BACKGROUND:Respiratory diseases such as cystic fibrosis (CF), chronic obstructive pulmonary disease, and non-CF bronchiectasis are significant global health burdens. Current treatments aim to improve mucus clearance but do not fully address these diseases, highlighting the need for novel treatments. This study presents the results from phase I and phase IIb trials of GDC-6988, an inhaled, selective, and potent TMEM16A potentiator, in healthy volunteers. OBJECTIVES:To assess the safety and tolerability of orally inhaled GDC-6988 (nebulized and as a dry powder inhaler) in healthy subjects compared with placebo. DESIGN:The phase I trial was a first-in-human, randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and pharmacokinetics (PK) of single and repeat doses of nebulized GDC-6988. METHODS:The study consisted of three parts: Part A with six cohorts (doses from 1.5 mg to 150 mg) using a single ascending dose (SAD) design; Part B with three cohorts (22.5 mg BID for 7 days, 75 mg BID for 14 days, and 45 mg BID for 14 days) using a multiple ascending dose (MAD) design; and Part C assessing the effect of salbutamol pretreatment on the highest dose tested in Part B (75 mg). The phase Ib study was a double-blind, randomized, placebo-controlled, single-center, multiple-dose escalation study evaluating the safety and PK of GDC-6988 DPI formulation, with and without salbutamol pretreatment. Three cohorts with doses of 11.2 mg, 28 mg, and 42 mg BID were tested. A bridging cohort compared PK in two capsule strengths of GDC-6988. RESULTS:In the phase I study, 76 healthy subjects received GDC-6988 or placebo; in the phase Ib study, 41 subjects were enrolled (31 in MAD cohorts, 10 in the bridging cohort). GDC-6988 was safe and generally well tolerated, with no serious, severe, or grade ⩾3 adverse events observed at any dose level. Mild-to-moderate dose-dependent FEV1 declines were observed in both studies, but were mitigated by salbutamol pretreatment. In both trials, plasma PK concentrations of GDC-6988 were low, as expected. CONCLUSION:Inhaled GDC-6988 was safe and well tolerated across all dose levels. The plasma PK of GDC-6988 was low and generally dose-proportional with a relatively short half-life. TRIAL REGISTRATION:Phase I: ClinicalTrials.gov Identifier NCT04488705; Phase Ib: ISRCTN30841680.

Rationale: The lung allocation score (LAS) was revised in 2015 to improve waiting list mortality and rate of transplant for patients with pulmonary arterial hypertension (PAH). Objectives: We sought to determine if the 2015 revision achieved its intended goals. Methods: Using the Standard Transplant Analysis and Research file, we assessed the impact of the 2015 LAS revision by comparing the pre- and postrevision eras. Registrants were divided into the LAS diagnostic categories: group A-chronic obstructive pulmonary disease; group B-pulmonary arterial hypertension; group C-cystic fibrosis; and group D-interstitial lung disease. Competing risk regressions were used to assess the two mutually exclusive competing risks of waiting list death and transplant. Cumulative incidence plots were created to visually inspect risks. Measurements and Main Results: The LAS at organ matching increased by 14.2 points for registrants with PAH after the 2015 LAS revision, the greatest increase among diagnostic categories (other LAS categories: D, 20.9 to 12.8 points). Before the revision, registrants with PAH had the highest risk of death and lowest likelihood of transplant. After the 2015 revision, registrants with PAH still had the highest risk of death, now similar to those with interstitial lung disease, and the lowest rate of transplant, now similar to those with chronic obstructive pulmonary disease. Conclusions: Although the 2015 LAS revision improved access to transplant and reduced the risk of waitlist death for patients with PAH, it did not go far enough. Significant differences in waitlist mortality and likelihood of transplant persist.

