Sublingual Allergen-Specific Immunotherapy Adjuvanted with Monophosphoryl Lipid A: A Phase I/IIa Study

Abstract

Background: Sublingual immunotherapy (SLIT) allergy vaccines have an excellent safety profile, but opinions vary on their efficacy, and treatment regimens are often lengthy. This study assessed the effects of the Toll-like receptor 4 agonist monophosphoryl lipid A (MPL®) on safety/tolerability and clinical and immunological efficacy when combined with grass pollen SLIT formulations in treating patients with seasonal allergic rhinitis. This is the first reported study of adjuvanted SLIT. Methods: In this double-blind placebo-controlled phase I/IIa study, 80 grass pollen-sensitive subjects were randomized into 4 groups of 20 subjects to receive daily treatment for 8 weeks. Sixteen patients per group received SLIT and 4 received placebo. The formulation given to each group varied with respect to grass pollen extract and MPL content. Grass allergen nasal challenge tests (NCTs) were performed prior to dosing and in weeks 4 and 10. Grass pollen-specific immunoglobulin G (IgG) and IgE antibodies were measured at baseline and prior to dosing in weeks 2, 3, 4, 5 and 10. Results: Local and systemic adverse events were generally comparable for patients who received active treatment and placebo. Patients in the 2 groups given SLIT containing the highest amount of MPL experienced the highest proportion of negative NCTs after 10 weeks (47 and 44%, vs. 20% with placebo). These patients also showed earlier median increases in specific IgG and smaller increases in IgE levels than those receiving other formulations. Conclusions: These results suggest that SLIT preparations containing MPL are well tolerated and alter the immunological response to grass antigens after 3 weeks of exposure, with an associated suppression of nasal challenge responses.

Recommendations for the standardization of clinical outcomes used in allergen immunotherapy trials for allergic rhinoconjunctivitis: an EAACI Position Paper

“…This organ-specific challenge test has been used in multiple proof-of-concept studies (62,73) and for evaluating mechanisms and the dose-response relationship for AIT, in order to select an appropriate dose for phase II/III trials (6). Explorative studies revealed a decrease in nasal allergen sensitivity after AIT (74)(75)(76). Nasal fluid may be sampled by lavage (77,78).…”

A New Era of Targeting the Ancient Gatekeepers of the Immune System: Toll-Like Agonists in the Treatment of Allergic Rhinitis and Asthma

“…Of note, IgG production is differed based on pollen since Timothy and rPhl p 5 allergen-containing vaccines induced greater values of IgG than other pollens. The allergen-specific lymphocyte proliferation response is increased with the maximum quantities prior to the last injection of Pollinex Quattro [64,136,139]. b The AIC schedule is as follows: weekly injection of up-dosing AIC with 0.06-12.0 µg (Amb a 1:1018 ISS molar ratio of 1:4).…”

A novel allergen-adjuvant conjugate suitable for specific immunotherapy of respiratory allergy

“…Furthermore, the administration of an MPL-adjuvanted grass pollen vaccine through the sublingual route (sublingual immunotherapy) seems to be safe and associated with suppression of nasal challenge. 9 Actually, the chemical conjugation between allergens and adjuvants can further improve vaccine constructs by providing the delivery of the 2 components inside the same antigenpresenting cell (APC) with a more focused innate activation and better interference with immunopathogenic mechanisms. The chemical linkage between antigens and TLR ligands eventually ensures safety, inducing protective IgG isotype antibody without nonspecific effects on B cells.…”