IWAMOTO, FABIO MASSAITI

Abstract PURPOSE Age over 40 years is commonly regarded as a “high risk” feature and potential indication for adjuvant chemoradiotherapy for patients with lower grade glioma in most clinical practice guidelines. However, these recommendations are based on retrospective observations and their subsequent incorporation into legacy clinical trials. It is unclear whether age remains a relevant prognostic factor in the molecular era. METHODS The Prospective Gliomas Research [PROGRES] Database contains individual patient-level data from 11 prospective clinical trials or observational registries, including seven international trials from the RTOG, EORTC, or Alliance cooperative groups. We determined the association of age with progression-free survival (PFS) in low grade or anaplastic glioma, stratified by isocitrate dehydrogenase (IDH1/2) status. We validated our findings in a separate multi-institutional retrospective cohort (Retrospective Glioma Research [REGRES] Database). RESULTS We identified 1,619 and 1,271 eligible patients in the PROGRES and REGRES cohorts, respectively. IDH-wildtype tumors were more common in patients >40 years (38% vs, 5%, odds ratio: 11.3 [95%CI 6.5 – 19.7]). Age was associated with PFS in IDH-wildtype (5-year PFS: 6% vs, 24%, P =.003) but not in IDH-mutant glioma (60% vs, 59%, P = 0.22, P value of interaction <.001). In IDH-wildtype tumors, older age predicted aggressive molecular features, including TERT promoter mutation (65% vs, 28%), EGFR amplification (41% vs, 15%), and chromosome +7/-10 alteration (57% vs, 25%). Age was not predictive of a benefit from chemoradiotherapy versus radiotherapy alone in IDH-mutant glioma. CONCLUSION Older age is a putative surrogate for IDH-wildtype status, but was not an independent predictor of progression in IDH-mutant lower grade glioma and did not predict benefit from chemoradiotherapy. In the absence of additional clinical or molecular risk factors, age alone should not be considered an indication for administration or deferral adjuvant treatment. Practice guidelines should be revised to reflect contemporary prognostic factors in the molecular era.