Angiopoietin-2 (Ang-2) is associated with vascular endothelial injury and permeability in the acute respiratory distress syndrome (ARDS) and sepsis. Elevated circulating Ang-2 levels may identify critically ill patients with distinct pathobiology amenable to targeted therapy. We hypothesized that plasma Ang-2 measured shortly after hospitalization among patients with sepsis would be associated with the development of ARDS and poor clinical outcomes. To test this hypothesis, we measured plasma Ang-2 in a cohort of 757 patients with sepsis, including 267 with ARDS, enrolled in the emergency department or early in their ICU course before the COVID-19 pandemic. Multivariable models were used to test the association of Ang-2 with the development of ARDS and 30-day morality. We found that early plasma Ang-2 in sepsis was associated with higher baseline severity of illness, the development of ARDS, and mortality risk. The association between Ang-2 and mortality was strongest among patients with ARDS and sepsis as compared to those with sepsis alone (OR 1.81 vs. 1.52 per log Ang-2 increase). These findings might inform models testing patient risk prediction and strengthen the evidence for Ang-2 as an appealing biomarker for patient selection for novel therapeutic agents to target vascular injury in sepsis and ARDS.

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.

Background: Janus Kinases (JAKs) mediate activity of many asthma-relevant cytokines. GDC-0214, an inhaled small molecule JAK1 inhibitor, has previously been shown to reduce fractional exhaled nitric oxide (FeNO) in patients with mild asthma, but required an excessive number of inhalations.Aim: To assess whether GDC-4379, a new inhaled JAK inhibitor, reduces FeNO and peripheral biomarkers of inflammation. Methods: This study assessed the activity of GDC-4379 in a double-blind, randomized, placebo-controlled, Phase 1 study in patients with mild asthma. Participants included adults (18-65y) with a diagnosis of asthma for > 6 months, forced expiratory volume in 1 s (FEV1)> 70% predicted, FeNO > 40 ppb, using as-needed short-acting beta-agonist medication only. Four sequential, 14-day, ascending-dose cohorts (10 mg QD, 30 mg QD, 40 mg BID, and 80 mg QD) of 12 participants each were randomized 2:1 to GDC-4379 or placebo. The primary activity outcome was percent change from baseline (CFB) in FeNO to Day 14 compared to the pooled placebo group. Safety, tolerability, pharmacokinetics, and pharmacodynamic biomarkers, including blood eosinophils, serum CCL17, and serum CCL18, were also assessed. Results: Of 48 enrolled participants, the mean age was 25 years and 54% were female. Median (range) FeNO at baseline was 79 (41-222) ppb. GDC-4379 treatment led to dose-dependent reductions in FeNO. Compared to placebo, mean (95% CI) percent CFB in FeNO to Day 14 was:-6 (-43, 32) at 10 mg QD,-26 (-53, 2) at 30 mg QD,-55 (-78,-32) at 40 mg BID and-52 (-72,-32) at 80 mg QD. Dose-dependent reductions in blood eosinophils and serum CCL17 were also observed. Higher plasma drug concentrations corresponded with greater FeNO reductions. No serious AEs occurred. The majority of AEs were mild to moderate. The most common AEs were headache and oropharyngeal pain. Minor changes in neutrophils were noted at 80 mg QD, but were not considered clinically meaningful. Conclusions: In patients with mild asthma, 14-day treatment with GDC-4379 reduced FeNO levels and peripheral biomarkers of inflammation. Treatment was well tolerated without any major safety concerns.

Genome-wide association studies (GWAS) have identified many common variant loci associated with asthma susceptibility, but few studies investigate the genetics underlying moderate-to-severe asthma risk. Here, we present a whole-genome sequencing study comparing 3181 moderate-to-severe asthma patients to 3590 non-asthma controls. We demonstrate that asthma risk is genetically correlated with lung function measures and that this component of asthma risk is orthogonal to the eosinophil genetics that also contribute to disease susceptibility. We find that polygenic scores for reduced lung function are associated with younger asthma age of onset. Genome-wide, seven previously reported common asthma variant loci and one previously reported lung function locus, near THSD4, reach significance. We replicate association of the lung function locus in a recently published GWAS of moderate-to-severe asthma patients. We additionally replicate the association of a previously reported rare (minor allele frequency < 1%) coding variant in IL33 and show significant enrichment of rare variant burden in genes from common variant allergic disease loci. Our findings highlight the contribution of lung function genetics to moderate-to-severe asthma risk, and provide initial rare variant support for associations with moderate-to-severe asthma risk at several candidate genes from common variant loci.

