Teri N. Kreisl

Phase II Trial of Single-Agent Bevacizumab Followed by Bevacizumab Plus Irinotecan at Tumor Progression in Recurrent Glioblastoma

PURPOSE To evaluate single-agent activity of bevacizumab in patients with recurrent glioblastoma. PATIENTS AND METHODS Patients with recurrent glioblastoma were treated with bevacizumab 10 mg/kg every 2 weeks. After tumor progression, patients were immediately treated with bevacizumab in combination with irinotecan 340 mg/m(2) or 125 mg/m(2) every 2 weeks, depending on use of enzyme-inducing antiepileptic drugs. Complete patient evaluations were repeated every 4 weeks. RESULTS Forty-eight heavily pretreated patients were accrued to this study. Thromboembolic events (12.5%), hypertension (12.5%), hypophosphatemia (6%), and thrombocytopenia (6%) were the most common drug-associated adverse events. Six patients (12.5%) were removed from study for drug-associated toxicity (five thromboembolic events, one bowel perforation). Thirty-four patients (71%) and 17 patients (35%) achieved radiographic response based on Levin and Macdonald criteria, respectively. Median progression-free survival (PFS) was 16 weeks (95% CI, 12 to 26 weeks). The 6-month PFS was 29% (95% CI, 18% to 48%). The 6-month overall survival was 57% (95% CI, 44% to 75%). Median overall survival was 31 weeks (95% CI, 21 to 54 weeks). Early magnetic resonance imaging response (first 96 hours and 4 weeks) was predictive of long-term PFS, with the Levin criteria being more predictive than Macdonald criteria. Of 19 patients treated with bevacizumab plus irinotecan at progression, there were no objective radiographic responses. Eighteen patients (95%) experienced disease progression by the second cycle, and the median PFS was 30 days. CONCLUSION We conclude that single-agent bevacizumab has significant biologic and antiglioma activity in patients with recurrent glioblastoma.

Scale to Predict Survival After Surgery for Recurrent Glioblastoma Multiforme

PURPOSE Despite initial treatment with surgical resection, radiotherapy, and chemotherapy, glioblastoma multiforme (GBM) virtually always recurs. Surgery is sometimes recommended to treat recurrence. In this study, we sought to devise a preoperative scale that predicts survival after surgery for recurrent glioblastoma multiforme. PATIENTS AND METHODS The preoperative clinical and radiographic data of 34 patients who underwent re-operation of recurrent GBM tumors were analyzed using Kaplan-Meier survival analysis and Cox proportional hazards regression modeling. The factors associated with decreased postoperative survival (P < .05) were used to devise a prognostic scale which was validated with a separate cohort of 109 patients. RESULTS The factors associated with poor postoperative survival were: tumor involvement of prespecified eloquent/critical brain regions (P = .021), Karnofsky performance status (KPS) < or = 80 (P = .030), and tumor volume > or = 50 cm(3) (P = .048). An additive scale (range, 0 to 3 points) comprised of these three variables distinguishes patients with good (0 points), intermediate (1 to 2 points), and poor (3 points) postoperative survival (median survival, 10.8, 4.5, and 1.0 months, respectively; P < .001). The scale identified three statistically distinct groups within the validation cohort as well (median survival, 9.2, 6.3, and 1.9 months, respectively; P < .001). CONCLUSION We devised and validated a preoperative scale that identifies patients likely to have poor, intermediate, and good relative outcomes after surgical resection of a recurrent GBM tumor. Application of this simple scale may be useful in counseling patients regarding their treatment options and in designing clinical trials.

A pilot study of everolimus and gefitinib in the treatment of recurrent glioblastoma (GBM)

Twenty-two patients with recurrent glioblastoma (GBM) were prospectively treated with everolimus and gefitinib, designed to test the combined inhibition of mammalian target of rapamycin (mTOR) and epidermal growth factor receptor (EGFR) as part of a larger clinical trial. The primary endpoint was radiographic response rate. Secondary endpoints included progression-free survival and correlation of molecular profiles with treatment response. 36% of patients had stable disease and 14% a partial response; however, responses were not durable and only one patient was progression-free at six months. Radiographic changes were not well characterized by conventional response criteria, and implied differential effects of therapy within the tumor and/or antiangiogenic effects. EGFR and PTEN status did not clearly predict response to treatment.

A phase I/II trial of enzastaurin in patients with recurrent high-grade gliomas.

