P17.07.A Metronomic temozolomide therapy in heavily pretreated patients with recurrent glioblastoma: a large mono-institutional retrospective study. (5th September 2022)

• Record Type: Journal Article
• Authors: Bosio, A; Padovan, M; Caccese, M; Cerretti, G; Zagonel, V; Lombardi, G
• Is Part Of: Neuro-oncology. Volume 24(2022)Supplement 2
• Page Start: ii90
• Page End: ii90
• Publication Date: 2022-09-05
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noac174.315
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: Background: Glioblastoma (GBM) is the most common and aggressive primary brain cancer. Despite advances in surgical and first-line treatment, all pts relapse. The aim of this study is to evaluate the benefit of metronomic Temozolomide (mTMZ) for recurrent GBM. Material and Methods: All pts treated at Veneto Institute of Oncology from September 2013 to March 2021 were retrospectively reviewed. Major inclusion criteria were: first-line therapy with Stupp protocol, relapse after first or subsequent line of therapy, treatment with mTMZ schedule (50mg/m 2 continuously), hystologically confirmed diagnosis of GBM. RANO criteria and CTCAE v 5.0 were used for response and toxicity assessment. Results: 120pts were enrolled. Median follow-up was 15.6ms. Median age was 59ys (range 18-81), ECOG-PS was 0-2 in 107pts (89%) and 3 in 11 (9%). MGMT was methylated and IDH mutated in 66 of 105 (62%) and in 9 of 106 (8%) evaluable pts, respectively. Median number of prior lines of treatment was 2 (range 1-7) and 41% of pts received the therapy beyond the third line. Median time between the last standard maintenance TMZ (sTMZ) cycle and the mTMZ administration was 6ms (range 1-50) and 40% of pts started mTMZ after 3ms from sTMZ. All pts were evaluable for response: 3 (2%) and 48 (40%) showed PR and SD. mOS from the start of mTMZ was 5.4ms (95% CI 4.3-6.4), mPFS was 2.6ms (95% CI 2.3-2.8). At univariate analysis, MGMTmet and MGMTunmet pts had a mOS of 5.6 and 4.4ms (p=0.03); mOS for patients with ECOG-PS > or ≤2 was 2.3 and 6.0ms (p<0.001); number of prior lines of therapies, time between sTMZ and mTMZ and age were not significant. At multivariate analysis, MGMT methylated status (HR=2.3, 95% CI, p=0.004) and ECOG-PS (HR=0.5, 95% CI, p=0.017) remained statistically significant for PFS, while ECOG-PS (HR=0.4, 95% CI, p=0.001) was the only factor significantly associated with OS. The most common grade 3-4 hematologic toxicities were lymphopenia (10%) and thrombocytopenia (3%). Grade 3-4 nonhematologic toxicities were uncommon. Conclusion: Rechallenge with mTMZ can be a well tolerated treatment option for recurrent GBM, even in heavily pretreated pts. Pts with MGMTmet and good ECOG-PS might report the major benefit.