Background Preclinical studies demonstrate activity of poly(adenosine 5'-diphosphate-ribose) polymerase (PARP) inhibitors in isocitrate dehydrogenase (IDH) mutant gliomas. We investigated safety, tolerability, pharmacokinetics, and efficacy of the PARP inhibitor pamiparib in conjunction with metronomic low-dose temozolomide in patients with recurrent IDH mutant (IDHmt) gliomas in a multicenter Phase I/II/window of opportunity study.Methods Patients received pamiparib in conjunction with daily temozolomide. Following Phase I determination of maximum tolerated dose (MTD), we enrolled 2 patient cohorts (Arm A, multiple prior chemotherapy regimens; Arm B, single prior regimen) in a 2-stage design. Exploratory cohorts examined grade 4 IDHmt patients and intratumoral pharmacokinetics of pamiparib. The primary endpoint was objective radiographic response (ORR) by RANO criteria.Results Sixty-six subjects were enrolled. We established pamiparib 60 mg twice daily with temozolomide 20 mg daily as the phase II dose. In non-enhancing and enhancing tumor, pamiparib exhibited an unbound tumor/plasma ratio of 0.92 and 0.98, respectively. 0/15 Arm A and 1/24 Arm B patients achieved a centrally confirmed partial response. Median progression-free survival for Arm A was 5.9 months (95% CI, 1.2-14.8 months), and for Arm B was 9.7 months (95% CI, 5.7-21.7 months). Grade 3+ anemia and neutropenia affected 24% and 33% of patients, respectively. Twenty-two of 66 patients (33.3%) discontinued study treatment for reasons other than tumor progression.Conclusions Pamiparib appeared to achieve sufficient pharmacologically active concentrations in both enhancing and non-enhancing tumors. While some patients achieved prolonged progression-free survival, combination with temozolomide did not produce a meaningful ORR in IDHmt recurrent gliomas. Cumulative hematologic toxicity was substantial and impacted long-term tolerability.

Inhibitors of murine double minute homolog 2 (MDM2) represent a promising therapeutic approach for the treatment of TP53 wild-type glioblastomas (GBMs), reactivating p53 signaling to induce cancer cell death. We conducted a surgical window-of-opportunity trial (NCT03107780) of the MDM2 inhibitor navtemadlin (KRT-232) in 21 patients with TP53 wild-type recurrent GBM to determine achievable drug concentrations within tumor tissues and biological mechanisms of response and resistance. Participants received navtemadlin at 120 mg (n = 10) or 240 mg (n = 11) for 2 days before surgical resection and after surgery until progression or unacceptable toxicity. Both 120 and 240 mg daily dosing achieved a pharmacodynamic impact, but median progression-free survival was 3.1 months. DNA sequencing of three recurrent tumors revealed an absence of TP53-inactivating mutations, indicating alternative mechanisms of resistance. To understand the mechanisms of response and resistance associated with navtemadlin, we conducted functional and spatial analyses of human tissue and patient-derived GBM neurosphere models. Navtemadlin induced partial tumor cell death as monotherapy, and combination with temozolomide enhanced apoptosis in GBM neurospheres while sparing normal bone marrow cells in vitro. We also observed up-regulation of oligodendrocyte differentiation genes with navtemadlin treatment and enrichment of oligodendrocyte transcription factor 2 (OLIG2)-positive cells at relapse, suggesting an unexplored mechanism of navtemadlin tolerance in GBM. Overall, these results indicated that clinically achievable doses of navtemadlin exert pharmacodynamic effects on GBM and suggest that combined treatment with temozolomide may be a route to more durable survival benefits.

Neuroinflammation is a major driver of secondary tissue damage after spinal cord injury (SCI). Within minutes after SCI, activated microglia and astrocytes produce proinflammatory mediators such as TNF-α, IL-6, iNOS, and COX-2 which induce tissue injury through cytotoxicity, vascular hyperpermeability, and secondary ischemia. The inflammatory cascade is amplified by chemokines like CCL2 and CXCL1 which recruit immune cells to the injured site. HuR is an RNA regulator that promotes glial expression of many proinflammatory factors by binding to adenylate- and uridylate-rich elements in the 3' untranslated regions of their mRNAs. SRI-42127 is a small molecule which blocks HuR function by preventing its nucleocytoplasmic translocation. This study aimed to evaluate the potential of SRI-42127 to suppress neuroinflammation after SCI and improve functional outcome. Adult female mice underwent a T10 contusion injury and received SRI-42127 1 h post injury for up to 5 days. Locomotor function was assessed by open field testing, balance beam, and rotarod. Immunohistochemistry was used to assess lesion size, neuronal loss, myelin sparing, microglial/astroglial activation, and HuR localization. Inflammatory mediator expression was assessed by qPCR, immunohistochemistry, ELISA, or western blot. We found that SRI-42127 treatment significantly attenuated loss of locomotor function and post-SCI pain. There was a reduction in lesion size and neuronal loss with an increase in myelin sparing. Microglia and astrocytes showed reduced activation and reduced nucleocytoplasmic translocation of HuR. There was a striking suppression of proinflammatory mediators at the epicenter along with peripheral suppression of inflammatory responses in serum, liver, and spleen. In conclusion, HuR inhibition with SRI-42127 may be a viable therapeutic approach for suppressing neuroinflammatory responses after SCI and improving functional outcome.

