A randomized phase II trial of veliparib (V), radiotherapy (RT) and temozolomide (TMZ) in patients (pts) with unmethylated MGMT (uMGMT) glioblastoma (GBM).

2011 Background: TMZ offers minimal benefit in uMGMT GBM pts. V is synergistic with both RT and TMZ in preclinical models, safe when combined with either RT or TMZ clinically, but the triplet (V+RT+TMZ) is poorly tolerated. This study examined a novel approach to patients with uMGMT GBM. Methods: VERTU is a randomized Phase 2 trial comparing Arm A (Standard of care) = RT (60Gy/30 fractions) + TMZ (75mg/m2 daily) followed by TMZ (150–200mg/m2D 1–5) every 28 days for 6 cycles vs Arm B (experimental arm) = RT (60Gy/30 fractions) + V (200mg PO BID) followed by TMZ (150–200mg/m2D 1–5) + V (40mg bid, D 1–7) every 28 days for 6 cycles in pts with newly diagnosed centrally determined uMGMT GBM. The study aims to randomize 120 pts (2:1 to the experimental arm). The primary endpoint was 6 months progression free survival (6mPFS) with multiple secondary and tertiary endpoints. Evaluation of feasibility and safety was planned after completion of RT in the first 60 pts (Stage 1). (ANZCTR #ACTRN12615000407594). Tumor tissue and serial bloods were collected for translational research. Results: 125 pts were randomized (41 Arm A, 84 Arm B). Mean (range) age 58 (22–78) years, 70% male, 61% ECOG 0, 86% macroscopic resection, 14% biopsy. At the time of analysis (cut-off date: 04/Feb/2019), median follow up was 16.5 months, 76 pts had died. 6mPFS (95% CI, Kaplan-Meier estimate) was 37% (22–52) in Arm A and 53% (41–63) in Arm B, and median PFS was 4.4m (95% CI 4.0–6.0) for Arm A and 6.2m (95% CI 4.9–7.1) for Arm B (HR = 0.81, 95%CI 0.54–1.21). 50% of pts in Arm A and 53% in Arm B experienced ≥ G3 adverse events (AEs). The most common G 3/4 AEs were decreased platelets, seizures, hyperglycemia and diarrhea (each 5%) in Arm A and decreased platelets (13%) and seizures (11%) in Arm B. Conclusions: In this multicenter, randomized study, the experimental therapy was feasible and well tolerated. The observed 6mPFS appeared longer in Arm B, but at the time of submitting the abstract, this result did not meet the prespecified primary endpoint. More mature results will be presented at the annual meeting. QoL in VERTU is reported separately. Central MR review, biomarker analyses, including DNA repair and methylation signature analyses are ongoing. Clinical trial information: ACTRN12615000407594.