Enzastaurin, a potent inhibitor of protein kinase C-beta, inhibits angiogenesis and has direct cytotoxic activity against glioma cells in preclinical studies. Patients with recurrent high-grade gliomas were stratified by histology and use of enzyme-inducing antiepileptic drugs (EIAEDs). Patients on EIAED were treated on the phase I dose-escalation portion of the trial with evaluation of serum pharmacokinetics as the primary endpoint. Patients not on EIAED were treated on the phase II portion of the trial with radiographic response and progression-free survival (PFS) as primary objectives. Patients in phase I received enzastaurin 525-900 mg/d. Phase II patients received 500 or 525 mg/d. One hundred and eighteen patients were accrued to this trial. Therapy was well tolerated with thrombosis, thrombocytopenia, hemorrhage, and elevated alanine aminotransferase as the most commonly observed drug-associated grade 3 or higher toxicities. Patients on EIAED had serum enzastaurin exposure levels approximately 80% lower than those not on EIAED. Dose escalations up to 900 mg/d did not substantially increase serum exposure levels and a maximally tolerated dose was never reached. Twenty-one of 84 evaluable patients (25%) experienced an objective radiographic response. The 6-month PFS was 7% for patients with glioblastoma and 16% for patients with anaplastic glioma. Phosphorylation of glycogen synthase kinase-3 in peripheral blood mononuclear cells was identified as a potential biomarker of drug activity. Enzastaurin has anti-glioma activity in patients with recurrent high-grade glioma, but does not appear to have enough single-agent activity to be useful as monotherapy.

A phase II trial of single-agent bevacizumab in patients with recurrent anaplastic glioma

The purpose of this study was to evaluate the activity of single-agent bevacizumab in patients with recurrent anaplastic glioma and assess correlative advanced imaging parameters. Patients with recurrent anaplastic glioma were treated with bevacizumab 10 mg/kg every 2 weeks. Complete patient evaluations were repeated every 4 weeks. Correlative dynamic contrast-enhanced MR and (18)fluorodeoxyglucose PET imaging studies were obtained to evaluate physiologic changes in tumor and tumor vasculature at time points including baseline, 96 h after the first dose, and after the first 4 weeks of therapy. Median overall survival was 12 months (95% confidence interval [CI]: 6.08-22.8). Median progression-free survival was 2.93 months (95% CI: 2.01-4.93), and 6-month progression-free survival was 20.9% (95% CI: 10.3%-42.5%). Thirteen (43%) patients achieved a partial response. The most common grade ≥ 3 treatment-related toxicities were hypertension, hypophosphatemia, and thromboembolism. Single-agent bevacizumab produces significant radiographic response in patients with recurrent anaplastic glioma but did not meet the 6-month progression-free survival endpoint. Early change in enhancing tumor volume at 4 days after start of therapy was the most significant prognostic factor for overall and progression-free survival.

A phase I/II trial of vandetanib for patients with recurrent malignant glioma

Vandetanib is a once-daily multitargeted tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2, epidermal growth factor receptor, and the rearranged-during-transfection oncogene. A phase I trial was conducted to describe the pharmacokinetics of vandetanib in patients with recurrent glioma on enzyme-inducing anti-epileptic drugs (EIAEDs) and to identify the maximum tolerated dose (MTD) in this population. A phase II trial evaluated the efficacy of vandetanib in patients with recurrent malignant glioma not on EIAEDs as measured by 6-month progression-free survival (PFS6). In the phase I trial, 15 patients were treated with vandetanib at doses of 300, 400, and 500 mg/day, in a standard dose-escalation design. The MTD in patients on EIAEDs was 400 mg/day, and steady-state levels were similar to those measured in patients not on EIAEDs. Dose-limiting toxicities were prolonged QTc and thromboembolism. Thirty-two patients with recurrent glioblastoma multiforme (GBM) and 32 patients with recurrent anaplastic gliomas (AGs) were treated in the phase II trial, at a dosage of 300 mg/day on 28-day cycles. Six patients (4 GBM, 2 AG) had radiographic response. PFS6 was 6.5% in the GBM arm and 7.0% in the AG arm. Median overall survival was 6.3 months in the GBM arm and 7.6 months in the AG arm. Seizures were an unexpected toxicity of therapy. Vandetanib did not have significant activity in unselected patients with recurrent malignant glioma.

Phase 2 Trial of Talampanel, a Glutamate Receptor Inhibitor, for Adults With Recurrent Malignant Gliomas

Glioma cells secrete glutamate and also express α‐amino‐3‐hydroxy‐5 methyl‐4‐isoxazolepropionate (AMPA) glutamate receptors, which contribute to the proliferation, migration, and neurotoxicity of malignant gliomas. Talampanel is an oral AMPA receptor inhibitor with excellent central nervous system penetration and good tolerability in clinical trials for epilepsy and other neurologic disorders.