Several inflammatory cytokines that promote inflammation and pathogenesis in asthma signal through the Janus kinase 1 (JAK1) pathway. This phase I, randomized, placebo‐controlled trial assessed the pharmacokinetics and safety of single and multiple ascending doses up to 15 mg twice daily for 14 days of a JAK1 inhibitor, GDC‐0214, in healthy volunteers (HVs; n = 66). Doses were administered with a dry powder, capsule‐based inhaler. An accompanying open‐label gamma scintigraphy study in HVs examined the lung deposition of a single dose of inhaled Technetium‐99m ( 99m Tc)‐radiolabeled GDC‐0214. GDC‐0214 plasma concentrations were linear and approximately dose‐proportional after both single and multiple doses. Peak plasma concentrations occurred at 15–30 min after dosing. The mean apparent elimination half‐life ranged from 32 to 56 h across all single and multiple dose cohorts. After single and multiple doses, all adverse events were mild or moderate, and none led to treatment withdrawal. There was no clear evidence of systemic toxicity due to JAK1 inhibition, and systemic exposure was low, with plasma concentrations at least 15‐fold less than the plasma protein binding‐corrected IC50 of JAK1 at the highest dose. Scintigraphy showed that approximately 50% of the emitted dose of radiolabeled GDC‐0214 was deposited in the lungs and was distributed well to the peripheral airways. 99m Tc‐radiolabeled GDC‐0214 (1 mg) exhibited a mean plasma C max similar to that observed in phase I at the same dose level. Overall, inhaled GDC‐0214 exhibited pharmacokinetic properties favorable for inhaled administration.

AbstractSeveral inflammatory cytokines that promote inflammation and pathogenesis in asthma signal through the Janus kinase 1 (JAK1) pathway. This phase I, randomized, placebo‐controlled trial assessed the pharmacokinetics and safety of single and multiple ascending doses up to 15 mg twice daily for 14 days of a JAK1 inhibitor, GDC‐0214, in healthy volunteers (HVs; n = 66). Doses were administered with a dry powder, capsule‐based inhaler. An accompanying open‐label gamma scintigraphy study in HVs examined the lung deposition of a single dose of inhaled Technetium‐99m (99mTc)‐radiolabeled GDC‐0214. GDC‐0214 plasma concentrations were linear and approximately dose‐proportional after both single and multiple doses. Peak plasma concentrations occurred at 15–30 min after dosing. The mean apparent elimination half‐life ranged from 32 to 56 h across all single and multiple dose cohorts. After single and multiple doses, all adverse events were mild or moderate, and none led to treatment withdrawal. There was no clear evidence of systemic toxicity due to JAK1 inhibition, and systemic exposure was low, with plasma concentrations at least 15‐fold less than the plasma protein binding‐corrected IC50 of JAK1 at the highest dose. Scintigraphy showed that approximately 50% of the emitted dose of radiolabeled GDC‐0214 was deposited in the lungs and was distributed well to the peripheral airways. 99mTc‐radiolabeled GDC‐0214 (1 mg) exhibited a mean plasma Cmax similar to that observed in phase I at the same dose level. Overall, inhaled GDC‐0214 exhibited pharmacokinetic properties favorable for inhaled administration.

Abstract Objective Many asthma patients remain uncontrolled on inhaled corticosteroids (ICS) and long-acting beta agonists (LABAs), but guidance for selecting add-on therapies, including long-acting muscarinic antagonists (LAMAs) or biologics, is limited. We describe how prescribing practices for add-on LAMA and biologic therapy have changed with increased treatment options and revised treatment guidelines. We further identify differences in treatment initiation and discontinuation rates by patient characteristics, including concomitant COPD. Methods This retrospective cohort study analyzed insurance claims in the IBM Marketscan database for adult US asthma patients treated with medium- or high-dose ICS/LABA between 2012 and 2019 (n = 277,373). We used negative binomial regression models to evaluate LAMA and biologic initiation rates and their association with patient characteristics, and survival analysis methods for assessing discontinuation rates. Results Between 2012 and 2019, LAMA and biologic uptake increased approximately 5-fold and 20-fold, respectively. LAMA initiation was significantly higher among patients with concomitant COPD, a group typically unstudied in clinical trials, versus those with asthma only (rate ratio of 5.90, 95% CI: 5.76–6.04). High-dose ICS/LABA treatment and the need for oral corticosteroid (OCS) bursts had stronger associations with biologic initiation. Probability of discontinuation (i.e. non-persistence) in the first year was 40.5% and 22.7% for those initiating LAMAs and biologics, respectively, with higher LAMA discontinuation rates among patients with asthma only versus those with concomitant COPD. Conclusions Our results provide insights into how clinicians apply treatment guidelines for initiating add-on LAMA and biologic therapies in moderate-to-severe asthma patients and highlight patients who have an unmet treatment need after discontinuation.

