Phase II pilot study of bevacizumab in combination with temozolomide and regional radiation therapy for up-front treatment of patients with newly diagnosed glioblastoma multiforme: interim analysis of safety and tolerability.

PURPOSE: To assess interim safety and tolerability of a 10-patient, Phase II pilot study using bevacizumab (BV) in combination with temozolomide (TMZ) and regional radiation therapy (RT) in the up-front treatment of patients with newly diagnosed glioblastoma. METHODS AND MATERIALS: All patients received standard external beam regional RT of 60.0 Gy in 30 fractions started within 3 to 5 weeks after surgery. Concurrently TMZ was given daily at 75 mg/m(2) for 42 days during RT, and BV was given every 2 weeks at 10 mg/kg starting with the first day of RT/TMZ. After a 2-week interval upon completion of RT, the post-RT phase commenced with resumption of TMZ at 150 to 200 mg/m(2) for 5 days every 4 weeks and continuation of BV every 2 weeks. RESULTS: For these 10 patients, toxicities were compiled until study discontinuation or up to approximately 40 weeks from initial study treatment for those remaining on-study. In terms of serious immediate or delayed neurotoxicity, 1 patient developed presumed radiation-induced optic neuropathy. Among the toxicities that could be potentially treatment related, relatively high incidences of fatigue, myelotoxicity, wound breakdown, and deep venous thrombosis/pulmonary embolism were observed. CONCLUSION: The observed toxicities were acceptable to continue enrollment toward the overall target group of 70 patients. Preliminary efficacy analysis shows encouraging mean progression-free survival. At this time data are not sufficient to encourage routine off-label use of BV combined with TMZ/RT in the setting of newly diagnosed glioblastoma without longer follow-up, enrollment of additional patients, and thorough efficacy assessment.

Phase 2 Study of Bortezomib Combined With Temozolomide and Regional Radiation Therapy for Upfront Treatment of Patients With Newly Diagnosed Glioblastoma Multiforme: Safety and Efficacy Assessment.

PURPOSE: To assess the safety and efficacy of upfront treatment using bortezomib combined with standard radiation therapy (RT) and temozolomide (TMZ), followed by adjuvant bortezomib and TMZ for ≤24 cycles, in patients with newly diagnosed glioblastoma multiforme (GBM). METHODS AND MATERIALS: Twenty-four patients with newly diagnosed GBM were enrolled. The patients received standard external beam regional RT with concurrent TMZ beginning 3 to 6 weeks after surgery, followed by adjuvant TMZ and bortezomib for ≤24 cycles or until tumor progression. During RT, bortezomib was given at 1.3 mg/m2 on days 1, 4, 8, 11, 29, 32, 36, and 39. After RT, bortezomib was given at 1.3 mg/m2 on days 1, 4, 8, and 11 every 4 weeks. RESULTS: No unexpected adverse events occurred from the addition of bortezomib. The efficacy analysis showed a median progression-free survival (PFS) of 6.2 months (95% confidence interval [CI] 3.7-8.8), with promising PFS rates at ≥18 months compared with historical norms (25.0% at 18 and 24 months; 16.7% at 30 months). In terms of overall survival (OS), the median OS was 19.1 months (95% CI 6.7-31.4), with improved OS rates at ≥12 months (87.5% at 12, 50.0% at 24, 34.1% at 36-60 months) compared with the historical norms. The median PFS was 24.7 months (95% CI 8.5-41.0) in 10 MGMT methylated and 5.1 months (95% CI 3.9-6.2) in 13 unmethylated patients. The estimated median OS was 61 months (95% CI upper bound not reached) in the methylated and 16.4 months (95% CI 11.8-21.0) in the unmethylated patients. CONCLUSIONS: The addition of bortezomib to current standard radiochemotherapy in newly diagnosed GBM patients was tolerable. The PFS and OS rates appeared promising, with more benefit to MGMT methylated patients. Further clinical investigation is warranted in a larger cohort of patients.

Irinotecan treatment for recurrent malignant glioma using an every-3-week regimen.

This phase II study was designed to evaluate the safety, tolerability, and efficacy of irinotecan (CPT-11) in the treatment of adults with malignant glioma. Patients with progressive or recurrent malignant gliomas were enrolled. CPT-11 was administered as a 90-minute intravenous infusion at a dose of 300 mg/m(2) once a week every 3 weeks. After 2 treatments, doses were increased to 350 mg/m(2) in those patients without grade III/IV toxicities. Dose modifications were made for toxicities. All 14 patients who enrolled (11 males and 3 females) were treated with CPT-11 and were assessable for survival, response, and toxicity. The majority of patients (86%) had prior surgery. Two patients had a confirmed partial response and 2 patients (14%) had stable disease. Median survival was 24 weeks. Median time to tumor progression was 6 weeks. The primary hematologic toxicity was grade III/IV neutropenia, which was observed in 14% of patients. Infrequent grade III/IV nonhematologic toxicity was observed, possibly because of the concomitant use of anticonvulsants, which may have altered pharmacokinetics. These results suggest that CPT-11 has activity against recurrent malignant glioma using a dosing regimen of 300 mg/m(2) every 3 weeks showing limited toxicity. The concurrent use of anticonvulsant medications may have played a role in altering pharmacokinetics and thus the maximum tolerated dose in this patient population.

Phase II study of bevacizumab plus temozolomide during and after radiation therapy for patients with newly diagnosed glioblastoma multiforme.

