STAR-121: A Phase III Randomized Study of Domvanalimab and Zimberelimab in Combination With Chemotherapy Versus Pembrolizumab With Chemotherapy in Untreated Metastatic Non–Small Cell Lung Cancer With No Actionable Gene Alterations

Introduction

Dual inhibition with a T-cell immunoreceptor with immunoglobulin and ITIM domains plus programmed death (ligand)-1 (PD[L]-1) inhibitors, with or without chemotherapy, is an emerging therapeutic strategy in metastatic non–small cell lung cancer (mNSCLC). The STAR-121 (NCT05502237) phase III, global, randomized, open-label study will investigate first-line domvanalimab (anti-TIGIT) and zimberelimab (anti–PD-1) plus chemotherapy versus pembrolizumab plus chemotherapy in mNSCLC with no actionable gene alterations.

Participants and Methods

Approximately 720 participants (≥18 years old) with untreated mNSCLC and no EGFR and ALK mutations will be randomized into 3 groups (A, B, or C) in a 4:4:1 ratio and stratified by baseline PD-L1 expression (tumor cells <50% vs. ≥50%), histology (squamous vs. nonsquamous), and geographic region (East Asia vs. non-East Asia). Group A will receive domvanalimab 1200 mg plus zimberelimab 360 mg plus platinum-doublet chemotherapy (PT), group B will receive pembrolizumab 200 mg plus PT, and group C will receive zimberelimab 360 mg plus PT, every 3 weeks. Treatment will be administered until disease progression or intolerable toxicity. Dual primary endpoints are progression-free survival (by blinded independent central review [BICR]) and overall survival for group A versus B. Key secondary endpoints comprise overall response rate (by BICR), safety, and quality of life. Exploratory endpoints include efficacy and safety between groups A and C, pharmacokinetics, patient-reported outcomes, and biomarkers.

Conclusion

Enrollment in the STAR-121 study commenced on October 12, 2022, and is currently ongoing with completion planned by September 2024. The study completion is expected by December 2027.