Introduction: Primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS), traditionally referred to as primary CNS lymphoma (PCNSL), is a rare type of primary large B-cell lymphoma of immune-privileged sites with significantly poorer prognosis than systemic DLBCL. Genetic profiles of PCNSL were widely studied, whereas the tumor microenvironment has not been well characterized. Patients and Methods: A series of molecular analyses were performed using DLBCL FFPE tissues collected by the International Lymphoma Consortium. First, multiplex fluorescent immunohistochemistry (mfIHC) using antibodies for CD20, PAX5, CD3, CD4, CD8, FOXP3, CD45RO, CD68, CD56, PD-1, PD-L1, PD-L2, and CTLA-4 was performed on PCNSL tissues from 121 immunocompetent patients and de novo systemic DLBCL tissues from 405 patients. Digital quantification results for 405 patients with EBV-negative systemic DLBCL or primary testicular (PT) DLBCL have been reported previously. The preliminary mfIHC results of PCNSL will be presented. Second, mfIHC for multiple B cell biomarkers, CD3, CD4, CD8, CD68, CD163, CD11c, and CD31 were performed for 10 PCNSL validation cases, 24 PT-DLBCL and 451 systemic DLBCL tissues (unpublished). Third, RNA samples were extracted and sequenced for the targeted 1408 cancer-associated genes, successfully in 142 PCNSL cases, including 102 cases evaluated by either of these two mfIHC panels and additional 40 PCNSL cases, Results: First, in the first large mfIHC cohort, PCNSLs compared with de novo systemic nodal or extranodal DLBCL had significantly higher mean/median CD56+ cell densities whereas lower T cell densities (consistent with the immune privilege), as well as lower CD45RO+, PD-1+, and FOXP3+ percentages in T cells whereas higher CD4¯CD8¯ double-negative percentages in T cells. Prognostic analysis in the PCNSL cohort showed that high CD56+ cell densities and high CD45RO+CD8+ T cell densities were associated with significantly poorer and better patient survival, respectively, which are opposite to their prognostic effects in systemic DLBCL as previously reported. Twelve patients had very high PD-L1 expression in B cells and significantly poorer survival in the PCNSL cohort. Second, as validation, the 10 PCNSL cases in the second mfIHC study showed significantly less T cells than systemic DLBCL and PT-DLBCL cases, and low CD8 T cell densities and having low percentage of CD8 T cells adjacent to tumor cells were associated with significantly poorer survival. Immunofluorescence landscapeand spatial analysisrevealed significant differences in immune privilege between PCNSL and PT-DLBCL. Third, gene expression profiling analysis by targeted RNA-seq identified 282 significantly differentially expressed genes between PCNSL and systemic DLBCL, referred to as the PCNSL signature. Unsupervised clustering analysis divided the PCNSL cohort into two clusters, which had no significant difference in MYD88 mutation frequencies analyzed at the mRNA level. Importantly, the cluster with higher expression of many neural glial genes in the PCNSL signature had significantly poorer survival, which remained significant in multivariate analysis adjusting for clinical factors and/or treatments, two PCNSL subcohorts (as training and validation cohorts), and methotrexate-treated patients. NCAM1 (Neural Cell Adhesion Molecule 1, encoding CD56) was among the upregulated PCNSL signature genes, explaining the poorer prognosis associated with higher CD56+ cell densities in PCNSL by the mfIHC analysis. Summary: Our studies represent the largest immunophenotypic and gene expression profiling studies currently in PCNSL, a rare type of primary DLBCL of immune-privileged sites. Multiplex immunofluorescence revealed the immune landscape in PCNSL in comparison with systemic and testicular DLBCL, and identified prognostic immune biomarkers. Targeted RNA-seq identified a PCNSL gene signature enriched with neuronal-glial genes and showing significant prognostic effect in PCNSL. These novel findings in the PCNSL microenvironment warrant further studies.

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 Standard of care (SOC) for ndGBM begins with maximal safe resection followed by adjuvant radiotherapy and temozolomide, and maintenance temozolomide. IGV-001 is an autologous biologic-device combination immunotherapy for the treatment of ndGBM that consists of autologous GBM tumor cells and an antisense oligonucleotide against IGF-1R mRNA, irradiated and administered via biodiffusion chambers implanted in the abdomen. In a phase 1b study, IGV-001 was well tolerated without unexpected adverse events in subjects with ndGBM. Multiple efficacy signals were observed, including significant improvements in progression-free survival (PFS), overall survival (OS), radiographic evidence of tumor response, and changes in immune response biomarkers. Here, we present early safety data from the phase 2b randomized, multicenter, double-blind, placebo-controlled study (NCT04485949) designed to assess efficacy and safety of IGV-001 in subjects with ndGBM across 20 sites in the United States. After surgical resection, subjects were randomized 2:1 and treated with IGV-001 or placebo followed by SOC. The primary outcome is PFS, defined as the time from randomization to first progression, as determined by blinded central radiology review, or death. Secondary outcomes include OS, defined as the time from randomization to death due to any cause, and safety. As of May 22, 2024, 99 subjects were randomized and 95 implanted with IGV-001 or placebo plus SOC. A total of 39/45 (86.7%) subjects had sufficient follow-up time after initiated treatment with concurrent radiation and temozolomide. Nine of 72 randomized (12.5%) discontinued treatment, including 7 who stopped during the SOC treatment period. None ceased treatment for adverse events, protocol deviations, or death. A total of 11/72 (15.3%) randomized subjects discontinued the study after randomization. A review of blinded safety data did not show any emerging risk and supports no change to the benefit-risk profile of IGV-001 versus placebo. Updated data will be presented.

