Preclinical safety and pharmacology of an anti-human interleukin-13 monoclonal antibody in normal macaques and in macaques with allergic asthma

Managing Atopic Dermatitis with Lebrikizumab - The Evidence to Date

Atopic dermatitis is a prevalent, inflammatory skin disease that presents with an eczematous, itchy rash. As of late, there have been many emerging monoclonal antibody inhibitor and small molecule therapies that have changed the course of eczema treatment. One of the treatments in the pipeline for atopic dermatitis is interleukin 13 monoclonal antibody inhibitor, lebrikizumab. As interleukin 13 has been identified as a pro-inflammatory cytokine in the immunological cascade of eczema, it is thought that lebrikizumab can be a great treatment choice for patients with atopic dermatitis. Lebrikizumab is currently being investigated in several studies. Thus far, lebrikizumab for the treatment of eczema has been found to be efficacious; in particular, a rapid response of pruritus improvement has been demonstrated in as early as 2 days. Additionally, it is well tolerated and has an acceptable safety profile, with reports suggesting that are decreased risks of infection when compared to dupilumab. In this review, we aim to summarize the current understanding of lebrikizumab in terms of the mechanism of action, preclinical pharmacology, pharmacokinetics and metabolism, efficacy and safety, and drug indications.

Efficacy of an Inhaled IL-13 Antibody Fragment in a Model of Chronic Asthma

RATIONALE

IL-13 is an important cytokine implicated in the pathogenesis of allergic asthma and is an attractive target for an inhaled therapeutic.

OBJECTIVE

To investigate the efficacy of CDP7766, a nebulized inhaled anti-IL-13 monoclonal antibody Fab fragment, in a model of allergic asthma in cynomolgus macaques naturally sensitized to Ascaris suum.

METHODS

CDP7766 was nebulized using a vibrating-membrane nebulizer on the basis of eFlow technology. The aerosol generated was analyzed to determine the particle size profile and the biophysical and functional properties of CDP7766. Nebulized CDP7766 (0.1-60 mg/animal, once daily for 5 d) was delivered via the inhaled route.

MEASUREMENTS AND MAIN RESULTS

The investigational eFlow nebulizer used in this study generated a respirable aerosol of CDP7766 with no evidence of degradation, loss of potency, aggregation, or formation of particulates. Inhaled CDP7766 was well tolerated in the model (no adverse effects related to local irritation) and significantly inhibited BAL allergen-induced cytokine and chemokine upregulation (60 mg vs. vehicle: eotaxin-3, P < 0.0008; MIP [macrophage inflammatory protein]-1β, IL-8, IFN-γ, P ≤ 0.01). CDP7766 significantly inhibited the increase in pulmonary resistance stimulated by inhaled allergen, measured 15 minutes and 24 hours after allergen challenge.

CONCLUSION

Inhaled CDP7766 potently inhibited the function of IL-13 generated during the airway response to inhaled allergen in cynomolgus macaques, demonstrating the potential of inhaled anti-IL-13 therapeutics for the treatment of allergic asthma.

Unexpected Toxicology Findings in Rats Dosed With an Antihuman IL-13 Monoclonal Antibody

Interleukin 13 (IL-13) is a type 2 helper T cytokine involved in allergic inflammation and immune responses to parasites. CNTO5825 is an antihuman IL-13 monoclonal antibody that inhibits the pharmacological activity of human, cynomolgus monkey, and rat IL-13. Repeated dose toxicology studies of 1- to 6-month duration were conducted in both rats and monkeys at doses of 20 to 100 mg/kg/wk. A decrease in the T cell-dependent antibody response to Keyhole Limpet Hemocyanin immunization was observed in monkeys but not in rats. In the 6-month rat study, there was a 2.2-fold increase in eosinophils in males at 3 and 6 months that was reversible. At necropsy (main and 4-month recovery), rats from control and CNTO5825-dosed groups were found to have pin worms, which may have contributed to the elevations in eosinophil. Testicular toxicity (dilatation of seminiferous tubules, atrophy, and degeneration of the germinal epithelium) was observed in 2 rats at 20 mg/kg and in 5 rats at 100 mg/kg (main and recovery). Brain lesions (unilateral focal accumulation of cells in the white matter of the cerebral cortex) were observed in 2 rats at 100 mg/kg, and vascular neoplasms (1 fatal multicentric hemangiosarcoma and 1 benign hemangioma) were observed at 100 mg/kg/wk. Overall, these studies show that CNTO5825 was without toxicity when administered to rats for up to 6 weeks and to monkeys for up to 6 months. However, when administered to rats for 6 months, a number of seemingly unrelated events occurred that could not be clearly linked to CNTO5825 administration, inhibition of IL-13, or to the immunological status of the animals.

