Intralymphatic immunotherapy for cat allergy induces tolerance after only 3 injections

Area of Science:

• Immunology
• Allergy Research
• Vaccine Development

Background:

• Subcutaneous allergen-specific immunotherapy has limitations including frequent allergic side effects and a lengthy treatment duration.
• A need exists for improved immunotherapy methods with fewer side effects and shorter treatment times.

Purpose of the Study:

• To evaluate the safety and efficacy of intralymphatic allergen administration (ILIT) using a novel modular antigen transporter (MAT) vaccine targeting the MHC class II pathway.
• To compare ILIT with MAT-Fel d 1 against a placebo in allergic patients.

Main Methods:

• Recombinant major cat dander allergen Fel d 1 was engineered into a modular antigen transporter (MAT) vaccine (MAT-Fel d 1).
• A randomized double-blind trial compared ILIT with MAT-Fel d 1 versus placebo (saline in alum) in allergic individuals.

Main Results:

• ILIT with MAT-Fel d 1 demonstrated no adverse events.
• Three intralymphatic injections of MAT-Fel d 1 resulted in a 74-fold increase in nasal tolerance, compared to a less than 3-fold increase with placebo (P < .001).
• MAT-Fel d 1 induced regulatory T-cell responses (P = .026) and increased specific IgG(4) levels (5.66-fold, P = .003), correlating with IL-10 production.

Conclusions:

• Intralymphatic immunotherapy with MAT-Fel d 1 is safe in a first-in-human clinical study.
• This novel approach effectively induces allergen tolerance after only three injections.