Raizer, Jeffrey J.

Abstract Background Glioblastoma (GBM) has a median survival of <2 years. Pexidartinib (PLX3397) is a small-molecule inhibitor of CSF1R, KIT, and oncogenic FTL3, which are implicated in GBM treatment resistance. Results from glioma models indicate that combining radiation therapy (RT) and pexidartinib reduces radiation resistance. We added pexidartinib to standard-of-care RT/temozolomide (TMZ) in patients with newly diagnosed GBM to assess the therapeutic benefit of altering the tumor microenvironment with pexidartinib. Methods In this open-label, dose-escalation, multicenter, Phase 1b/2 trial, pexidartinib was administered in combination with RT/TMZ followed by adjuvant pexidartinib + TMZ. During Phase 1b, pexidartinib was given 5 or 7 days/week at multiple dosing levels. The primary Phase 1b endpoint was the recommended Phase 2 dose (RP2D). Phase 2 patients received the RP2D with the primary endpoint of median progression-free survival (mPFS). Secondary objectives were median overall survival (mOS), pharmacokinetics, and safety. Results The RP2D of pexidartinib was 800 mg/day for 5 days/week during RT/TMZ, followed by 800 mg/day for 7 days/week with adjuvant TMZ. mPFS was 6.7 months (90% CI: 4.5, 11.5) for the modified intention-to-treat population. The actual mOS was 13.1 months (90% CI: 11.5, 24.5), and the mOS corrected for comparison with matched historical controls was 18.8 months (95% CI: 12.6, 28.0). Conclusions This trial established the RP2D of pexidartinib in combination with RT/TMZ and adjuvant TMZ. Pexidartinib was generally safe and well tolerated. Although the study regimen with pexidartinib was not efficacious, pharmacodynamic studies showed modulation of systemic markers that could lead to alteration of the tumor microenvironment.

Abstract BACKGROUND The original 3-arm CODEL design included a radiotherapy (RT)-alone control arm, an RT plus temozolomide (TMZ) arm, and an exploratory TMZ-alone arm. We report the analysis involving patients treated per the initial design. METHODS Adults (18+ years) with newly-diagnosed 1p/19q codeleted WHO grade III oligodendroglioma were randomized to RT (5940 cGy) alone (Arm A); RT with concomitant and adjuvant TMZ (Arm B); or TMZ alone (Arm C). Primary endpoint was OS, Arm A vs. B. Secondary comparisons were performed for OS and PFS, comparing pooled RT arms with the TMZ-alone arm. RESULTS 36 patients were randomized equally to the three arms. At median follow-up of 7.5 years, 83.3% (10/12) TMZ-alone patients had progressed, versus 37.5% (9/24) patients on the RT arms. PFS was shorter in TMZ-alone patients compared to RT-treated patients (HR=3.12; 95% CI: 1.26, 7.69; p=0.014). Death from disease progression occurred in 3/12 (25%) of TMZ-alone patients and 4/24 (16.7%) of RT-treated patients. OS did not statistically differ between arms, although this comparison was underpowered. After adjustment for IDH status (mutated vs. wildtype) in a Cox regression model, with IDH status and RT treatment status as co-variables (Arm C vs pooled A and B), PFS remained shorter for patients not receiving RT (HR= 3.33; 95% CI: 1.31, 8.45; p=0.011), and OS differences remained non-significant ((HR = 2.78; 95% CI 0.58, 13.22, p=0.20). Grade 3+ adverse events occurred in 25%, 42% and 33% patients (Arms A, B and C, respectively). Neurocognitive assessments, comparing baseline and 3 month timepoints, showed no significant differences between arms. CONCLUSIONS TMZ-alone treated patients experienced significantly shorter PFS than patients treated on the pooled RT arms, which remained significant when adjusting for IDH status. CODEL has been redesigned to compare the efficacy and toxicity of RT+PCV versus RT+TMZ. Clinicaltrials.gov Identifier: NCT00887146. Support: U10CA180821, U10CA180882, https://acknowledgments.alliancefound.org.

Abstract Background We report the analysis involving patients treated on the initial CODEL design. Methods Adults (>18) with newly diagnosed 1p/19q World Health Organization (WHO) grade III oligodendroglioma were randomized to radiotherapy (RT; 5940 centigray ) alone (arm A); RT with concomitant and adjuvant temozolomide (TMZ) (arm B); or TMZ alone (arm C). Primary endpoint was overall survival (OS), arm A versus B. Secondary comparisons were performed for OS and progression-free survival (PFS), comparing pooled RT arms versus TMZ-alone arm. Results Thirty-six patients were randomized equally. At median follow-up of 7.5 years, 83.3% (10/12) TMZ-alone patients progressed, versus 37.5% (9/24) on the RT arms. PFS was significantly shorter in TMZ-alone patients compared with RT patients (hazard ratio [HR] = 3.12; 95% CI: 1.26, 7.69; P = 0.014). Death from disease progression occurred in 3/12 (25%) of TMZ-alone patients and 4/24 (16.7%) on the RT arms. OS did not statistically differ between arms (comparison underpowered). After adjustment for isocitrate dehydrogenase (IDH) status (mutated/wildtype) in a Cox regression model utilizing IDH and RT treatment status as covariables (arm C vs pooled arms A + B), PFS remained shorter for patients not receiving RT (HR = 3.33; 95% CI: 1.31, 8.45; P = 0.011), but not OS ((HR = 2.78; 95% CI: 0.58, 13.22, P = 0.20). Grade 3+ adverse events occurred in 25%, 42%, and 33% of patients (arms A, B, and C). There were no differences between arms in neurocognitive decline comparing baseline to 3 months. Conclusions TMZ-alone patients experienced significantly shorter PFS than patients treated on the RT arms. The ongoing CODEL trial has been redesigned to compare RT + PCV versus RT + TMZ.

