Longitudinal brain volumetrics in glioma survivors.

OBJECTIVE: Radiation therapy (RT) is used selectively for patients with low-grade glioma (LGG) given the concerns for potential cognitive effects in survivors, but prior cognitive outcome studies among LGG survivors have had inconsistent findings. Translational studies that characterize changes in brain anatomy and physiology after treatment of LGG may help to both contextualize cognitive findings and improve the overall understanding of radiation effects in normal brain tissue. This study aimed to investigate the hypothesis that patients with LGG who are treated with RT will experience greater brain volume loss than those who do not receive RT. METHODS: This retrospective longitudinal study included all patients with WHO grade 2 glioma who received posttreatment surveillance MRI at the University of Alabama at Birmingham. Volumetric analysis of contralateral cortical white matter (WM), cortical gray matter (GM), and hippocampus was performed on all posttreatment T1-weighted MRI sequences using the SynthSeg script. The effect of clinical and treatment variables on brain volumes was assessed using two-level hierarchical linear models. RESULTS: The final study cohort consisted of 105 patients with 1974 time points analyzed. The median length of imaging follow-up was 4.6 years (range 0.36-18.9 years), and the median number of time points analyzed per patient was 12 (range 2-40). Resection was performed in 79 (75.2%) patients, RT was administered to 61 (58.1%) patients, and chemotherapy was administered to 66 (62.9%) patients. Age at diagnosis (ß = -0.06, p < 0.001) and use of RT (ß = -1.12, p = 0.002) were associated with the slope of the contralateral cortical GM volume model (i.e., change in GM over time). Age at diagnosis (ß = -0.08, p < 0.001), midline involvement (ß = 1.31, p = 0.006), and use of RT (ß = -1.45, p = 0.001) were associated with slope of the contralateral cortical WM volume model. Age (ß = -0.0027, p = 0.001), tumor resection (ß = -0.069, p < 0.001), use of chemotherapy (ß = -0.0597, p = 0.003), and use of RT (ß = -0.0589, p < 0.001) were associated with the slope of the contralateral hippocampus volume model. CONCLUSIONS: This study demonstrated volume loss in contralateral brain structures among LGG survivors, and patients who received RT experienced greater volume loss than those who did not. The results of this study may help to provide context for cognitive outcome research in LGG survivors and inform the design of future strategies to preserve cognition.

Activity of a first-in-class oral HIF2-alpha inhibitor, PT2385, in patients with first recurrence of glioblastoma.

INTRODUCTION: Hypoxia inducible factor 2-alpha (HIF2α) mediates cellular responses to hypoxia and is over-expressed in glioblastoma (GBM). PT2385 is an oral HIF2α inhibitor with in vivo activity against GBM. METHODS: A two-stage single-arm open-label phase II study of adults with GBM at first recurrence following chemoradiation with measurable disease was conducted through the Adult Brain Tumor Consortium. PT2385 was administered at the phase II dose (800 mg b.i.d.). The primary outcome was objective radiographic response (ORR = complete response + partial response, CR + PR); secondary outcomes were safety, overall survival (OS), and progression free survival (PFS). Exploratory objectives included pharmacokinetics (day 15 Cmin), pharmacodynamics (erythropoietin, vascular endothelial growth factor), and pH-weighted amine- chemical exchange saturation transfer (CEST) MRI to quantify tumor acidity at baseline and explore associations with drug response. Stage 1 enrolled 24 patients with early stoppage for ≤ 1 ORR. RESULTS: Of the 24 enrolled patients, median age was 62.1 (38.7-76.7) years, median KPS 80, MGMT promoter was methylated in 46% of tumors. PT2385 was well tolerated. Grade ≥ 3 drug-related adverse events were hypoxia (n = 2), hyponatremia (2), lymphopenia (1), anemia (1), and hyperglycemia (1). No objective radiographic responses were observed; median PFS was 1.8 months (95% CI 1.6-2.5) and OS was 7.7 months (95% CI 4.9-12.6). Drug exposure varied widely and did not differ by corticosteroid use (p = 0.12), antiepileptics (p = 0.09), or sex (p = 0.37). Patients with high systemic exposure had significantly longer PFS (6.7 vs 1.8 months, p = 0.009). Baseline acidity by pH-weighted CEST MRI correlated significantly with treatment duration (R2 = 0.49, p = 0.017). Non-enhancing infiltrative disease with high acidity gave rise to recurrence. CONCLUSIONS: PT2385 monotherapy had limited activity in first recurrent GBM. Drug exposure was variable. Signals of activity were observed in GBM patients with high systemic exposure and acidic lesions on CEST imaging. A second-generation HIF2α inhibitor is being studied.