Abstract Background IDH-wild type (-wt) status is a prerequisite for the diagnosis of glioblastoma (GBM); however, IDH-wt gliomas with low-grade or anaplastic morphology have historically been excluded from GBM trials and may represent a distinct prognostic entity. While alkylating agent chemotherapy improves overall survival (OS) and progression-free survival (PFS) for IDH-wt GBM and also IDH-mutant gliomas, irrespective of grade, the benefit for IDH-wt diffuse histologic lower-grade gliomas is unclear. Methods We performed a meta-analysis of randomized clinical trials for World Health Organization (WHO) grades 2–3 gliomas (2009 to present) to determine the effect of alkylating chemotherapy on IDH-wt and -mutant gliomas using a random-effects model with inverse-variance pooling. Results We identified 6 trials with 1204 patients (430 IDH-wt, 774 IDH-mutant) that evaluated alkylating chemoradiotherapy versus radiotherapy alone, allowing us to perform an analysis focused on the value of adding alkylating chemotherapy to radiotherapy. For patients with IDH-wt tumors, alkylating chemotherapy added to radiotherapy was associated with improved PFS (HR:0.77 [95% CI: 0.62–0.97], P = .03) but not OS (HR:0.87 [95% CI: 0.64–1.18], P = .17). For patients with IDH-mutant tumors, alkylating chemotherapy added to radiotherapy improved both OS (HR:0.52 [95% CI: 0.42–0.64], P < .001) and PFS (HR = 0.47 [95% CI: 0.39–0.57], P < .001) compared to radiotherapy alone. The magnitude of benefit was similar for IDH-mutant gliomas with or without 1p19q-codeletion. Conclusions Alkylating chemotherapy reduces mortality by 48% and progression by 53% for patients with IDH-mutant gliomas. Optimal management of IDH-wt diffuse histologic lower-grade gliomas remains to be determined, as there is little evidence supporting an OS benefit from alkylating chemotherapy.

Abstract RTOG 9402 demonstrated procarbazine (P), lomustine (CCNU/C), and vincristine (V), collectively PCV, added to radiation therapy significantly improved survival for patients with newly diagnosed anaplastic oligodendroglial tumors. The improvement was most pronounced in 1p19q codeleted cases, and to a lesser extent, IDH-mutant cases, with no survival benefit in cases with neither biomarker. Analogous results were observed in other phase III trials. However, vincristine (V) can cause substantial toxicity and requires intravenous administration, both negatively affecting quality of life, with debatable contribution to PCV efficacy. As a randomized trial comparing PCV to PC is unlikely to be conducted, we explored correlations between survival and V-dosing in patients randomized to PCV in RTOG 9402. We performed post-hoc analyses of all evaluable participants (n = 143) randomized to PCV on RTOG 9402, supplemented by restricting the analyses to the chemosensitive molecular subsets (IDH-mutant and/or 1p/19q codeleted, n = 118). Total V dose by quartile (Q) was calculated. Survival from six months post-randomization was compared among V dose groups, adjusting for age, extent of resection (EOR), and Karnofsky Performances Status (KPS) in a Cox proportional hazards model. Higher V dose received correlated with longer survival in multivariate analyses (n = 134, median-Q3 vs. < Q1, HR 0.40 (0.22, 0.73), p = 0.003; ≥Q3 vs. < Q1, HR 0.39 (0.22, 0.72), p = 0.002). Excluding chemoresistant cases (IDH wild-type/not codeleted), survival was also significantly longer in evaluable participants receiving the highest doses of vincristine (≥Q3 vs. < Q1 HR 0.42 (0.21,0.81), p = 0.01). In this post-hoc analysis, higher overall V-dose received correlated with longer survival in evaluable patients with anaplastic oligodendroglial tumors receiving PCV chemotherapy in RTOG 9402. Of note, as vincristine dosing was not assigned by randomization, confounding due to differences in patient characteristics among V dose groups cannot be ruled out. Caution should be exercised when considering discarding V from the PCV regimen.

