Sacituzumab tirumotecan in advanced non-small-cell lung cancer with or without EGFR mutations: phase 1/2 and phase 2 trials

Abstract

Trophoblast cell-surface antigen 2 (TROP2)-directed antibody-drug conjugate (ADC) is a promising anticancer agent that has shown remarkable efficacy in several malignancies. However, in lung cancer, two phase 3 trials on TROP2-ADCs in unselected patients with advanced non-small-cell lung cancer (NSCLC) have both failed. Sacituzumab tirumotecan (sac-TMT) is a novel TROP2-directed ADC. Here we report the efficacy and safety of sac-TMT in previously treated, advanced NSCLC with or without activating EGFR mutations from the phase 1/2 KL264-01 and phase 2 SKB264-II-08 studies. Primary endpoint was objective response rate (ORR). KL264-01 enrolled EGFR-wild-type and EGFR-mutant NSCLC (n = 43). Confirmed ORR was 40% (17 of 43; 95% confidence interval (CI), 25-56). Median progression-free survival (PFS) was 6.2 months (95% CI, 5.3-11.3). Post-hoc subgroup analyses found better outcomes in the EGFR-mutant subset (22 of 43, 51%) with a confirmed ORR of 55% (12 of 22) and median PFS of 11.1 months. These findings were independently supported by results from SKB264-II-08, where sac-TMT led to confirmed ORR of 34% (22 of 64; 95% CI, 23-47) and median PFS of 9.3 months (95% CI, 7.6-11.4) in 64 patients with EGFR-mutant NSCLC. For a total of 107 patients receiving sac-TMT, the most common treatment-related adverse events were hematologic toxicities. Diarrhea (4%) and interstitial lung disease (1%) were uncommon. Exploration of potential mechanisms revealed that the presence of EGFR mutation substantially increased the internalization and activity of sac-TMT in vitro. Overall, sac-TMT showed encouraging single-agent activity and manageable tolerability in previously treated, advanced NSCLC with EGFR mutations. Randomized phase 3 trials in treatment-naive and previously treated patients with EGFR-mutant NSCLC are ongoing. ClinicalTrials.gov Identifiers: NCT04152499 , NCT05631262 .