A randomised controlled trial testing the rebound-preventing benefit of four days of prednisolone during the induction of oclacitinib therapy in dogs with atopic dermatitis

Evaluation of oclacitinib maleate and prednisolone combined therapy for the control of atopic dermatitis in dogs: A controlled clinical trial

BACKGROUND

Canine atopic dermatitis (cAD) is a chronic inflammatory and pruritic dermatopathy requiring a multimodal therapeutic approach.

OBJECTIVE

To assess the effectiveness, safety and cost of oclacitinib and prednisolone treatment in dogs with AD.

ANIMALS

Twenty-three client-owned dogs with cAD.

MATERIALS AND METHODS

Dogs were randomly assigned to one of two groups: Group 1 received prednisolone (0.5 mg/kg every 24 h) for 7 days, then oclacitinib (0.5 mg/kg) and prednisolone (0.5 mg/kg), were administered alternately with a 1 day pause between each drug, for 7 additional weeks. Group 2 received oclacitinib (0.5 mg/kg every 12 h for 14 days, then every 24 h) for 8 weeks. Assessments included the Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04) and pruritus Visual Analog Scale (PVAS) on Day (D)0, D7, D14, D30, D45 and D60.

RESULTS

Both groups showed significant CADESI and PVAS reductions on D7 (p < 0.001). From D14 to D60, mean scores remained stable compared to D7, with no significant differences between groups. Adverse events included two dogs with polyuria and polydipsia, and three with polyphagia in Group 1, all of which resolved by D14. In Group 2, one dog experienced polyphagia, and two had self-limiting vomiting. Three dogs in Group 1 and one dog in Group 2 had mild increases in liver enzyme concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

The combined protocol was effective and safe for managing itch and inflammation over a 60 day period. It had a 73.3% lower cost compared to oclacitinib alone.

Comparative efficacy and safety of ilunocitinib and oclacitinib for the control of pruritus and associated skin lesions in dogs with atopic dermatitis

BACKGROUND

Janus kinase inhibitors (JAKi) have been shown to reduce pruritus and improve associated inflammatory skin lesions in canine atopic dermatitis (cAD).

OBJECTIVE

To evaluate the efficacy and safety of ilunocitinib, in comparison to oclacitinib, for the control of cAD in a randomised, blinded trial.

ANIMALS

Three-hundred-and-thirty-eight dogs with cAD.

MATERIALS AND METHODS

Dogs were randomised to receive oclacitinib (0.4-0.6 mg/kg twice daily for 14 days; then once daily) or ilunocitinib (0.6-0.8 mg/kg once daily), for up to 112 days. Owners assessed pruritus using an enhanced Visual Analog Scale (PVAS). Investigators assessed skin lesions using the Canine Atopic Dermatitis Extent and Severity Index, 4th interaction (CADESI-04).

RESULTS

Reduction in pruritus and CADESI-04 scores was similar for both treatment groups from Day (D)0-D14. PVAS scores increased between D14 and D28 for oclacitinib and decreased for ilunocitinib. On D28 to D112, mean PVAS and CADESI-04 scores were significantly lower for ilunocitinib compared to oclacitinib (p ≤ 0.003 and p ≤ 0.023, respectively). On D28 to D112, a greater number of ilunocitinib-treated dogs achieved clinical remission of pruritus (i.e. PVAS score <2). Subjective assessment of overall response was significantly better for ilunocitinib on D28 to D112 (p ≤ 0.002). Both drugs demonstrated similar safety throughout the study.

CONCLUSIONS AND CLINICAL RELEVANCE

Ilunocitinib rapidly and safely controlled signs of cAD. Ilunocitinib demonstrated significantly better control of pruritus and skin lesions compared to oclacitinib, with more dogs achieving clinical remission of pruritus.

Treatment of moderate-to-severe canine atopic dermatitis with modified-release mycophenolate (OKV-1001): A pilot open-label, single-arm multicentric clinical trial

BACKGROUND

Mycophenolate is an immunomodulating agent successfully used for the treatment of moderate-to-severe atopic dermatitis (AD) in people. Mycophenolate is an effective steroid-sparing treatment option for use in dogs with inflammatory skin diseases.

