Efficacy of verdinexor for the treatment of naïve canine epitheliotropic cutaneous T‐cell lymphoma: An open‐label pilot study

Abstract

AbstractBackgroundVerdinexor (Laverdia‐CA1; Dechra Veterinary Products), a selective inhibitor of nuclear export, has been utilised for treatment of non‐Hodgkin T‐cell lymphoma in dogs. However, the efficacy of verdinexor has not been evaluated for cutaneous epitheliotropic T‐cell lymphoma (CETL).Hypothesis/ObjectivesTo evaluate the efficacy of verdinexor for the treatment of CETL.AnimalsEight client‐owned animals with CETL.Materials and MethodsPatients received between 1.28 and 1.45 mg/kg verdinexor per os twice weekly with a minimum of 72 h between doses until disease progression or voluntary withdrawal. Adjunctive therapy with lokivetmab or prednisone was permitted after Day (D)14. Assessment of clinical lesions (canine Response Evaluation Criteria in Solid Tumors [cRECIST v1.0] and novel Canine Epitheliotropic Lymphoma Extent and Severity Index [CELESI]), pruritus (Visual Analog Scale) and treatment efficacy (owner global assessment of treatment efficacy [OGATE]) were evaluated every 14 days for 3 months, then monthly thereafter (mean 70 ± 43.4 days).ResultsSeventy‐five percent of patients achieved complete response, partial response or stable disease. The mean time to disease progression was 56 ± 41 days. There was a significant reduction (p = 0.026) in total CELESI score when the lowest score for each dog was compared to their score at D0. Verdinexor did not significantly reduce pruritus at any time point (p = 0.45), including when given as a monotherapy or concurrently with lokivetmab ± glucocorticoids. On D28, 75% of owners rated response to treatment as ‘fair’ to ‘excellent’. The most common adverse effects included weight loss, inappetence, vomiting and lethargy.Conclusions and Clinical RelevanceVerdinexor could be considered a safe, palliative treatment for canine CETL.