Acknowledgements
This study was funded by Centre for Interdisciplinary Research in Animal
Health (CIISA, Lisbon, Portugal: UIDB/00276/2020), Associate Laboratory
for Animal and Veterinary Sciences (AL4AnimalS, Portugal:
LA/P/0059/2020) and Fundação para a Ciência e a Tecnologia (FCT, Lisbon,
Portugal: PhD individual grant UI/BD/153072/2022 to Marta Pinto;
UIDB/04138/2020 and UIDP/04138/2020 to iMed.ULisboa; CEECINST/00145/2018
to Joana Marto), to whom the authors are grateful. The authors also
thank LETIPharma S.L.U. (Barcelona, Spain) for supporting this study,
Nuno Ferreira for designing the 3D patch prototype, and the owners of
healthy and atopic dogs for participating in this study.
Conflicts of interest: None declared.
ABSTRACT: 248 words
Background – Allergen immunotherapy is a well-established
treatment for canine atopic dermatitis (CAD), but non-invasive, safe,
effective, and easy-to-use home-administration routes that promote
owner’s compliance are needed. Epicutaneous immunotherapy (EPIT) has
been suggested as a promising alternative treatment for human allergies.
This study primarily evaluated EPIT’s feasibility, effectiveness, and
safety for CAD.
Methods – Sixteen client-owned dogs with spontaneous,
nonseasonal, mite-sensitive CAD were enrolled for a 6-month,
once-weekly, 12-hour EPIT. A costume-made 3D-printed device was designed
to deliver the allergen-based formulation. Primary efficacy outcomes
included the owner’s assessed pruritus (PVAS10) and treatment efficacy
(OGATE), and veterinarian-assessed skin lesions (2D-IGA). Secondary
efficacy outcomes were the quality-of-life (QoL) and serological
allergen-specific IgE’s concentrations. Effectiveness was defined by the
success of the primary efficacy outcomes, according to the ICADA’s
COSCAD’18 recommendations. EPIT was deemed safe in the absence of severe
side-effects.
Results – EPIT effectively improved clinical condition, with a
success rate of 73.3% for pruritus, 66.7% for skin lesions, and 93.3%
for QoL. A good-to-excellent response to EPIT was rated by 93.3% of
owners in OGATE. EPIT significantly improved PVAS10 (p=0.000015), 2D-IGA
(p=0.006) and QoL (p=0.000014) scores over six months. A significant
difference was evident within one month for PVAS10 (p=0.003) and 2D-IGA
(p=0.009) scores. Seven dogs partially desensitised to at least one mite
and two fully desensitised to all mites after six months. Severe adverse
events were not recorded.
Conclusions – This pioneer study emphasises EPIT’s potential
as a novel and promising, non-invasive, feasible, effective, safe, and
well-tolerated CAD treatment, supporting further investigation.
Keywords: Allergen immunotherapy; atopic dermatitis; canine;
epicutaneous immunotherapy (EPIT); vaccine.
TEXT: 3500 words