PURPOSE:Glioma arises from glial cells and comprises ∼80 % of malignant adult brain tumors. The polymorphic mitochondrial genome plays a key role in maintaining redox homeostasis and generation of reactive oxygen species (ROS). ROS have a well-established role in glial tumors. We investigated associations between germline mtDNA variants and haplogroups with glioma grade and glioblastoma (GBM) survival. METHODS:We conducted germline mtDNA sequencing for 388 patients (300 Caucasians, 88 African Americans [AA]) with incident glioma (105 non-GBM, 283 GBM). Across all patients we identified 1431 homoplasmic mtDNA variants, including 692 variants observed only in Caucasians, 474 only in AAs, and 265 in both groups. We estimated Odds Ratios (OR) and 95 % Confidence Intervals (CI) for mtDNA common variants, haplogroups, and gene variant burden in relation to glioma grade and tertiles of survival in GBM patients. Bonferroni and Benjamini-Hochberg correction were applied for multiple comparisons. RESULTS:No mtDNA haplogroup was associated with glioma grade or patient survival in GBM. Common variants m.3010G>A, m.195T>C, and m.16189T>C were linked to lower-grade glioma risk. For GBM survival, m.1719G>A, m.14766T>C, m.16129G>A, and m.204T>C were associated with a poorer prognosis while variant m.73A>G was associated with an improved prognosis. A higher variant burden in MT-ND1 and MT-ND5 was associated with a better prognosis. No results remained statistically significant after correction. CONCLUSION:This is the first comprehensive study of germline mtDNA sequence variation in relation to glioma grade at diagnosis and gliobastoma patient survival. Results warrant further study in larger populations and investigation of biologic mechanisms linking mtDNA polymorphism to these endpoints.

Abstract Purpose: Adavosertib is an oral small-molecule inhibitor of Wee1. The Adult Brain Tumor Consortium conducted a phase I study evaluating adavosertib in combination with radiation (RT) and temozolomide (TMZ) in patients with newly diagnosed glioblastoma (GBM), as well as a surgical window-of-opportunity study in recurrent GBM. Patients and Methods: The MTD of adavosertib was determined in adult patients with newly diagnosed GBM using a standard 3+3 design in two separate cohorts: with concurrent RT/TMZ or with adjuvant TMZ. A combination cohort with both concurrent and adjuvant adavosertib at MTD followed. We also performed intratumoral drug distribution studies in patients with recurrent GBM undergoing surgery. Results: As separate cohorts, the MTD for concurrent adavosertib with RT/TMZ was 200 mg daily Monday through Friday × 6 weeks during RT, and the MTD for adjuvant adavosertib with TMZ was 425 mg daily for 5 days of each 28-day cycle. However, six of 12 patients experienced dose-limiting toxicities (DLT) in the combination cohort. The mean ratios of the intratumoral to plasma concentration of adavosertib were 4.18 ± 3.36 for contrast-enhancing tissue and 0.74 ± 0.63 in nonenhancing tissue. Conclusions: Adavosertib at 200 mg daily Monday through Friday × 6 weeks with RT/TMZ and at 425 mg daily on a 5-day/28-day cycle with TMZ had an unacceptable DLT rate. Additional dose levels in combination cohorts resulted in DLT, and we deemed concurrent adavosertib too toxic for further examination. Adavosertib 425 mg daily on a 5-day/28-day cycle with adjuvant TMZ is the recommended phase II dosage. Tissue pharmacokinetics in tissue homogenates and by microdialysis provided complementary information about drug penetration.

