Abstract
BACKGROUND: Thymic stromal lymphopoietin (TSLP) has been shown to play a central role in the initiation and persistence of allergic responses. OBJECTIVE: We evaluated whether tezepelumab, a human monoclonal anti-TSLP antibody, improved the efficacy of subcutaneous allergen immunotherapy (SCIT) and promoted the development of tolerance in patients with allergic rhinitis. METHODS: We conducted a double-blind parallel design trial in patients with cat allergy. A total of 121 patients were randomized to receive either intravenous tezepelumab plus subcutaneous cat SCIT, cat SCIT alone, tezepelumab alone, or placebo for 52 weeks, followed by 52 weeks of observation. Nasal allergen challenge (NAC), skin testing, and blood and nasal samples were obtained throughout the study. RESULTS: At week 52, the NAC-induced total nasal symptom scores (TNSS) (calculated as area under the curve [AUC(0-1h)] and as peak score [Peak(0-1h)] during the first hour after NAC) were significantly reduced in patients receiving tezepelumab/SCIT compared to SCIT alone. At week 104, one year after stopping treatment, the primary end point TNSS AUC(0-1h) was not significantly different in the tezepelumab/SCIT group compared to SCIT alone, while TNSS Peak(0-1h) was significantly lower in those receiving combination treatment versus SCIT. Transcriptomic analysis of nasal epithelial samples demonstrated that treatment with the combination of SCIT/tezepelumab, but neither monotherapy, caused persistent downregulation of a gene network related to type 2 inflammation that was associated with improvement in NAC responses. CONCLUSIONS: Inhibition of TSLP augments the efficacy of SCIT during therapy and may promote tolerance after a 1-year course of treatment. (ClinicalTrials.gov NCT02237196).