Response Assessment In Neuro-Oncology Criteria Research Articles

FLAIR MRI sequence synthesis using squeeze attention generative model for reliable brain tumor segmentation

Manual segmentation of brain tumors using structural magnetic resonance imaging (MRI) is an arduous and time-consuming task. Therefore, automatic and robust segmentation will considerably influence neuro-oncological clinical trials by reducing excessive manual annotation time. Herein, we propose a deep learning model that automatically segments brain tumors even in cases of missing MRI sequences, which are common in practical clinical settings. To address this issue, we enhance a generative adversarial network (GAN) by incorporating a squeeze-and-excitation (SE) attention module into its generator and a PatchGAN into its discriminator. The SE module recalibrates channel responses by explicitly modeling interdependencies, enabling the network to focus on critical regions such as tumor areas. Our proposed generative model is optimized using a combination of adversarial, structural similarity, and mean absolute error losses to synthesize missing MRI sequences more effectively. This enhancement allows our model to synthesize the missing MRI sequence (fluid attenuated inversion recovery [FLAIR]) by leveraging information from other available sequences (T1-weighted, T2-weighted, or contrast-enhanced T1-weighted [T1ce]). For the segmentation task, we employ an optimized nnU-Net model, which is trained using existing sequences and evaluated using both available and synthesized sequences (including missing ones), mimicking real-world scenarios where often only limited MRI sequences are available or usable. Our findings reveal a notable enhancement in brain tumor segmentation, as indicated by a significant increase in overall the Dice similarity coefficient (DSC) from 0.688% (when FLAIR is missing) to 0.873% (when using synthesized FLAIR derived from T2). This improvement brings the segmentation performance closer to what was achieved when real FLAIR was available, where the DSC reaches 0.901%. Moreover, our synthesizing model was also tested on two additional datasets: the BraTS 2020 validation set and BraTS Africa 2023 training set, which produces results comparable to those of BraTS 2021, thereby proving its robustness and generalizability. In addition, the resulting tumor segmentations are subsequently employed to assess the response to treatment in cases where all sequences were available and when synthesis was employed, according to response assessment in neuro-oncology criteria.

MRI and 18F-FET PET for Multimodal Treatment Monitoring in Patients with Brain Metastases: A Cost-Effectiveness Analysis.

PET using the radiolabeled amino acid O-(2-[18F]fluoroethyl)-l-tyrosine (18F-FET) has been shown to be of value for treatment monitoring in patients with brain metastases after multimodal therapy, especially in clinical situations with equivocal MRI findings. As medical procedures must be justified socioeconomically, we determined the effectiveness and cost-effectiveness of 18F-FET PET for treatment monitoring of multimodal therapy, including checkpoint inhibitors, targeted therapies, radiotherapy, and combinations thereof in patients with brain metastases secondary to melanoma or non-small cell lung cancer. Methods: We analyzed already-published clinical data and calculated the associated costs from the German statutory health insurance system perspective. Two clinical scenarios were considered: decision tree model 1 determined the effectiveness of 18F-FET PET alone for identifying treatment-related changes, that is, the probability of correctly identifying patients with treatment-related changes confirmed by neuropathology or clinicoradiographically using the Response Assessment in Neuro-Oncology criteria for immunotherapy. The resulting cost-effectiveness ratio showed the cost for each correctly identified patient with treatment-related changes in whom MRI findings remained inconclusive. Decision tree model 2 calculated the effectiveness of both 18F-FET PET and MRI, that is, the probability of correctly identifying nonresponders to treatment. The incremental cost-effectiveness ratio was calculated to determine cost-effectiveness, that is, the cost for each additionally identified nonresponder by 18F-FET PET who would have remained undetected by MRI. One-way deterministic and probabilistic sensitivity analyses tested the robustness of the results. Results: 18F-FET PET identified 94% of patients with treatment-related changes, resulting in €1,664.23 (€1.00 = $1.08 at time of writing) for each correctly identified patient. Nonresponders were correctly identified in 60% by MRI and in 80% by 18F-FET PET, resulting in €3,292.67 and €3,915.83 for each correctly identified nonresponder by MRI and 18F-FET PET, respectively. The cost to correctly identify 1 additional nonresponder by 18F-FET PET, who would have remained unidentified by MRI, was €5,785.30. Conclusion: Given the considerable annual cost of multimodal therapy, the integration of 18F-FET PET can potentially improve patient care while reducing costs.

Abstract CT104: Results from a phase 1 study of the anti-immunoglobulin-like transcript 4 (ILT4) monoclonal antibody MK-4830 plus pembrolizumab in patients with previously treated advanced solid tumors

