Cyclophosphamide rescue therapy for relapsed low-grade alimentary lymphoma after chlorambucil treatment in cats.

Abstract

OBJECTIVES: The aims of this study were to evaluate the response, outcome and prognostic factors in cats with clinically presumed relapsed low-grade alimentary lymphoma (LGAL) receiving cyclophosphamide as a first-line rescue therapy after failing chlorambucil treatment. METHODS: The medical records of 20 cats (from three institutions, between 2002 and 2017) treated with cyclophosphamide for relapsed LGAL after initial treatment with chlorambucil were retrospectively reviewed. Progression-free survival (PFS), overall survival time (OST) and the association of select variables with measures of outcome were assessed. Adverse events (AEs) were also described. RESULTS: Eighteen cats (90%) achieved a complete clinical response (CR) for a median duration of 239 days. The median PFS was 215 days. The median OST was 1065 days. The only clinical factor associated with a longer PFS was achievement of a CR with cyclophosphamide treatment. Cyclophosphamide was associated with few and reversible constitutional, gastrointestinal and hematologic AEs. CONCLUSIONS AND RELEVANCE: Cyclophosphamide appears to be a safe and effective first-rescue therapeutic option for cats with relapsed LGAL.