A phase II trial of enzastaurin (LY317615) in combination with bevacizumab in adults with recurrent malignant gliomas

We evaluated the efficacy of combination enzastaurin (LY317615) and bevacizumab for recurrent malignant gliomas and explored serologic correlates. We enrolled 81 patients with glioblastomas (GBM, n = 40) and anaplastic gliomas (AG, n = 41). Patients received enzastaurin as a loading dose of 1125 mg, followed by 500 or 875 mg daily for patients on non-enzyme-inducing or enzyme-inducing antiepileptics, respectively. Patients received bevacizumab 10 mg/kg intravenously biweekly. Clinical evaluations were repeated every 4 weeks. Magnetic resonance imaging was obtained at baseline and every 8 weeks from treatment onset. Phosphorylated glycogen synthase kinase (GSK)-3 levels from peripheral blood mononuclear cells (PBMCs) were checked with each MRI. Median overall survival was 7.5 and 12.4 months for glioblastomas and anaplastic glioma cohorts, with median progression-free survivals of 2.0 and 4.4 months, respectively. Of GBM patients, 3/40 (7.5 %) were not evaluable, while 8/37 (22 %) had partial or complete response and 20/37 (54 %) had stable disease for 2+ months. Of the 39 evaluable AG patients, 18 (46 %) had an objective response, and 16 (41 %) had stable disease for 2+ months. The most common grade 3+ toxicities were lymphopenia (15 %), hypophosphatemia (8.8 %) and thrombotic events (7.5 %). Two (2.5 %) GBM patients died suddenly; another death (1.3 %) occurred from intractable seizures. Phosphorylated GSK-3 levels from PBMCs did not correlate with treatment response. A minimally important improvement in health-related quality of life was self-reported in 7-9/24 (29.2-37.5 %). Early response based on Levin criteria was significantly associated with significantly longer progression free survival for glioblastomas. Enzastaurin (LY317615) in combination with bevacizumab for recurrent malignant gliomas is well-tolerated, with response and progression-free survival similar to bevacizumab monotherapy.