Sulman, Erik P.

Abstract Therapeutic advances for glioblastoma have been minimal over the past 2 decades. In light of the multitude of recent phase III trials that have failed to meet their primary endpoints following promising preclinical and early-phase programs, a Society for Neuro-Oncology Think Tank was held in November 2020 to prioritize areas for improvement in the conduct of glioblastoma clinical trials. Here, we review the literature, identify challenges related to clinical trial eligibility criteria and trial design in glioblastoma, and provide recommendations from the Think Tank. In addition, we provide a data-driven context with which to frame this discussion by analyzing key study design features of adult glioblastoma clinical trials listed on ClinicalTrials.gov as “recruiting” or “not yet recruiting” as of February 2021.

Abstract Background This secondary image analysis of a randomized trial of proton radiotherapy (PT) versus photon intensity-modulated radiotherapy (IMRT) compares tumor progression based on clinical radiological assessment versus Response Assessment in Neuro-Oncology (RANO). Methods Eligible patients were enrolled in the randomized trial and had MR imaging at baseline and follow-up beyond 12 weeks from completion of radiotherapy. “Clinical progression” was based on a clinical radiology report of progression and/or change in treatment for progression. Results Of 90 enrolled patients, 66 were evaluable. Median clinical progression-free survival (PFS) was 10.8 (range: 9.4–14.7) months; 10.8 months IMRT versus 11.2 months PT (P = .14). Median RANO-PFS was 8.2 (range: 6.9, 12): 8.9 months IMRT versus 6.6 months PT (P = .24). RANO-PFS was significantly shorter than clinical PFS overall (P = .001) and for both the IMRT (P = .01) and PT (P = .04) groups. There were 31 (46.3%) discrepant cases of which 17 had RANO progression more than a month prior to clinical progression, and 14 had progression by RANO but not clinical criteria. Conclusions Based on this secondary analysis of a trial of PT versus IMRT for glioblastoma, while no difference in PFS was noted relative to treatment technique, RANO criteria identified progression more often and earlier than clinical assessment. This highlights the disconnect between measures of tumor response in clinical trials versus clinical practice. With growing efforts to utilize real-world data and personalized treatment with timely adaptation, there is a growing need to improve the consistency of determining tumor progression within clinical trials and clinical practice.

AbstractBackgroundIt remains unknown how the COVID-19 pandemic has changed neuro-oncology clinical practice, training, and research efforts.MethodsWe performed an international survey of practitioners, scientists, and trainees from 21 neuro-oncology organizations across 6 continents, April 24–May 17, 2020. We assessed clinical practice and research environments, institutional preparedness and support, and perceived impact on patients.ResultsOf 582 respondents, 258 (45%) were US-based and 314 (55%) international. Ninety-four percent of participants reported changes in their clinical practice. Ninety-five percent of respondents converted at least some practice to telemedicine. Ten percent of practitioners felt the need to see patients in person, specifically because of billing concerns and pressure from their institutions. Sixty-seven percent of practitioners suspended enrollment for at least one clinical trial, including 62% suspending phase III trial enrollments. More than 50% believed neuro-oncology patients were at increased risk for COVID-19. Seventy-one percent of clinicians feared for their own personal safety or that of their families, specifically because of their clinical duties; 20% had inadequate personal protective equipment. While 69% reported increased stress, 44% received no psychosocial support from their institutions. Thirty-seven percent had salary reductions and 63% of researchers temporarily closed their laboratories. However, the pandemic created positive changes in perceived patient satisfaction, communication quality, and technology use to deliver care and mediate interactions with other practitioners.ConclusionsThe pandemic has changed treatment schedules and limited investigational treatment options. Institutional lack of support created clinician and researcher anxiety. Communication with patients was satisfactory. We make recommendations to guide clinical and scientific infrastructure moving forward and address the personal challenges of providers and researchers.