Inaugural Results of the Individualized Screening Trial of Innovative Glioblastoma Therapy: A Phase II Platform Trial for Newly Diagnosed Glioblastoma Using Bayesian Adaptive Randomization.

PURPOSE: The Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) is a phase II platform trial that uses response adaptive randomization and genomic profiling to efficiently identify novel therapies for phase III testing. Three initial experimental arms (abemaciclib [a cyclin-dependent kinase [CDK]4/6 inhibitor], neratinib [an epidermal growth factor receptor [EGFR]/human epidermal growth factor receptor 2 inhibitor], and CC-115 [a deoxyribonucleic acid-dependent protein kinase/mammalian target of rapamycin inhibitor]) were simultaneously evaluated against a common control arm. We report the results for each arm and examine the feasibility and conduct of the adaptive platform design. PATIENTS AND METHODS: Patients with newly diagnosed O6-methylguanine-DNA methyltransferase-unmethylated glioblastoma were eligible if they had tumor genotyping to identify prespecified biomarker subpopulations of dominant glioblastoma signaling pathways (EGFR, phosphatidylinositol 3-kinase, and CDK). Initial random assignment was 1:1:1:1 between control (radiation therapy and temozolomide) and the experimental arms. Subsequent Bayesian adaptive randomization was incorporated on the basis of biomarker-specific progression-free survival (PFS) data. The primary end point was overall survival (OS), and one-sided P values are reported. The trial is registered with ClinicalTrials.gov (identifier: NCT02977780). RESULTS: Two hundred thirty-seven patients were treated (71 control; 73 abemaciclib; 81 neratinib; 12 CC-115) in years 2017-2021. Abemaciclib and neratinib were well tolerated, but CC-115 was associated with ≥ grade 3 treatment-related toxicity in 58% of patients. PFS was significantly longer with abemaciclib (hazard ratio [HR], 0.72; 95% CI, 0.49 to 1.06; one-sided P = .046) and neratinib (HR, 0.72; 95% CI, 0.50 to 1.02; one-sided P = .033) relative to the control arm but there was no PFS benefit with CC-115 (one-sided P = .523). None of the experimental therapies demonstrated a significant OS benefit (P > .05). CONCLUSION: The INSIGhT design enabled efficient simultaneous testing of three experimental agents using a shared control arm and adaptive randomization. Two investigational arms had superior PFS compared with the control arm, but none demonstrated an OS benefit. The INSIGhT design may promote improved and more efficient therapeutic discovery in glioblastoma. New arms have been added to the trial.

Clinical and descriptive characteristics associated with high-grade meningioma in a large clinical series.

PURPOSE: We studied 571 patients with intracranial meningioma for clinical characteristics and tumor location associated with high grade meningioma (WHO II/III). MATERIALS AND METHODS: Patients were participants in a multicentre epidemiologic study of risk factors for primary brain tumors including meningioma recruited from September 2005 to November 2019. We included patients 18 or older with a recent diagnosis of a primary intracranial meningioma of any subtype (ICD9/10: 9530-0, 9531-0, 9532-0, 9537-0, 9533-0, 9534-0, 9530-0, 9538-1, 9538-3) who were enrolled at neuro-oncology and neuro-surgery clinics in the southeastern U.S. RESULTS: The median patient age was 58 years (IQR: 48-68) and the majority of patients were female (n = 415; 72.7%) and Caucasian (n = 516; 90.4%). Most patients were symptomatic (n = 460; 80.6%) and their tumours more commonly occurred in a non-skull base location (n = 298; 52.2%). A total of 86 patients (15.0%) had a WHO grade II/III meningioma. Compared to patients with WHO grade I tumours, patients with WHO II/III meningiomas were over 3-times more likely to be male (odds ratio (OR): 3.25; 95% confidence interval (CI): 1.98, 5.35) adjusting for age, race, symptomatic presentation, and skull-based location. Moreover, a WHO grade II/III meningioma was substantially less likely to be observed in asymptomatic patients (OR: 0.15, 95% CI: 0.04, 0.42), and in patients with a skull-based tumour (OR: 0.40, 95% CI: 0.24, 0.66), adjusting for other factors. Male gender, symptomatic tumour, and a non-skull base location were independently associated with WHO grade II/III meningioma. CONCLUSION: These findings may shed additional light on the underlying pathogenesis of meningioma.

