QLTI-03. Exceptional and Sustained Response to Temozolomide Rechallenge in MGMT Promoter-Methylated Glioblastoma

Abstract We report two cases of patients with MGMT promoter-methylated glioblastoma who experienced tumor recurrence and demonstrated exceptional responses to temozolomide (TMZ) rechallenge. The first patient received TMZ rechallenge at the time of second recurrence (48 months from original diagnosis). The second patient received TMZ rechallenge at both first and second recurrence (53 and 90 months from original diagnosis). Remarkably, both patients achieved complete radiographic responses after two cycles of TMZ rechallenge, with sustained responses confirmed on follow-up imaging. Both patients are alive and well in complete response, 56 and 95 months from original diagnosis).