ImportanceMolecular techniques, including next-generation sequencing, genomic copy number profiling, fusion transcript detection, and genomic DNA methylation arrays, are now indispensable tools for the workup of central nervous system (CNS) tumors. Yet there remains a great deal of heterogeneity in using such biomarker testing across institutions and hospital systems. This is in large part because there is a persistent reluctance among third-party payers to cover molecular testing. The objective of this Review is to describe why comprehensive molecular biomarker testing is now required for the accurate diagnosis and grading and prognostication of CNS tumors and, in so doing, to justify more widespread use by clinicians and coverage by third-party payers.ObservationsThe 5th edition of the World Health Organization (WHO) classification system for CNS tumors incorporates specific molecular signatures into the essential diagnostic criteria for most tumor entities. Many CNS tumor types cannot be reliably diagnosed according to current WHO guidelines without molecular testing. The National Comprehensive Cancer Network also incorporates molecular testing into their guidelines for CNS tumors. Both sets of guidelines are maximally effective if they are implemented routinely for all patients with CNS tumors. Moreover, the cost of these tests is less than 5% of the overall average cost of caring for patients with CNS tumors and consistently improves management. This includes more accurate diagnosis and prognostication, clinical trial eligibility, and prediction of response to specific treatments. Each major group of CNS tumors in the WHO classification is evaluated and how molecular diagnostics enhances patient care is described.Conclusions and RelevanceRoutine advanced multidimensional molecular profiling is now required to provide optimal standard of care for patients with CNS tumors.

Background:Currently, no definitive method reliably differentiates pseudoprogression from true progression. Misclassification can either halt effective therapy or prolong ineffective treatment. We hypothesized that the diagnostic accuracy could be improved using quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) after error correction via point-of-care portable perfusion phantoms (P4s). This study aimed to develop a P4 for quantitative DCE-MRI of the brain and enhance accuracy in distinguishing between pseudo and true glioblastoma progression. Methods:Twelve patients with potential glioblastoma progression after adjuvant chemoradiation therapy were recruited. Each subject underwent two DCE-MRI exams within a week using a single 3T MRI scanner. Quantitative DCE-MRI parameters were retrieved based on the extended Tofts model (ETM), Tofts model (TM), and shutter speed model (SSM) before and after P4-based error correction. The consistency of the pharmacokinetic (PK) parameter measurements was evaluated based on the within-subject coefficient of variation (wCV) before and after P4-based error correction. Glioblastoma progression status was determined using the Response Assessment in Neuro-Oncology (RANO) criteria about five months after DCE-MRI exams. Results:Among the participants, five had true progression, and seven had pseudoprogression. The wCVs of the Ktrans measurement based on TM, ETM, and SSM were 22%, 22%, and 24%, respectively, before error correction but improved to 7%, 6%, and 8%, respectively, after correction. Similarly, their accuracies in differentiating between pseudo and true progression were 0.88 regardless of the PK models before error correction. However, those after error correction were improved to 100% in TM (or ETM) and 96% in SSM. Conclusions:Following P4-based error correction, a quantitative DCE-MRI parameter, Ktrans , demonstrated 100% accuracy in discriminating between pseudo and true progression when TM or ETM were employed.

Supplementary Table S3: Adverse events.

BackgroundThe extended acquisition times required for MRI limit its availability in resource-constrained settings. Consequently, accelerating MRI by undersampling k-space data, which is necessary to reconstruct an image, has been a long-standing but important challenge. We aimed to develop a deep convolutional neural network (dCNN) optimisation method for MRI reconstruction and to reduce scan times and evaluate its effect on image quality and accuracy of oncological imaging biomarkers.MethodsIn this multicentre, retrospective, cohort study, MRI data from patients with glioblastoma treated at Heidelberg University Hospital (775 patients and 775 examinations) and from the phase 2 CORE trial (260 patients, 1083 examinations, and 58 institutions) and the phase 3 CENTRIC trial (505 patients, 3147 examinations, and 139 institutions) were used to develop, train, and test dCNN for reconstructing MRI from highly undersampled single-coil k-space data with various acceleration rates (R=2, 4, 6, 8, 10, and 15). Independent testing was performed with MRIs from the phase 2/3 EORTC-26101 trial (528 patients with glioblastoma, 1974 examinations, and 32 institutions). The similarity between undersampled dCNN-reconstructed and original MRIs was quantified with various image quality metrics, including structural similarity index measure (SSIM) and the accuracy of undersampled dCNN-reconstructed MRI on downstream radiological assessment of imaging biomarkers in oncology (automated artificial intelligence-based quantification of tumour burden and treatment response) was performed in the EORTC-26101 test dataset. The public NYU Langone Health fastMRI brain test dataset (558 patients and 558 examinations) was used to validate the generalisability and robustness of the dCNN for reconstructing MRIs from available multi-coil (parallel imaging) k-space data.FindingsIn the EORTC-26101 test dataset, the median SSIM of undersampled dCNN-reconstructed MRI ranged from 0·88 to 0·99 across different acceleration rates, with 0·92 (95% CI 0·92–0·93) for 10-times acceleration (R=10). The 10-times undersampled dCNN-reconstructed MRI yielded excellent agreement with original MRI when assessing volumes of contrast-enhancing tumour (median DICE for spatial agreement of 0·89 [95% CI 0·88 to 0·89]; median volume difference of 0·01 cm3 [95% CI 0·00 to 0·03] equalling 0·21%; p=0·0036 for equivalence) or non-enhancing tumour or oedema (median DICE of 0·94 [95% CI 0·94 to 0·95]; median volume difference of –0·79 cm3 [95% CI –0·87 to –0·72] equalling –1·77%; p=0·023 for equivalence) in the EORTC-26101 test dataset. Automated volumetric tumour response assessment in the EORTC-26101 test dataset yielded an identical median time to progression of 4·27 months (95% CI 4·14 to 4·57) when using 10-times-undersampled dCNN-reconstructed or original MRI (log-rank p=0·80) and agreement in the time to progression in 374 (95·2%) of 393 patients with data. The dCNN generalised well to the fastMRI brain dataset, with significant improvements in the median SSIM when using multi-coil compared with single-coil k-space data (p<0·0001).InterpretationDeep-learning-based reconstruction of undersampled MRI allows for a substantial reduction of scan times, with a 10-times acceleration demonstrating excellent image quality while preserving the accuracy of derived imaging biomarkers for the assessment of oncological treatment response. Our developments are available as open source software and hold considerable promise for increasing the accessibility to MRI, pending further prospective validation.FundingDeutsche Forschungsgemeinschaft (German Research Foundation) and an Else Kröner Clinician Scientist Endowed Professorship by the Else Kröner Fresenius Foundation.

