Investigational new drugs for allergic rhinitis

ABSTRACT

Introduction: Allergic rhinitis (AR) is a multifactorial disease characterized by paroxysmal symptoms of sneezing, rhinorrhea, postnasal drip and nasal congestion. For over a century, subcutaneous allergen immunotherapy (SCIT) has been recognized as the most effective therapy to date that may modify the underlying disease course and provide long-term benefits for individuals refractory to pharmacotherapy. However, over the past 25 years, there has been substantial growth in developing alternative therapies to traditional SCIT.

Areas covered: This article will review the most current literature focusing on advancements of AR therapies. Novel AR therapies that are currently under investigation include: the addition of omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody (mAb), to SCIT; altering the method of delivery of allergen immunotherapy (AIT) including sublingual (SLIT), epicutaneous (EIT), intralymphatic (ILIT), intranasal (INIT) and oral mucosal immunotherapy (OMIT); use of capsaicin spray; novel H3 and H4 antihistamines; activation of the innate immune system through Toll-like receptor agonists; and the use of chemically altered allergens, allergoids, recombinant allergens and relevant T-cell epitope peptides to improve the efficacy and safety of AIT.

Expert opinion: These promising novel therapies may offer more effective and/or safer treatment options for AR patients, and in some instances, induce immunologic tolerance.

KEYWORDS:

• Allergic rhinitis
• allergoids
• capsaicin
• EIT
• ILIT
• INIT
• novel antihistamines
• omalizumab
• OMIT
• peptides
• recombinant allergens
• SCIT
• SLIT
• TLR agonists

Article Highlights

• Allergic rhinitis (AR) is a multifactorial disease characterized by paroxysmal symptoms of sneezing, rhinorrhea, postnasal drip and nasal congestion and its prevalence has increased over the last 20 years, affecting more than 40 to 50 million people in the United States and over 500 million people worldwide.

• For over a century, subcutaneous immunotherapy (SCIT) has been a mainstay in the treatment of allergic diseases and in contrast to pharmacotherapy, it is the only disease-modifying allergen-specific therapy for AR and asthma. Although successful in treating refractory cases of AR, SCIT has a risk of systemic allergic reactions (SARs).

• Given improvements in understanding the pathogenesis of AR, novel forms of immunotherapy have been implemented and similar to SCIT, help shift the immune response to a specific allergen from a predominantly allergic profile (T_H2) to a non-allergic profile (T_H1) while inducing regulatory T-cells.

• Currently, there are many novel AR therapies under investigation and these include: the addition of omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody (mAb), to SCIT; altering the method of delivery of allergen immunotherapy (AIT) including sublingual (SLIT), epicutaneous (EIT), intralymphatic (ILIT), intranasal (INIT) and oral mucosal immunotherapy (OMIT); use of capsaicin spray; novel H3 and H4 antihistamines; activation of the innate immune system through Toll-like receptor agonists; and the use of chemically altered allergens, allergoids, recombinant allergens and relevant T-cell epitope peptides as AIT.

• Despite promising trials with many of these novel therapies, more studies are needed to demonstrate clinical efficacy and enhanced safety to traditional AIT in the treatment of refractory cases of AR. Additionally, it is likely that a combination of these and traditional therapies may be needed to achieve enhanced clinical efficacy and/or safety to manage this complex inflammatory disease.

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Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This paper was not funded.