First-in-Human, Phase I Study of Sigvotatug Vedotin, an Integrin Beta-6–Directed Antibody-Drug Conjugate: Results From Dose Expansion in Advanced Non–Small Cell Lung Cancer

PURPOSE: Integrin beta-6 (IB6) is highly expressed in non-small cell lung cancer (NSCLC) and other solid tumors and potentially associated with poor outcomes. Sigvotatug vedotin (SV), a novel IB6-directed antibody-drug conjugate, demonstrated acceptable safety and encouraging antitumor activity in dose escalation. We report updated results for dose-expansion regimens in advanced NSCLC (aNSCLC). METHODS: SGNB6A-001 is an open-label, multicenter, dose-escalation/dose-expansion phase I study evaluating safety, tolerability, pharmacokinetics (PK), and antitumor activity of SV in patients with select advanced solid tumors. After dose escalation, dose expansion further explored three regimens: 1.25 mg/kg total body weight (TBW) on Days 1 and 8 of a 21-day cycle, 1.5 mg/kg TBW on Days 1 and 15 of a 28-day cycle (once every 2 weeks), and 1.8 mg/kg adjusted ideal body weight (AiBW) once every 2 weeks. Eligible patients had prior chemotherapy and immunotherapy or targeted therapy if indicated. Primary end points were safety and determination of an optimal dosing schedule. Secondary end points were antitumor activity, PK, and immunogenicity. RESULTS: As of November 26, 2024, 117 patients with aNSCLC were treated in the above cohorts. Any-grade and grade ≥3 treatment-emergent adverse events occurred in 98% and 48% of all patients, respectively, and in 94% and 35% of patients receiving SV 1.8 mg/kg AiBW once every 2 weeks. Modeling revealed that the AiBW regimen resulted in lower PK variability than TBW regimens. The objective response rate and median duration of response were 19% and 11.3 months in the overall population, respectively, and 29% and 12.8 months in patients with nonsquamous, taxane-naïve NSCLC. CONCLUSION: SV demonstrated a manageable safety profile and promising antitumor activity with durable responses in aNSCLC. PK and clinical data support further investigation with the recommended 1.8-mg/kg AiBW once every 2 weeks dosing regimen.