Study Start Date: 10/01/2020
Study End Date: 10/01/2022

Measurement of IL-31 Levels in Dogs with Cutaneous Epitheliotropic T Cell Lymphoma: Its Association with Pruritus and the Use of Lokivetmab (Cytopoint) as an Antipruritic Treatment

Humans as well as dogs with cutaneous epitheliotropic T cell lymphoma (CETL) often suffer from intense itchiness which can cause significant discomfort and can affect quality of life. IL-31 is a substance produced by the immune system associated with itchiness. It has been found to be increased in the blood of CETL human patients and to correlate with itch severity. This correlation with IL-31 has not been described in dogs so far, but it has been reported that up to 40% of dogs with CETL are itchy because of the disease.

The objective of this study is to measure IL-31 expression in dogs with CETL and evaluate its potential association with itchiness and disease severity. Also to evaluate the use of lokivetmab (Cytopoint) as an itchiness treatment for dogs with CETL. Lokivetmab is an injectable antibody that specifically targets IL-31 used for the treatment of dogs with allergies. Itchy and non-itchy dogs with CETL diagnosis confirmed by histopathological exam of the skin seen at different veterinary practices throughout the United States will be enrolled. To quantify IL-31 levels, blood will be drawn from itchy and non-itchy CETL dogs at the start of the study by participating veterinarians. Itchiness in dogs will be measured based on a score assessed by the owners. All dogs will be grouped based on the severity of itchiness. Itchy dogs will receive a lokivetmab injection. The itchiness score will be noted prior to treatment with lokivetmab and reassessed by phone calls or recheck visits at one, two and four weeks after application. Treatment success will be determined as =2 cm reduction in the score. Non-itchy dogs will not be treated, however the score will also be assessed on the first visit and 4 weeks later.

Study Design:
Prospective, case-control

Inclusion Criteria:

• Diagnosis of cutaneous epitheliotropic T cell lymphoma confirmed by a board-certified pathologist.
• Medications withdrawal time include: - 2 weeks for antihistamines, essential fatty acids and topicals containing steroids or pramoxine - 4 weeks for oral steroids, oclacitinib and cyclosporine - 8 weeks for injectable steroids - 12 weeks for cytopoint
• Dogs receiving chemotherapeutic drugs can be enrolled if they have been treated for at least 4 weeks at the time of enrollment.
• Dogs do not need to be pruritic to be enrolled in the study
• Dogs need to be in the United States to qualify for shipping reimbursement
• Dogs do NOT need to be referred to the investigators – they can be managed by the primary clinician.  Cytopoint will be shipped to the clinician upon inclusion.

Study Controls:
Non-pruritic dogs with epitheliotropic cutaneous T-cell lymphoma.

Study Endpoints:
Assessment of pruritus after Cytopoint treatment

Samples:
Serum from 3ml blood drawn - centrifuged or collected in serum separator tube. Serum should be shipped on ice.

Website for study:
https://vetmed.illinois.edu/research/clinical-trials/

Costs/Reimbursements
Shipment will be covered by the study for colleagues in the United States. Pruritic dogs will receive a Cytopoint injection - Cytopoint will be provided by the study.

Full Disclosure information:
The study is funded by a grant from Zoetis.
The investigator does not have a conflict of interest.
The authors will acknowledge VIN if the study is published