Butowski, Nicholas

PURPOSE STELLAR (ClinicalTrials.gov identifier: NCT02796261 ) was a phase III, randomized, open-label trial of eflornithine + lomustine versus lomustine monotherapy in patients with recurrent grade 3 astrocytoma. METHODS At trial initiation, eligibility criteria included: age ≥18 years, anaplastic astrocytoma (2016 WHO CNS Tumor classification [WHO CNS4]), first recurrence ≥6 months after radiation and temozolomide (TMZ), Karnofsky performance status ≥70, and no imaging findings consistent with grade 4 glioblastoma. Random assignment (1:1) was stratified by isocitrate dehydrogenase ( IDH ) mutation, age, resection extent, and geography. Patients received eflornithine (2.8 g/m 2 orally, every 8 hours [2 weeks on, 1 week off]) + lomustine (90 mg/m 2 orally, once every 6 weeks), or lomustine monotherapy (110 mg/m 2 once every 6 weeks). The primary end point was overall survival (OS). RESULTS Among 343 patients randomly assigned across 74 sites in eight countries, there was no difference in survival between eflornithine + lomustine and lomustine monotherapy (median OS 23.4 v 20.3 months, hazard ratio [HR], 0.94). Following changes in classification and grading in the 2021 WHO CNS5, a subset analysis of patients with IDH- mutant, grade 3 astrocytoma (n = 196), defined in 2024, before unblinding, showed clinically meaningful improvements in median OS with eflornithine + lomustine versus lomustine monotherapy (34.9 v 23.5 months, HR, 0.64) and median progression-free survival (PFS, 15.8 v 7.2 months, HR, 0.57). No differences were observed among patients with CNS grade 4 disease. Grade ≥3 treatment-emergent adverse events of relevance were related to reversible myelosuppression (eflornithine + lomustine 42% v lomustine monotherapy 29% of patients) and hearing impairment (24% v 0%). No new safety signals were identified. CONCLUSION Clinically meaningful improvements were observed; eflornithine + lomustine doubled PFS and improved OS in patients with recurrent IDH -mutant, grade 3 astrocytoma, but not grade 4 tumors, after prior radiotherapy and TMZ, consistent with its cytostatic mechanism of action.

Abstract Background DNA methylation profiling can be used to robustly predict postsurgical outcomes and response to radiotherapy (RT) for meningioma patients. To allow for seamless integration of these complementary models into clinical practice, a practical framework is needed. Methods We leveraged a cohort of nearly 2000 surgically-treated meningiomas with DNA methylation profiling and clinical outcomes data. Existing methylation-based prediction models were dichotomized to yield four risk groups: low and high recurrent risk, each with RT sensitive and resistant subgroups. Risk groups were correlated with progression-free survival in the context of existing biomarkers including extent of resection and WHO grade. Results We first demonstrated that all risk groups benefit from gross total resection. All “high-risk, RT sensitive” tumors (n = 306, 15.7%) also benefited from adjuvant RT: after GTR, median PFS increased from 4.68 (4.13-9.48) years to not reached (P = .003); after subtotal resection (STR), from 2.12 (1.59-3.02) to 4.09 (3.41-not reached) years (P = .004). “Low-risk, RT sensitive cases” (n = 1207, 61.8%) also benefited from RT after STR (median PFS 7.39 (6.66-12.8) vs. 16.53 (10.35-not reached) years, P = .03), suggesting that RT be considered in these patients. Neither “low-risk RT resistant” (n = 84, 4.3%) nor “high-risk RT resistant” (n = 356, 18.2%) cases benefited from RT, and the latter group was associated with universally poor outcomes. Conclusions We identify methylation-defined risk groups of meningioma for which additional benefit is gained from adjuvant RT, leading to a clinical decision-making framework for straightforward integration of molecular models into clinical practice.

