TRASTUZUMAB-EMTANSINE VERSUS OTHERANTI-HER2 REGIMENS IN EARLY OR UNRESECTABLE OR METASTATIC HER2 POSITIVE BREAST CANCER: SYSTEMATIC REVIEW AND NETWORK META-ANALYSIS

Objective. We aimed to study the efficacy and safety of trastuzumab-emtansine (T-DM1) versus other anti-HER2 therapies in HER2+ breast cancer (BC). Materials and Methods. We performed a network meta-analysis (NMA) of randomized controlled trials (RCTs). Our study focused on patients undergoing treatment for unresectable locally advanced breast cancer (LAB C) or metastatic breast cancer (mBC), which included regimens involving trastuzumab and taxanes. Additionally, we considered cases within the first 6 months of treatment for HER2+ early breast cancer (EBC). Results. A total of 23 RCTs and 41 reports were included in our analysis. LABC and mBC showed no statistically significant difference in any of the comparisons of T-DM1 versus the other anti-HER2+ therapies. When assessing progression-free survival (PFS), trastuzumab-deruxtecan (T-DXd) and PyroCap demonstrated greater efficacy compared to other treatments (Hazard Ratio [HR]: 3.57; 95% confidence interval [CI]: 2.75-4.63 and HR: 1.82; 95% CI: 1.35-2.44; respectively), while T-DM1 alone exhibited superior effectiveness compared to LapCap (HR: 0.65; 95% CI: 0.55-0.77), TrasCap (HR: 0.65; 95% CI: 0.46-0.91), LapCapCitu (HR: 0.60; 95% CI: 0.33-1.10), Nera (HR: 0.55; 95% CI: 0.39-0.77), and Cap (HR: 0.37; 95% CI: 0.28-0.49). Conclusions. NMA allows a ranking based on the comparative efficacy and safety among the interventions available. Although superior to other schemes, T-DM1 showed a lower efficacy performance in PFS and overall response rate and a trend towards worse overall survival than T-DXd.