Abstract Background: In the dose escalation phase of a first-in-human phase 1 study (NCT03564691), the anti-ILT4 IgG4 monoclonal antibody MK-4830 + pembrolizumab (pembro) had a manageable safety profile and demonstrated promising antitumor activity in patients (pts) with previously treated advanced solid tumors, including those with PD on immunotherapy. Here, we present safety, efficacy, and biomarker analyses for MK-4830 + pembro for the previously treated pancreatic adenocarcinoma, glioblastoma, head and neck squamous cell carcinoma (HNSCC), and gastric cancer cohorts of the expansion phase. Methods: Eligible pts were aged ≥18 y with metastatic pancreatic adenocarcinoma and 1-3 lines of prior therapy (cohort A), unresectable glioblastoma and 1 prior line of therapy (cohort B), recurrent or metastatic HNSCC that progressed on a platinum-based chemotherapy and PD-(L)1 inhibitor (cohort C), or recurrent or metastatic gastric or gastroesophageal junction adenocarcinoma that progressed on ≥2 prior chemotherapy regimens (cohort I). Pts in cohorts A, B, and I had not previously received a PD-(L)1 inhibitor. All pts received MK-4830 800 mg + pembro 200 mg Q3W for 35 cycles or until PD, unacceptable toxicity, or study withdrawal. Primary objectives were to evaluate safety and ORR per RECIST v1.1 (cohorts A, C, and I) or Response Assessment in Neuro-Oncology (RANO) criteria (cohort B) by investigator assessment. Exploratory objectives included evaluating DOR and PFS per RECIST v1.1 (cohorts A, C, and I) or RANO criteria (cohort B) by investigator assessment. Results: At data cut-off (September 27, 2023), 33 pts were enrolled and received treatment in cohort A, 20 pts in cohort B, 35 pts in cohort C, and 35 pts in cohort I. Median follow-up duration was 38.4 mo (range, 35.5-39.9) in cohort A, 34.1 mo (32.3-36.2) in cohort B, 37.5 mo (33.4-42.1) in cohort C, and 29.5 mo (22.3-36.4) in cohort I. Treatment-related adverse events (TRAEs) occurred in 15 pts (45%) in cohort A, 13 pts (65%) in cohort B, 19 pts (54%) in cohort C, and 16 pts (46%) in cohort I; grade 3 or 4 TRAEs occurred in 3 pts (9%), 0 pts, 2 pts (6%), and 4 pts (11%), respectively. No deaths due to TRAEs occurred. ORR was 6% (95% CI, 1-20) in cohort A, 5% (0-25) in cohort B, 0% (0-10) in cohort C, and 20% (8-37) in cohort I. Median DOR was 14.3 mo (range, 14.0-14.7) in cohort A, 7.4 mo (7.4-7.4) in cohort B, and 9.6 mo (3.0-27.6+) in cohort I. Median PFS was 1.9 mo (95% CI, 1.6-2.0) in cohort A, 1.2 mo (1.1-1.4) in cohort B, 2.2 mo (1.9-4.1) in cohort C, and 1.4 mo (1.3-3.0) in cohort I. Conclusions: In pts with select previously treated advanced or metastatic solid tumors, MK-4830 + pembro had a manageable AE profile but no significant antitumor activity beyond that historically observed with pembro monotherapy. Other treatment options must be explored for these difficult-to-treat tumors. Citation Format: Lillian L. Siu, Marta Gil-Martin, Byoung Chul Cho, Ruth Perets, John Hilton, Ravit Geva, Iwona Lugowska, Martin Gutierrez, Marcelo Bonomi, Rafal Dziadziuszko, Drew Rasco, Eytan Ben-Ami, Cristina P. Rodriguez, Shabana Siddiqi, Nicole Myer, Leah Suttner, Douglas Wilson, Ombololaji O. Akala, Maria de Miguel. Results from a phase 1 study of the anti-immunoglobulin-like transcript 4 (ILT4) monoclonal antibody MK-4830 plus pembrolizumab in patients with previously treated advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT104.

Ga68] DOTATATE PET/MRI-Guided Radiosurgical Treatment Planning and Response Assessment in Meningiomas.

Our purpose was to determine the utility of [68Ga]-DOTATATE PET/MRI in meningioma response assessment following radiosurgery. Patients with meningioma prospectively underwent postoperative DOTATATE PET/MRI. Co-registered PET and gadolinium-enhanced T1-weighted MRI were employed for radiosurgery planning. Follow-up DOTATATE PET/MRI was performed at 6-12 months post radiosurgery. Maximum absolute standardized uptake value (SUV) and SUV ratio (SUVRSSS) referencing superior sagittal sinus (SSS) blood pool were obtained. Size change was determined by Response Assessment in Neuro-Oncology (RANO) criteria. Association of SUVRSSS change magnitude and PFS was evaluated using Cox regression. 27 patients with 64 tumors (26% WHO-1, 41% WHO-2, 26% WHO-3, 7% WHO-unknown) were prospectively followed post stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT) (mean dose: 30 Gy, modal dose 35 Gy, mean of 5 fractions). Post-irradiation SUV and SUVRSSS decreased by 37.4% and 44.4%, respectively (p < 0.0001). Size product decreased by 8.9%, thus failing to reach the 25% significance threshold as determined by RANO guidelines. Mean follow-up time was 26 months (range: 6-44). Overall mean PFS was 83% and 100%/100%/54% in WHO-1/-2/-3 subcohorts, respectively, at 34 months. At maximum follow-up (42-44 months), PFS was 100%/83%/54% in WHO-1/-2/-3 subcohorts, respectively. Cox regression analyses revealed a hazard ratio of 0.48 for 10-unit reduction in SUVRSSS in the SRS cohort. DOTATATE PET SUV and SUVRSSS demonstrated marked, significant decrease post radiosurgery. Lesion size decrease was statistically significant, however it was not clinically significant by RANO criteria. DOTATATE PET/MR thus represents a promising imaging biomarker for response assessment in meningiomas treated with radiosurgery.