OBJECTIVE

To evaluate whether once-daily modified-release mycophenolate (OKV-1001) is safe and effective for treating moderate-to-severe canine AD.

ANIMALS

Client-owned atopic dogs (n = 9) were enrolled.

MATERIALS AND METHODS

In an open-label multicentre pilot study, OKV-1001 (30 mg/kg every 24 h) was given orally for ≤84 days. Concomitant tapering doses of glucocorticoids were administered up to Day (D)28. Clinicians assessed Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04) on D0, D14, D28, D56 and D84. Body weight and clinical pathological parameters were measured at baseline and at the end of the study.

RESULTS

Treatment with OKV-1001 combined with glucocorticoids significantly reduced the severity of AD within two weeks in seven of nine (77.8%) dogs. The mean percentage change from baseline in the CADESI-04 score was 29% (p = 0.009) at D14 (n = 9), 39% (p = 0.008) at D28 (n = 9) and 49% (p = 0.03) at D56 (n = 7) at which point glucocorticoids had been withdrawn. In two dogs the improvement in CADESI-04 was 62% and 23% (respectively) on D84. No significant adverse events including clinical pathological findings were reported.

CONCLUSIONS AND CLINICAL RELEVANCE

Modified-release mycophenolate (OKV-1001) may represent a promising alternative treatment option for dogs with moderate-to-severe AD. The safety and efficacy profile of OKV-1001 will need to be established in larger, placebo-controlled clinical trials.

Epicutaneous house dust mite (HDM)-induced skin lesions feature early activation of T helper 2 inflammatory and pruritogenic pathways in HDM-nonsensitised dogs

BACKGROUND

Epicutaneously house dust mite-sensitised (HDM-S) healthy dogs are commonly used as canine atopic dermatitis (cAD) models; however, the exact mechanisms of HDM-induced AD immune activation in HDM-S and HDM-nonsensitised (NS) dogs remain unclear.

OBJECTIVES

To characterise the inflammatory and pruritogenic transcriptome of acute epicutaneous HDM-induced skin lesions at 6 h and 24 h in HDM-NS and HDM-S dogs; untreated skin at 0 h from each dog served as control.

ANIMALS

Six HDM-S and six HDM-NS laboratory beagles.

MATERIALS AND METHODS

Processed expression data from GEO deposited by Schamber et al. (G3 (Bethesda), 2014, 4 and 1787) (GSE58442) were downloaded and analysed using R and the Bioconductor package. Significance analysis was performed with the limma package; genes with false discovery rate <0.05 and fold-change ≤/≥1.5 were considered significantly differentially expressed (DEGs).

RESULTS

A 2D principal component analysis revealed no clear separation between HDM-NS and HDM-S dogs at 6 h and 24 h time points. HDM-induced skin lesions in sensitised and nonsensitised dogs at the 24 h time point showed significant upregulation of T helper cell (Th)2 genes (interleukin [IL]-4R, IL-5, IL-13, CCL13 and CCL17), as well as proinflammatory- (LTB, IL-1A and IL-18), Th1- (CXCL10, OASL and MX-1) and Th17-related markers (IL-17B, IL-17F, CCL19 and CCL20). The key Th22-related maker, IL-22, was upregulated only in the HDM-S group at the 24 h time point. Both groups at 24 h featured significant upregulation of several noncytokine pruritogens, such as trypsin, chymase, cathepsin S, periostin and neuromedin B.

CONCLUSIONS AND CLINICAL RELEVANCE

Taken together, we establish that epicutaneous HDM patch application induces immune changes in HDM-NS dogs with Th2 dominance and activates several itch-promoting pathways.

