Efficacy and safety of IBI110 (anti-LAG-3 mAb) in combination with sintilimab (anti-PD-1 mAb) in first-line advanced squamous non-small cell lung cancer (sqNSCLC): Initial results from a phase Ib study.

e21145 Background: Although PD-1/L1 inhibitors have shown efficacy in advanced/metastatic sqNSCLC, many patients do not respond to this treatment. More effective combination therapies are needed. The efficacy and safety of IBI110 in combination with sintilimab as first-line therapy for advanced sqNSCLC was evaluated in a phase Ib study. Here, we report the initial results. Methods: Eligible patients with previously untreated, unresectable, locally advanced or metastatic NSCLC were enrolled in cohort D. Patients received IBI110 200mg IV Q3W and sintilimab 200mg IV Q3W until disease progression, unacceptable toxicity or death, in combination with chemo regimen (paclitaxel 175 mg/m2 plus carboplatin) IV Q3W for 4 cycles. The primary objective was to evaluate the safety, tolerability and efficacy of the combination therapy. Results: Totally, 20 patients were enrolled (median age: 63 [range: 52-74]; male: n = 19; ECOG 1: n = 16). As of data cutoff date, Jan 20, 2022, median follow up was 3.3 months (range: 2.6-7.0). The median exposure of combination therapy was 15.1 weeks (range: 6-52). The objective response rate was 80% (16/20, 9 patients with ≥2 efficacy assessments were confirmed PR and 7 needed further confirmation). The median progression-free survival and overall survival were not reached. The most common treatment-related adverse events (TRAEs) included white blood cell count decreased (50%), alopecia (50%), anaemia (45%), asthenia (40%), neutrophil count decreased (35%), rash (35%), and hyperglycaemia (30%); most common TRAEs ≥ grade 3 were neutrophil count decreased (30%), and white blood cell count decreased (20%). Immune-related AEs occurred in 11 patients (55%) and most were grade 1-2. The biomarker analysis including LAG-3 and PD-L1 expression in tumor specimen was ongoing. Conclusions: IBI110 in combination with sintilimab in first-line advanced sqNSCLC showed promising anti-tumor activity with acceptable safety. The study is still ongoing. Clinical trial information: NCT04085185.