Abstract BACKGROUND Glioblastoma (GBM) is an aggressive central nervous system (CNS) malignancy with poor prognosis. TTFields are electric fields that exert physical forces to disrupt cellular processes critical for cancer cell viability. TTFields therapy is approved for recurrent and newly diagnosed GBM, and pleural mesothelioma. We report long-term safety data from pediatric, adult and elderly patients with CNS malignancies receiving TTFields, from a global post-marketing surveillance (PMS) dataset. METHODS Unsolicited PMS data were collected from patients receiving TTFields (October 2011–October 2022). AEs were categorized using MedDRA version 25.1, and data stratified by age group (< 18, 18–65, and > 65 years). RESULTS Overall, 25,898 patients from the US, Europe, Israel, and Japan were included. Of these, 93 (0.4%) were < 18 years (pediatric), 17,817 (69%) were 18–65 years (adult), and 7,808 (30%) were > 65 years (elderly). Two-thirds (66%) of all patients were male. Demographic characteristics were therefore consistent with a typical GBM population. Of pediatric patients, 62% experienced ≥ 1 AE, with 53% related to TTFields. This was comparable in adults (72% and 56%, respectively), and elderly patients (75% and 57%, respectively). The most common TTFields-related AEs were skin reaction (pediatric: 39%; adult: 42%; elderly: 45%), heat (warmth) sensation (pediatric: 14%; adult: 12%; elderly: 12%), and electric (tingling) sensation (pediatric: 10%; adult: 15%; elderly: 10%). All-cause serious AEs occurred in 14%, 21% and 25% of pediatric, adult and elderly patients, respectively. No systemic toxicities were reported, regardless of age. CONCLUSIONS These long-term, real-world PMS data demonstrate that TTFields has a tolerable safety profile in pediatric, adult and elderly patients with CNS malignancies, with no new safety signals in any age group. Most AEs were localized skin reactions which are manageable. These data provide supportive evidence of the safety and broad applicability of TTFields, regardless of patient age.

Abstract AIMS Glioblastoma (GBM) has a poor prognosis, which is compounded by an increase in treatment-related toxicity with age. TTFields are electric fields that exert physical forces to disrupt cellular processes critical for cancer cell viability. Subgroup analysis of the phase 3 EF-14 study demonstrated TTFields therapy to be well-tolerated in patients ≥65 years with newly diagnosed (nd) GBM. We report safety data in elderly patients from a global post- marketing surveillance (PMS) analysis of patients with central nervous system (CNS) malignancies receiving TTFields. METHOD PMS data was collected from patients receiving TTFields (October 2011–March 2022) in North America, Europe, Middle East, Africa, and Japan. Adverse events (AEs) were categorized using MedDRA version 25.1. RESULTS Overall, 25,898 patients were included (diagnoses: ndGBM [68%], recurrent GBM [26%], anaplastic astrocytoma/oligodendroglioma [4%], other [2%]). Of these, 7808 patients (30%) were elderly (>65 years). 75% of elderly patients experienced ≥1 AE, with 57% related to TTFields; comparable frequencies to the overall population (73% and 56%, respectively). The most common treatment-related AE in elderly patients was skin reaction (45%; overall population: 43%). Incidence of treatment-related fall and fracture in elderly patients was 1% and <1%, respectively. Incidence of treatment-related ‘quality-of-life decreased’ was 2% (elderly and overall). No systemic toxicities were reported, regardless of age group. CONCLUSIONS These real-world data demonstrate TTFields has a tolerable safety profile in elderly patients with CNS malignancies, consistent with elderly subgroup data from EF-14, and with no new safety signals. Most AEs were localised, manageable, mild–moderate skin reactions.

