Efficacy of Der f 2/Zen 1-LAMP1 Plasmid-Based Vaccine Immunotherapy in Dogs With Atopic Dermatitis: A Proof-of-Concept Study.

backgroundDNA-based vaccination rapidly induces strong cellular and humoral immune responses, which may be enhanced by inclusion of lysosomal-associated membrane protein-1 (LAMP).

objectivesThis proof-of-concept study evaluated the efficacy and safety of a Der f 2/Zen 1-LAMP-based DNA vaccine immunotherapy in client-owned dogs with nonseasonal AD sensitised to Dermatophagoides farinae (Df). ANIMALS: Fifteen dogs positive for Df only and 20 dogs with reactivity to additional environmental allergens received either a low (0.5 mg/0.1 mL) or high (2 mg/0.4 mL) dose of the vaccine intradermally. MATERIALS AND

methodsFour doses of vaccine were administered every 2 weeks. Pruritus, Canine Atopic Dermatitis Extent and Severity Index (CADESI)-04, average daily medication scores (AvdMS) and adverse events (AE) were recorded over 24 weeks. Owner perception of treatment efficacy (OGATE) was assessed at the end.

resultsPruritus and CADESI-04 improved regardless of the sensitisation profile and the vaccine dose. After 24 weeks, despite a statistically insignificant reduction of AvdMS, 71%, 46% and 86% of dogs reached PVAS < 3.6, PVAS < 2 and CADESI-04 < 10, respectively. There was no statistically significant effect of AvdMS on PVAS or CADESI-04, meaning that the concurrently administered topical and/or systemic treatment(s) were unlikely to have been responsible for the observed PVAS and CADESI-04 reduction. Twenty-one owners (60%) rated the vaccine efficacy as good-to-excellent. No severe AEs were reported. CONCLUSIONS AND CLINICAL RELEVANCE: These results of this proof-of-concept study support not only the safety of DNA vaccine immunotherapy in dogs with AD, but also its potential clinical benefits. A double-blinded, ≥ 12 month long, controlled study with more subjects should follow to further confirm the true efficacy of this vaccine.