Abstract BACKGROUND STELLAR was a phase III randomized, open-label trial of eflornithine (ornithine decarboxylase inhibitor) with lomustine versus lomustine alone in patients with recurrent anaplastic astrocytoma (AA). We previously reported an overall survival (OS) and progression free survival (PFS) of the combination in the patients with grade 3 IDH-mutant astrocytoma. Here we report updated OS and PFS outcomes based on additional molecular classification and blinded independent central review (BICR). METHOD Eligibility included: age ≥ 18 years, AA (2016 WHO criteria) with first recurrence ≥ 6 months after radiation, KPS ≥ 70, and no imaging findings consistent with grade 4 glioblastoma. Patients received eflornithine (2.8 g/m2 TID Q 2/3 weeks) with lomustine (90 mg/m2 Q 6 weeks) (Arm A) or lomustine alone (110 mg/m2 Q 6 weeks) (Arm B). Primary endpoint was OS. RESULTS Updated molecular data resulted in re-classification of the 343 AA patients enrolled into 3 WHO 2021 defined tumor subtypes, 196 tumors were IDHmut, CDKN2A/B intact, consistent with diagnosis of astrocytoma, IDHmut, WHO grade 3, 33 tumors had CDKN2A/B loss consistent with astrocytoma, IDHmut, WHO grade 4, 106 tumors were IDHwt consistent with diagnosis of glioblastoma, IDHwt, WHO grade 4. Updated results strengthen initial conclusion that eflornithine plus lomustine resulted in significant survival benefit in the astrocytoma, IDHmut, WHO grade 3 group (mOS 34.9 vs, 23.5 months, HR = 0.64, stratified log rank p =0.0136). PFS with eflornithine was also improved (15.8 vs, 7.2 months, HR = 0.57, stratified log rank p =0.0113). BICR demonstrated a high correlation between investigator and centrally determined PFS (p=0.0305), and high correlation between OS and PFS (p=.0001). CONCLUSION The clinically meaningful OS and PFS benefits observed with eflornithine in the molecularly defined 2021 WHO CNS grade 3 astrocytomas is further confirmed and expanded based on additional molecular classification and BICR of PFS.

Abstract BACKGROUND Glioblastoma (GBM) is highly aggressive with poor prognosis, especially in recurrent cases where treatments are limited. Intra-arterial (IA) Yttrium-90 (Y90) microsphere therapy, FDA-approved for hepatocellular carcinoma, offers the potential for targeted radiotherapy in recurrent GBM (rGBM). The FRONTIER trial evaluated the safety and feasibility of IA Y90-glass microsphere treatment for rGBM under an FDA Investigational Device Exemption. Materials and METHODS This prospective, single-arm, multi-center study included patients with rGBM in non-dominant, non-eloquent regions. The primary endpoint was 30-day incidence of treatment-related limiting toxicities (primarily ≥grade 3 non-hematologic, with exclusions). Secondary endpoints included adverse event (AE) rate, neurological changes, technical success (PET absorbed dose within ±20% of target), and efficacy. Treatment regions, defined via cerebral angiography-MRI fusion to cover the recurrent lesion, were targeted with 40±4Gy. Post-treatment evaluations included MRI, Y90-PET, and neurological assessments. RESULTS The procedure was well-tolerated by all twelve subjects and discharge occurred the following day with no decline in neurologic status. No limiting toxicities or device-related AEs were reported. Five patients experienced 8 procedure-related AEs (6 Grade 1, 2 Grade 3). Technical success was 100%, with post-treatment Y90-PET derived median absorbed dose of 41.5 Gy to the treatment region (median volume 80.3 cc). The median tumor absorbed dose was considerably higher at 124.2 Gy (median tumor volume 5.8 cc), indicating preferential tumor perfusion. At 2 months, 67% had stable disease, and 33% showed reduced T1-contrast enhancing volume within the treated area. Median progression-free survival was 3.1 (95% CI 0.92-NE) and overall survival (OS) was 9.3 months (95% CI 5.0-NE) from Y90 treatment. Exploratory analysis revealed a significant OS benefit for patients receiving a tumor absorbed dose above the median (11.9 vs 5.7 months, p=0.0073). CONCLUSION Results from this initial cohort suggest IA Y90-microsphere therapy is technically feasible and well-tolerated in rGBM. Further investigation is warranted.