Homoegonol attenuates the asthmatic responses induced by ovalbumin challenge

Homoegonol is a lignan derived from styraxlignolide A, which was isolated from Styrax japonica, a medicinal plant widely used for treatment of inflammatory diseases in Korea. We investigated the efficacy of homoegonol for the treatment of allergic asthma using an ovalbumin (OVA)-induced murine asthma model. The mice were sensitized through intraperitoneal injections of OVA on days 0 and 14. On days 21, 22 and 23 after the initial OVA sensitization, the mice were received OVA airway challenge. Homoegonol was administered by oral gavage at a dose of 30 mg/kg 1 h prior to the OVA challenge. The homoegonol-treated mice exhibited reduced inflammatory cell counts and Th2 cytokines in BALF, AHR, and IgE in the serum compared with the OVA-sensitized/challenged mice. The histological analysis of the lung tissue revealed that the administration of homoegonol attenuated the airway inflammation and the mucus overproduction in airway epithelial lesions induced by OVA through a reduction in expression of inducible nitric oxide synthase and matrix metalloproteinase-9. These findings indicate that homoegonol effectively suppresses the asthmatic responses induced by OVA challenge and suggests that homoegonol exhibits potential as therapeutic drug for allergic asthma.

Unexpected hematologic effects of biotherapeutics in nonclinical species and in humans

Biotherapeutics are expanding the arsenal of therapeutics available for treating and preventing disease. Although initially thought to have limited side effects due to the specificity of their binding, these drugs have now been shown to have potential for adverse drug reactions including effects on peripheral blood cell counts or function. Hematotoxicity caused by a biotherapeutic can be directly related to the activity of the biotherapeutic or can be indirect and due to autoimmunity, biological cascades, antidrug antibodies, or other immune system responses. Biotherapeutics can cause hematotoxicity primarily as a result of cellular activation, cytotoxicity, drug-dependent and independent immune responses, and sequelae from initiating cytokine and complement cascades.  The underlying pathogenesis of biotherapeutic-induced hematotoxicity often is poorly understood. Nonclinical studies have generally predicted clinical hematotoxicity for recombinant cytokines and growth factors.  However, most hematologic liabilities of biotherapeutics are not based on drug class but are species specific, immune-mediated, and of low incidence. Despite the potential for unexpected hematologic toxicity, the risk-benefit profile of most biotherapeutics is favorable; hematologic effects are readily monitorable and managed by dose modification, drug withdrawal, and/or therapeutic intervention.  This article reviews examples of biotherapeutics that have unexpected hematotoxicity in nonclinical or clinical studies. 

Nebulized anti-IL-13 monoclonal antibody Fab' fragment reduces allergen-induced asthma

IL-13 is a prototypic T helper type 2 cytokine and a central mediator of the complex cascade of events leading to asthmatic phenotype. Indeed, IL-13 plays key roles in IgE synthesis, bronchial hyperresponsiveness, mucus hypersecretion, subepithelial fibrosis, and eosinophil infiltration. We assessed the potential efficacy of inhaled anti-IL-13 monoclonal antibody Fab' fragment on allergen-induced airway inflammation, hyperresponsiveness, and remodeling in an experimental model of allergic asthma. Anti-IL-13 Fab' was administered to mice as a liquid aerosol generated by inExpose inhalation system in a tower allowing a nose-only exposure. BALB/c mice were treated by PBS, anti-IL-13 Fab', or A33 Fab' fragment and subjected to ovalbumin exposure for 1 and 5 weeks (short-term and long-term protocols). Our data demonstrate a significant antiasthma effect after nebulization of anti-IL-13 Fab' in a model of asthma driven by allergen exposure as compared with saline and nonimmune Fab fragments. In short- and long-term protocols, administration of the anti-IL-13 Fab' by inhalation significantly decreased bronchial responsiveness to methacholine, bronchoalveolar lavage fluid eosinophilia, inflammatory cell infiltration in lung tissue, and many features of airway remodeling. Levels of proinflammatory mediators and matrix metalloprotease were significantly lower in lung parenchyma of mice treated with anti-IL-13 Fab'. These data demonstrate that an inhaled anti-IL-13 Fab' significantly reduces airway inflammation, hyperresponsiveness, and remodeling. Specific neutralization of IL-13 in the lungs using an inhaled anti-IL-13 Fab' could represent a novel and effective therapy for the treatment of asthma.

