OBJECTIVES: Currently, three CDK 4/6 inhibitors abemaciclib, palbociclib, and dalpiciclib approved in China for breast cancer. The objective was to compare ribociclib versus CDK4/6 inhibitors and ET in patients with the 1L pre/post-menopausal HR+/HER2-metastatic/advanced breast cancer patients in Asia.

METHODS: A systematic literature review (SLR) was conducted using key English and Chinese literature databases from 2007 till September 2022. Data reported on Asia population was extracted and considered for Bayesian network meta-analysis (NMA), comparing overall survival (OS) and progression-free survival (PFS).

RESULTS: Eight randomized controlled trials included in SLR contributed to NMA for both post-menopausal (n=7) and pre-menopausal (n=2) inclusively. In post-menopausal, PFS data was available for CDK4/6 inhibitors, but OS was reported only for abemaciclib and ribociclib in the Asia subgroup. Limited data were reported for Asia subgroup in pre-menopausal patients; no trial was identified for palbociclib and abemaciclib, while dalpiciclib trial reported only PFS. In post-menopausal patients, significant PFS benefit was observed with ribociclib plus aromatase inhibitors (AI) compared to AI (HR: 0.26 [0.13, 0.52]), fulvestrant (HR: 0.33 [0.13, 0.81]), and palbociclib plus AI (HR: 0.41 [0.20, 0.83]) whereas results were numerically favouring ribociclib plus AI against dalpiciclib plus AI (HR: 0.51 [0.24, 1.08]) and abemaciclib plus AI (HR: 0.72 [0.34,1.52]). Favorable OS was associated with ribociclib plus AI versus AI alone (HR: 0.64 [0.35,1.17]), while results were comparable against abemaciclib plus AI (HR: 1.01 [0.45, 2.24]). In pre-menopausal patients, PFS was significantly better with ribociclib plus ET versus ET (HR: 0.42 [0.27, 0.66]) and numerically better compared to dalpiciclib plus ET (HR: 0.79 [0.41,1.52]).

CONCLUSIONS: Ribociclib was associated with significant PFS benefit against palbociclib in post-menopausal patients and was comparable or numerically better against other CDK4/6 inhibitors (abemaciclib and dalpiciclib) among pre-/post-menopausal patients. Furthermore, ribociclib has proven OS benefits in 1L pre-/post-menopausal patients.