Impact of phase II trials with progression-free survival as end-points on survival-based phase III studies in patients with anaplastic gliomas

Abstract Background To assess progression-free survival (PFS) as the appropriate end-point for phase II trials for anaplastic gliomas (AGs) and to determine the impact of PFS on survival-based phase III trials. Methods Combined data from 16 phase II studies (N = 529 patients) were analyzed to determine progression-free survival (PFS) at 6, 9, and 12 months and the impact of age, Karnofsky performance score (KPS), number of prior chemotherapies, and response to treatment on PFS. Results The specific chemotherapy used was the major effector of PFS at 6, 9, and 12 months. Age, KPS, treatment response rate, and number of prior chemotherapies did not affect PFS to the same extent. Hierarchical cluster analyses and linear least squares fitting of PFS9 v PFS12 demonstrated the existence of three therapeutic efficacy groups with PFS rates at 6, 9, and 12 months ranging from lowest (A) to highest (C). The PFS6 was 15% in group A and 41% in group C (p 12 was 9% in group A and 33% in group C (p 1 year of additional life. Conclusion Based on PFS rates at 6, 9, and 12 months for AG patients, a differential of 1.5 to 2 years is the norm and could invalidate overall survival as an end-point for phase III studies in patients with AG. PFS is a more reliable end-point because it reflects the true antitumor benefit of the chemotherapy.</p

A multicenter phase II trial of intrathecal topotecan in patients with meningeal malignancies

To determine the therapeutic efficacy (13-week and 26-week CNS progression-free survival [PFS], response rate, and overall survival) and safety of intraventricular (IVent) topotecan in patients with neoplastic meningitis (NM), we conducted a phase II, open-label, nonrandomized, single-arm trial of IVent topotecan in patients with NM using 400 μg of topotecan IVent twice weekly for 6 weeks, followed by evaluation with imaging, cerebrospinal fluid (CSF), and physical examinations. In the absence of disease progression, patients were then treated with IVent topotecan weekly for 6 weeks, twice monthly for 4 months, and monthly thereafter. Sixty-two patients (23 males and 39 females) were enrolled from April 2001 through March 2006. Median age and KPS at enrollment were 56 (range 5–83) and 80 (range 60–100), respectively. Primary cancers included breast (19), lung (13), CNS (14), and others (16). Forty patients (65%) completed the 6-week induction period, among whom 13 (21%) had CSF clearance of malignant cells. Kaplan-Meier estimates of PFS at 13 and 26 weeks were 30% (95% confidence interval [CI], 20%–45%) and 19% (95% CI, 11%–34%). Overall median survival (50 deaths) was 15 weeks (95% CI, 13–24 weeks). The most common side effect was chemical meningitis in 32% of patients (5% grade 3); 32% experienced no drug side effects. IVent topotecan is well tolerated, but provides no added benefit over other IVent therapies. Because of its modest side effect profile, combining IVent topotecan with other IVent or systemic interventions should be considered

Phase II trial of irinotecan and thalidomide in adults with recurrent glioblastoma multiforme

This phase II study aimed at determining the efficacy and safety of irinotecan combined with thalidomide in adults with recurrent glioblastoma multiforme (GBM) not taking enzyme-inducing anticonvulsants (EIACs). Adult patients (⩾18 years) with recurrent GBM with up to three relapses following surgery and radiation therapy were eligible for this trial. The primary end point was rate of progression-free survival at 6 months (PFS-6); secondary end points were response rate, overall survival, and toxicity. Patients were treated in 6-week cycles with 125 mg/m2 irinotecan weekly for 4 weeks followed by 2 weeks off treatment and 100 mg of thalidomide daily increased as tolerated to 400 mg/day. Of 32 evaluable patients, 8 (25%) were alive and progression free at 6 months. The median PFS was 13 weeks. One patient experienced a complete response, one a partial response, and 19 stable disease. Median overall survival time from entry into the study was 36 weeks, and the 1-year survival rate was 34%. Adverse events (grade 3 or 4) included diarrhea, abdominal cramps, lymphopenia, neutropenia, and fatigue. Two of the four deaths that occurred were possibly due to treatment-related toxicity. The combination of irinotecan, a cytotoxic agent, and thalidomide, an antiangiogenic agent, shows promising activity against recurrent GBM in patients not receiving EIACs and warrants further study. The results also provide support for similar strategies using combination therapies with newer targeted antiangiogenic agents to generate effective therapies against malignant gliomas