Efficacy and safety of benralizumab in chronic rhinosinusitis with nasal polyps: A randomized, placebo-controlled trial

BACKGROUND

Eosinophilic inflammation has been implicated in the pathogenesis, severity, and treatment responsiveness of chronic rhinosinusitis with nasal polyps (CRSwNP).

OBJECTIVE

We sought to assess the efficacy and safety of benralizumab-mediated eosinophil depletion for treating CRSwNP.

METHODS

The phase 3 OSTRO study enrolled patients with severe CRSwNP who were symptomatic despite treatment with intranasal corticosteroids and who had a history of systemic corticosteroid (SCS) use and/or surgery for nasal polyps (NP). Patients were randomized 1:1 to treatment with benralizumab 30 mg or placebo every 4 weeks for the first 3 doses and every 8 weeks thereafter. Coprimary end points were change from baseline to week 40 in NP score (NPS) and patient-reported mean nasal blockage score reported once every 2 weeks.

RESULTS

The study population comprised 413 randomized patients (207 in the benralizumab group and 206 in the placebo group). Benralizumab significantly improved NPS and nasal blockage score compared to placebo at week 40 (P ≤ .005). Improvements in Sinonasal Outcome Test 22 score at week 40, time to first NP surgery and/or SCS use for NP, and time to first NP surgery were not statistically significant between treatment groups. Nominal significance was obtained for improvement in difficulty in sense of smell score at week 40 (P = .003). Subgroup analyses suggested influences of comorbid asthma, number of NP surgeries, sex, body mass index, and baseline blood eosinophil count on treatment effects. Benralizumab was safe and well tolerated.

CONCLUSION

Benralizumab, when added to standard-of-care therapy, reduced NPS, decreased nasal blockage, and reduced difficulty with sense of smell compared to placebo in patients with CRSwNP.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03401229.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Eosinophilic sialodochitis: redefinition of 'allergic parotitis' and 'sialodochitis fibrinosa'

Sialodochitis fibrinosa and allergic parotitis have described rare patients with recurrent salivary gland swelling and mucus plugs, often with atopy. We have evaluated three patients with atopic disease, recurrent salivary gland swelling, and an eosinophilic sialodochitis. Two had eosinophil-rich mucus plugs. Fifty-six additional cases were identified in a medical literature database search, each defined by recurrent salivary gland swelling associated with eosinophil-rich mucus plugs or sialodochitis with periductal eosinophilic infiltration. The majority (78%) were reported from Japan. Females were predominantly affected (F:M = 2.3) with a median age of 47 years at evaluation. The parotid and submandibular glands were involved, respectively, in 71% and 46%. Allergic symptoms were present in 66%, atopic disease in 63% of those with reported allergy testing, and blood eosinophilia in 71%. Contrast sialography and other imaging modalities documented ductal dilatation in 82%. Treatments included anti-allergic medications (58%), systemic glucocorticoids (25%), duct cannulation with irrigation, steroid injection, and/or duct dilatation (36%), and glandular resection (19%). We recommend the diagnosis 'eosinophilic sialodochitis' be applied to patients who meet this case definition. The disease is a unique cause of chronic recurrent salivary gland swelling. Its likely allergic etiology may be amenable to current or future biologic therapies.

Subcutaneous allergen immunotherapy restores human dendritic cell innate immune function

BACKGROUND

We recently reported that human blood dendritic cells from allergic subjects have impaired IFN-alpha production following toll-like receptor 9 (TLR9)-dependent innate immune stimulation. It is not known how subcutaneous allergen immunotherapy (SCIT) affects dendritic cell immune responses.

OBJECTIVE

The aim of this study is to determine how SCIT affects human dendritic cell function.

METHODS

Peripheral blood mononuclear cell (PBMC) and plasmacytoid dendritic cells (pDCs) were isolated from the blood of seven dust mite allergic subjects at baseline and upon reaching a standard SCIT maintenance dose that included dust mite and other aeroallergens. Cells were stimulated with various adaptive and innate immune receptor stimuli, or media alone for 20 h with secreted cytokine levels determined by ELISA. A portion of the cells were used to measure intracellular signalling proteins by flow cytometry. Humoral immune responses were measured from plasma.

RESULTS

SCIT resulted in a threefold increase in PBMC production of IFN-alpha in response to CpG at 100 nM (P=0.015) and at 500 nM (P=0.015), n=7. The predominant cell type known to produce IFN-alpha in response to CpG (CpG ODN-2216) and other TLR9 agonists is the pDC. As expected, a robust innate immune response from isolated pDCs was re-established among allergic subjects undergoing SCIT resulting in a fivefold increase in IFN-alpha production in response to CpG at 500 nM (P=0.046), n=7. In contrast, IL-6 production was unaffected by SCIT (P=0.468). Consistent with published reports, IgG4 blocking antibody increased 10-fold with SCIT (P=0.031), n=7. There was no significant increase in the frequency of pDCs or the expression of TLR9 that would account for the rise in IFN-alpha production.

CONCLUSIONS

Allergen immunotherapy increases dendritic cell TLR9-mediated innate immune function, which has previously been shown to be impaired at baseline in allergic subjects.

Human blood dendritic cells from allergic subjects have impaired capacity to produce interferon-alpha via Toll-like receptor 9

BACKGROUND

High-affinity IgE receptor (Fc epsilon RI) expression on blood dendritic cells reportedly correlates with serum IgE levels. Our studies demonstrate that plasmacytoid dendritic cells (pDCs) secrete pro-inflammatory cytokines (IL-6, TNF-alpha) following Fc epsilon RI stimulation - a mode of activation that simultaneously reduces expression of Toll-like receptor 9 (TLR9). Whether or not TLR9 and/or Fc epsilon RI levels and their function on dendritic cells relate to allergic status is unknown.

OBJECTIVE

The aim of this study is to compare the innate (TLR9-mediated) immune response of human pDCs to TLR9 and Fc epsilon RI alpha receptor expression in allergic and non-allergic subjects.

METHODS

Basophil-depleted mononuclear cell fractions containing pDCs were prepared from peripheral blood of allergic and non-allergic subjects. Intracellular TLR9 and surface Fc epsilon RI alpha expression in blood dendritic cell antigen-2-positive cells were determined by flow cytometry. Activating anti-IgE antibody, anti-Fc epsilon RI alpha antibody, and TLR9 agonist were used to stimulate cell suspensions, with cytokine levels determined by ELISA.

RESULTS

No difference in the frequency of pDCs was detected among allergic (n=9) vs. non-allergic (n=11) subjects (P=0.261). While there was also no difference in the baseline expression of TLR9, pDCs from allergic subjects produced sixfold less IFN-alpha when stimulated with CpG (P=0.002). Conversely, there was higher Fc epsilon RI alpha expression (P=0.01) on the pDCs of allergic subjects.

CONCLUSIONS

Impaired TLR9-dependent immune responses in human pDCs are associated with allergic status and inversely correlated with Fc epsilon RI alpha expression. This impaired innate immune response among dendritic cells of allergic subjects may lead to more targeted therapeutic approaches and could provide a better understanding of the mechanisms underlying conventional and CpG-based immunotherapy.