A phase I trial of enzastaurin in patients with recurrent gliomas.

Purpose: Enzastaurin is a selective inhibitor of protein kinase C β. Prior phase I studies did not show increased drug exposures with escalating once daily administration. Limits from gastrointestinal absorption may be overcome by twice daily dosing, potentially improving antitumor effects. Experimental Design: We conducted a phase I dose escalation study in 26 patients with recurrent malignant glioma, stratified by use of enzyme-inducing antiepileptic drugs, to investigate whether divided twice daily dosing results in higher exposures compared with once daily dosing. Phosphorylated glycogen synthase 3 β was analyzed as a potential biomarker of enzastaurin activity. Results: Enzastaurin was poorly tolerated at all dose levels evaluated (500, 800, and 1,000 mg total daily), with thrombocytopenia and prolonged QTc as dose-limiting toxicities. The average drug concentration of enzastaurin under steady-state conditions was doubled by twice daily dosing compared with daily dosing [1.990; 90% confidence interval (CI), 1.450-2.730]. Additionally, geometric mean ratios doubled with 800 versus 500 mg dosing for both daily (2.687; 90% CI, 1.232-5.860) and twice daily regimens (1.852; 90% CI, 0.799-4.292). Two patients achieved long-term benefit (over 150 weeks progression free). Conclusions: Higher and more frequent dosing of enzastaurin resulted in improved drug exposure but with unacceptable toxicity at the doses tested. Phosphorylated glycogen synthase 3 β may be a useful biomarker of the biological activity of enzastaurin. Enzastaurin has activity in a subset of malignant glioma patients and warrants continued study in combination with other agents using a maximal once daily dose of 500 mg.

Ischemic stroke in patients with primary brain tumors

Background: Primary brain tumor patients are at increased risk for stroke from disease and treatment-specific mechanisms. Methods: We conducted a retrospective review of patients with primary brain tumors diagnosed with MRI-confirmed ischemic stroke between 1996 and 2006. Data were collected including risk factors, diagnostic workup, and treatment for stroke. Modified Rankin Scale (MRS) scores at stroke diagnosis were determined, and stroke etiology was assigned using Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria for nonpostoperative strokes. Results: Sixty-eight cases of confirmed ischemic stroke in 66 patients (56% men) were analyzed. The median age at time of stroke was 60 years. The distribution of stroke risk factors was comparable to the general stroke population. The most common brain tumors were gliomas, 60%; meningiomas, 25%; and primary CNS lymphoma, 6%. Stroke was the initial clinical diagnosis in only 43% of cases. The distribution of stroke etiology was operative complication, 49%; cardioembolic, 12%; small vessel lacune, 12%; large vessel, 6%; other, 15%; and undetermined, 7%. Seventeen patients (25%) had strokes related to delayed effects of radiation. The median latency from radiation to stroke diagnosis was 3.2 years. Therapy for secondary prevention of stroke was added in one-half of patients. Median survival from the time of stroke was 1.7 years and was correlated with MRS scores. Conclusions: Treatment complications from surgery and radiotherapy account for the majority of ischemic strokes in patients with primary brain tumors. Stroke is often a missed diagnosis that can contribute additional neurologic disability in an already susceptible patient population.

Treatment patterns and prognosis in patients with human immunodeficiency virus and primary central system lymphoma

The incidence of human immunodeficiency virus (HIV)-associated primary central nervous system lymphoma (PCNSL) has decreased in the era of highly active anti-retroviral therapy, but PCNSL continues to be a prominent AIDS-defining illness. Using surveillance epidemiology and end results, cancer registry data linked with Medicare, we identified PCNSL cases diagnosed from 1994 to 2002. The effects of comorbidity, year of diagnosis, and sociodemographic characteristics on the odds of receiving treatment were assessed. One hundred and eighty-four patients with both HIV and PCNSL were identified. Forty-six per cent were treated with radiation therapy (RT) alone, 10% received RT and chemotherapy, 4% received chemotherapy alone, and 40% received no treatment. No time trends in treatment patterns were observed, and no sociodemographic factors were associated with receipt of treatment. Median survival was 2 months. Age did not impact survival. Survival was improved for patients diagnosed with PCNSL after 1996 (p = 0.028). Despite improved treatment for both diseases over the past decade, survival remains dismal in this cohort of Medicare/Medicaid beneficiaries with HIV-related PCNSL. These results may not apply to the general HIV population.