Abstract Background To determine if proton radiotherapy (PT), compared to intensity-modulated radiotherapy (IMRT), delayed time to cognitive failure in patients with newly diagnosed glioblastoma (GBM). Methods Eligible patients were randomized unblinded to PT vs IMRT. The primary endpoint was time to cognitive failure. Secondary endpoints included overall survival (OS), intracranial progression-free survival (PFS), toxicity, and patient-reported outcomes (PROs). Results A total of 90 patients were enrolled and 67 were evaluable with median follow-up of 48.7 months (range 7.1-66.7). There was no significant difference in time to cognitive failure between treatment arms (HR, 0.88; 95% CI, 0.45-1.75; P = .74). PT was associated with a lower rate of fatigue (24% vs 58%, P = .05), but otherwise, there were no significant differences in PROs at 6 months. There was no difference in PFS (HR, 0.74; 95% CI, 0.44-1.23; P = .24) or OS (HR, 0.86; 95% CI, 0.49-1.50; P = .60). However, PT significantly reduced the radiation dose for nearly all structures analyzed. The average number of grade 2 or higher toxicities was significantly higher in patients who received IMRT (mean 1.15, range 0-6) compared to PT (mean 0.35, range 0-3; P = .02). Conclusions In this signal-seeking phase II trial, PT was not associated with a delay in time to cognitive failure but did reduce toxicity and patient-reported fatigue. Larger randomized trials are needed to determine the potential of PT such as dose escalation for GBM and cognitive preservation in patients with lower-grade gliomas with a longer survival time.

Abstract Background We investigated differences in radiation-induced grade 3+ lymphopenia (G3+L), defined as an absolute lymphocyte count (ALC) nadir of <500 cells/µL, after proton therapy (PT) or X-ray (photon) therapy (XRT) for patients with glioblastoma (GBM). Methods Patients enrolled in a randomized phase II trial received PT (n = 28) or XRT (n = 56) concomitantly with temozolomide. ALC was measured before, weekly during, and within 1 month after radiotherapy. Whole-brain mean dose (WBMD) and brain dose-volume indices were extracted from planned dose distributions. Univariate and multivariate logistic regression analyses were used to identify independent predictive variables. The resulting model was evaluated using receiver operating characteristic (ROC) curve analysis. Results Rates of G3+L were lower in men (7/47 [15%]) versus women (19/37 [51%]) (P < 0.001), and for PT (4/28 [14%]) versus XRT (22/56 [39%]) (P = 0.024). G3+L was significantly associated with baseline ALC, WBMD, and brain volumes receiving 5‒40 Gy(relative biological effectiveness [RBE]) or higher (ie, V5 through V40). Stepwise multivariate logistic regression analysis identified being female (odds ratio [OR] 6.2, 95% confidence interval [CI]: 1.95‒22.4, P = 0.003), baseline ALC (OR 0.18, 95% CI: 0.05‒0.51, P = 0.003), and whole-brain V20 (OR 1.07, 95% CI: 1.03‒1.13, P = 0.002) as the strongest predictors. ROC analysis yielded an area under the curve of 0.86 (95% CI: 0.79–0.94) for the final G3+L prediction model. Conclusions Sex, baseline ALC, and whole-brain V20 were the strongest predictors of G3+L for patients with GBM treated with radiation and temozolomide. PT reduced brain volumes receiving low and intermediate doses and, consequently, reduced G3+L.

LBA2010 The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Sunday, June, 2, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Sunday edition of ASCO Daily News.

1 The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Sunday, June, 2, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Sunday edition of ASCO Daily News.

Abstract Purpose: Glioblastoma is the most frequent and lethal primary brain tumor. Development of novel therapies relies on the availability of relevant preclinical models. We have established a panel of 96 glioblastoma patient-derived xenografts (PDX) and undertaken its genomic and phenotypic characterization. Experimental Design: PDXs were established from glioblastoma, IDH-wildtype (n = 93), glioblastoma, IDH-mutant (n = 2), diffuse midline glioma, H3 K27M-mutant (n = 1), and both primary (n = 60) and recurrent (n = 34) tumors. Tumor growth rates, histopathology, and treatment response were characterized. Integrated molecular profiling was performed by whole-exome sequencing (WES, n = 83), RNA-sequencing (n = 68), and genome-wide methylation profiling (n = 76). WES data from 24 patient tumors was compared with derivative models. Results: PDXs recapitulate many key phenotypic and molecular features of patient tumors. Orthotopic PDXs show characteristic tumor morphology and invasion patterns, but largely lack microvascular proliferation and necrosis. PDXs capture common and rare molecular drivers, including alterations of TERT, EGFR, PTEN, TP53, BRAF, and IDH1, most at frequencies comparable with human glioblastoma. However, PDGFRA amplification was absent. RNA-sequencing and genome-wide methylation profiling demonstrated broad representation of glioblastoma molecular subtypes. MGMT promoter methylation correlated with increased survival in response to temozolomide. WES of 24 matched patient tumors showed preservation of most genetic driver alterations, including EGFR amplification. However, in four patient–PDX pairs, driver alterations were gained or lost on engraftment, consistent with clonal selection. Conclusions: Our PDX panel captures the molecular heterogeneity of glioblastoma and recapitulates many salient genetic and phenotypic features. All models and genomic data are openly available to investigators.