Background: The Janus kinase (JAK) pathway mediates the activity of many asthma-relevant cytokines, including IL-4 and IL-13. GDC-0214 is a potent, inhaled, small-molecule JAK inhibitor being developed for the treatment of asthma. Objective: We sought to determine whether GDC-0214 reduces fractional exhaled nitric oxide (FENO), a JAK1-dependent biomarker of airway inflammation, in patients with mild asthma. Methods: We conducted a double-blind, randomized, placebo controlled, phase 1 proof-of-activity study in adults with mild asthma and FENO higher than 40 parts per billion (ppb). Subjects were randomized 2:1 (GDC-0214:placebo) into 4 sequential ascending-dose cohorts (1 mg once daily [QD], 4 mg QD, 15 mg QD, or 15 mg twice daily). All subjects received 4 days of blinded placebo, then 10 days of either active drug or placebo. The primary outcome was placebo-corrected percent reduction in FENO from baseline to day 14. Baseline was defined as the average FENO during the blinded placebo period. Pharmacokinetics, safety, and tolerability were also assessed. Results: Thirty-six subjects (mean age, 28 years; 54% females) were enrolled. Mean FENO at baseline across all subjects was 93 +/- 43 ppb. At day 14, placebo-corrected difference in FENO was -23% (95% CI, -37.3 to -9) for 15 mg QD and -42% (95% CI, -57 to -27.4) for 15 mg twice daily. Higher plasma exposure was associated with greater FENO reduction. No dose-limiting adverse events, serious adverse events, or treatment discontinuations occurred. There were no major imbalances in adverse events or laboratory findings, or evidence of systemic JAK inhibition. Conclusions: GDC-0214, an inhaled JAK inhibitor, caused dose-dependent reductions in FENO in mild asthma and was well tolerated without evidence of systemic toxicity.

Background: Janus Kinases (JAKs) mediate activity of many asthma-relevant cytokines. GDC-0214, an inhaled small molecule JAK1 inhibitor, has reduced FeNO ~40% in patients with mild asthma. Aim: To assess whether GDC-4379, a structurally related JAK inhibitor, also reduces FeNO. Methods: This double-blind, randomized, placebo-controlled, Phase 1 study assessed activity of GDC-4379 in patients with mild asthma. Patients were adults (18–65y) with a diagnosis of asthma for ≥6 months, FeNO >40 ppb, using as-needed relief medication only. Three sequential, 14-day, ascending-dose cohorts (Table) were randomized 2:1 (GDC-4379:placebo). The primary activity outcome was percent change from baseline (CFB) in FeNO to Day 14. We assessed pharmacokinetics, safety, and tolerability. Results: Of 36 enrolled patients (mean age, 25y), 56% were female. Baseline mean FeNO was 92 ppb. GDC-4379 treatment led to dose-dependent reductions in FeNO; at 40 mg BID, mean FeNO decreased 58% (-52 ppb) vs. pooled placebo (Table). Higher plasma drug concentrations corresponded with greater FeNO reductions. No dose-limiting adverse events (AEs), serious AEs, or treatment discontinuations occurred. Most common AEs were headache and oropharyngeal pain (sore throat), without imbalances in AEs or laboratory findings between groups. Conclusions: In patients with mild asthma, 14-day treatment with GDC-4379 reduced FeNO. Treatment was well tolerated, without evidence of systemic toxicity.

