193P Efficacy of sacituzumab govitecan versus treatment of physician’s choice in previously treated hormone receptor-positive/HER2-negative metastatic breast cancer: A meta-analysis of TROPiCS-02 and EVER-132-002 trials

TROPiCS-02 (T-02) and EVER-132-002 (E-002) are both phase III randomized controlled trials comparing sacituzumab govitecan (SG) to treatment of physician's choice (TPC) in patients with HR+/HER2- locally recurrent inoperable or metastatic breast cancer (MBC) who have progressed after 2-4 prior chemotherapy regimens for metastatic disease. T-02, but not E-002, required prior CDK4/6 inhibitor (CDK4/6i) treatment. Here, we explored if efficacy of SG vs TPC would vary in a population with or without prior CDK4/6i treatment via a meta-analysis of the two studies. Meta-analytic models were developed to adjust for cross-trial differences while comparing efficacy of SG versus TPC. Individual patient data and study level hazard ratios from T-02 and E-002 were combined to estimate pooled treatment effects for comparison of overall survival (OS) and progression-free survival (PFS) in the overall and CDK4/6i pretreated populations. In general, T-02 and E-002 had similar distribution of baseline population characteristics (low heterogeneity, I-square = 0.0%-9.6%) except for prior CDK4/6i treatment and geography. In all meta-analytic models SG showed a significant improvement over TPC in OS and PFS. Similar patterns in efficacy were observed in the subgroup of patients previously treated with CDK4/6i (Table).Table: 193PSG vs TPC comparison of OS and PFSPooled Treatment Effect HR (95% CI)Overall populationPrior CDK4/6 treatedCombined individual patient dataOS0.66 (0.55-0.80); p<0.0010.65 (0.53-0.80); p<0.001PFS0.62 (0.50-0.77); p<0.0010.65 (0.52-0.81); p<0.001Combined study level hazard ratiosOS0.70 (0.58-0.86); p<0.0010.68 (0.55-0.84); p<0.001PFS0.67 (0.55-0.83); p<0.0010.66 (0.52-0.84); p=0.001 Open table in a new tab SG significantly improves OS and PFS vs. TPC in the meta-analysis of T-02 and E-002 trial in the overall and CDK4/6i pre-treated MBC populations. The results obtained from this analysis are consistent with trial-level results from T-02 and E-002, reinforcing the efficacy benefits of SG over TPC.