Abstract 6199: Defining and capturing progression in glioma by harnessing NLP in unstructured electronic health records

Abstract Gliomas exhibit nearly uniform recurrence and poor prognosis. Management of high-grade tumors is surgery followed by chemoirradiation (CRT). Radiographic progression is assessed using contrast-enhanced MRI with reporting captured in Electronic Health Records (EHR). The ability to harness large scale EHR data is limited by the Response Assessment in Neuro-Oncology (RANO) tumor progression criteria, which defines progression as an aggregate of clinical and/or radiographic parameters requiring clinician judgement. As a result, glioma progression is not captured systematically in large data sets, limiting Progression Free Survival (PFS) as an outcome endpoint in data analysis. We developed an AI-based method using natural language processing to capture PFS parameters for analysis of MRI radiology reports. 1088 available brain MRI radiology reports for 81 patients with a pathologically confirmed diagnosis of glioblastoma (GBM) were aggregated in the NIH Integrated Data Analysis Platform. MRI reports were systematically analyzed and PFS manually captured using RANO criteria as ground truth. Common report terms indicating progression were compiled and included in task prompts applied to Large Language Model (LLM) Extraction Tools. The words progression (n=1047) and stable (n=1133) did not necessarily indicate either overall progression or stability in a report. Yet, in the 24 (30%) patients who progressed within 3 months of CRT, recurrence and mass effect occurred in 3.7% and 53% of reports, respectively, which was comparable to the term frequencies of 5.8% and 54% in patients with stable disease. Thus, mass effect and recurrence could not necessarily be used alone as terms to signal overall progression. The analysis identified other commonly employed radiology report terms relevant to determining tumor progression including enhancement (n=2445), perfusion (n=2085), enhancing (n=1785), resection (n=1576), and increased (n=1331), which allowed for experimentation with more detailed LLM extraction task prompts. Our method flagged radiographic progression prior to clinician-coded progression in 43 (53%) patients. Future directions include handling further clinical context such as surgical features, radiation therapy dates, progress notes, and the coadministration of agents such as bevacizumab and steroids. These results indicate the feasibility of LLMs to identify tumor progression dates using EHR text with potential transferability to large glioma data sets pending further optimization and validation. Citation Format: Shreya Chappidi, Hawon Lee, Sarisha Jagasia, Casey Syal, George Zaki, Dylan Junkin, Nathan Golightly, Patrick Chitwood, Kevin Camphausen, Andra Krauze. Defining and capturing progression in glioma by harnessing NLP in unstructured electronic health records [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6199.

Intrathecal bivalent CAR T cells targeting EGFR and IL13Rα2 in recurrent glioblastoma: phase 1 trial interim results.

Recurrent glioblastoma (rGBM) remains a major unmet medical need, with a median overall survival of less than 1 year. Here we report the first six patients with rGBM treated in a phase 1 trial of intrathecally delivered bivalent chimeric antigen receptor (CAR) T cells targeting epidermal growth factor receptor (EGFR) and interleukin-13 receptor alpha 2 (IL13Rα2). The study's primary endpoints were safety and determination of the maximum tolerated dose. Secondary endpoints reported in this interim analysis include the frequency of manufacturing failures and objective radiographic response (ORR) according to modified Response Assessment in Neuro-Oncology criteria. All six patients had progressive, multifocal disease at the time of treatment. In both dose level 1 (1 ×107 cells; n = 3) and dose level 2 (2.5 × 107 cells; n = 3), administration of CART-EGFR-IL13Rα2 cells was associated with early-onset neurotoxicity, most consistent with immune effector cell-associated neurotoxicity syndrome (ICANS), and managed with high-dose dexamethasone and anakinra (anti-IL1R). One patient in dose level 2 experienced a dose-limiting toxicity (grade 3 anorexia, generalized muscle weakness and fatigue). Reductions in enhancement and tumor size at early magnetic resonance imaging timepoints were observed in all six patients; however, none met criteria for ORR. In exploratory endpoint analyses, substantial CAR T cell abundance and cytokine release in the cerebrospinal fluid were detected in all six patients. Taken together, these first-in-human data demonstrate the preliminary safety and bioactivity of CART-EGFR-IL13Rα2 cells in rGBM. An encouraging early efficacy signal was also detected and requires confirmation with additional patients and longer follow-up time. ClinicalTrials.gov identifier: NCT05168423 .

Selective DRD2 antagonist and ClpP agonist ONC201 in a recurrent non-midline H3 K27M-mutant glioma cohort.

Diffuse midline glioma, H3 K27-altered (H3 K27M-altered DMG) are invariably lethal, disproportionately affecting the young and without effective treatment besides radiotherapy. The 2016 World Health Organization (WHO) Central Nervous System (CNS) Tumors Classification defined H3 K27M mutations as pathognomonic but restricted diagnosis to diffuse gliomas involving midline structures by 2018. Dordaviprone (ONC201) is an oral investigational small molecule, DRD2 antagonist, and ClpP agonist associated with durable responses in recurrent H3 K27M-mutant DMG. Activity of ONC201 in non-midline H3 K27M-mutant diffuse gliomas has not been reported. Patients with recurrent non-midline H3 K27M-mutant diffuse gliomas treated with ONC201 were enrolled in 5 trials. Eligibility included measurable disease by Response Assessment in Neuro-Oncology (RANO) high-grade glioma, Karnofsky/Lansky performance score ≥60, and ≥90 days from radiation. The primary endpoint was overall response rate (ORR). Five patients with cerebral gliomas (3 frontal, 1 temporal, and 1 parietal) met inclusion. One complete and one partial response were reported by investigators. Blinded independent central review confirmed ORR by RANO criteria for 2, however, 1 deemed nonmeasurable and another stable. A responding patient also noted improved mobility and alertness. H3 K27M-mutant diffuse gliomas occasionally occur in non-midline cerebrum. ONC201 exhibits activity in H3 K27M-mutant gliomas irrespective of CNS location.

Evolution of RANO in Assessing Brain Tumour Outcomes.

Assessing treatment response is extremely important in management of brain tumours. Response assessment in neuro-oncology (RANO) was introduced in 2008 for the purpose of making recommendations for it by addressing and countering the limitations in previously reported response criteriae. Subsequently, multiple RANO working groups have been formed to cater to different tumour types and to update their previous recommendations to counter the limitations in their criteria. Herein we have a summarized list of RANO criteria for adult brain tumours.

