Introduction

Nimustine (ACNU) is an alkylating agent that belongs to nitrosourea as lomustine (CCNU). To date, few studies have examined the usefulness of ACNU treatment for canine lymphoma. The objective of this retrospective study was to evaluate adverse events and efficacies of ACNU treatment as rescue therapy for canine refractory high-grade multicentric lymphoma.

Methods

This study included dogs with high-grade multicentric lymphoma that were refractory to CHOP protocol and treated by ACNU, and medical records of these dogs were retrospectively reviewed.

Results

Fourteen dogs were included in this study. The median starting dosage of ACNU was 23 mg/m² (range, 20 to 25 mg/m²) with dosing intervals of 3 weeks. Three dogs (21%) developed grade 4 neutropenia, two dogs (14%) developed grade 4 thrombocytopenia, and three dogs (21%) showed grade 3 ALT elevation. No significant gastrointestinal toxicity and febrile neutropenia were observed. Nine of the 14 dogs were eligible for assessment of the response to ACNU treatment, and three, four, and two dogs achieved CR, SD, and PD, respectively. The median overall survival after administration of ACNU was 88 days (range, 11 to >626 days), and the median progression-free survival was seven days (range, 0 to >626 days).

Conclusion

ACNU treatment was well tolerated in dogs with high-grade multicentric lymphoma refractory to CHOP protocol. The response rates and remission durations in this study were comparable to those in other rescue protocols, but further studies using larger number of dogs are needed to investigate the efficacies of ACNU treatment.

Funding Information

No conflicts of interest have been declared. None of the authors of this study has a financial or personal relationship with other people or organizations that could inappropriately influence or bias the content of this study.