Abstract BACKGROUND Glioblastoma (GBM) is highly aggressive with poor prognosis, especially in recurrent cases where treatments are limited. Intra-arterial (IA) Yttrium-90 (Y90) microsphere therapy, CE-marked for hepatic neoplasia, offers the potential for targeted high-dose beta radiation in GBM by leveraging tumor hypervascularity. The FRONTIER trial evaluated the safety and feasibility of IA Y90-glass microsphere treatment for recurrent GBM. MATERIAL AND METHODS FRONTIER is a prospective, single-arm, multi-center study with Investigational Device Exemption approval from the US FDA. This initial cohort included patients with recurrent GBM in non-dominant, non-eloquent regions after 1-2 lines of prior therapy. The primary endpoint was the 30-day incidence of treatment-related toxicities (primarily ≥grade 3 non-hematologic, with exclusions). Secondary endpoints included overall treatment-related adverse events (AE), neurological function changes, technical success, and efficacy measures. Treatment regions, defined via cerebral angiography-MRI fusion to cover the recurrent lesion were targeted with 40±4Gy. Post-treatment evaluations included MRI, Y90-PET for absorbed dose distribution, and serial neurological assessments. Changes in post-contrast T1-enhancing tissue volume (T1C-vol) were tracked longitudinally. RESULTS Twelve subjects (67% male; average age 57 years) were treated. The procedure was well-tolerated with no limiting toxicities reported or device-related AEs reported. Five patients experienced 8 procedure-related AEs (6 Grade 1, 2 Grade 3). At discharge one day after treatment, there was no decline in neurologic status per NIHSS. Technical success was 100%, with post-treatment Y90-PET showing a median absorbed dose of 41.5 Gy (range 39.2-45.4) to the treatment region (median volume 80.3 cc [40.9-118.5]). The median tumor absorbed dose was significantly higher at 124.2 Gy (range 58.5-508.5) within a median tumor volume of 5.8 cc (range 0.5-55.4), indicating preferential tumor perfusion. At 1 month, the best response was partial response in 17% (2/12), stable disease (SD) in 67% (8/12), and progressive disease in 17% (2/12). At 2 months, 73% (8/11 evaluable) had SD, and 33% (4/12) showed reduced T1C-vol within the treated area. Median progression-free survival was 3.0 (95% CI 1.1-3.7) and median overall survival (OS) was 9.3 months (95% CI 5.0-NE) from Y90 treatment. Exploratory analysis revealed a significant OS benefit for patients receiving a tumor absorbed dose above the median (>124 Gy) compared to those below (13.1 vs 5.8 months, p=0.0054). CONCLUSION Results from this initial cohort of the FRONTIER trial suggest IA Y90 glass microsphere therapy is technically feasible and well-tolerated in patients with recurrent GBM. The observed dose-response relationship warrants further investigation of this modality as a potential treatment option.

Abstract BACKGROUND Recurrent anaplastic astrocytoma (AA), a grade 3 brain cancer, remains an unmet medical need. STELLAR was a phase III randomized, open-label trial of eflornithine (ornithine decarboxylase inhibitor) with lomustine versus lomustine alone, originally for patients with recurrent AA. However, as the WHO definition of AA evolved during trial conduct (e.g., excluding IDH wild-type disease), we determined results in both the original ITT population and by revised molecularly defined WHO 2021 diagnoses in pre-planned analyses. METHOD Key eligibility: age ≥ 18, AA (2016 WHO criteria), first recurrence ≥ 6 months after radiation and temozolomide, KPS ≥ 70, no imaging findings consistent with grade 4 glioblastoma. Stratification: IDH, age, resection extent, and geography. Patients were randomized to Arm A: eflornithine (2.8 g/m2 TID Q 2/3 weeks) with lomustine (90 mg/m2 Q 6 weeks) or Arm B: lomustine (110 mg/m2 Q 6 weeks). Primary endpoint was OS. The pre-specified hazard ratio (HR) goal was 0.667 based on projected median OS (mOS) increase to 18 months from 12 months. RESULTS 343 pts (172/171 Arms A/B) were randomized (105 sites, 8 countries). ITT analysis found no difference between arms (mOS 23.4 vs. 20.3 months, HR = 0.94). However, a pre-specified subset analysis in IDH mutant, 2021 WHO-defined grade 3 astrocytoma (n=194), showed significant improvement with eflornithine (mOS 34.9 vs. 23.5 months, HR = 0.64, log rank p = 0.016) and PFS (15.8 vs. 7.2 months, HR = 0.58, log rank p = 0.015). No difference was observed in the IDH wild-type subset. AEs were consistent with historic data. CONCLUSION There was no difference in OS between arms in the ITT analysis. However, medically meaningful and statistically significant OS and PFS benefits were observed with eflornithine in the pre-planned analysis of patients with molecularly defined 2021 WHO CNS grade 3 astrocytoma.