A phase I dose-escalation study of pulsatile afatinib in patients with recurrent or progressive brain cancer.

Afatinib (BIBW2992; Gilotrif®) is a selective and irreversible inhibitor of the epidermal growth factor receptor (ErbB; EGFR) family. It inhibits EGFR, HER2, and HER4 phosphorylation, resulting in tumor growth inhibition and regression. This phase I dose-escalation trial of pulsatile afatinib examined the safety, drug penetration into the central nervous system, preliminary antitumor activity, and recommended phase II dose in patients with progressive or recurrent brain cancers. Afatinib was taken orally once every 4 days or once every 7 days depending on dose cohort, until disease progression or unacceptable toxicity. A total of 24 patients received the investigational agent and were evaluable for safety analyses, and 21 patients were evaluable for efficacy. Dosing was administered at 80mg every 4 days, 120mg every 4 days, 180mg every 4 days, or 280mg every 7 days. A recommended phase II dose of pulsatile afatinib was established at 280mg every 7 days as there were no dose-limiting toxicities in any of the dosing cohorts and all toxicities were deemed manageable. The most common drug-related toxicities were diarrhea, rash, nausea, vomiting, fatigue, stomatitis, pruritus, and limb edema. Out of the 21 patients evaluable for efficacy, 2 patients (9.5%) exhibited partial response based on Response Assessment in Neuro-Oncology criteria and disease stabilization was seen in 3 patients (14.3%). Afatinib taken orally was safe and well-tolerated up to 280mg every 7 days in brain cancer patients.

Assessment of the clinical effectiveness and safety of immune checkpoint inhibitors for glioblastoma: A systematic review

Glioblastoma (GBM) is a malignant primary brain tumor which is commonly found in humans. Conventional therapeutic approaches for GBM offer only a short median overall survival (MOS), thereby accentuating its poor clinical outcome. Despite the promising potential shown by use of immune checkpoint inhibitor (ICI) in animal models to treat GBM, human trials result remains inconclusive. This systematic review evaluated the safety and clinical efficacy of ICIs in GBM patients. A literature search from Embase and MEDLINE (Ovid) was completed in October 2023. A total of 10 suitable articles, which encompass 168 patients (164 recurrent and 4 newly-diagnosed GBM), are taken into account. 3 studies assessed the OS, 7 studies assessed the PFS and/or response assessment in neuro-oncology (RANO) criteria and 8 studies assessed the safety, tolerability and/or adverse events. These studies show that the range of MOS of ICI treatments was between 2.6-10.4 months (MOS using current standard treatment for recurrent GBM = 3.5-12.5 months). The median PFS and the median period until patients reach partial response score based on RANO criteria are ranging from 1.5 months to 4.6 months (PFS using current standard treatment is 5.5 months). In conclusion, ICIs are safe in patients with GBM. Reported adverse effects only include mild fatigue, headache, hyperglycemia, and diarrhea. However, ICIs display suboptimal clinical efficacy compared to conventional GBM treatments. Therefore, further research is needed in order to improve the clinical efficacy of ICIs.

NIMG-74. COMPARING VOLUMETRIC GROWTH-RATE AND RANO CRITERIA IN DETERMINING THE RESPONSE OF MENINGIOMA TO BEVACIZUMAB THERAPY

Abstract Meningioma is the most prevalent primary tumor in the central nervous system (CNS). Although mostly benign, 15- 20% are aggressive and tend to recur and progress despite surgery and adjuvant radiation. Recent publications show that bevacizumab, a vascular endothelial growth factor inhibitor, effectively treats these refractory meningiomas. The standard method to monitor treatment’s effect on imaging is Response Assessment in Neuro-Oncology criteria (RANO). Recently, an alternative tool called 3D volumetric growth rate (3DVGR) has emerged. Our aim is to compare the effectiveness of conventional RANO criteria and the 3DVGR measure in evaluating the response to bevacizumab treatment in patients with refractory meningiomas. We will also assess their correlation with clinical outcomes over a period of up to 9 months. 68 MRI scans of 20 patients with aggressive meningiomas treated with bevacizumab were evaluated. For each tumor both RANO and 3DVGR were conducted in two subsequent head MRI studies acquired prior to the initiation of bevacizumab treatment and then in at least one exam within 6 months post-treatment. Measurements were obtained using PACS and BRAIN LAB software by two radiologists. A total of 43 lesions derived from 20 patients were included in the analysis. The mean age was 65.5; mean number of radiation treatments was 2.66; mean number of pre-surgical treatments was 2.7 and mean number of bevacizumab cycles was 22.7. All lesions showed a decrease or stabilization in growth rate compared to baseline. More specifically, 34 out of 43 lesions (79%) showed a negative growth rate value indicating decrease in tumor size. Comparison of treatment response using RANO criteria was not always in concordance with the 3DVGR measurement and showed inaccurate correlation with clinical outcome. 3DVGR measure seems to be more precise compared to RANO criteria. Furthermore, our results show great promise for treatment of refractory meningiomas with bevacizumab.

Incidence and outcome of pseudoprogression after radiation therapy in glioblastoma patients: A cohort study.

