Effect of Dalteparin and Radiation on Survival and Thromboembolic Events in Glioblastoma Multiforme: A Phase II ECOG Trial

Laboratory and clinical studies support the concept that heparins, particularly the low molecular component, may serve as an inhibitor of angiogenesis, providing anti-neoplastic effects. Further, treatment with low molecular weight heparin (LMWH) may provide prophylaxis for thromboembolic events (TEE), in glioblastoma (GBM) patients. Dalteparin (5,000 U sub-Q daily) was given with and after conventional radiotherapy to newly diagnosed GBM patients. Forty-five patients were accrued between 5/02 and 9/04; 3 were ineligible. At time of progression, patients could continue dalteparin in addition to standard regimens. Pretreatment characteristics included: median age 61 (range 26–78); ECOG Performance status: 0 = 38%, 1 = 57%, 2 = 5%; gross total resection 45%. There were no grade 3/4 bleeding or thrombocytopenic events, and no TEE occurred while on dalteparin. Median time on dalteparin was 6.3 months, median time to progression was 3.9 months; median survival was 11.9 months. There was no significant improvement in survival when compared to the RTOG GBM database (with various radiation/drug doublets including BCNU) using recursive partitioning analysis. Historically the incidence of TEE in GBM patients is ∼30%. As this study suggests dalteparin reduces the incidence of TEE, and does not have significant overlapping toxicities with most other drugs; its testing in a combined modality approach with other medications may be warranted in future trials.