Updated insights into the molecular pathogenesis of canine atopic dermatitis

Atopic dermatitis (AD) is a common and chronic inflammatory skin disease with frequent relapses. The genomics revolution has greatly contributed and revolutionised our knowledge of human AD; understanding the molecular skin fingerprint of AD and associated pathogenic immune pathways has led to preclinical assessments of several novel treatments. Initial studies using microarray analysis to analyse transcriptome (gene expression) changes provided relevant insight on the inflammatory and structural changes occurring at the time of acute or chronic AD skin lesions, or after immunomodulating treatments with drugs ciclosporin and dupilumab, a monoclonal antibody anti-IL4 receptor. The studies revealed that human AD is characterised by the activation of multiple cytokine pathways (predominance of T helper cell [Th]2 with some activation of Th1, Th17 and Th22) as well as dysregulated expression of barrier components in the skin. There are several reports on the expression of different single molecular targets (e.g. interleukin [IL]-13, CCL17 and periostin) in spontaneous canine AD (cAD). However, significant studies of the transcriptome have been limited to a single microarray study analysing chronic AD skin lesions in dogs. While revealing a large number of genes differentially expressed in cAD skin, the small sample size (n = 13 dogs) and the lack of changes in key epidermal barrier and inflammatory cytokine genes in the microarrays have inhibited discussion towards specific immunological changes. This review summarises the current literature regarding the molecular mechanisms of spontaneous cAD, including the recent data regarding RNA sequencing, and compares some pathogenic aspects to the previously published data from human AD.

A randomized double-blind clinical trial: Comparison of oclacitinib with a traditional Chinese herbal medicine product (Dihuang Guiqin capsule) in the treatment of canine atopic dermatitis

Canine atopic dermatitis (cAD) is a common chronic inflammatory skin disease, which seriously affects the quality of life for both dogs and their owners. Currently, the common therapeutic drugs in the clinic have disadvantages such as obvious adverse effects and high prices. Traditional Chinese herbal medicine (TCHM) has great potential for the treatment of cAD. The aim of this study is to compare the effects of different doses of the TCHM product (Dihuang Guiqin capsule) and oclacitinib in the treatment of cAD through a randomized, double-blind trial. Sixty dogs diagnosed with AD were randomly and evenly divided into four groups (n = 15). The TCHM treatment group consisted of three subgroups that received three different oral doses (20, 40, and 60 mg/kg BW), while the control group received 0.5 mg/kg BW of oclacitinib. Each group was administered twice daily for 14 consecutive days. The results showed that both TCHM and oclacitinib significantly improved cAD-induced itching (evaluated by pVAS) and skin lesions (evaluated by CADESI-04), while interleukin 31 (IL-31) concentrations decreased significantly (P < 0.05) and serum biochemical indicators returned to normal. In particular, The therapeutic effects of TCHM medium- and high-dose groups were similar to those of oclacitinib (P > 0.05). The preliminary recommended dose of Dihuang Guiqin capsule for the treatment of cAD has been determined to be 40-60 mg/kg BW twice daily for 14 consecutive days, which can be reduced to once daily as appropriate. Dihuang Guiqin capsule was safe and well tolerated, which may be a new option for the treatment of cAD.

A Randomized Controlled Trial to Evaluate the Impact of a Novel Probiotic and Nutraceutical Supplement on Pruritic Dermatitis and the Gut Microbiota in Privately Owned Dogs

Pruritic dermatitis (PD) is a common presentation of canine allergic skin diseases, with diversity in severity and treatment response due to complex etiopathogenesis. Evidence suggests the gut microbiota (GM) may contribute to the development of canine allergies. A 10-week double-blind randomized controlled trial evaluated a novel probiotic and nutraceutical blend (PNB) on clinical signs of skin allergy, health measures, and the GM of privately owned self-reported pruritic dogs. A total of 105 dogs were enrolled, with 62 included in pruritus and health analysis and 50 in microbiome analysis. The PNB supported greater improvement of owner-assessed clinical signs of PD at week 2 than the placebo (PBO). More dogs that received the PNB shifted to normal pruritus (digital PVAS10-N: <2) by week 4, compared to week 7 for the PBO. While a placebo effect was identified, clinical differences were supported by changes in the GM. The PNB enriched three probiotic bacteria and reduced abundances of species associated with negative effects. The PBO group demonstrated increased abundances of pathogenic species and reduced abundances of several beneficial species. This trial supports the potential of the PNB as a supplemental intervention in the treatment of PD; however, further investigation is warranted, with stricter diagnostic criteria, disease biomarkers and direct veterinary examination.