Abstract Low-grade primary central nervous system lymphoma is a very rare subtype of primary central nervous system lymphoma (PCNSL), for which almost no data is currently available. The purpose of this retrospective study was to characterize the clinical presentation, course and outcome of patients with low-grade PCNSL. Forty patients (18 male, 22 female) from 18 cancer centers in five countries were identified with a median age of 58 (range, 19–78) years and a median Eastern Cooperative Oncology Group (ECOG) performance status of 1 (range, 0–4). The mean time to diagnosis was 14.8 months (range, 0.25–84). Thirty-two patients (80%) had a B-cell and eight a T-cell lymphoma. Thirty-seven patients (92.5%) showed involvement of a cerebral hemisphere or deeper brain structures, while two evidenced only leptomeningeal involvement, and one patient had spinal cord disease. Treatment was performed in 39 patients: chemotherapy and radiotherapy in 15 (38%), radiotherapy alone in 12 (30%), chemotherapy alone in 10 (25%), and tumor resection alone in two. The median progression-free survival (PFS), disease-specific survival (DSS) and overall survival (OAS) were 61.5 (range, 0–204), 130 (range, 1–204), and 79 (range, 1–204) months, respectively. An age ≥60 years was associated with a shorter PFS (P = .009), DSS (P = .015) and OAS (P = .001) in multivariate analysis. Low-grade PCNSL differ from the high-grade subtype in pathological, clinical and radiological features. In this study, the long-term outcome was better as compared to the results obtained in PCNSL in general with age ≥60 years adversely affecting survival.

PURPOSE The Congress of Neurological Surgeons (CNS) has developed a series of guidelines for the treatment of adults with metastatic brain tumors, including systemic therapy and supportive care topics. ASCO has a policy and set of procedures for endorsing clinical practice guidelines that have been developed by other professional organizations. METHODS Two CNS guidelines were reviewed for developmental rigor by methodologists, and an independent multidisciplinary Expert Panel was formed to review the content and assess agreement with the recommendations. The Expert Panel voted to endorse the two guidelines, and ASCO and Society for Neuro-Oncology (SNO) independently reviewed and approved the ASCO/SNO guideline endorsement. RESULTS The ASCO/SNO Expert Panel determined that the recommendations from the CNS anticonvulsants and steroids guidelines, published January 9, 2019, are clear, thorough, and based on the most relevant scientific evidence. ASCO/SNO endorsed these two CNS guidelines with minor alterations. RECOMMENDATIONS Key recommendations include the following: prophylactic antiepileptic drugs were not recommended for routine use; and corticosteroids, specifically dexamethasone, were recommended for temporary symptomatic relief in patients with neurologic symptoms and signs related to mass effect from brain metastases. Additional information is available at www.asco.org/neurooncology-guidelines .

Abstract This report describes results from our analysis of the activity and biodistribution of a novel pan-ERBB inhibitor, NT113, when used in treating mice with intracranial glioblastoma (GBM) xenografts. Approaches used in this investigation include: bioluminescence imaging (BLI) for monitoring intracranial tumor growth and response to therapy; determination of survival benefit from treatment; analysis of tumor IHC reactivity for indication of treatment effect on proliferation and apoptotic response; Western blot analysis for determination of effects of treatment on ERBB and ERBB signaling mediator activation; and high-performance liquid chromatography for determination of NT113 concentration in tissue extracts from animals receiving oral administration of inhibitor. Our results show that NT113 is active against GBM xenografts in which wild-type EGFR or EGFRvIII is highly expressed. In experiments including lapatinib and/or erlotinib, NT113 treatment was associated with the most substantial improvement in survival, as well as the most substantial tumor growth inhibition, as indicated by BLI and IHC results. Western blot analysis results indicated that NT113 has inhibitory activity, both in vivo and in vitro, on ERBB family member phosphorylation, as well as on the phosphorylation of downstream signaling mediator Akt. Results from the analysis of animal tissues revealed significantly higher NT113 normal brain-to-plasma and intracranial tumor-to-plasma ratios for NT113, relative to erlotinib, indicating superior NT113 partitioning to intracranial tissue compartments. These data provide a strong rationale for the clinical investigation of NT113, a novel ERBB inhibitor, in treating patients with GBM. Mol Cancer Ther; 13(12); 2919–29. ©2014 AACR.