Differentiating post-radiation MRI changes from progressive disease (PD) in glioblastoma (GBM) patients represents a major challenge. The clinical problem is two-sided; avoid termination of effective therapy in case of pseudoprogression (PsP) and continuation of ineffective therapy in case of PD. We retrospectively assessed the incidence, management, and prognostic impact of PsP and analyzed factors associated with PsP in a GBM patient cohort. Consecutive GBM patients diagnosed in the South-Eastern Norway Health Region from 2015 to 2018 who had received RT and follow-up MRI were included. Tumor, patient, and treatment characteristics were analyzed in relationship to re-evaluated MRI examinations at 3 and 6 months post-radiation using Response Assessment in Neuro-Oncology criteria. A total of 284 patients were included in the study. PsP incidence 3 and 6 months post-radiation was 19.4% and 7.0%, respectively. In adjusted analyses, methylated O6-methylguanine-DNA methyltransferase (MGMT) promoter and the absence of neurological deterioration were associated with PsP at both 3 (p < .001 and p = .029, respectively) and 6 months (p = .045 and p = .034, respectively) post-radiation. For patients retrospectively assessed as PD 3 months post-radiation, there was no survival benefit of treatment change (p = .838). PsP incidence was similar to previous reports. In addition to the previously described correlation of methylated MGMT promoter with PsP, we also found that absence of neurological deterioration significantly correlated with PsP. Continuation of temozolomide courses did not seem to compromise survival for patients with PD at 3 months post-radiation; therefore, we recommend continuing adjuvant temozolomide courses in case of inconclusive MRI findings.

RANO 2.0: Update to the Response Assessment in Neuro-Oncology Criteria for High- and Low-Grade Gliomas in Adults.

The Response Assessment in Neuro-Oncology (RANO) criteria for high-grade gliomas (RANO-HGG) and low-grade gliomas (RANO-LGG) were developed to improve reliability of response assessment in glioma trials. Over time, some limitations of these criteria were identified, and challenges emerged regarding integrating features of the modified RANO (mRANO) or the immunotherapy RANO (iRANO) criteria. Informed by data from studies evaluating the different criteria, updates to the RANO criteria are proposed (RANO 2.0). We recommend a standard set of criteria for both high- and low-grade gliomas, to be used for all trials regardless of the treatment modalities being evaluated. In the newly diagnosed setting, the postradiotherapy magnetic resonance imaging (MRI), rather than the postsurgical MRI, will be used as the baseline for comparison with subsequent scans. Since the incidence of pseudoprogression is high in the 12 weeks after radiotherapy, continuation of treatment and confirmation of progression during this period with a repeat MRI, or histopathologic evidence of unequivocal recurrent tumor, are required to define tumor progression. However, confirmation scans are not mandatory after this period nor for the evaluation of treatment for recurrent tumors. For treatments with a high likelihood of pseudoprogression, mandatory confirmation of progression with a repeat MRI is highly recommended. The primary measurement remains the maximum cross-sectional area of tumor (two-dimensional) but volumetric measurements are an option. For IDH wild-type glioblastoma, the nonenhancing disease will no longer be evaluated except when assessing response to antiangiogenic agents. In IDH-mutated tumors with a significant nonenhancing component, clinical trials may require evaluating both the enhancing and nonenhancing tumor components for response assessment. The revised RANO 2.0 criteria refine response assessment in gliomas.

Dabrafenib plus Trametinib in Pediatric Glioma with BRAF V600 Mutations

BackgroundDetection of the BRAF V600E mutation in pediatric low-grade glioma has been associated with a lower response to standard chemotherapy. In previous trials, dabrafenib (both as monotherapy and in combination with trametinib) has shown efficacy in recurrent pediatric low-grade glioma with BRAF V600 mutations, findings that warrant further evaluation of this combination as first-line therapy.MethodsIn this phase 2 trial, patients with pediatric low-grade glioma with BRAF V600 mutations who were scheduled to receive first-line therapy were randomly assigned in a 2:1 ratio to receive dabrafenib plus trametinib or standard chemotherapy (carboplatin plus vincristine). The primary outcome was the independently assessed overall response (complete or partial response) according to the Response Assessment in Neuro-Oncology criteria. Also assessed were the clinical benefit (complete or partial response or stable disease for ≥24 weeks) and progression-free survival.ResultsA total of 110 patients underwent randomization (73 to receive dabrafenib plus trametinib and 37 to receive standard chemotherapy). At a median follow-up of 18.9 months, an overall response occurred in 47% of the patients treated with dabrafenib plus trametinib and in 11% of those treated with chemotherapy (risk ratio, 4.31; 95% confidence interval [CI], 1.7 to 11.2; P<0.001). Clinical benefit was observed in 86% of the patients receiving dabrafenib plus trametinib and in 46% receiving chemotherapy (risk ratio, 1.88; 95% CI, 1.3 to 2.7). The median progression-free survival was significantly longer with dabrafenib plus trametinib than with chemotherapy (20.1 months vs. 7.4 months; hazard ratio, 0.31; 95% CI, 0.17 to 0.55; P<0.001). Grade 3 or higher adverse events occurred in 47% of the patients receiving dabrafenib plus trametinib and in 94% of those receiving chemotherapy.ConclusionsAmong pediatric patients with low-grade glioma with BRAF V600 mutations, dabrafenib plus trametinib resulted in significantly more responses, longer progression-free survival, and a better safety profile than standard chemotherapy as first-line therapy. (Funded by Novartis; ClinicalTrials.gov number, NCT02684058.)

