Retrospective evaluation of toceranib phosphate (Palladia?) use in the treatment of gastrointestinal stromal tumors of dogs

摘要

h3 class="article-section__sub-title section1" Background/h3 pGastrointestinal stromal tumors (GISTs) are uncommon intestinal neoplasms in the dog. Literature regarding adjunctive therapy for GISTs in dogs is sparse. High‐risk GISTs in humans respond to tyrosine kinase inhibition in the adjuvant setting. h3 class="article-section__sub-title section1" Objectives/h3 pTo review cases of toceranib phosphate use in dogs with GISTs and provide initial assessment of possible biological activity. A secondary aim was to evaluate patient and tumor characteristics for possible prognostic value. h3 class="article-section__sub-title section1" Animals/h3 pTwenty‐seven dogs with confirmed GISTs based on histopathology and immunohistochemistry treated with toceranib. h3 class="article-section__sub-title section1" Methods/h3 pRetrospective study in which cases of toceranib use in dogs with GIST were solicited using the American College of Veterinary Internal Medicine Oncology and Small Animal Internal Medicine listservs. h3 class="article-section__sub-title section1" Results/h3 pFive of 7 dogs with gross disease experienced clinical benefit (71%; 3 complete responses, 1 partial response, 1 stable disease). These included 2 dogs with durable responses after toceranib discontinuation. Median progression‐free interval (PFI) in dogs with gross disease was 110?weeks (range, 36‐155?weeks). Median PFI in dogs with microscopic disease was 67?weeks (range, 9‐257?weeks). Metastasis at diagnosis ( P =?0.04) and high mitotic index ( P ?0.001) were associated with shorter PFI in toceranib‐treated dogs. h3 class="article-section__sub-title section1" Conclusions and Clinical Importance/h3 pBiological activity of toceranib is evident in dogs with gross disease. Metastasis of GIST at diagnosis, as well as high tumor mitotic index, was associated with shorter PFI in toceranib‐treated dogs. Larger studies are needed to define postsurgical risk and refine the use of toceranib in dogs with gross and microscopic GIST.