Phase 2a, randomized, double-blind, placebo-controlled, multicentre, parallel-group study of an H4 R-antagonist (JNJ-39758979) in adults with uncontrolled asthma.

BACKGROUND: The effects of H4 R antagonists in preclinical asthma models support the study of antagonists of the H4 R in the treatment of asthma in humans. JNJ-39758979 is a potent and highly selective oral H4 R antagonist. OBJECTIVE: We sought to evaluate the safety and efficacy of the H4 R-antagonist JNJ-39758979 in adult patients with uncontrolled asthma. METHODS: One hundred and fifteen eligible patients were randomly assigned to JNJ-39758979 300 mg or placebo once daily for 12 weeks in this phase 2a, double-blind, multicenter, placebo-controlled study. Primary efficacy was assessed via week-12 change from baseline in pre-bronchodilator forced expiratory volume in 1 second (FEV1 ). Secondary efficacy assessments included patient-reported outcome (PRO) asthma assessments (Asthma Daily Diary data [AM and PM peak expiratory flow rate, number of puffs of albuterol/salbutamol, the presence of nocturnal awakenings and asthma symptom score]). RESULTS: The study did not meet the primary end-point. However, nominally significant improvements in pre-bronchodilator FEV1 were observed with JNJ-39758979 versus placebo at week 12 in pre-specified subgroups with elevated exhaled nitric oxide, sputum eosinophils or blood eosinophils at baseline. Nominally significant improvements across PRO assessments were consistently observed in the overall population, as well as in eosinophilic subgroups. Safety, such as adverse event rates, was comparable between JNJ-39758979 and placebo. No serious adverse events were reported. No clinically relevant changes in laboratory values were observed. CONCLUSIONS AND CLINICAL RELEVANCE: The findings suggest potential benefit of H4 R antagonists on lung function and asthma control in eosinophilic asthma patients and warrant further evaluation of this mechanism in asthma with eosinophilic inflammation. NCT00946569.

Longitudinal stability of asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study.

BACKGROUND: Asthma is a biologically heterogeneous disease and development of novel therapeutics requires understanding of pathophysiologic phenotypes. There is uncertainty regarding the stability of clinical characteristics and biomarkers in asthma over time. This report presents the longitudinal stability over 12 months of clinical characteristics and clinically accessible biomarkers from ADEPT. METHODS: Mild, moderate, and severe asthma subjects were assessed at 5 visits over 12 months. Assessments included patient questionnaires, spirometry, bronchodilator reversibility, fractional exhaled nitric oxide (FENO), and biomarkers measured in induced sputum. RESULTS: Mild (n = 52), moderate (n = 55), and severe (n = 51) asthma cohorts were enrolled from North America and Western Europe. For all clinical characteristics and biomarkers, group mean data showed no significant change from visit to visit. However, individual data showed considerable variability. FEV1/FVC ratio showed excellent reproducibility while pre-bronchodilator FEV1 and FVC were only moderately reproducible. Of note bronchodilator FEV1 reversibility showed low reproducibility, with the nonreversible phenotype much more reproducible than the reversible phenotype. The 7-item asthma control questionnaire (ACQ7) demonstrated moderate reproducibility for the combined asthma cohorts, but the uncontrolled asthma phenotype (ACQ7 > 1.5) was inconstant in mild and moderate asthma but stable in severe asthma. FENO demonstrated good reproducibility, with the FENO-low phenotype (FENO < 35 ppb) more stable than the FENO-high phenotype (FENO ≥ 35 ppb). Induced sputum inflammatory phenotypes showed marked variability across the 3 sputum samples taken over 6 months. CONCLUSIONS: The ADEPT cohort showed group stability, individual stability in some parameters e.g. low FEV1/FVC ratio, and low FENO, but marked individual variability in other clinical characteristics and biomarkers e.g. type-2 biomarkers over 12 months. This variability is possibly related to seasonal variations in climate and allergen exposure, medication changes and acute exacerbations. The implications for patient selection strategies based on clinical biomarkers may be considerable.

Asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) longitudinal profiling study.

BACKGROUND: Asthma is a heterogeneous disease and development of novel therapeutics requires an understanding of pathophysiologic phenotypes. The purpose of the ADEPT study was to correlate clinical features and biomarkers with molecular characteristics, by profiling asthma (NCT01274507). This report presents for the first time the study design, and characteristics of the recruited subjects. METHODS: Patients with a range of asthma severity and healthy non-atopic controls were enrolled. The asthmatic subjects were followed for 12 months. Assessments included history, patient questionnaires, spirometry, airway hyper-responsiveness to methacholine, fractional exhaled nitric oxide (FENO), and biomarkers measured in induced sputum, blood, and bronchoscopy samples. All subjects underwent sputum induction and 30 subjects/cohort had bronchoscopy. RESULTS: Mild (n = 52), moderate (n = 55), severe (n = 51) asthma cohorts and 30 healthy controls were enrolled from North America and Western Europe. Airflow obstruction, bronchodilator response and airways hyperresponsiveness increased with asthma severity, and severe asthma subjects had reduced forced vital capacity. Asthma control questionnaire-7 (ACQ7) scores worsened with asthma severity. In the asthmatics, mean values for all clinical and biomarker characteristics were stable over 12 months although individual variability was evident. FENO and blood eosinophils did not differ by asthma severity. Induced sputum eosinophils but not neutrophils were lower in mild compared to the moderate and severe asthma cohorts. CONCLUSIONS: The ADEPT study successfully enrolled asthmatics across a spectrum of severity and non-atopic controls. Clinical characteristics were related to asthma severity and in general asthma characteristics e.g. lung function, were stable over 12 months. Use of the ADEPT data should prove useful in defining biological phenotypes to facilitate personalized therapeutic approaches.

