Ribociclib and Palbociclib Are Safe and Effective for Treating Metastatic Breast Cancer: A Retrospective Study.
Cyclin-dependent kinase (CDK) 4/6 inhibitors are standard for treating hormone receptor-positive metastatic breast cancer when combined with endocrine therapy. However, comparisons of first-line treatments are scarce.
In this retrospective study, we aimed to determine the effects and safety of ribociclib and palbociclib as first-line treatments for metastatic hormone receptor-positive breast cancer in real-world settings at two tertiary medical centers.
This retrospective observational study, conducted in two tertiary medical centers, included patients receiving palbociclib or ribociclib in combination with endocrine therapy. Treatment responses were assessed by imaging studies according to RECIST 1.1 criteria. The primary endpoint was 24-month progression-free survival (PFS). Safety outcomes were also recorded and compared between the treatment groups. The median follow-up times for the ribociclib and palbociclib groups were 19.7 and 24.6 months, respectively. The 24-month PFS rates were comparable between the ribociclib and palbociclib cohorts (55.4% vs. 55.2%, respectively; hazard ratio [HR] = 1.110, 95% confidence interval [CI]: 0.605-2.035; p = 0.736), but the objective response rate was significantly higher in the palbociclib group than in the ribociclib group (43.2% vs. 30.2%, p = 0.035). A high rate of dose reduction was observed in both cohorts due to treatment-related toxicities (41.2% in the palbociclib group vs. 47.2% in the ribociclib group). The adverse effect profiles were comparable, although the incidence of grade 1 fatigue was slightly higher in the ribociclib group than in the palbociclib group (p = 0.043).
In Taiwanese real-world practice, ribociclib and palbociclib demonstrated comparable 24-month efficacy. Our findings show that dose reductions do not compromise targeted treatment efficacy, supporting proactive toxicity-guided dose to optimize patient tolerability without sacrificing oncological outcomes in Asian populations.
In this retrospective study, we aimed to determine the effects and safety of ribociclib and palbociclib as first-line treatments for metastatic hormone receptor-positive breast cancer in real-world settings at two tertiary medical centers.
This retrospective observational study, conducted in two tertiary medical centers, included patients receiving palbociclib or ribociclib in combination with endocrine therapy. Treatment responses were assessed by imaging studies according to RECIST 1.1 criteria. The primary endpoint was 24-month progression-free survival (PFS). Safety outcomes were also recorded and compared between the treatment groups. The median follow-up times for the ribociclib and palbociclib groups were 19.7 and 24.6 months, respectively. The 24-month PFS rates were comparable between the ribociclib and palbociclib cohorts (55.4% vs. 55.2%, respectively; hazard ratio [HR] = 1.110, 95% confidence interval [CI]: 0.605-2.035; p = 0.736), but the objective response rate was significantly higher in the palbociclib group than in the ribociclib group (43.2% vs. 30.2%, p = 0.035). A high rate of dose reduction was observed in both cohorts due to treatment-related toxicities (41.2% in the palbociclib group vs. 47.2% in the ribociclib group). The adverse effect profiles were comparable, although the incidence of grade 1 fatigue was slightly higher in the ribociclib group than in the palbociclib group (p = 0.043).
In Taiwanese real-world practice, ribociclib and palbociclib demonstrated comparable 24-month efficacy. Our findings show that dose reductions do not compromise targeted treatment efficacy, supporting proactive toxicity-guided dose to optimize patient tolerability without sacrificing oncological outcomes in Asian populations.