Preclinical development of CAT-354, an IL-13 neutralizing antibody, for the treatment of severe uncontrolled asthma

BACKGROUND AND PURPOSE

IL-13 is a pleiotropic Th2 cytokine considered likely to play a pivotal role in asthma. Here we describe the preclinical in vitro and in vivo characterization of CAT-354, an IL-13-neutralizing IgG4 monoclonal antibody (mAb), currently in clinical development.

EXPERIMENTAL APPROACH

In vitro the potency, specificity and species selectivity of CAT-354 was assayed in TF-1 cells, human umbilical vein endothelial cells and HDLM-2 cells. The ability of CAT-354 to modulate disease-relevant mechanisms was tested in human cells measuring bronchial smooth muscle calcium flux induced by histamine, eotaxin generation by normal lung fibroblasts, CD23 upregulation in peripheral blood mononuclear cells and IgE production by B cells. In vivo CAT-354 was tested on human IL-13-induced air pouch inflammation in mice, ovalbumin-sensitization and challenge in IL-13 humanized mice and antigen challenge in cynomolgus monkeys.

KEY RESULTS

CAT-354 has a 165 pM affinity for human IL-13 and functionally neutralized human, human variant associated with asthma and atopy (R130Q) and cynomolgus monkey, but not mouse, IL-13. CAT-354 did not neutralize human IL-4. In vitro CAT-354 functionally inhibited IL-13-induced eotaxin production, an analogue of smooth muscle airways hyperresponsiveness, CD23 upregulation and IgE production. In vivo in humanized mouse and cynomolgus monkey antigen challenge models CAT-354 inhibited airways hyperresponsiveness and bronchoalveolar lavage eosinophilia.

CONCLUSIONS AND IMPLICATIONS

CAT-354 is a potent and selective IL-13-neutralizing IgG4 mAb. The preclinical data presented here support the trialling of this mAb in patients with moderate to severe uncontrolled asthma.

Targeting interleukin-4 in asthma: lost in translation?

The first discovery that interleukin-4 (IL-4) is crucial in the development of allergic airway inflammation originates from the early 1990s. Whereas initial studies in experimental animal models provided the community with the optimistic view that targeting IL-4 would be the ultimate solution for treating asthma, the translation of these findings to the clinic has not been evident and has not yet fulfilled the expectations. Many technical challenges have been encountered in the attempts to modulate IL-4 expression or activity and in transferring knowledge of preclinical studies to clinical trials. Moreover, biological redundancies between IL-4 and IL-13 have compelled a simultaneous blockade of both cytokines. A number of phase I/II studies are now providing us with clinical evidence that targeting IL-4/IL-13 may provide some clinical benefit. However, the initial view that asthma is a purely Th2-mediated disease had to be revised. Currently, different asthma phenotypes have been described, implying that blocking specifically Th2 cytokines, such as IL-4, IL-5, and IL-13, should be targeted to only a specific subset of patients. Taking this into consideration, IL-4 (together with IL-13) deserves attention as subject of further investigations to treat asthma. In this review, we will address the role of IL-4 in asthma, describe IL-4 signaling, and give an overview of preclinical and clinical studies targeting the IL-4 Receptor pathway.

New roles for mast cells in modulating allergic reactions and immunity against pathogens

Mast cells (MCs) have primarily been associated with mediating the pathological secondary responses to allergens in sensitized hosts. In view of the recent evidence for a MC role in modulating primary immune responses to pathogens, the likelihood for a role of MCs in influencing primary immune response to allergens has grown. New evidence suggests that MCs drive the development of Th2 responses to allergens, particularly when allergen exposure occurs concomitantly with exposure to pathogen products present in the environment. These new roles for MCs in allergy and infection suggest additional drug targets to prevent the development of allergic disease and allergic exacerbations of established disease.