Impact of lokivetmab for Canine Atopic Dermatitis on Owner and Canine Health-Related Quality of Life and Owner Treatment Satisfaction

Background Lokivetmab is a caninised monoclonal antibody that neutralises circulating interleukin‑31 (IL‑31), a cytokine implicated in the pathogenesis of canine atopic dermatitis (AD). The objectives are to evaluate changes in quality of life (QOL) for atopic dogs and their owners, owner treatment satisfaction (TS), and pruritus (PVAS) over 91 days following initiation of lokivetmab into multi-modal managed cases. A prospective, open‑label, multi‑centre, practice‑based outcomes study in 10 U.S. general veterinary practices. Lokivetmab was administered per label on Days 0, 28, 63 and 91; visits targeted ± 2–3-day windows. Seventy‑five dogs with AD and their owners were enrolled; 68 dogs contributed evaluable data. At each visit, veterinarians assessed dermatitis severity; owners completed the Pruritus Visual Analog Scale (PVAS) and the Canine Dermatitis Quality of Life and Treatment Satisfaction Questionnaire (CDQOL‑TSQ). Primary endpoints were Dog QOL, Owner QOL, TS and PVAS. A linear mixed model for repeated measures estimated least-squares means (LSMeans) over time with veterinarian as a random effect; covariance structure was selected by the Akaike Information Criterion (AIC). The protocol specified a minimum of 2 mg/kg per label at each dosing visit. Concomitant medications were recorded on day 0 and 91. Previously published minimally important change (MIC) thresholds were ≥ 12.5 for Dog QOL and ≥ 18.8 for Owner QOL. Results Dog QOL, Owner QOL and TS improved significantly from baseline at all timepoints (overall time effect P < 0.0001 by mixed model); for each outcome, every post‑baseline timepoint differed from Day 0 (P ≤ 0.001) in pairwise LSMeans comparisons. PVAS decreased at every timepoint; mean PVAS ≤ 20 ("normal itch") was reached by Day 63. Owner QOL gains were maximal by Day 42, with numerically highest mean scores observed at Day 91; Dog QOL and Treatment Satisfaction were numerically highest at Day 91, whereas PVAS and veterinarian‑assessed dermatitis severity were lowest at Day 91. PVAS declined 57% from Day 0 (78.16) to Day 7 (33.39, P ≤ 0.001), indicating an early treatment‑associated improvement prior to subsequent doses. The veterinarian‑assessed dermatitis severity score (0 = normal to 6 = extremely severe) decreased from 5.02 at Day 0 to 2.24 at Day 91 (~ 55% decrease). MIC responder proportions for Dog and Owner QOL increased over time. By Day 28, 34/71 (47.9%) exceeded the Dog QOL MIC; by Day 42, 46/55 (83.6%) exceeded the Owner QOL MIC; PVAS ≤ 20 was achieved by 47/67 (70.1%) at Day 63 and 52/65 (80.0%) at Day 91. Moderate positive Owner–Dog QOL correlations and inverse Owner QOL–PVAS correlations were statistically significant across timepoints (P ≤ 0.01). Conclusions In routine practice, initiating lokivetmab within multimodal management was associated with rapid reductions in pruritus and clinically meaningful improvements in canine and owner QOL and owner TS.