"It's Not Just the Seizures": Brain Tumor Caregivers' Experiences and Educational Needs in Out-of-Hospital Seizure Management.

Objective: Family caregivers (FCGs) of persons with primary brain tumors (PBTs) report high levels of distress related to concerns about out-of-hospital seizures. This study aims to explore their experiences and needs with seizure management. Methods: Semi-structured interviews were held with 15 FCGs of persons with PBTs, both those who have and those who have not experienced a seizure, to elicit their concerns about out-of-hospital seizure management and related information needs. A qualitative descriptive study using thematic analysis was conducted based on interview data. Results: Three primary themes were identified relative to FCG experiences and needs related to care of PBTs patients, especially seizure management: (1) FCGs' experiences with caring for persons with PBTs; (2) FCGs' educational needs for seizure preparation and resources; and (3) FCGs' desired type of educational resources and information about seizures. Often FCGs were reported being fearful of seizures and nearly all expressed difficulty knowing when to call emergency services. FCGs equally desired written and online resources, and most preferred graphics or videos detailing seizures. Most FCGs thought that seizure-related training should come after rather than at the time of PBTs diagnosis. FCGs of patients who have not experienced seizures were significantly less prepared to manage seizures than those with a prior seizure. Conclusions: Recognizing and managing out-of-hospital seizures can be a difficult and distressing task for FCGs of patients with PBTs and seizure-related resources are needed. Our results suggest that FCGs of care recipients with PBTs need early supportive interventions to provide self-care strategies and problem-solving skills to manage their roles as caregivers. Interventions should include educational components to assist them in understanding the best mechanisms to maintain a safe environment for their care recipients, and those that deepen knowledge about when to contact EMS.

Isocitrate dehydrogenase (IDH) mutant gliomas: A Society for Neuro-Oncology (SNO) consensus review on diagnosis, management, and future directions.

Isocitrate dehydrogenase (IDH) mutant gliomas are the most common adult, malignant primary brain tumors diagnosed in patients younger than 50, constituting an important cause of morbidity and mortality. In recent years, there has been significant progress in understanding the molecular pathogenesis and biology of these tumors, sparking multiple efforts to improve their diagnosis and treatment. In this consensus review from the Society for Neuro-Oncology (SNO), the current diagnosis and management of IDH-mutant gliomas will be discussed. In addition, novel therapies, such as targeted molecular therapies and immunotherapies, will be reviewed. Current challenges and future directions for research will be discussed.

Targeting the TREM1-positive myeloid microenvironment in glioblastoma.

Background: Tumor cellular and molecular heterogeneity is a hallmark of glioblastoma and underlies treatment resistance and recurrence. This manuscript investigated the myeloid-derived microenvironment as a driver of glioblastoma heterogeneity and provided a pharmacological pathway for its suppression. Methods: Transcriptomic signatures of glioblastoma infiltrated myeloid-derived cells were assessed using R2: genomic platform, Ivy Glioblastoma Spatial Atlas, and single-cell RNA-seq data of primary and recurrent glioblastomas. Myeloid-derived cell prints were evaluated in five PDX cell lines using RNA-seq data. Two immunocompetent mouse glioblastoma models were utilized to isolate and characterize tumor-infiltrated myeloid-derived cells and glioblastoma/host cell hybrids. The ability of an inhibitor of HuR dimerization SRI42127 to suppress TREM1+-microenvironment and glioblastoma/myeloid-derived cell interaction was assessed in vivo and in vitro. Results: TREM1+-microenvironment is enriched in glioblastoma peri-necrotic zones. TREM1 appearance is enhanced with tumor grade and associated with poor patient outcomes. We confirmed an expression of a variety of myeloid-derived cell markers, including TREM1, in PDX cell lines. In mouse glioblastoma models, we demonstrated a reduction in the TREM1+-microenvironment and glioblastoma/host cell fusion after treatment with SRI42127. In vitro assays confirmed inhibition of cell fusion events and reduction of myeloid-derived cell migration towards glioblastoma cells by SRI42127 and TREM1 decoy peptide (LP17) versus control treatments. Conclusions: TREM1+-myeloid-derived microenvironment promulgates glioblastoma heterogeneity and is a therapeutic target. Pharmacological inhibition of HuR dimerization leads to suppression of the TREM1+-myeloid-derived microenvironment and the neoplastic/non-neoplastic fusogenic cell network.

Inhibition of the RNA Regulator HuR by SRI-42127 Attenuates Neuropathic Pain After Nerve Injury Through Suppression of Neuroinflammatory Responses.

