Overall survival (OS) and health related Quality of Life (hrQoL) analyses of data from the MONALEESA-2 study, which evaluated ribociclib (Kisqali® ; Novartis) plus letrozole (Femara®; Novartis), demonstrated that the combination of the two drugs helped maintain an OS benefit for postmenopausal patients with HR+/HER2- advanced or metastatic breast cancer treated in the first-line. 
This conclusion and supportive data were presented during the annual meeting of the American Society of Clinical Oncology (ASCO) held from June 3-7, 2022 in Chicago, Il.
In a new exploratory analysis of data from the Phase III MONALEESA-2 study, ribociclib, a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor developed by the Novartis Institutes for BioMedical Research (NIBR) under a research collaboration with Astex Pharmaceuticals, plus letrozole, an endocrine therapy for patients with hormone receptor-positive/human epidermal growth factor receptor-negative (HR+/HER2-) advanced or metastatic breast cancer, maintained an OS benefit for postmenopausal patients with HR+/HER2- metastatic breast cancer treated in the first-line, including for those patients who required dose modification of ribociclib.
Median OS, obtained using a modified Kaplan-Meier method, seen in this analysis was 66.0 months (95% CI, 57.6-75.7) in patients with at least one ribociclib dose reduction from the 600 mg starting dose compared to 60.6 months (95% CI, 42.5-79.2) in patients who did not have a dose reduction (HR, 0.87 [95% CI, 0.65-1.18]). Additionally, an OS benefit was observed in all patient subgroups treated with ribociclib and letrozole
“Ribociclib is the only CDK4/6 inhibitor to have consistently demonstrated statistically significant overall survival across its entire Phase III program,” noted Reshema Kemps-Polanco, Executive Vice President, US Oncology at Novartis.
health related Quality of Life
hrQoL is an important end point that affects treatment decisions. Understanding the impact of CDK4/6i on hrQoL is of increasing importance given use in earlier treatment lines for advanced or metastatic breast cancer and an emerging role in treating early breast cancer, where hrQoL considerations may be more relevant. 
“Overall survival is the ultimate goal of oncology clinical trials and what patients hope for—to live longer, and to thrive. We are extremely proud of our quality of life data and that Kisqali has the longest median overall survival ever reported in HR+/HER2- metastatic breast cancer,” Kemps-Polanco added.
A matching-adjusted indirect comparison (MAIC), a method used to estimate the comparative effectiveness of treatments after adjusting for differences in the patient populations where head-to-head trials do not exist, indicated that treatment with ribociclib plus aromatase inhibitor is associated with better symptom-related hrQoL when indirectly compared to abemaciclib (Verzenio®, Eli Lilly and Company) plus an aromatase inhibitor in the first-line setting for postmenopausal patients with HR+/HER2- metastatic breast cancer. 
Results from the MAIC favored the ribociclib-aromatase inhibitor combination in time to sustained deterioration (TTSD), including appetite loss (HR=0.46; 95% CI: 0.27-0.81), diarrhea (HR=0.23; 95% CI: 0.23-0.79), fatigue (HR=0.63; 95% CI: 0.41-0.96) and arm symptoms (HR=0.49; 95% CI: 0.30-0.79).
“As a clinician and clinical researcher who treats patients with metastatic breast cancer, I always strive to find a therapy that gives patients more time while also maintaining the (health related) quality [of life] of that time,” noted Hope S. Rugo, MD, Professor of Medicine and Director, Breast Oncology and Clinical Trials Education, University of California, San Francisco (UCSF) Helen Diller Family Comprehensive Cancer Center.
“Our indirect comparison of ribociclib plus aromatase inhibitor gives initial insight into variations in symptoms that may impact quality of life and may vary between different treatment options.”
Study of Efficacy and Safety of LEE011 in Postmenopausal Women With Advanced Breast Cancer.(MONALEESA-2) – NCT01958021
Highlights of Prescribing information
Ribociclib (Kisqali® ; Novartis) (Prescribing Information)
Letrozole (Femara®; Novartis)(Prescribing Information)
Abemaciclib (Verzenio® Eli Lilly and Company) (Prescribing Information)
 Hart LL, Bardia A, Beck JT, Chan A, Neven P, Hamilton EP, Sohn J, et al. Impact of ribociclib (RIB) dose modifications (mod) on overall survival (OS) in patients (pts) with HR+/HER2- advanced breast cancer (ABC) in MONALEESA(ML)-2. J Clin Oncol 40, 2022 (suppl 16; abstr 1017) | DOI 10.1200/JCO.2022.40.16_suppl.1017
 Rugo HS, O’Shaughnessy J, Jhaveri KL, Tolaney SM, Cardoso F, Bardia A, Maheshwari VK, et al. Quality of life (QOL) with ribociclib (RIB) plus aromatase inhibitor (AI) versus abemaciclib (ABE) plus AI as first-line (1L) treatment (tx) of hormone receptor-positive/human epidermal growth factor receptor–negative (HR+/HER2−) advanced breast cancer (ABC), assessed via matching-adjusted indirect comparison (MAIC). J Clin Oncol 40, 2022 (suppl 16; abstr 1015) | DOI 10.1200/JCO.2022.40.16_suppl.1015
Featured image: General Views during the 58th annual meeting of the American Society of Clinical Oncology (ASCO) held from June 3-7, 2022 in Chicago, Il. Photo courtesey: © 2022 ASCO/Nick Agro. Used with permission.