Abstract CT199: Rescuing response to ICI by blocking the type-2 immune axis in patients with NSCLC progressing on immunotherapy: A phase 1b/2 trial of dupilumab administered with checkpoint blockade

Type-2 cytokines are hypothesized to promote an immune-permissive milieu for cancer to grow. Through scRNAseq and CITEseq on human non-small cell lung cancer (NSCLC) and the krasG12Dp53−/− lung cancer model we previously described a tumor-enriched dendritic cell program of concomitant immunosuppression and activation which we termed the “mregDC,” that was also notable for a strong Th2 immune signature. We subsequently blocked the canonical Th2 cytokine IL-4 in vivo in tumor-bearing mice, and found that this significantly decreased lung tumor burden, which was recapitulated in multiple other tumor models. Furthermore, this effect synergized with PD-L1 blockade. Based on this data, we designed a clinical trial to assess if the addition of dupilumab, an anti-IL-4Ra antibody widely used for treatment of atopic diseases, may rescue responses to checkpoint blockade (NCT05013450). In this Phase 1b/2 trial, up to 21 patients with NSCLC that have progressed on prior anti-PD-(L)1 therapy will be enrolled. Patients continue PD-(L)1 blockade while receiving three doses of dupilumab, administered every three weeks, with initial radiographic assessment of response at 9 weeks. Patients without progression of disease then continue anti-PD-(L)1 alone. The primary endpoint of Phase 1b is safety and tolerability, while the primary endpoint of Phase 2, inclusive of patients from Phase 1b, is efficacy as per RECIST. Patients undergo pre- and on-treatment biopsies, pre-treatment stool collection for microbiome analysis, as well as blood collection at 6 timepoints for PBMCs, plasma and ctDNA. Here we report the Phase 1b portion that has completed accrual in which 6 patients were enrolled in a Phase 1b run-in to confirm safety and tolerability. There were no adverse events attributable to study treatment during Phase 1b in any of the 6 patients treated. Serum proteomic analysis of this cohort revealed that dupilumab treatment induced a profound increase in proinflammatory/tumoricidal immune effector molecules, and reversed a systemic Th2 cytokine signature. Furthermore, mass cytometry of circulating immune populations showed an expansion of cytotoxic lymphocyte populations and a reduction in immunosuppressive myeloid cells. The fourth patient treated on trial who had progressive disease after 9 cycles of consolidation checkpoint blockade following concurrent chemoradiation for squamous NSCLC was enrolled, and had a partial response at 9 weeks, with deepening of the PR at 25 weeks