Intralymphatic immunotherapy for mountain cedar pollinosis A randomized, double-blind, placebo-controlled trial

Background: Allergen immunotherapy can provide long-term benefits, including symptomatic relief and reduced disease progression, but it requires a lengthy regimen that presents barriers to patient adherence. Thus, there is a need for improved approaches to immunotherapy. Recently, several clinical trials have reported successful results from intralymphatic immunotherapy. Objective: To evaluate the efficacy, safety, and tolerability of intralymphatic immunotherapy for allergies caused by mountain cedar pollen in a proof-of-concept study. Methods: A total of 21 patients with allergic rhinoconjunctivitis because of mountain cedar pollen were randomized to receive 3 monthly intralymphatic injections of allergenic extract or placebo before the 2018-2019 mountain cedar pollen season. Safety was monitored during treatment to the end of the pollen season using structured and spontaneous reports. Clinical efficacy information was collected using a daily electronic diary of symptoms and allergy medication. Allergen-specific serum immunoglobulin E was assessed before treatment and at the end of the study. Results: There were no serious adverse events or systemic reactions in either group. A total of 4 patients experienced mild injection-site reactions. Patients receiving intralymphatic immunotherapy experienced a significant improvement in allergy symptoms and medication use relative to patients receiving placebo (P < .001), and the active treatment group had lower average total combined scores on 20 of 27 days during the peak pollen season (P < .05). There was no significant difference among groups in changes to mean mountain cedar-specific serum immunoglobulin E levels. Conclusion: In this proof-of-concept trial, intralymphatic immunotherapy was well tolerated and improved the symptoms and medication use associated with allergic rhinoconjunctivitis caused by mountain cedar pollen. (C) 2020 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.