10090-CS-8 Retrospective Analysis of PMV Therapy for Anaplastic Oligodendroglioma at a Single Institution

Abstract Background While PCV therapy (Procarbazine, CCNU, Vincristine) is the global standard for oligodendroglial tumors, CCNU (lomustine) is not approved in Japan. As a result, alternative regimens using ACNU (nimustine) or MCNU (ranimustine), such as PAV or PMV therapy, have been employed domestically. However, reports on PMV therapy remain limited. This study aimed to evaluate the efficacy and safety of PMV therapy at our institution. Methods We retrospectively reviewed 12 patients diagnosed with anaplastic oligodendroglioma (WHO grade III) at our institution between 2007 and 2025. Patients were divided into a PMV group (n = 9) and a non-PMV group (n = 3). We compared progression-free survival (PFS) and overall survival (OS) between the two groups. Results The median age was 50 years, with 5 males and 7 females. Among the 12 patients, 9 received PMV therapy, and 3 did not. The median PFS was not reached in the PMV group and was 129 months in the non-PMV group. Median OS was 69 months in the PMV group and 141. 5 months in the non-PMV group. There were no statistically significant differences in PFS or OS. In the PMV group, serious hematologic toxicities included leukopenia in 6 patients, thrombocytopenia in 5, and anemia in 1. Three patients discontinued PMV therapy and were switched to temozolomide due to bone marrow suppression. Discussion Although PMV therapy showed a trend toward prolonged PFS, hematologic toxicity led to treatment modification in several cases. Reports on PAV and PMV therapy in Japan are limited. Our findings are consistent with prior case series but are limited by the small sample size and lack of molecular data. Conclusion PMV may be a viable alternative to PCV with careful monitoring for hematologic adverse events.