Inflammatory signaling in asthma is driven by multiple Janus kinase (JAK)-associated cytokines, including interleukin-13 (IL-13) and IL-4. Inhibiting these cytokine pathways has clinical efficacy in asthma. Inhaled GDC-0214 is a novel JAK1 inhibitor being developed for the treatment of asthma. This study evaluated safety, tolerability, and pharmacokinetics of single- and multiple-ascending doses (SAD, MAD) of inhaled GDC-0214 in healthy adult volunteers. The SAD stage included 5 cohorts receiving single doses of 0.15–15-mg GDC-0214 or placebo. The MAD stage included 4 cohorts receiving 1-mg QD, 3-mg QD, 10-mg QD or 15-mg BID of GDC-0214 or placebo for 14 days. Thirty-four (SAD) and 32 (MAD) volunteers were dosed. No serious adverse events (SAEs), dose-limiting AEs, or AEs leading to discontinuation occurred. There were no concerning trends in vital signs, electrocardiograms, spirometry, or laboratory values suggestive of systemic JAK inhibition (e.g. NK cells, lipids). Seventeen (50%; SAD) and 25 (78%; MAD) subjects experienced AEs. All AEs were mild to moderate, except one severe AE in a patient receiving placebo. No major imbalance of AEs was observed between placebo and active arms. In the SAD stage, plasma GDC-0214 exhibited biphasic pharmacokinetics, with maximum concentrations ranging from 70–7270 pg/mL across cohorts and a mean terminal half-life of ∼38 (CV: 17.2%) hours. In the MAD stage, GDC-0214 achieved steady-state by ∼Day 6. Plasma pharmacokinetics for both stages was approximately dose proportional. Inhaled GDC-0214 was well tolerated in healthy volunteers with pharmacokinetics indicating low systemic exposure and long retention in the lung.

The energetic performance of aluminum(Al)-based nanothermite composites is hindered by the native alumina shell on the surface of Al nanoparticles. To maximize the energetic release and lower the reaction temperature between Al and metal oxide nanoparticles, a novel fluorine and oxygen co-functionalized graphene (FGO) is reported. The material was synthesized by gas-solid reaction between graphene oxide paper and XeF2 gas. The stability of FGO in atmospheric humidity, heating, and exfoliation by sonication in different solvents were obtained by FTIR and SEM-EDS. The FGO contained both unstable acyl fluoride groups and stable carbon-fluorine covalent/semi-ionic bonds in its structure. The FGO was introduced as a functional additive in an Al/Bi2O3 nanothermite composite, leading to a heat of reaction heat of 1123 J/g, 58% greater than that from loose Al/Bi2O3 powder. The reaction completed before reaching the melting temperature of Al, indicating a novel all-solid-state reaction between Al and Bi2O3. The decreased reaction temperature is attributed to fluorine etching of the native alumina shell surrounding the Al nanoparticle fuel. Keywords: Nanomaterial Graphene Fluorinated graphene Nanothermite fuel. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Inhibition of interleukin (IL)-13, a Type 2 inflammatory mediator in asthma, improves lung function and reduces exacerbations; however, more effective therapies are needed. A subset of asthma patients also exhibits elevated IL-17, which is associated with greater disease severity, neutrophilic inflammation, and steroid resistance. BITS7201A is a novel, humanized bispecific antibody that binds and neutralizes both IL-13 and IL-17. Safety, pharmacokinetics, and immunogenicity of BITS7201A were evaluated in a phase 1 study. Part A was a single ascending-dose design with 5 cohorts: 30-, 90-, and 300-mg subcutaneous (SC), and 300- and 750-mg intravenous (IV). Part B was a multiple ascending-dose design with 3 cohorts: 150-, 300-, and 600-mg SC every 4 weeks × 3 doses. Both parts enrolled approximately 8 healthy volunteers into each cohort (6 active: 2 placebo). Part B included an additional cohort of patients with mild asthma (600-mg SC). Forty-one subjects (31 active, 10 placebo) and 26 subjects (20 active, 6 placebo) were enrolled into Parts A and B, respectively. The cohort with mild asthma patients was terminated after enrollment of a single patient. No deaths, serious adverse events, or dose-limiting adverse events occurred. In Part A, 12 active (39%) and 5 placebo subjects (50%), and in Part B, 6 active (30%) and 3 placebo subjects (50%) experienced at least 1 treatment-emergent adverse event (TEAE). The most common AEs were fatigue (n = 3) and influenza-like illness (n = 2). One injection-site reaction was reported. Two subjects with elevated blood eosinophil counts at baseline had transient elevations in blood eosinophils (≥Grade 2, > 1500 cells/μL). In Parts A and B, 16 of 30 (53%) and 16 of 17 (94%) active subjects, respectively, tested positive for anti-drug antibodies (ADAs). No anaphylaxis or hypersensitivity events occurred. BITS7201A exhibited single- and multiple-dose pharmacokinetic characteristics consistent with an IgG monoclonal antibody; exposure generally increased dose-proportionally. Postdose elevations of the serum pharmacodynamic biomarkers, IL-17AA and IL-17FF, occurred, confirming target engagement. BITS7201A was well tolerated, but was associated with a high incidence of ADA formation. ClinicalTrials.gov , NCT02748642; registered April 6, 2016 (retrospectively registered).