Microglial activation with the production of pro-inflammatory mediators such as IL-6, TNF-α, and IL-1ß, is a major driver of neuropathic pain (NP) following peripheral nerve injury. We have previously shown that the RNA binding protein, HuR, is a positive node of regulation for many of these inflammatory mediators in glia and that its chemical inhibition or genetic deletion attenuates their production. In this report, we show that systemic administration of SRI-42127, a novel small molecule HuR inhibitor, attenuates mechanical allodynia, a hallmark of NP, in the early and chronic phases after spared nerve injury in male and female mice. Flow cytometry of lumbar spinal cords in SRI-42127-treated mice shows a reduction in infiltrating macrophages and a concomitant decrease in microglial populations expressing IL-6, TNF-α, IL-1ß, and CCL2. Immunohistochemistry, ELISA, and qPCR of lumbar spinal cord tissue indicate suppression of these cytokines and other inflammatory mediators. ELISA of plasma samples in the acute phase also shows attenuation of inflammatory responses. In summary, inhibition of HuR by SRI-42127 leads to the suppression of neuroinflammatory responses and allodynia after nerve injury and represents a promising new direction in the treatment of NP.

High-dose methotrexate and rituximab induction regimen in immunocompetent patients with primary CNS lymphoma: a retrospective single-center study of survival predictors.

PURPOSE: Primary Central Nervous System Lymphoma (PCNSL) is an aggressive tumor that is confined to the CNS. Although the provision of high-dose methotrexate (HD-MTX) has remarkably improved outcomes in PCNSL patients, the optimal treatment regimens and standard MTX dose for induction therapy have been largely controversial. Herein, we sought to explore the impact of adjuvant rituximab and different dosages of induction HD-MTX on survival outcomes of immunocompetent patients with PCNSL. METHODS: In this study, we examined patients with PCNSL treated at a single NCI-designated comprehensive cancer center to evaluate their survival outcomes. We conducted a retrospective analysis of 51 immunocompetent patients with PCNSL who received their induction chemotherapy at the University of Alabama at Birmingham (UAB) between 2001 and 2019. Only adult patients with a confirmed diagnosis of PCNSL who had either HD-MTX alone or in combination with rituximab were included. Patients' demographics, clinical characteristics, and survival data were collected and analyzed. RESULTS: There is no significant difference in survival among patients who received MTX alone versus MTX plus rituximab (HR = 0.996 (95% CI: 0.398-2.493), p = 0.994). Lower doses of MTX were associated with worse survival outcomes (HR = 0.680 (95% CI: 0.530-0.872), p = 0.002); however, this difference in survival was not significant when adjusted to age (HR = 0.797 (95% CI: 0.584-1.088), p = 0.153). CONCLUSION: Our experience challenges the role of rituximab in PCNSL during induction therapy. Our study also highlights the shorter survival in elderly patients with PCNSL which can be related, to some extent, to the relatively lower doses of HD-MTX. There is an unmet need to establish a consensus on the most effective upfront regimen in PCNSL through prospective studies.

Mitochondrial DNA sequence variation and risk of meningioma.

BACKGROUND: Risk factors for meningioma include female gender, African American race, high body mass index (BMI), and exposure to ionizing radiation. Although genome-wide association studies (GWAS) have identified two nuclear genome risk loci for meningioma (rs12770228 and rs2686876), the relation between mitochondrial DNA (mtDNA) sequence variants and meningioma is unknown. METHODS: We examined the association of 42 common germline mtDNA variants (minor allele frequency ≥ 5%), haplogroups, and genes with meningioma in 1080 controls and 478 meningioma cases from a case-control study conducted at medical centers in the southeastern United States. Associations were examined separately for meningioma overall and by WHO grade (n = 409 grade I and n = 69 grade II/III). RESULTS: Overall, meningioma was significantly associated with being female (OR 2.85; 95% CI 2.21-3.69), self-reported African American race (OR 2.38, 95% CI 1.41-3.99), and being overweight (OR 1.48; 95% CI 1.11-1.97) or obese (OR 1.70; 95% CI 1.25-2.31). The variant m.16362T > C (rs62581341) in the mitochondrial control region was positively associated with grade II/III meningiomas (OR 2.33; 95% CI 1.14-4.77), but not grade I tumors (OR 0.99; 95% CI 0.64-1.53). Haplogroup L, a marker for African ancestry, was associated with meningioma overall (OR 2.92; 95% CI 1.01-8.44). However, after stratifying by self-reported race, this association was only apparent among the few self-reported Caucasians with this haplogroup (OR 6.35; 95% CI 1.56-25.9). No other mtDNA variant, haplogroup, or gene was associated with meningioma. CONCLUSION: Common mtDNA variants and major mtDNA haplogroups do not appear to have associations with the odds of developing meningioma.

