O01 - Retrospective Evaluation of Melphalan, Vincristine, and Cytarabine Chemotherapy for the Treatment of Relapsed Canine Lymphoma

Abstract: Background – The standard of care for treatment-naive canine lymphoma is a multi-agent protocol consisting of prednisone, vincristine, cyclophosphamide and doxorubicin. However, most patients relapse and combination chemotherapy can be an effective option for treating resistant lymphoma.





Hypothesis/Objectives – We hypothesized the combination of melphalan, vincristine and cytarabine (MOC) would be well tolerated and an effective treatment for dogs with relapsed or refractory lymphoma.





Animals – Twenty-three dogs met the inclusion criteria for response and toxicity assessment. Two dogs were excluded from progression-free survival (PFS) analysis. Both dogs had experienced clinical benefit after one cycle and were switched to a different protocol due gastrointestinal adverse events and owner preference.









Methods – Data was collected retrospectively. Dogs were treated with cytarabine and vincristine on day one. On day seven, dogs were treated with melphalan. This two-week protocol was repeated for at least three cycles or until treatment failure.





Results – The overall response rate was 42%. The median PFS was 33 days. The overall clinical benefit was 74% for a median of 36 days. The majority of adverse events were mild and were hematologic or gastrointestinal in nature.





Conclusions and clinical importance – The combination of melphalan, vincristine and cytarabine is a safe treatment option for relapsed or refractory lymphoma in dogs. Additional studies are warranted to validate the potential benefit of the MOC protocol in a larger cohort and explore optimal dosing.