OS09.4.A RANO 2.0: UPDATE TO THE RESPONSE ASSESSMENT IN NEURO-ONCOLOGY (RANO) CRITERIA FOR HIGH- AND LOW-GRADE GLIOMAS IN ADULTS

Abstract BACKGROUND The Response Assessment in Neuro-Oncology (RANO) criteria for high-grade gliomas (RANO-HGG) and low-grade gliomas (RANO-LGG) were developed to improve reliability of response assessment in glioma trials. Over time some limitations of these criteria were identified, and uncertainty emerged regarding integrating features of the modified RANO (mRANO) or the immunotherapy RANO (iRANO) criteria. MATERIAL AND METHODS Informed by data from a cohort of glioblastoma patients and other evaluations of RANO criteria that allowed evaluation of features of the different criteria, the RANO working group developed updates to the RANO criteria (RANO 2.0). RESULTS Based on the 2021 WHO classification of gliomas, we recommend a standard set of criteria for both high and low-grade gliomas, to be used for all trials regardless of the treatment modalities being evaluated. In the newly diagnosed setting, the post-radiotherapy MRI, rather than the post-surgical MRI, will be used as the baseline for future comparison. Since the incidence of pseudoprogression is high in the 12 weeks following radiotherapy, continuation of treatment and confirmation of progression during this period with a repeat MRI, or histopathologic evidence of unequivocal recurrent tumor, is required to define tumor progression. However, confirmation scans are not mandatory after this period nor for recurrent tumors. For treatments with a high likelihood of pseudoprogression, mandatory confirmation of progression with a repeat MRI is highly recommended. The primary measurement remains the maximum cross-sectional area of tumor (2-dimensional) but volumetric measurements are an option. For IDH-wildtype glioblastoma, the non-enhancing disease will no longer be evaluated. In IDH-mutated tumors with a significant non-enhancing component, clinical trials may require evaluating both the enhancing and non-enhancing tumor components for response assessment. CONCLUSION These criteria represent a work in progress that will hopefully improve the assessment of response in glioma trials. Future updates will incorporate novel developments, advanced imaging techniques, and endpoints as they become validated.

KS03.5.A COMPARING VOLUMETRIC GROWTH-RATE AND RANO CRITERIA IN DETERMINING THE RESPONSE OF MENINGIOMA TO BEVACIZUMAB THERAPY

Abstract INTRODUCTION Meningioma is the most prevalent primary tumor in the central nervous system (CNS). Although mostly benign, 15- 20% are aggressive and tend to recur and progress despite surgery and adjuvant radiation. Recent publications show that bevacizumab, a vascular endothelial growth factor inhibitor, effectively treats these refractory meningiomas. The standard method to monitor treatment’s effect on imaging is Response Assessment in Neuro-Oncology criteria (RANO). Recently, an alternative tool called 3D volumetric growth rate (3DVGR) has emerged as a result of significant advancements in the accuracy of volumetric measurement techniques. Our aim is to compare the effectiveness of conventional RANO criteria and the emerging 3DVGR measure in evaluating the response to bevacizumab treatment in patients with refractory meningiomas. We will also assess their correlation with clinical outcomes over a period of up to 9 months. METHODS 68 MRI scans of 20 patients with aggressive meningiomas that progressed after radiation therapy and then received Bevacizumab were evaluated. Scans were obtained from two tertiary cancer centers. For each tumor both RANO and 3DVGR were conducted in two subsequent head MRI studies acquired prior to the initiation of bevacizumab treatment and then in at least one exam within 6 months post-treatment. Measurements were obtained using PACS and BRAIN LAB software by two radiologists. RESULTS A total of 43 lesions derived from 13 males and 7 females were included in the final analysis. The mean age was 65.5; mean number of pre-radiation treatments was 2.66; mean number of pre-surgical treatments was 2.7 and mean number of bevacizumab cycles was 22.7. All lesions showed a decrease or stabilization in growth rate compared to baseline. More specifically, 34 out of 43 lesions (79%) showed a negative growth rate value indicating decrease in tumor size. Comparison of treatment response using RANO criteria was not always in concordance with the 3DVGR measurement and showed inaccurate correlation with clinical outcome. CONCLUSIONS Although widely accepted for treatment response evaluation, RANO criteria are not an accurate technique for irregularly shaped lesions. As shown in our study, for atypical meningiomas, the 3DVGR measure seems to be more precise compared to RANO criteria. Furthermore, our results show great promise for treatment of refractory meningiomas with bevacizumab.

P17.04.B A PHASE 2 STUDY OF NIRAPARIB CONCOMITANT WITH TUMOR TREATING FIELDS (TTFIELDS) IN PATIENTS WITH RECURRENT HIGH-GRADE GLIOMA (HGG)