Abstract BACKGROUND Yttrium-90 (Y90) microsphere treatment is an FDA-approved endovascular radiotherapy for Hepatocellular Carcinoma; however, extra-hepatic experience is limited. The FRONTIER trial (NCT05303467) is a first-in-human study conducted under an IDE from the FDA evaluating the safety and feasibility of intra-arterial Y90 endovascular radiotherapy in patients with recurrent glioblastoma (rGBM). METHODS The primary endpoint is the incidence of treatment-related limiting toxicities through 30 days, in 12 patients with rGBM. Eight subjects (50% male) with non-dominant hemisphere rGBM have been enrolled to date, with 6 patients reported herein. The treatment region, encompassing the recurrent lesion, excluding eloquent regions, and defined using cerebral angiography-MRI fusion, was selectively targeted with 40±4Gy. Immediate post-treatment imaging included MRI to evaluate acute treatment-related effects and Y90-PET to evaluate the absorbed dose distribution. Neurological assessments were performed pre- and post-treatment. Analysis of post-contrast T1w enhancing tissue volume (T1wvol) inside and outside the treated region was performed longitudinally. RESULTS All patients tolerated the procedure well and were discharged the following day. No decrease in neurological function and no limiting toxicities were reported through 30 days. Post-treatment MRI revealed no device-related acute ischemia or hemorrhage. Mean absorbed dose to the treatment region was 42.1±2.4Gy, within 3% of the targeted value, suggesting technical feasibility. Mean tumor absorbed dose within the treatment region was 65.1±22.6Gy most likely due to increased tumor perfusion in the treatment region. A reduction in T1wvol at 2m was observed in 4/6 patients, with the remaining 2 patients showing increased T1wvol. Disease progression by T1wvol occurred more rapidly outside the treatment region than within. All patients received subsequent therapy, with 2 patients receiving surgery 82 and 120 days post Y90 treatment. CONCLUSION Interim results in this first-in-human feasibility study demonstrated technical feasibility and no limiting toxicities through 30 days. Enrollment is ongoing. These data warrant additional investigation.

Abstract Recurrent glioblastoma (rGBM) is a lethal brain tumor with no effective standard of care option and an extremely poor prognosis (median survival 6 to 8 months after first recurrence). Sonodynamic therapy (SDT) is a non-invasive combination therapy that utilizes a drug, aminolevulinic acid HCL (SONALA-001, ALA), and a device, the Exablate 4000 Type 2.0 to deliver MR-guided focused ultrasound (MRgFUS). Preclinical studies have shown that SDT activates protoporphyrin IX (PpIX) to generate reactive oxygen species that lead to tumor cell death and improved survival in animal glioma models. A first-in-human Phase 0 trial (NCT04559685) indicated that ALA SDT was well-tolerated and not associated with off-target cellular or radiographic effects and provided direct evidence of reactive oxygen species formation and targeted tumor cell death in recurrent high-grade glioma (rHGG). SDT-202 is a Phase 1/2 multicenter, open-label, dose escalation and expansion study (NCT05370508) of iv SONALA-001 (ALA) in combination with MRgFUS for SDT in patients with progressive or recurrent GBM. Dose escalation will include an initial drug and energy dose escalation of ALA SDT utilizing an accelerated titration design with single subject cohorts for dose level cohorts 1 and 2, followed by cohort 3 with 3 + 3 design for additional dose escalation. SONALA-001 is administered 6 to 9 hours prior to MRgFUS treatment. Once the RP2D is determined, Phase 2 dose expansion will enroll approximately 36 additional subjects to assess safety and efficacy of repeated cycles of ALA SDT at the optimized RP2D. Endpoints of this study are safety evaluation, maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and determination of pharmacokinetic (PK) parameters. The Phase 2 portion will further characterize safety of RP2D along with evaluation of efficacy with PFS6 (mRANO), ORR, CBR, DOR, DOCR, TTR, and OS. Preliminary PK and safety results will be presented.