PURPOSE: This open-label, prospective, multicenter single-arm phase II study combined bevacizumab (BV) with radiation therapy (RT) and temozolomide (TMZ) for the treatment of newly diagnosed glioblastoma (GBM). The objectives were to determine the efficacy of this treatment combination and the associated toxicity. PATIENTS AND METHODS: Seventy patients with newly diagnosed GBM were enrolled between August 2006 and November 2008. Patients received standard RT starting within 3 to 6 weeks after surgery with concurrent administration of daily TMZ and biweekly BV. After completion of RT, patients resumed TMZ for 5 days every 4 weeks and continued biweekly BV. MGMT promoter methylation was assessed on patient tumor tissue. A University of California, Los Angeles/Kaiser Permanente Los Angeles (KPLA) control cohort of newly diagnosed patients treated with first-line RT and TMZ who had mostly received BV at recurrence was derived for comparison. RESULTS: The overall survival (OS) and progression-free survival (PFS) were 19.6 and 13.6 months, respectively, compared to 21.1 and 7.6 months in the University of California, Los Angeles/KPLA control cohort, and 14.6 and 6.9 months in the European Organisation for Research and Treatment of Cancer-National Cancer Institute of Canada cohort. Correlation of MGMT promoter methylation and improved OS and PFS was retained in the study group. Comparative subset analysis showed that poor prognosis patients (recursive partitioning analysis class V/VI) may derive an early benefit from the use of first-line BV. Toxicity attributable to RT/TMZ was similar, and additional toxicities were consistent with those reported in other BV trials. CONCLUSION: Patients treated with BV and TMZ during and after RT showed improved PFS without improved OS compared to the University of California, Los Angeles/KPLA control group. Additional studies are warranted to determine if BV administered first-line improves survival compared to BV at recurrence.

A prospective blinded study of the predictive value of an extreme drug resistance assay in patients receiving CPT-11 for recurrent glioma.

This adjunct to a prospective phase II blinded study of 48 patients with recurrent malignant glioma evaluated the predictive reliability of an extreme drug resistance (EDR) to identify clinical resistance to irinotecan (CPT-11), using fresh tumor biopsies obtained from recurrent patients immediately prior to their first dose of CPT-11 therapy. In vitro tumor response to SN38 (bioactive species of CPT-11 used in the EDR assay) determined prior to treatment was correlated with objective response, time to tumor progression (TTP) and survival following the administration of CPT-11. SN38 activity was tested in 19 of 29 tumors, with 15 of 18 assay results evaluable for correlation with clinical outcomes. In vitro drug resistance was classified as either extreme, intermediate (IDR), or low (LDR). TTP and survival were estimated by the Kaplan-Meier method, and compared using the Mantel-Haenszel log-rank and Fisher's exact test statistics. In vitro tumor response was bifurcated into either EDR (n = 4) or IDR/LDR (n = 11) categories for comparison with outcomes. Results correlated significantly with both TTP and survival. Median TTP for IDR/LDR cases was 3 months versus 6 weeks for EDR cases (log-rank test; p = 0.0288, hazards ratio = 3.06). A 13-week median survival for EDR cases was significantly shorter compared to 38 weeks for IDR/LDR cases (p = 0.029). Further, 100-day survival favored the IDR/LDR cases (Fisher's exact test; p = 0.008). At last follow-up, two of three survivors were patients who had tumors IDR/LDR to SN38. These prospective data support the notion that patients should avoid agents to which their tumor demonstrates EDR.

Two studies evaluating irinotecan treatment for recurrent malignant glioma using an every-3-week regimen.

Two studies were performed to evaluate the safety, tolerability, and efficacy of irinotecan (CPT-11) in the treatment of adults with malignant glioma. Patients with progressive or recurrent malignant gliomas were enrolled. In the first study, CPT-11 was administered once every 3 weeks as a 90-minute intravenous infusion at a dose of 300 mg/m(2). After 2 treatments, doses were increased to 350 mg/m(2) in those patients without Grade 3/4 toxicities. Dose modifications were made for toxicities. All 14 patients who enrolled (11 males and 3 females) were treated with CPT-11 and were assessable for survival, response, and toxicity. The majority of patients (86%) had prior surgery. Two patients had a confirmed partial response (PR), and 2 patients (14%) had stable disease (SD). Median survival was 24 weeks; median time to tumor progression (TTP) was 6 weeks. The primary hematologic toxicity was Grade 3/4 neutropenia, which was observed in 14% of patients. Infrequent Grade 3/4 nonhematologic toxicity was observed, possibly due to the concomitant use of anticonvulsants that might have altered pharmacokinetics. The second study evaluated the potential underdosing observed in patients who did or did not receive enzyme-inducing antiepileptic drugs (EIAED) by implementing an intrapatient dose escalation design. In this open-label study, treatment of patients with recurrent malignant glioma (rMG) was started at 300-400 mg/m(2) of CPT-11 every 3 weeks and, depending on individual safety and efficacy evaluation, escalated by steps of 100 mg/m(2) in subsequent courses. Thirty-five patients (median age, 43 years; gender, 11F and 24M; histology, 26 glioblastoma multiforme and 9 anaplastic glioma) have completed at least two cycles of chemotherapy and are evaluable for toxicity and response. Dose-limiting toxicity (DLT) was reached in 12 patients at doses ranging from 400-1700 mg/m(2). Preliminary efficacy data show that 3 patients exhibited PR and 15 patients exhibited SD. Median TTP was 2.7 months, and median survival was 8.5 months. Patients who did not receive anticonvulsants achieved higher peak concentrations, relative to dose, of the active metabolite SN-38 than did patients in the EIAED group. This study confirmed the activity of CPT-11 in malignant glioma and indicated that the maximum tolerated dose (MTD) for patients with rMG was considerably higher than expected but still possessed significant variability. A higher level of efficacy for CPT-11 may be observed if an MTD can efficiently be established for each patient.