Actionable molecular alterations in newly diagnosed and recurrent IDH1/2 wild-type glioblastoma patients and therapeutic implications: a large mono-institutional experience using extensive next-generation sequencing analysis.

BACKGROUND: Next-generation sequencing (NGS) panels enable the identification of alterations in cancer-related genes. This may guide a molecularly targeted strategy for the treatment of glioblastoma (GBM). MATERIAL AND METHODS: We retrospectively analysed data obtained using FoundationOne®CDx in a large cohort of IDH1/2 wild-type GBM. We aimed to 1) identify potentially actionable molecular alterations at diagnosis and/or recurrence based on ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT) defined categories of targetability, 2) understand the clinical implications of NGS in terms of access to and activity of targeted therapies. RESULTS: In 442 samples, an NGS profile was available in 98.2%. The median time from diagnosis to NGS profiling was 7.4 months (interquartile range (IQR): 3.4-13.2). Although about half of the patients had at least one actionable molecular alteration, only 3.4% of them were classified as ESCAT IB-IC and 6.7% as ESCAT IIB. Only 36 patients (10.5%) received personalised treatment in clinical trials or as off-label/compassionate use from second-line (median line 3). Most patients did not receive targeted therapy due to clinical deterioration/death (49.6%). Patients treated with dabrafenib/trametinib (9 patients) had the highest disease control rate of 77% and an objective response rate of 22%, with a median progression-free survival (PFS) of 5.2 months. No complete/partial responses were seen with the other regimens. 4/9 (44.4%) patients on anti-BRAF/anti-MEK, 2/4 patients (50%) on erdafitinib and 1/1 patient on capmatinib had a PFS ratio > 1.3. One recurrent GBM patient with ROS1-GOCP fusion maintained a complete response for 11.3 months on entrectinib. CONCLUSIONS: Our study demonstrated the feasibility of NGS in GBM samples. As the number of clinically relevant targets was limited and only a small group of GBM patients were treated with targeted therapy, NGS testing should be performed in the context of clinical trials. Our results support the activity of anti-BRAF/anti-MEK, while for the other agents prospective study results are needed to draw solid conclusions.

Efficacy and safety of chlorpromazine as an adjuvant therapy for glioblastoma in patients with unmethylated MGMT gene promoter: RACTAC, a phase II multicenter trial.

Introduction: Drug repurposing is a promising strategy to develop new treatments for glioblastoma. In this phase II clinical trial, we evaluated the addition of chlorpromazine to temozolomide in the adjuvant phase of the standard first-line therapeutic protocol in patients with unmethylated MGMT gene promoter. Methods: This was a multicenter phase II single-arm clinical trial. The experimental procedure involved the combination of CPZ with standard treatment with TMZ in the adjuvant phase of the Stupp protocol in newly-diagnosed GBM patients carrying an unmethylated MGMT gene promoter. Progression-free survival was the primary endpoint. Secondary endpoints were overall survival and toxicity. Results: Forty-one patients were evaluated. Twenty patients (48.7%) completed 6 cycles of treatment with TMZ+CPZ. At 6 months, 27 patients (65.8%) were without progression, achieving the primary endpoint. Median PFS was 8.0 months (95% CI: 7.0-9.0). Median OS was 15.0 months (95% CI: 13.1-16.9). Adverse events led to reduction or interruption of CPZ dosage in 4 patients (9.7%). Discussion: The addition of CPZ to standard TMZ in the first-line treatment of GBM patients with unmethylated MGMT gene promoter was safe and led to a longer PFS than expected in this population of patients. These findings provide proof-of-concept for the potential of adding CPZ to standard TMZ treatment in GBM patients with unmethylated MGMT gene promoter. Clinical trial registration: https://clinicaltrials.gov/study/NCT04224441, identifier NCT04224441.