Medical Oncology Resident University of Pennsylvania Philadelphia, Pennsylvania, United States
Abstract:
Background: Most naïve high-grade canine lymphoma patients treated with standard of care multiagent chemotherapy will achieve complete remission, however, disease recurrence is common and rescue protocols are needed to reinduce remission. MOPP (mechlorethamine, vincristine, procarbazine, and prednisone) is an effective rescue protocol, but associated with gastrointestinal toxicity and can be a less desirable option for patients that previously failed vincristine-containing protocols. Previous studies have suggested cross-resistance between members of the vinca alkaloid family may be incomplete, thus vinblastine may be used as a substitute for vincristine to reduce gastrointestinal toxicity and chemoresistance.
Hypothesis/
Objectives: The objective of this study was to report clinical outcomes and toxicity in dogs with relapsed or refractory multicentric lymphoma treated with a modified MOPP protocol whereby vincristine was replaced with vinblastine (MVPP).
Animals: Thirty-six client owned dogs with relapsed or refractory lymphoma treated with MVPP.
Methods: Medical records of patients treated with MVPP between 2009-2021 were retrospectively reviewed. Clinical responses and toxicities were recorded in line with Veterinary Cooperative Oncology Group recommendations.
Results: The overall response rate to MVPP was 25.7% with a median progression free survival of 15 days and a median overall survival of 45 days. The median number of chemotherapy protocols prior to MVPP was 3 (range 1-8). MVPP at the prescribed doses was well tolerated with no treatment delays or hospitalizations secondary to side effects.
Conclusions and Clinical Importance: MVPP resulted in modest and transient anti-tumor activity. Given the minimal toxicity, vinblastine dose intensification could be considered to improve clinical responses.
