TQB2450 with or without anlotinib as maintenance treatment in subjects with locally advanced/unresectable non-small cell lung cancer that have not progressed after prior concurrent/sequential chemoradiotherapy (R-ALPS): study protocol for a randomized, double-blind, placebo-controlled, multicenter phase III trial.

Background: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of non-small cell lung cancer (NSCLC). TQB2450 (benmelstobart) is a novel humanized immunoglobulin G1 monoclonal antibody against programmed death-ligand 1 (PD-L1). Anlotinib, an oral multitargeted anti-angiogenic agent with potential synergy with ICIs, has shown efficacy in relapsed and advanced NSCLC. Accumulating preclinical data suggest a synergism between immunological and anti-angiogenic therapies through the improvement of the immune microenvironment of the tumor. In this study, we hypothesized that the combination of TQB2450 and anlotinib as maintenance treatment would enable further improvements in the outcomes of patients with locally advanced/unresectable NSCLC without driver mutations that have not progressed after definitive chemoradiotherapy. Methods: The Radiotherapy and Anlotinib Let PD-L1 Superb (R-ALPS) study is a randomized, double-blind, placebo-controlled, multicenter phase III study (Clinicaltrials.gov identifier, NCT04325763). A total of 534 eligible participants will be randomized to receive TQB2450 (1,200 mg) plus anlotinib (8 mg), or TQB2450 (1,200 mg) plus placebo, or placebo as maintenance therapy. Progression-free survival (PFS), assessed by the independent review committee is the primary endpoint. The secondary endpoints include additional measures of efficacy, safety, and biomarkers. An interim analysis of the effectiveness will be conducted when 70% (286 cases) of the total PFS events have been reached. Discussion: The development of the R-ALPS study will contribute to a deeper insight into the interplay between immunotherapy and anti-angiogenic therapy and thus might expand the treatment options available to patients with locally advanced or unresectable NSCLC. Trial Registration: Clinicaltrials.gov identifier: NCT04325763. Date of registration: May 27, 2020. Protocol version: Version 4.0, Sep 16, 2022 (https://classic.clinicaltrials.gov/ct2/show/NCT04325763).