Atopy, asthma, and experimental approaches based on the linear model of T cell maturation.

The linear model of maturation of IFN-gamma-producing cells from a proliferative pool of type 2 cytokine-producing T cells represents a fundamental shift in interpreting how changes in cytokine production by T cell populations are regulated. A major tenet of this model is antigen-independent, bystander proliferation of type 2 T cells and their maturation to IFN-gamma+ cells. Both clinical observations and prevailing theories of immune system development in asthma are consistent with this highly interpretative in vitro model, which allows unambiguous characterization of the modulation of the intrinsic features of T cell proliferation and differentiation by environmental and genetic factors. Hypotheses based on the linear model of T cell maturation are readily testable and should lead to a greater understanding of not only allergen-specific responses, but also the non-specific, bystander effects associated with specific responses to allergens or pathogens. Topics to be discussed in the context of the linear model of T cell maturation in this review include: (1) allergic responses to an inciting allergen that may enhance sensitivity to subsequent yet different allergens; (2) dampening the preferential accumulation of type 2 T cells during a typical immune response against viral and bacterial pathogens; (3) allergen-independent sensitization in asthmatics: (4) the 'hygiene hypothesis' for the reported increased allergy development in industrialized countries; (5) elevated IFN-gamma levels in asthmatics, in addition to the expected high levels of type 2 cytokines; (6) testing the effects of inflammatory mediators, as well as various anti-inflammation therapies on T cell maturation; and (7) testing the influence of gene variation on T cell maturation.

Human NKT cells mediate antitumor cytotoxicity directly by recognizing target cell CD1d with bound ligand or indirectly by producing IL-2 to activate NK cells.

alpha-Galactosylceramide (alphaGalCer) stimulates NKT cells and has antitumor activity in mice. Murine NKT cells may directly kill tumor cells and induce NK cell cytotoxicity, but the mechanisms are not well defined. Newly developed human CD1d/alphaGalCer tetrameric complexes were used to obtain highly purified human alphaGalCer-reactive NKT cell lines (>99%), and the mechanisms of NKT cell cytotoxicity and activation of NK cells were investigated. Human NKT cells were cytotoxic against CD1d(-) neuroblastoma cells only when they were rendered CD1d(+) by transfection and pulsed with alphaGalCer. Four other CD1d(-) tumor cell lines of diverse origin were resistant to NKT cells, whereas Jurkat and U937 leukemia cell lines, which are constitutively CD1d(+), were killed. Killing of the latter was greatly augmented in the presence of alphaGalCer. Upon human CD1d/alphaGalCer recognition, NKT cells induced potent cytotoxicity of NK cells against CD1d(-) neuroblastoma cell lines that were not killed directly by NKT cells. NK cell activation depended upon NKT cell production of IL-2, and was enhanced by secretion of IFN-gamma. These data demonstrate that cytotoxicity of human NKT cells can be CD1d and ligand dependent, and that TCR-stimulated NKT cells produce IL-2 that is required to induce NK cell cytotoxicity. Thus, NKT cells can mediate potent antitumor activity both directly by targeting CD1d and indirectly by activating NK cells.

Final steps of natural killer cell maturation: a model for type 1-type 2 differentiation?

Analysis of cytokine and differentiation antigen expression in human natural killer (NK) cells revealed that interleukin 13 (IL-13) and interferon gamma (IFN-gamma) are produced at sequential stages during irreversible IL-12-induced differentiation. In human NK cell clones, polyclonal CD3-CD161+CD56- cells and peripheral lymphocytes, IL-4 induced the proliferation of both IL-13+ NK and T cells, whereas IL-12 allowed a proliferation-independent accumulation of IFN-gamma+ cells. These data disproved the NK1-NK2 hypothesis and challenge the current T helper 1 (TH1)-TH2 paradigm. We propose that the cytokine environment regulates a type 2-->0-->1 developmental progression, with IL-12 needed for terminal differentiation and IL-4 delaying this process, rather than a type 1 versus type 2 decision of a type 0 cell.

B-Myb overexpression results in activation and increased Fas/Fas ligand-mediated cytotoxicity of T and NK cells.

The human B-myb gene encodes a transcriptional regulator that plays an important role in cell cycle progression, differentiation, and survival. To assess the in vivo role of B-myb, we investigated the phenotype of mouse transgenic lines in which B-Myb expression in lymphoid tissues was driven by the LCK proximal promoter. Overexpression of B-Myb had no measurable effect on the subsets of splenic and thymic lymphocytes, but was associated with increased expression of Fas ligand in NK and T cells. B-Myb-overexpressing splenocytes expressed higher IFN-gamma levels and contained higher percentages of cytokine-producing cells than wild-type (wt) splenocytes, as detected by Western blot analysis and ELISPOT assays, respectively. Ex vivo-cultured transgenic thymocytes and splenocytes had decreased survival compared with the corresponding cells from wt mice, possibly dependent on increased expression of Fas ligand. In addition, Fas ligand-dependent cytotoxicity of transgenic T and NK cells was significantly higher than that mediated by their wt counterparts. Together, these results indicate that B-Myb overexpression results in T and NK cell activation and increased cytotoxicity. Therefore, in addition to its well-established role in proliferation and differentiation, B-myb also appears to be involved in activation of NK and T cells and in their regulation of Fas/Fas ligand-mediated cytotoxicity