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.

AbstractPurpose: Patients with glioblastoma (GBM) have a dismal prognosis. Although the DNA alkylating agent temozolomide (TMZ) is the mainstay of chemotherapy, therapeutic resistance rapidly develops in patients. Base excision repair inhibitor TRC102 (methoxyamine) reverses TMZ resistance in preclinical glioma models. We aimed to investigate the efficacy and safety of oral TRC102+TMZ in recurrent GBM (rGBM). Patients and Methods: A preregistered (NCT02395692), nonrandomized, multicenter, phase 2 clinical trial (BERT) was planned and conducted through the Adult Brain Tumor Consortium (ABTC-1402). Arm 1 included patients with bevacizumab-naïve GBM at the first recurrence, with the primary endpoint of response rates. If sufficient activity was identified, a second arm was planned for the bevacizumab-refractory patients. The secondary endpoints were overall survival (OS), progression-free survival (PFS), PFS at 6 months (PFS6), and toxicity. Results: Arm 1 enrolled 19 patients with a median of two treatment cycles. Objective responses were not observed; hence, arm 2 did not open. The median OS was 11.1 months [95% confidence interval (CI), 8.2–17.9]. The median PFS was 1.9 months (95% CI, 1.8–3.7). The PFS6 was 10.5% (95% CI, 1.3%–33.1%). Most toxicities were grades 1 and 2, with two grade 3 lymphopenias and one grade 4 thrombocytopenia. Two patients with PFS ≥ 17 months and OS > 32 months were deemed “extended survivors.” RNA sequencing of tumor tissue, obtained at diagnosis, demonstrated significantly enriched signatures of DNA damage response (DDR), chromosomal instability (CIN70, CIN25), and cellular proliferation (PCNA25) in “extended survivors.” Conclusions: These findings confirm the safety and feasibility of TRC102+TMZ in patients with rGBM. They also warrant further evaluation of combination therapy in biomarker-enriched trials enrolling GBM patients with baseline hyperactivated DDR pathways.

Cellular therapies, including chimeric antigen receptor T cell therapies (CAR-T), while generally successful in hematologic malignancies, face substantial challenges against solid tumors such as glioblastoma (GBM) due to rapid growth, antigen heterogeneity, and inadequate depth of response to cytoreductive and immune therapies, We have previously shown that GBM constitutively express stress associated NKG2D ligands (NKG2DL) recognized by gamma delta (γδ) T cells, a minor lymphocyte subset that innately recognize target molecules via the γδ T cell receptor (TCR), NKG2D, and multiple other mechanisms. Given that NKG2DL expression is often insufficient on GBM cells to elicit a meaningful response to γδ T cell immunotherapy, we then demonstrated that NKG2DL expression can be transiently upregulated by activation of the DNA damage response (DDR) pathway using alkylating agents such as Temozolomide (TMZ). TMZ, however, is also toxic to γδ T cells. Using a p140K/MGMT lentivector, which confers resistance to TMZ by expression of O(6)-methylguanine-DNA-methyltransferase (MGMT), we genetically engineered γδ T cells that maintain full effector function in the presence of therapeutic doses of TMZ. We then validated a therapeutic system that we termed Drug Resistance Immunotherapy (DRI) that combines a standard regimen of TMZ concomitantly with simultaneous intracranial infusion of TMZ-resistant γδ T cells in a first-in-human Phase I clinical trial (NCT04165941). This manuscript will discuss DRI as a rational therapeutic approach to newly diagnosed GBM and the importance of repeated administration of DRI in combination with the standard-of-care Stupp regimen in patients with stable minimal residual disease.

