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

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.

To evaluate the efficacy, safety, and tolerability of intralymphatic immunotherapy for allergies caused by mountain cedar pollen in a proof-of-concept study.

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.

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.

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.

This study was registered at ClinicalTrials.gov under the registration number NCT03682965 before the enrollment of the first subject.