Abstract BACKGROUND Preclinical data have demonstrated that application of TTFields reduces gene expression within the FA-BRCA DNA-damage response pathway, thus inducing potential sensitivity to PARP inhibition. We conducted a phase 2 trial of TTFields concomitant with niraparib in patients with recurrent HGG. MATERIAL AND METHODS This single-center trial enrolled patients with recurrent grade 4 glioma, including both rGBM (IDH-wt) and IDH-mutant grade 4 astrocytoma. The study included a single-arm, primary efficacy cohort (A) and a window-of-opportunity cohort (B) for patients needing surgical resection. In Cohort A, TTFields therapy was administered for 5 - 7 days prior to start of niraparib (300mg daily, 28-day cycles). Cohort B received TTFields therapy starting 5 - 7 days prior to surgery and stopped 1 hour before incision. TTFields therapy was resumed post-operatively with niraparib added 5-7 days thereafter. Primary endpoint: disease control rate (DCR) in Cohort A, defined as achievement of either objective response (CR or PR) or stable disease (SD) lasting at least 16 weeks, using Modified Response Assessment in Neuro-Oncology criteria. Cohort A had a Simon two-stage design: null hypothesis, DCR 30%; alternative hypothesis, DCR 60%; n = 24 for 80% power, one-sided α = 0.05. After enrollment of n=8 in Stage 1, advancement to Stage 2 (n=16) was allowed if ≥ 4 patients in Stage 1 met the primary endpoint. Secondary endpoints: safety, progression-free survival (PFS), overall survival (OS). Exploratory endpoints: pre- vs. post-TTFields 18F FluorThanatrace (18F-FTT) PET imaging for PARP-1 expression, and assessment of homologous recombination deficiency (HRD) in TTFields-treated tumor tissue. RESULTS Nine patients were enrolled: Cohort A, n=8 (n=6 rGBM, n=2 grade 4 IDH-mutant astrocytoma); Cohort B, n=1 (rGBM). Median age 53; all patients were male; 6/9 (67%) were MGMT unmethylated. All patients received prior radiation/temozolomide; 3/9 (33%) received prior bevacizumab. Most common treatment-related adverse events (trAEs): grade 1-2 dermatologic AEs (scalp, n=6) grade 1-2 nausea (n=5), grade 1-2 vomiting (n=4), grade 2 anorexia (n=2), grade 1 constipation (n=2). Grade 3-4 trAEs included fatigue (n=1), thrombocytopenia (n=1), cerebral edema (n=1). Mean TTFields usage at niraparib initiation was 80.7% (19.4 hours/day). In Cohort A, there were no objective responses and 1/8 patients (12.5%) achieved SD. The efficacy benchmark to proceed to Stage 2 was not met. Median PFS and OS in Cohort A were 1.3 months (95% CI, 0.8 - 3.0 months) and 6.5 months (95% CI, 2.3 - 16.4 months), respectively. Cohort B was terminated early due to slow accrual. Correlative data (18F-FTT PET imaging, HRD assessment in TTFields-treated tumor tissue) will be presented. CONCLUSION Niraparib concomitant with TTFields therapy for recurrent HGG was safe and well tolerated but did not demonstrate a signal of efficacy.

P11.75.B PSEUDOPROGRESSION IN A REAL-WORLD GLIOBLASTOMA COHORT: INCIDENCE, MANAGEMENT, PROGNOSTIC IMPACT, AND ASSOCIATED FACTORS

Abstract BACKGROUND Radiotherapy remains a cornerstone in glioblastoma (GBM) management. A continued and unmet need in neuro-oncology is efficient non-invasive methods to differentiate post-radiation magnetic resonance imaging (MRI) changes from progressive disease (PD) in GBM patients. The clinical challenge is two-sided; avoid termination of effective therapy in case of pseudoprogression (PsP) and continuation of ineffective therapy in case of PD. We retrospectively assessed incidence, management, prognostic impact, and associated factors with PsP in a real-world GBM patient cohort. MATERIAL AND METHODS Adult (≥18 years) GBM patients diagnosed in the South-Eastern Health Region of Norway from 2015 to 2018, had received radiotherapy, and follow-up MRIs were included. Patient, tumor, and treatment characteristics were analyzed in relationship to re-evaluated MRI examinations at three and six months post-radiation using response assessment in neuro-oncology criteria. RESULTS PsP incidences at three and six months post-radiation were 20% and 8%, respectively. In adjusted analyses, methylated O6-methylguanine-DNA methyltransferase (MGMT) promoter and absence of neurological deterioration were associated with PsP at both three (p&amp;lt;0.001 and p=0.04, respectively) and six months (p=0.003 and p=0.04, respectively) post-radiation. Patients with PsP at MRI three months post-radiation had a median OS of 24.8 months compared to 11.4 months for patients with PD and 18.7 months in patients with stable disease (SD); the difference was significant only when comparing patients with PsP and PD (p&amp;lt;0.001). There was no survival benefit of treatment change for patients retrospectively evaluated as PD three months post-radiation (p=0.8). Median OS for patients in the PsP group was 31.8 months and thus longer than in the PD group (13.1 months) and the SD group (24.1 months). The difference was only significant when comparing patients with PsP and PD (p&amp;lt;0.001). CONCLUSION PsP incidence in this retrospective material was similar to previous reports. In addition to the previously described correlation of methylated MGMT promoter with PsP, we also found that the absence of neurological deterioration significantly correlated to PsP. Continuation of temozolomide courses did not compromise survival for patients with PD at three months post-radiation; therefore, we recommend continuing adjuvant temozolomide courses in case of inconclusive MRI findings. Funding: European Union's Horizon 2020 Programme European Research Council Grant 758657-ImPRESS.

P17.06.B TARGETED THERAPY MATCHED TO GENOMIC ALTERATIONS (BRAFV600E, NTRK, FGFR, ROS1, PIK3CA, PTEN) IN PATIENTS WITH RECURRENT IDH WILDTYPE GLIOBLASTOMA: A REAL-LIFE COHORT ANALYSIS FROM VENETO INSTITUTE OF ONCOLOGY, PADUA (ITALY)