Basophils are believed to play an important role in the pathophysiology of chronic idiopathic/spontaneous urticaria (CIU/CSU) (Vonakis and Saini, 2008Vonakis B.M. Saini S.S. New concepts in chronic urticaria.Curr Opin Immunol. 2008; 20: 709-716Crossref PubMed Scopus (101) Google Scholar). Notably, basopenia has been reported in patients with CIU/CSU (Rorsman, 1961Rorsman H. Basopenia in urticaria.Acta Allergol. 1961; 16: 185-215Crossref PubMed Scopus (17) Google Scholar) and is postulated to be the result of migration of basophils from the circulation into the skin (Caproni et al., 2005Caproni M. Giomi B. Volpi W. Melani L. Schincaglia E. Macchia D. et al.Chronic idiopathic urticaria: infiltrating cells and related cytokines in autologous serum-induced wheals.Clin Immunol. 2005; 114: 284-292Crossref PubMed Scopus (100) Google Scholar, Ito et al., 2011Ito Y. Satoh T. Takayama K. Miyagishi C. Walls A.F. Yokozeki H. Basophil recruitment and activation in inflammatory skin diseases.Allergy. 2011; 66: 1107-1113Crossref PubMed Scopus (188) Google Scholar, Ying et al., 2002Ying S. Kikuchi Y. Meng Q. Kay A.B. Kaplan A.P. TH1/TH2 cytokines and inflammatory cells in skin biopsy specimens from patients with chronic idiopathic urticaria: comparison with the allergen-induced late-phase cutaneous reaction.J Allergy Clin Immunol. 2002; 109: 694-700Abstract Full Text Full Text PDF PubMed Scopus (214) Google Scholar). Consistent with this hypothesis, the degree of basopenia has been shown to correlate with disease severity (Grattan et al., 2003Grattan C.E. Dawn G. Gibbs S. Francis D.M. Blood basophil numbers in chronic ordinary urticaria and healthy controls: diurnal variation, influence of loratadine and prednisolone and relationship to disease activity.Clin Exp Allergy. 2003; 33: 337-341Crossref PubMed Scopus (126) Google Scholar) and improves during times of remission (Eckman et al., 2008Eckman J.A. Hamilton R.G. Gober L.M. Sterba P.M. Saini S.S. Basophil phenotypes in chronic idiopathic urticaria in relation to disease activity and autoantibodies.J Invest Dermatol. 2008; 128: 1956-1963Abstract Full Text Full Text PDF PubMed Scopus (117) Google Scholar, Kern and Lichtenstein, 1976Kern F. Lichtenstein L.M. Defective histamine release in chronic urticaria.J Clin Invest. 1976; 57: 1369-1377Crossref PubMed Scopus (121) Google Scholar). It is theorized that binding of free IgE by omalizumab, a humanized monoclonal antibody against IgE, may influence the behavior of basophils and mast cells via downregulation of the high-affinity receptor (FcεRI). To evaluate the effect of omalizumab on circulating basophils in CIU/CSU, we conducted a post hoc analysis of randomized clinical trial data examining changes in blood basophil counts in relation to treatment. Patient data were obtained from three pivotal trials conducted to evaluate the safety and efficacy of omalizumab in patients with CIU/CSU: ASTERIA I (NCT01287117), ASTERIA II (NCT01292473), and GLACIAL (NCT01264939). Written informed consent for participation in the trials was obtained from all patients or their parent or legal guardian, and study protocols were developed in accordance with the principles of the Declaration of Helsinki and approved by the institutional review board or ethics committee at each center. Detailed information regarding these studies has been previously reported (Kaplan et al., 2013Kaplan A. Ledford D. Ashby M. Canvin J. Zazzali J.L. Conner E. et al.Omalizumab in patients with symptomatic chronic idiopathic/spontaneous urticaria despite standard combination therapy.J Allergy Clin Immunol. 2013; 132: 101-109Abstract Full Text Full Text PDF PubMed Scopus (417) Google Scholar, Maurer et al., 2013Maurer M. Rosén K. Hsieh H.J. Saini S. Grattan C. Gimenéz-Arnau A. et al.Omalizumab for the treatment of chronic idiopathic or spontaneous urticaria.N Engl J Med. 2013; 368: 924-935Crossref PubMed Scopus (729) Google Scholar, Saini et al., 2015Saini S.S. Bindslev-Jensen C. Maurer M. Grob J.J. Bülbül Baskan E. Bradley M.S. et al.Efficacy and safety of omalizumab in patients with chronic idiopathic/spontaneous urticaria who remain symptomatic on H1 antihistamines: a randomized, placebo-controlled study.J Invest Dermatol. 