Abstract Current standard of care for IDH-wildtype glioblastoma (GBM) includes maximal safe resection, adjuvant radiation, and chemotherapy with the alkylating agent temozolomide. A subset of gliomas treated with temozolomide develop somatic hypermutation with a predominance of C>T transitions due to the alkylation effects on DNA. However, the frequency of occurrence, clinical ramifications, and predictive biomarkers for developing temozolomide-induced hypermutation (TMZ-HM) in GBM are unknown. Here we performed comprehensive histopathologic, genomic, and epigenomic evaluation of paired initial and recurrent GBM from 106 patients. Seven patients (7%) developed hypermutation at time of first recurrence, while an additional five patients (5%) developed hypermutation at a subsequent recurrence. Patients who developed TMZ-HM had a significantly longer interval between initial surgery and first recurrence (27.8 vs. 9.9 months, p<0.001). In contrast to IDH-mutant gliomas where TMZ-HM is associated with poor prognosis, those patients with IDH-wildtype GBM who developed TMZ-HM had significantly longer overall survival from both initial surgery (67.9 vs. 20.3 months, p<0.001) and from time of recurrence after development of hypermutation (30.9 vs. 9.5 months, p=0.001). There was no difference in oncogenic alteration frequency in initial GBM that subsequently developed TMZ-HM. However, 4 specific CpG sites out of 12 total interrogated sites in the promoter region of MGMT (a DNA repair enzyme) and 5 specific CpG sites in the promoter region of KCNQ1DN (a negative regulator of c-Myc) were significantly more hypermethylated in those GBM that developed TMZ-HM. We then generated a weighted risk score across these CpG sites that can be used to prospectively identify GBM likely to develop TMZ-HM associated with favorable survival. In summary, patients with GBM that develop TMZ-HM follow a more favorable clinical course, and specific MGMT and KCNQ1DN promoter hypermethylation patterns could serve as a biomarker to identify these patients who may potentially benefit from extended alkylating chemotherapy treatment.

Importance The prognosis for patients with glioblastoma is poor following standard therapy with surgical resection, radiation, temozolomide, and tumor-treating fields. Objectives To evaluate the combination of veliparib and temozolomide in glioblastoma based on preclinical data demonstrating significant chemosensitizing effects of the polyadenosine diphosphate-ribose polymerase 1/2 inhibitor veliparib when combined with temozolomide. Design, Setting, and Participants Patients with newly diagnosed glioblastoma with MGMT promoter hypermethylation who had completed concomitant radiation and temozolomide were enrolled between December 15, 2014, and December 15, 2018, in this Alliance for Clinical Trials in Oncology trial. The data for this analysis were locked on April 21, 2023. Interventions Patients were randomized and treated with standard adjuvant temozolomide (150-200 mg/m 2 orally, days 1-5) combined with either placebo or veliparib (40 mg orally, twice daily, days 1-7) for 6 cycles. Main Outcomes and Measures The primary end point for the phase 3 portion of the trial was overall survival (OS). Results There were 322 patients randomized during the phase 2 accrual period and an additional 125 patients randomized to complete the phase 3 accrual, for a total of 447 patients in the final phase 3 analysis. The median (range) age for patients was 60 (20-85) years and 190 patients (42.5%) were female. The median OS was 24.8 months (90% CI, 22.6-27.7) for the placebo arm and 28.1 months (90% CI, 24.3-33.3) for the veliparib arm ( P = .17). The difference in survival did not meet the prespecified efficacy end point. However, there was a separation of the survival curves that favored the veliparib arm over 24 to 48 months of follow-up. The experimental combination was well tolerated with an acceptable elevation in grade 3 or 4 hematologic toxic effects. Conclusions and Relevance This trial found that adding veliparib to adjuvant temozolomide did not significantly extend OS in patients with newly diagnosed, MGMT -hypermethylated glioblastoma. Trial Registration ClinicalTrials.gov Identifier: NCT02152982