Data Matching to Support Analysis of Cancer Epidemiology Among Veterans Compared With Non-Veteran Populations-An Exemplar in Brain Tumors.

PURPOSE: State and national cancer registries do not systematically include Veteran data, which hinders analysis of the diagnosis patterns, treatment trajectories, and clinical outcomes of Veterans compared with non-Veteran populations. This study used data matching approaches to compare cases included in the Oncology Domain of the Veterans Affairs (VA) Corporate Data Warehouse and the Ohio Cancer Incidence Surveillance System, using brain tumors as an exemplar. METHODS: We used direct data matching, on the basis of protected health information (PHI) common to both databases, to compare primary brain tumors from Veterans and non-Veterans diagnosed from 2000 to 2016. Working with this matched data set, we used six data elements that did not contain PHI, to assess the feasibility of using deterministic data matching to compare Veterans and non-Veterans. RESULTS: Between 2000 and 2016, 223 Veterans from Ohio had a primary brain tumor; of those, 55 (25%) were not included in Ohio Cancer Incidence Surveillance System. Direct data matching showed that Veterans experienced a greater proportion of glioblastomas (41%) compared with non-Veterans (21%). Sex did not account for this difference. Deterministic data matching within the matched data set found that 75% (126 of 168) of Veterans had exact matches for at least five of six non-PHI variables common to both databases. CONCLUSION: This study indicated that direct and deterministic data matching approaches to compare brain tumors in Veterans and in non-Veterans is feasible. This approach has the potential to promote comparisons of the distribution of tumors, the impact of chemical and environmental exposures, treatment trajectories, and clinical outcomes among Veteran and non-Veteran populations with brain tumors as well as other cancers and rare diseases.

Optimizing eligibility criteria and clinical trial conduct to enhance clinical trial participation for primary brain tumor patients.

Building on an initiative to enhance clinical trial participation involving the Society for Neuro-Oncology, the Response Assessment in Neuro-Oncology Working Group, patient advocacy groups, clinical trial cooperative groups, and other partners, we evaluate the impact of eligibility criteria and trial conduct on neuro-oncology clinical trial participation. Clinical trials often carry forward eligibility criteria from prior studies that may be overly restrictive and unnecessary and needlessly limit patient accrual. Inclusion and exclusion criteria should be evaluated based on the goals and design of the study and whether they impact patient safety and/or treatment efficacy. In addition, we evaluate clinical trial conduct as a barrier to accrual and discuss strategies to minimize such barriers for neuro-oncology trials.

Glioma risk associated with extent of estimated European genetic ancestry in African Americans and Hispanics.

Glioma incidence is highest in non-Hispanic Whites, and to date, glioma genome-wide association studies (GWAS) to date have only included European ancestry (EA) populations. African Americans and Hispanics in the US have varying proportions of EA, African (AA) and Native American ancestries (NAA). It is unknown if identified GWAS loci or increased EA is associated with increased glioma risk. We assessed whether EA was associated with glioma in African Americans and Hispanics. Data were obtained for 832 cases and 675 controls from the Glioma International Case-Control Study and GliomaSE Case-Control Study previously estimated to have <80% EA, or self-identify as non-White. We estimated global and local ancestry using fastStructure and RFMix, respectively, using 1,000 genomes project reference populations. Within groups with ≥40% AA (AFR≥0.4 ), and ≥15% NAA (AMR≥0.15 ), genome-wide association between local EA and glioma was evaluated using logistic regression conditioned on global EA for all gliomas. We identified two regions (7q21.11, p = 6.36 × 10-4 ; 11p11.12, p = 7.0 × 10-4 ) associated with increased EA, and one associated with decreased EA (20p12.13, p = 0.0026) in AFR≥0.4 . In addition, we identified a peak at rs1620291 (p = 4.36 × 10-6 ) in 7q21.3. Among AMR≥0.15 , we found an association between increased EA in one region (12q24.21, p = 8.38 × 10-4 ), and decreased EA in two regions (8q24.21, p = 0. 0010; 20q13.33, p = 6.36 × 10-4 ). No other significant associations were identified. This analysis identified an association between glioma and two regions previously identified in EA populations (8q24.21, 20q13.33) and four novel regions (7q21.11, 11p11.12, 12q24.21 and 20p12.13). The identifications of novel association with EA suggest regions to target for future genetic association studies.

