluate outcomes of breast cancer patients treated with ribociclib therapy in terms of progression-free survival (PFS), overall survival (OS), overall response rate (ORR), duration of response (DOR), and assessment of frequency and severity of toxicity at a tertiary care setup in a resource-limited setting.  Methodology  This was a single-center, retrospective observational study. Patients aged 18 years and older, diagnosed with HR+ HER2- ABC/MBC, registered between January 2016 and December 2021, and treated with ribociclib therapy were included in this study. Results  Median PFS for the overall cohort (n = 50) was 14.7 months, with 10 (20%) patients having no progression on last follow-up. Median OS was 30.8 months, and 19 (38%) patients were alive at the time of last follow-up. Median PFS and OS were significantly longer in patients with non-visceral metastatic disease than with extracranial visceral and brain metastatic disease. The ORR was 48%, whereas the clinical benefit rate was 76%, and the median DOR was 18.9 months. Eleven patients achieved a complete response during the course of their treatment. The most common adverse effect was neutropenia (68%), which was manageable with appropriate dose reductions. Conclusion Our retrospective data support the notion that ribociclib-based therapy is effective and safe in patients with HR+/HER2- ABC/MBC; however, as it is a retrospective study with a small sample size, further prospective studies are necessary to further prove these results in the local population, and efforts should be taken in society at large to make this treatment available to all patients who require this treatment.