2015; 135: 67-75Abstract Full Text Full Text PDF PubMed Scopus (275) Google Scholar). Patients received subcutaneous omalizumab (75 mg, 150 mg, or 300 mg in ASTERIA I and ASTERIA II; 300 mg in GLACIAL) or placebo every 4 weeks for 12 (ASTERIA II) or 24 (ASTERIA I, GLACIAL) weeks with a 16-week follow-up period. Blood samples for basophil analyses were collected at baseline and every 12 weeks. The presence of blood basophils was quantified using two different methods: whole blood histamine assay and basophil percentage by flow cytometry. Basophils are highly enriched for histamine content relative to plasma or other cellular components of blood. Evidence suggests that the cell-free fraction of histamine is minimal compared with the cell fraction in patients with CIU/CSU (Cho et al., 2013Cho H.J. Cho S.I. Kim H.O. Park C.W. Lee C.H. Lack of association of plasma histamine with diamine oxidase in chronic idiopathic urticaria.Ann Dermatol. 2013; 25: 189-195Crossref PubMed Scopus (15) Google Scholar), and thus the measurement of histamine in whole blood lysate correlates closely with basophil levels in the blood (Sabroe et al., 1998Sabroe R.A. Francis D.M. Barr R.M. Black A.K. Greaves M.W. Anti-Fc∈RI auto antibodies and basophil histamine releasability in chronic idiopathic urticaria.J Allergy Clin Immunol. 1998; 102: 651-658Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar, Siraganian, 1974Siraganian R.P. An automated continuous-flow system for the extraction and fluorometric analysis of histamine.Anal Biochem. 1974; 57: 383-394Crossref PubMed Scopus (664) Google Scholar, Siraganian, 1975Siraganian R.P. Refinements in the automated fluorometric histamine analysis system.J Immunol Methods. 1975; 7: 283-290Crossref PubMed Scopus (244) Google Scholar). Histamine concentrations (measured in lysates only for patients participating in US-based sites) were determined using the method described by Siraganian, 1974Siraganian R.P. An automated continuous-flow system for the extraction and fluorometric analysis of histamine.Anal Biochem. 1974; 57: 383-394Crossref PubMed Scopus (664) Google Scholar, Siraganian, 1975Siraganian R.P. Refinements in the automated fluorometric histamine analysis system.J Immunol Methods. 1975; 7: 283-290Crossref PubMed Scopus (244) Google Scholar. Flow cytometric assessment of basophils was conducted using samples of sodium heparin anticoagulated peripheral blood. Basophils were identified through gating CD123+/HLA–DR–/CD303– cells. Overall, the three pivotal trials included a total of 766 patients; 586 received omalizumab and 180 received placebo. The histamine analysis included data from 578 patients (omalizumab, 440; placebo, 138). The basophil percentage by flow cytometry analysis included data from 608 patients (omalizumab, 469; placebo, 139). Baseline demographic and clinical characteristics were similar across studies and treatment groups (Supplementary Table S1 online). Mean ± standard deviation histamine concentrations were generally similar across treatment groups at baseline (Supplementary Table S2 online). Changes from baseline in histamine concentration are depicted in Figure 1a. The mean changes from baseline in histamine were greater in the omalizumab 300 mg group versus placebo for all three trials at weeks 12 and 24. Although this difference was not always statistically significant in individual trials, the difference was significant at week 12 when data from all three trials were pooled (omalizumab 300 mg, 4.34, vs. placebo, 0.97; P < 0.001). Changes in histamine concentration for the lower-dose omalizumab cohorts were less consistent and not statistically significant. Mean ± standard deviation basophil percentages were generally similar across treatment groups at baseline (Supplementary Table S3 online). Changes from baseline in blood basophil percentage are shown in Figure 1b. As observed for histamine concentration, the mean change in basophil percentage was higher in the