The medical necessity of advanced molecular testing in the diagnosis and treatment of brain tumor patients.

Accurate pathologic diagnoses and molecularly informed treatment decisions for a wide variety of cancers depend on robust clinical molecular testing that uses genomic, epigenomic, and transcriptomic-based tools. Nowhere is this more essential than in the workup of brain tumors, as emphasized by the incorporation of molecular criteria into the 2016 World Health Organization classification of central nervous system tumors and the updated official guidelines of the National Comprehensive Cancer Network. Despite the medical necessity of molecular testing in brain tumors, access to and utilization of molecular diagnostics is still highly variable across institutions, and a lack of reimbursement for such testing remains a significant obstacle. The objectives of this review are (i) to identify barriers to adoption of molecular testing in brain tumors, (ii) to describe the current molecular tools recommended for the clinical evaluation of brain tumors, and (iii) to summarize how molecular data are interpreted to guide clinical care, so as to improve understanding and justification for their coverage in the routine workup of adult and pediatric brain tumor cases.

Anti-cancer effects of the HuR inhibitor, MS-444, in malignant glioma cells.

Glioblastoma is a highly malignant and typically fatal tumor of the central nervous system. The tumor is characterized by marked cellular and molecular heterogeneity, including a subpopulation of brain tumor initiating cells (BTICs) that are highly resistant to radiation and chemotherapy. We previously reported that the RNA-binding protein HuR is: (1) overexpressed in glioblastoma, (2) necessary for tumor growth in vivo, and (3) a positive regulator of tumor-promoting genes in glioblastoma. These findings provide strong evidence that HuR might be a viable therapeutic target in glioblastoma. In this report, we investigated the effects of MS-444, a small molecule inhibitor of HuR, in xenograft-derived human glioblastoma cells and BTICs. We found that MS-444 treatment of glioblastoma cells resulted in loss of viability and induction of apoptosis, with evidence implicating death receptor 5. BTICs were particularly sensitive to MS-444. At sub-lethal doses, MS-444 attenuated invasion of glioblastoma cells and BTICs in a transwell model. At the molecular level, MS-444 treatment led to an attenuation of mRNAs in different tumor promoting pathways including angiogenesis, immune evasion and suppression of apoptosis. Although cytoplasmic HuR was reduced with MS-444 treatment, the attenuation of mRNAs could not be explained by RNA destabilization. In summary, this report provides proof of concept that small molecule inhibition of HuR could be a viable approach for treatment of glioblastoma.

Phase II Study of Iniparib with Concurrent Chemoradiation in Patients with Newly Diagnosed Glioblastoma.

PURPOSE: Iniparib is a purported prodrug causing cell death through intracellular conversion to nitro radical ions. We assessed the efficacy and safety of iniparib with standard radiotherapy and temozolomide in patients with newly diagnosed glioblastoma (GBM). PATIENTS AND METHODS: Adults meeting eligibility criteria were enrolled in this prospective, single-arm, open-label multi- institution phase II trial with median overall survival (mOS) compared with a historical control as the primary objective. A safety run-in component of radiotherapy + temozolomide + iniparib (n = 5) was followed by an efficacy study (n = 76) with the recommended phase II doses of iniparib (8.0 mg/kg i.v. twice/week with radiotherapy + daily temozolomide followed by 8.6 mg/kg i.v. twice/week with 5/28-day temozolomide). RESULTS: The median age of the 81 evaluable participants was 58 years (63% male). Baseline KPS was ≥ 80% in 87% of participants. The mOS was 22 months [95% confidence interval (CI), 17-24] and the HR was 0.44 (95% CI, 0.35-0.55) per-person-year of follow-up. The 2- and 3-year survival rates were 38% and 25%, respectively. Treatment-related grade 3 adverse events (AEs) occurred in 27% of patients; 9 patients had AEs requiring drug discontinuation including infusion-related reaction, rash, gastritis, increased liver enzymes, and thrombocytopenia. CONCLUSIONS: Iniparib is well tolerated with radiotherapy and temozolomide in patients with newly diagnosed GBM at up to 17.2 mg/kg weekly. The primary objective of improved mOS compared with a historical control was met, indicating potential antitumor activity of iniparib in this setting. Dosing optimization (frequency and sequence) is needed prior to additional efficacy studies.