PURPOSE:High-dose methotrexate (HD-MTX) is the backbone of curative therapy for CNS lymphoma. Because of toxicity, MTX is administered in the inpatient setting along with hyperhydration and monitoring until MTX clearance is documented (3-5 days). Frequent hospitalizations result in patient time away from work, home, and exposure to potential iatrogenic/nosocomial complications. Here, we aim to demonstrate feasibility of HD-MTX administration in the outpatient setting with low-dose glucarpidase facilitating clearance. METHODS:This is a prospective nonrandomized study of outpatient HD-MTX followed by glucarpidase 2000u (ClinicalTrials.gov identifier: NCT03684980). Eligible patients had CNS lymphoma, creatinine <1.3 mg/dL, and previously tolerated HD-MTX. Patients were enrolled between May 2020 December 2021 for one HD-MTX treatment. Patients could re-enroll for subsequent doses of HD-MTX as eligibility and slots permitted. MTX 3.5 g/m2 was administered once over 2 hours, preceded by standard hydration and followed by an additional 2 hours of dextrose 5% in water with NaHCO3 75 mEq at 150 cc/h. Glucarpidase 2000u was administered once in the clinic 24 hours later. The primary end point was MTX level 48 hours after HD-MTX. RESULTS:Twenty doses of outpatient HD-MTX with glucarpidase were administered to seven patients. After 20 of 20 (100%) treatments, serum MTX levels were reduced to <100 nmol/L. Treatments were well-tolerated, and no admissions were required. One patient received additional outpatient hydration for elevated creatinine. Development of antiglucarpidase antibody was rare and did not affect treatment. CONCLUSION:Outpatient HD-MTX with glucarpidase is safe and well-tolerated and has the potential to alter standard treatment for CNS lymphoma.

Supplementary Figure S2: CNV signatures for all tumor samples.

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

2042 Background: γδ T cells can target NKG2D ligands that are upregulated on tumor cells after alkylating chemotherapy exposure. IN8bio’s DeltEx drug resistant immunotherapy (DRI) are genetically engineered γδ T cells expressing methylguanine-DNA methyltransferase (MGMT), which conveys TMZ resistance to enable concomitant therapy and continued surveillance against tumor cells. Updated results from the Phase 1 trial which fully enrolled adult newly diagnosed GBM patients with adequate organ function, KPS ≥ 70% follow. Methods: Cohorts (C) 1, 2 and 3 received 1, 3 or 6 doses (1 x 107 DRI cells/dose) into the resection cavity with 150 mg/m2 of IV TMZ on Day (D) 1 of each Stupp maintenance cycle. The primary endpoint is safety and secondary endpoints include survival; immunologic correlative analyses are included. Dose limiting toxicities (DLTs) are defined as treatment related ≥ grade (G) 3 cardiopulmonary or hepatic toxicity, G4 toxicity exceeding 72 hours or neurologic deterioration that exceeds 2 weeks. Results: 23 patients were enrolled, with 11 dosed and 2 awaiting dosing (61% male; median age 68 (range: 21-74); 92% IDH-WT, 54% MGMT unmethylated). No DLTs, cytokine release syndrome (CRS) or neurotoxicity (ICANS) are reported. Most common adverse events were decreased WBC/platelet count, asthenia, fatigue, hydrocephalus, headache, decreased appetite, urinary tract infection, thrombosis and balance disorder. Conclusions: γδ T cells successfully infused with peripheral TMZ-based lymphodepletion evidenced with near or below normal range T, B, and NK subsets for up to 1 year. The majority of dosed patients who received DRI exceeded the expected median PFS of 7 months (5.8-8.2 months) with Stupp alone and had manageable toxicity with a continued encouraging trend in PFS. Long-term follow-up for durability of PFS and OS continue. Clinical trial information: NCT04165941 . [Table: see text]

Supplementary Material: Clinical Trial Protocol.

Supplementary Table S1: Representativeness of study participants.