Abstract BACKGROUND The use of next-generation sequencing (NGS) allows the identification of subgroups of patients that may respond to personalized targeted therapies (TT). Despite the acquired deep knowledge about biology, there are only a few data available regarding TT efficacy and feasibility for patients with glioblastoma (GBM). MATERIAL AND METHODS We retrospectively analyzed a cohort of patients with recurrent GBM treated at Veneto Institute of Oncology, Padua (Italy) with TT based on their individual NGS profile. NGS was obtained with FoundationOne®CDx on formalin-fixed paraffin-embedded (FFPE) tissue samples. We identified 6 druggable genomic alterations, classified according to ESCAT (ESMO Scale for Clinical Actionability of molecular Targets): BRAFV600E mutation (IB), NTRK1-2-3 fusions (IC), FGFR1-2-3 alterations (IIB), ROS1 fusions (IIIA), PIK3CA mutations (IIIA) and PTEN loss/mutations (IIIA). TT was given as agnostic approval, part of compassionate use programs or in clinical trials. Response assessment was based on RANO (Response Assessment in Neuro-Oncology) criteria. RESULTS Between March 2020 and December 2022, 34 patients with recurrent glioblastoma received TT (19 males, 15 females, median age of 54 years at time of TT initiation). ECOG PS was 0-1 in 29 pts. All patients received radiotherapy and temozolomide as first-line therapy. The median line of therapy with TT was 3 (range 2-7). TT was dabrafenib/trametinib (9 pts), larotrectinib (2 pts), erdafitinib (4 pts), entrectinib (1 pt), alpelisib (6 pts), ipatasertib+/-atezolizumab (12 pts). At data cut-off (March 2023), 19 patients had died. In the entire cohort, median overall survival and progression-free survival (PFS) after starting TT was 8.72 and 2.14 months, respectively. The dabrafenib/trametinib subgroup had the longest median PFS (5.23 months), a disease control rate (DCR) of 77%, an objective response rate of 22%, and a median duration of response of 22.5 months. 7/9 pt had died and 2 pts are continuing dabrafenib/trametinib. The pt with ROS1-GOCP fusion maintained a complete response for 12 months with entrectinib. Among the others, no complete/partial responses were detected. DCR due to stable disease was 50% in larotrectinib and erdafitinib, 8.3% in ipatasertib+/-atezolizumab, 0% in alpelisib subgroup. No toxicities were reported in dabrafenib/trametinib subgroup. Among all patients, no grade 4 drug-related adverse events were observed and in any case TT was interrupted for toxicity. CONCLUSION Our results confirm the activity of dabrafenib/trametinib in BRAFV600E mutant glioblastoma pts and might suggest deeper explorations in targeting ROS1 and FGFR. Further correlation among patients' outcome, molecular characteristics and TT timing are still under investigation.

Combined cytotoxic and immune-stimulatory gene therapy for primary adult high-grade glioma: a phase 1, first-in-human trial

High-grade gliomas have a poor prognosis and do not respond well to treatment. Effective cancer immune responses depend on functional immune cells, which are typically absent from the brain. This study aimed to evaluate the safety and activity of two adenoviral vectors expressing HSV1-TK (Ad-hCMV-TK) and Flt3L (Ad-hCMV-Flt3L) in patients with high-grade glioma. In this dose-finding, first-in-human trial, treatment-naive adults aged 18-75 years with newly identified high-grade glioma that was evaluated per immunotherapy response assessment in neuro-oncology criteria, and a Karnofsky Performance Status score of 70 or more, underwent maximal safe resection followed by injections of adenoviral vectors expressing HSV1-TK and Flt3L into the tumour bed. The study was conducted at the University of Michigan Medical School, Michigan Medicine (Ann Arbor, MI, USA). The study included six escalating doses of viral particles with starting doses of 1×1010 Ad-hCMV-TK viral particles and 1×109 Ad-hCMV-Flt3L viral particles (cohort A), and then 1×1011 Ad-hCMV-TK viral particles and 1×109 Ad-hCMV-Flt3L viral particles (cohort B), 1×1010 Ad-hCMV-TK viral particles and 1×1010 Ad-hCMV-Flt3L viral particles (cohort C), 1×1011 Ad-hCMV-TK viral particles and 1×1010 Ad-hCMV-Flt3L viral particles (cohort D), 1×1010 Ad-hCMV-TK viral particles and 1×1011 Ad-hCMV-Flt3L viral particles (cohort E), and 1×1011 Ad-hCMV-TK viral particles and 1×1011 Ad-hCMV-Flt3L viral particles (cohort F) following a 3+3 design. Two 1 mL tuberculin syringes were used to deliver freehand a mix of Ad-hCMV-TK and Ad-hCMV-Flt3L vectors into the walls of the resection cavity with a total injection of 2 mL distributed as 0·1 mL per site across 20 locations. Subsequently, patients received two 14-day courses of valacyclovir (2 g orally, three times per day) at 1-3 days and 10-12 weeks after vector administration and standad upfront chemoradiotherapy. The primary endpoint was the maximum tolerated dose of Ad-hCMV-Flt3L and Ad-hCMV-TK. Overall survival was a secondary endpoint. Recruitment is complete and the trial is finished. The trial is registered with ClinicalTrials.gov, NCT01811992. Between April 8, 2014, and March 13, 2019, 21 patients were assessed for eligibility and 18 patients with high-grade glioma were enrolled and included in the analysis (three patients in each of the six dose cohorts); eight patients were female and ten were male. Neuropathological examination identified 14 (78%) patients with glioblastoma, three (17%) with gliosarcoma, and one (6%) with anaplastic ependymoma. The treatment was well-tolerated, and no dose-limiting toxicity was observed. The maximum tolerated dose was not reached. The most common serious grade 3-4 adverse events across all treatment groups were wound infection (four events in two patients) and thromboembolic events (five events in four patients). One death due to an adverse event (respiratory failure) occurred but was not related to study treatment. No treatment-related deaths occurred during the study. Median overall survival was 21·3 months (95% CI 11·1-26·1). The combination of two adenoviral vectors demonstrated safety and feasibility in patients with high-grade glioma and warrants further investigation in a phase 1b/2 clinical trial. Funded in part by Phase One Foundation, Los Angeles, CA, The Board of Governors at Cedars-Sinai Medical Center, Los Angeles, CA, and The Rogel Cancer Center at The University of Michigan.