Abstract BACKGROUND TTFields are electric fields that exert physical forces to disrupt cellular processes critical for cancer cell viability and tumor progression. TTFields therapy is approved for adults with recurrent (r) and newly diagnosed (nd) glioblastoma (GBM), based on the phase 3 EF-11 (TTFields 200 kHz) and EF-14 studies (TTFields therapy 200 kHz + temozolomide), respectively, which showed clinical benefit without increase in systemic adverse events (AEs). Pediatric patients were not included in the EF-11 and EF-14 studies. Here, we present pediatric safety data from an updated global post-marketing surveillance (PMS) analysis of patients with brain tumors treated with TTFields therapy, over an 11-year timeframe. METHODS Unsolicited PMS data from patients with brain tumors who received TTFields therapy from October 2011-March 2022 in North America, Europe, Middle East, Africa, and Japan were included. AEs were categorized using MedDRA version 25.1. RESULTS Overall, 25,898 patients were included. Diagnoses were ndGBM (68%), rGBM (26%), anaplastic astrocytoma/oligodendroglioma (4%) and other (2%). Two-thirds of patients were male. The analysis included 93 (0.4%) pediatric/adolescent patients (<18 years). In pediatric patients, 62% experienced ≥1 AE, with 53% related to TTFields therapy; these values were comparable with the overall population (73% and 56%, respectively). The most common treatment-related AEs in pediatric patients were: skin reaction (39%), heat sensation (14%), and headache (12%); and in the overall population were: skin reaction (43%), electric sensation (14%), and heat sensation (12%). CONCLUSIONS This long-term, global, real-world data analysis, including pediatric patients with brain tumors, demonstrates a tolerable safety profile of TTFields therapy, consistent with pivotal clinical studies. There were no major differences in AEs between pediatric and adult patients and no new safety signals identified in the pediatric population. Consistent with the overall dataset, most AEs in pediatric patients were localized mild–moderate skin events, which are typically easily managed.

2049 Background: Glioblastoma (GBM) has a poor prognosis. Standard treatments are associated with systemic toxicity, further increasing the disease burden in this patient population. Tumor Treating Fields (TTFields) are electric fields that disrupt cancer cell processes which affect cancer cell viability, and are generated by a portable, wearable device which is locoregional and noninvasive. TTFields therapy was approved by the FDA for the treatment of newly diagnosed (nd) and recurrent (r) GBM based on the phase 3 EF-14 (TTFields therapy 200 kHz + temozolomide) and EF-11 (TTFields 200 kHz) studies, respectively. TTFields therapy is also approved for pleural mesothelioma. We report an updated global, post-marketing surveillance (PMS) safety analysis of patients with CNS malignancies treated with TTFields therapy over an 11-year timeframe. This analysis represents the largest dataset of TTFields therapy use to date. Methods: Unsolicited safety data were collected from routine post-marketing activities for patients (N = 25,898) in North America, Europe, Middle East and Africa and Japan, from October 2011 to March 2022. AEs were stratified by diagnosis, age, and sex and categorized using MedDRA version 25.1. Results: Diagnoses were ndGBM (68%), rGBM (26%), anaplastic astrocytoma/oligodendroglioma (4%) and other (2%). Baseline demographics were reflective of real-world practice: median (range) age was 59 (3–103) years; two-thirds of patients were male. Most (69%) patients were 18–65 years; 0.4% were < 18 years, and 30% were > 65 years. All-cause and TTFields-related AEs occurred in 18,798 (73%) and 14,599 (56%), patients, respectively. The most common device-related AE was skin reaction (43% patients overall). There were no major differences in occurrence of this AE between pediatric, adult, and elderly groups (39%, 42%, and 45%, respectively), or between males and females (41% and 46%, respectively). The incidence of device-related skin reactions was higher in ndGBM than rGBM (46% vs 34%, respectively), in line with previous reports. Only 405 (2%) of patients overall reported an AE of treatment-related ‘quality-of-life decreased’. In line with the phase 3 studies, there were no treatment-related systemic AEs. Conclusions: In this updated global PMS safety analysis, TTFields therapy demonstrated a tolerable safety profile in patients with CNS malignancies, with no new safety findings. In line with previous real-world and clinical data, most AEs were localized, non-serious skin events, which were consistent between age groups. Such events can typically be managed easily using prophylaxis and topical therapies, together with optimization of caregiver techniques. Importantly, no TTFields therapy-related systemic AEs were detected.