are employees of Genentech, Inc, a member of the Roche group, and own Roche stock. C. E. Brightling is a consultant with fees paid to his institution from Genentech, Inc, and Regeneron; received research grants and was a consultant with fees paid to his institution from AstraZeneca, GlaxoSmithKline, Sanofi, Boehringer Ingelheim, Roche/Genentech, Chiesi, 4D Pharma, Mologics, and Novartis.Background: The IL-33/ST2 pathway is linked with asthma susceptibility. Inhaled allergens, pollutants, and respiratory viruses, which trigger asthma exacerbations, induce release of IL-33, an epithelial-derived ''alarmin.'' Astegolimab, a human IgG 2 mAb, selectively inhibits the IL-33 receptor, ST2. Approved biologic therapies for severe asthma mainly benefit patients with elevated blood eosinophils (type 2-high), but limited options are available for patients with low blood eosinophils (type 2-low). Inhibiting IL-33 signaling may target pathogenic pathways in a wider spectrum of asthmatics. Objectives: This study evaluated astegolimab efficacy and safety in patients with severe asthma. Methods: This double-blind, placebo-controlled, dose-ranging study (ZENYATTA [A Study to Assess the Efficacy and Safety of MSTT1041A in Participants With Uncontrolled Severe Asthma]) randomized 502 adults with severe asthma to subcutaneous placebo or 70-mg, 210-mg, or 490-mg doses of astegolimab every 4 weeks. The primary endpoint was the annualized asthma exacerbation rate (AER) at week 54. Enrollment caps ensured 30 patients who were eosinophil-high (> _300 cells/mL) and 95 patients who were eosinophil-low (<300 cells/mL) per arm. Results: Overall, adjusted AER reductions relative to placebo were 43% (P 5 .005), 22% (P 5 .18), and 37% (P 5 .01) for 490mg, 210-mg, and 70-mg doses of astegolimab, respectively. Adjusted AER reductions for patients who were eosinophil-low were comparable to reductions in the overall population: 54% (P 5 .002), 14% (P 5 .48), and 35% (P 5 .05) for 490-mg, 210mg, and 70-mg doses of astegolimab. Adverse events were similar in astegolimab-and placebo-treated groups. Conclusions: Astegolimab reduced AER in a broad population of patients, including those who were eosinophil-low, with inadequately controlled, severe asthma. Astegolimab was safe and well tolerated. (J Allergy Clin Immunol 2021;nnn:nnnnnn.)

Background and Purpose Develop a translational assay of Transient Receptor Potential Ankyrin 1 (TRPA1) activity for use as a preclinical and clinical biomarker. Experimental Approach Allyl isothiocyanate (AITC), capsaicin or citric acid were applied to ears of wildtype and Trpa1‐knock out (Trpa1 KO) rats, and changes in dermal blood flow (DBF) were measured by laser speckle contrast imaging. In humans, the DBF, pain and itch responses to 5‐20% AITC applied to the forearm were measured and safety was evaluated. Reproducibility of the DBF, pain and itch responses to topically applied 10% and 15% AITC were assessed at two visits separated by 13‐15 days. DBF changes were summarized at 5‐minute intervals as areas under the curve (AUC) and maxima. Intraclass correlation coefficient (ICC) was calculated to assess arm‐arm and period‐period reproducibility. Key Results AITC‐ and citric acid‐induced DBF were significantly reduced in Trpa1 KO rats compared to wildtype (90 ± 2% and 65 ± 11% reduction, respectively), whereas capsaicin response did not differ. In humans, each AITC concentration significantly increased DBF compared to vehicle with the maximal increase occurring 5 minutes post application. Ten percent and 15% AITC were selected as safe and effective stimuli. AUC from 0 to 5 minutes was the most reproducible metric of AITC‐induced DBF across arms (ICC = 0.92) and periods (ICC = 0.85). Subject‐reported pain was more reproducible than itch across visits (ICC = 0.76 vs 0.17, respectively). Conclusion and Implications AITC‐induced DBF is a suitable target engagement biomarker of TRPA1 activity for preclinical and clinical studies of TRPA1 antagonists.

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OBJECTIVES:Severe cases of COVID-19 pneumonia can lead to acute respiratory distress syndrome (ARDS). Release of interleukin (IL)-33, an epithelial-derived alarmin, and IL-33/ST2 pathway activation are linked with ARDS development in other viral infections. IL-22, a cytokine that modulates innate immunity through multiple regenerative and protective mechanisms in lung epithelial cells, is reduced in patients with ARDS. This study aimed to evaluate safety and efficacy of astegolimab, a human immunoglobulin G2 monoclonal antibody that selectively inhibits the IL-33 receptor, ST2, or efmarodocokin alfa, a human IL-22 fusion protein that activates IL-22 signaling, for treatment of severe COVID-19 pneumonia. DESIGN:Phase 2, double-blind, placebo-controlled study (COVID-astegolimab-IL). SETTING: Hospitals.PATIENTS: Hospitalized adults with severe COVID-19 pneumonia. INTERVENTIONS:Patients were randomized to receive IV astegolimab, efmarodocokin alfa, or placebo, plus standard of care. The primary endpoint was time to recovery, defined as time to a score of 1 or 2 on a 7-category ordinal scale by day 28. MEASUREMENTS AND MAIN RESULTS:The study randomized 396 patients. Median time to recovery was 11 days (hazard ratio [HR], 1.01 d; p = 0.93) and 10 days (HR, 1.15 d; p = 0.38) for astegolimab and efmarodocokin alfa, respectively, versus 10 days for placebo. Key secondary endpoints (improved recovery, mortality, or prevention of worsening) showed no treatment benefits. No new safety signals were observed and adverse events were similar across treatment arms. Biomarkers demonstrated that both drugs were pharmacologically active. CONCLUSIONS:Treatment with astegolimab or efmarodocokin alfa did not improve time to recovery in patients with severe COVID-19 pneumonia.