Abstract BACKGROUND While glioblastoma (GBM) is more prevalent in males, studies show that females with GBM tend to have longer overall survival (OS) than males. Pretreatment neutrophil to lymphocyte ratio (NLR) has also proven to be prognostic in GBM, with lower NLR having favorable outcomes. This secondary analysis of a prospective randomized trial of proton vs. photon intensity modulated radiotherapy aims to explore the interaction of gender and NLR on GBM outcomes. METHODS Analysis was performed on the full patient population. Kaplan-Meier methods estimated OS with censoring at last follow-up for those who were alive. Univariate (UVA) and multivariate (MVA)Cox proportional hazards models assessed predictors of OS. RESULTS Of 90 patients, 77 were included (43 males; 34 females) with median age of 52 years (range: 26–82 years). Median OS was longer for females than males (30.7 vs 18.2 months, p=0.004). On UVA, patients with NLR below median value (NLR= 3.1) tended to have longer OS than those above median, though not meeting statistical significance (23.1 vs. 17.9 months, p=0.051). Difference in OS was statistically significant in females (OS 36.4 months NLR >median vs. 16.7 months NLR< median, p=0.002), but not in males (OS 17.8 months NLR >median vs. 19.1 NLR< median, p=0.95). MVA analysis was consistent, with female gender predicting reduced hazard ratio (HR) (0.28, p=0.034) and females with below median NLR showing a reduced HR over those with above median (0.28, p=0.005). Again, males did not benefit (HR 0.90, p=0.77). CONCLUSION Consistent with prior publications, females and all patients with lower pre-treatment NLR with newly diagnosed GBM had longer OS. However, combining these two factors revealed that the benefits from lower pre-treatment NLR were conferred only in females with no impact on males. This different impact of NLR between genders may suggest innate immune differences in gender during response to malignancy.

Abstract PURPOSE/OBJECTIVE Dose constraints for re-irradiation of recurrent primary brain tumors are not well-established, especially for treatment volumes too large for stereotactic radiotherapy. This prospective trial was performed to test dose constraints for conventionally-fractionated re-irradiation of recurrent primary brain tumors MATERIALS/METHODS A single-institution, prospective trial of 21 adults with recurrent brain tumors was performed. Electronic dosimetry records from the first course of radiation (RT1) were obtained and deformed onto the simulation CT for the second course of radiation (RT2). Treatment plans for RT2 were developed that met protocol-assigned dose constraints for RT2 alone and the composite dose of RT1+RT2. Dose constraints were also based on histology and interval since RT1. The primary endpoint was the rate of symptomatic brain necrosis after RT2. RESULTS Twenty one adults enrolled from March 2017 to May 2018. Twelve had glioblastoma, four had oligodendroglioma, two had anaplastic astrocytoma, and one each had choroid plexus papilloma, hemangiopericytoma, and pleomorphic xanthroastrocytoma (PXA). Twenty patients were treated with VMAT and one was treated with proton CSI. Median RT1-RT2 interval was 45 months (range, 9–141 months). Median RT2 dose was 42.8 Gy (range, 17.5–60 Gy). Median PTV volume was 208 cc (range, 7–1537 cc). Median imaging followup was 9 months (range, 1–20 months). Two months after RT2, the patient with PXA developed a trapped temporal horn adjacent to the RT2 treatment volume; pathology from emergent resection revealed necrotic brain tissue. The patient recovered fully and lived another 18 months until dying of disease progression. No other patient developed symptomatic radionecrosis. Median overall survival from RT2 for all patients was 11 months (range, 3–20 months). CONCLUSION Re-irradiation can be performed with conventionally fractionated schemes. Given the low rate of symptomatic radionecrosis, the dose constraints described here are a starting point for future studies of conventionally fractionated re-irradiation.