omalizumab 300 mg group versus placebo for all three trials at weeks 12 and 24. Although this difference was not always statistically significant in individual trials, the difference was significant at week 12 (omalizumab 300 mg, 0.16, vs. placebo, 0.03; P < 0.001) and at week 24 (omalizumab 300 mg, 0.19, vs. placebo, 0.08; P = 0.018) when data were pooled across trials. A similar trend of increased basophil percentage at week 12 was observed for the 75-mg group (omalizumab 75 mg, 0.08; P = 0.072) and the 150-mg group (omalizumab 150 mg, 0.10; P = 0.039). Across all three trials, histamine concentrations correlated well with basophil percentages (r = 0.659, P < 0.001 at baseline and r = 0.656, P < 0.001 at week 12; Figure 2). Among the subset of patients from the pivotal trials included in this post hoc analysis, we observed improvements in the weekly itch severity score that paralleled the improvements in blood basophil numbers (Figure 1c). Changes in clinical efficacy, as measured by the weekly itch severity score, correlated weakly with changes in histamine concentration (r = −0.2139; P ≤ 0.001; n = 582) as well as changes in basophil percentage (r = −0.1486; P ≤ 0.001; n = 637). To our knowledge, this is the first report to prospectively measure the basophil presence in circulation relative to clinical measures of CIU/CSU activity, and also the first to examine basophil counts on a large scale within an interventional study. Our analysis of data from the pivotal trials of omalizumab for CIU/CSU showed that circulating blood basophils increased in response to treatment with omalizumab 300 mg. Parallel improvements in disease severity, as measured by the weekly itch severity score, were observed across all treatment groups, with the omalizumab 300 mg group demonstrating the greatest clinical benefit. Correlations between the weekly itch severity score and blood basophil measures were weak but significant, suggesting a possible relationship. Taken together, our data suggest that the clinical improvement observed with omalizumab treatment may be related to its effect on basophils. This analysis is subject to the same limitations of any post hoc analysis of clinical trial data. Whole blood histamine concentrations and flow cytometry data were available for only a subset of patients; thus, power to detect smaller changes in these measures was limited. Although statistical significance was not achieved at every individual time point, the trends observed were consistent between trials as well as between the two methods used to assess basophils, supportive of an overall treatment-related effect. In summary, our findings lend further evidence to the hypothesis that basophils play an important role in pathobiology of CIU/CSU. Future investigation is needed to determine whether circulating basophils could serve as a potential useful biomarker for clinical response to omalizumab in patients with CIU/CSU. SSS has received research support from AstraZeneca, Genentech, the National Institutes of Health, and Novartis, and has served as a consultant to Array, Genentech, Kendle, MedImmune, Novartis, Pharmacyclics, and Teva. TAO, BT, KR, and HC are all employees of Genentech and receive stock options from Roche. HNH is a paid consultant to Genentech. PMS and J-PC state no conflict of interest. AL is an employee of LabCorp Clinical Trials, which received payment for performing the flow cytometry assay described in this paper. The funding for ASTERIA I, ASTERIA II, and GLACIAL, as well as for the current analysis, was provided by Genentech, South San Francisco, CA, and Novartis Pharma AG, Basel, Switzerland. Medical writing support for this manuscript was provided by Charlotte Kenreigh and Margit Rezabek of Excel Scientific Solutions and funded by Genentech and Novartis Pharmaceuticals Corporation. Download .pdf (.15 MB) Help with pdf files Supplementary Tables S1–S3 CorrigendumJournal of Investigative DermatologyVol. 139Issue 2PreviewEffect of Omalizumab on Blood Basophil Counts in Patients with Chronic Idiopathic/Spontaneous Urticaria Full-Text PDF Open Access