Long-term multicenter comparison shows equivalent efficacy of monoclonal antibodies in severe asthma therapy

BACKGROUND

Monoclonal antibodies (biologics) drastically changed severe asthma therapy. Mepolizumab (anti-interleukin (IL) 5), benralizumab (anti-IL5 receptor alpha), and dupilumab (anti-IL4/13) are the most used biologics in this context. While all biologics are efficient individually, the choice of biologic is complicated by insufficient data on their comparative long-term treatment efficacy. Here, we compare the real-life efficacy of these biologics in asthma therapy over 12 months.

METHODS

280 severe asthma patients treated with mepolizumab (129/280, 46%), benralizumab (83/280, 30%) or dupilumab (68/280, 24%) for one year were analyzed retrospectively. Data were collected at baseline and after 6 and 12 months of therapy. Endpoints were changes pulmonary function (PF), exacerbation rate, oral corticosteroid (OCS) use and dose, asthma control test (ACT) score and fractional exhaled nitric oxide (FeNO) levels as well as responder status measured by the recently published "Biologic Asthma Response Score" (BARS).

RESULTS

All biologics led to significant improvements in PF, ACT and OCS dose. Only Mepolizumab and Benralizumab significantly decreased the exacerbation rate, while only Mepolizumab and Dupilumab significantly decreased FeNO. Responder rates measured by BARS were high across all groups: roughly half of all patients achieved full response and most of the remainder achieved at least partial responder status. Overall, outcomes were similar between groups after both 6 and 12 months.

CONCLUSIONS

All biologics showed great efficacy in individual parameters and high responder rates measured by BARS without a clinically relevant advantage for any antibody. Response was usually achieved after 6 months and retained at 12 months, emphasizing the utility of early response assessment.

[Biologicals in the Treatment of Bronchial Asthma]

Biologicals are a therapeutic option for patients with severe asthma. Difficult asthma in patients with untreated comorbidities or persistent trigger factors is much more common than severe refractory asthma. Optimized medical treatment, adherence to medication, elimination of trigger factors and treatment of comorbidities are essential before escalating the therapy with a biological. A careful phenotyping of patient with severe asthma is necessary because all available biological are only effective in certain phenotypes of the disease. For patients with severe allergic asthma an antibody against IgE (Omalizumab) is available. For patients with severe asthma and eosinophilic inflammation the Interleukin (IL)-5 Antibodies Mepolizumab and Reslizumab have recently been approved. The most prominent effect of biological treatment is the reduction of acute exacerbations in these patients. Further antibodies against IL-5 receptor (Benralizumab) or against the IL-4 receptor alpha chain (Dupilumab) are in advanced clinical development.

CD4-mediated regulatory T-cell activation inhibits the development of disease in a humanized mouse model of allergic airway disease

BACKGROUND

Based on their potency to control allergic diseases, regulatory T (Treg) cells represent a promising target for novel strategies to interfere with allergic airway inflammation. We have previously demonstrated that stimulation of the CD4 molecule on human Treg cells activates their suppressive activity in vitro and in vivo.

OBJECTIVE

We sought to determine the effect of CD4-mediated Treg-cell activation on pulmonary inflammation in a humanized mouse model of allergic airway inflammation.

METHODS

PBMCs obtained from donors allergic to birch pollen or from healthy donors were injected into NOD-severe combined immunodeficiency γc(-/-) mice, followed by allergen airway challenges and analysis of airway responsiveness and inflammation. For Treg-cell activation, mice were treated with the CD4-binding, lck-activating recombinant HIV-1 surface protein gp120 after sensitization prior to allergen challenge. Control experiments with CD25-depleted PBMCs were performed to evaluate the role of Treg cells.

RESULTS

PBMCs from allergic donors but not from healthy donors induced airway inflammation and airway hyperresponsiveness. Treatment with gp120 prior to allergen challenge abrogated airway hyperresponsiveness and reduced the inflammatory immune response. In contrast, treatment had no effect on inflammation and airway hyperresponsiveness in mice that received CD25-depleted PBMCs, demonstrating Treg-cell dependency of disease prevention.

CONCLUSION

Allergic airway inflammation can be prevented by stimulation of human Treg cells by CD4. These results suggest a clinical potential of Treg-cell activation by high-affinity CD4 ligands in allergic diseases.

[Asthma: new insights and advances in treatment]

In mild asthma low-dose steroid inhalation treatment reduces severe exacerbations and exacerbation associated loss of lung function. In patients with mild asthma, symptom-driven use of a combination of inhaled steroid and short-acting beta-2-sympathomimetics in a single inhaler is feasible. In moderate and severe asthma the fixed combination of formoterol and budesonide can be used a maintenance therapy but also as treatment of acute symptoms. Monotherapy with long-acting beta 2-sympathomimetics should be completely avoided. Long-acting anticholinergic drugs are equally efficacious as long-acting beta-2-sympathomimetics, but have not yet been approved for use in patients with asthma. The correct identification of various phenotypes is especially important in severe asthma, because there are different specific treatment approaches.