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11 result(s) for "Friker, Lea L."
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L-RNA aptamer-based CXCL12 inhibition combined with radiotherapy in newly-diagnosed glioblastoma: dose escalation of the phase I/II GLORIA trial
The chemokine CXCL12 promotes glioblastoma (GBM) recurrence after radiotherapy (RT) by facilitating vasculogenesis. Here we report outcomes of the dose-escalation part of GLORIA (NCT04121455), a phase I/II trial combining RT and the CXCL12-neutralizing aptamer olaptesed pegol (NOX-A12; 200/400/600 mg per week) in patients with incompletely resected, newly-diagnosed GBM lacking MGMT methylation. The primary endpoint was safety, secondary endpoints included maximum tolerable dose (MTD), recommended phase II dose (RP2D), NOX-A12 plasma levels, topography of recurrence, tumor vascularization, neurologic assessment in neuro-oncology (NANO), quality of life (QOL), median progression-free survival (PFS), 6-months PFS and overall survival (OS). Treatment was safe with no dose-limiting toxicities or treatment-related deaths. The MTD has not been reached and, thus, 600 mg per week of NOX-A12 was established as RP2D for the ongoing expansion part of the trial. With increasing NOX-A12 dose levels, a corresponding increase of NOX-A12 plasma levels was observed. Of ten patients enrolled, nine showed radiographic responses, four reached partial remission. All but one patient (90%) showed at best response reduced perfusion values in terms of relative cerebral blood volume (rCBV). The median PFS was 174 (range 58-260) days, 6-month PFS was 40.0% and the median OS 389 (144-562) days. In a post-hoc exploratory analysis of tumor tissue, higher frequency of CXCL12 + endothelial and glioma cells was significantly associated with longer PFS under NOX-A12. Our data imply safety of NOX-A12 and its efficacy signal warrants further investigation. Recent studies show that targeting CXCL12 can improve the effect of radiotherapy (RT) in preclinical models of glioblastoma (GBM). Here, the authors report the safety and preliminary efficacy of a phase I/II clinical trial investigating an L-RNA aptamer-based CXCL12 inhibitor (NOX-A12) in combination with RT in patients with newly-diagnosed GBM.
Flow cytometry protocol for cell death analysis in glioblastoma organoids: A technical note
Tumor organoid models have emerged as a promising tool in cancer research. By preserving intra- and intertumoral heterogeneity and structural integrity they provide a physiologically relevant platform for drug-response studies. However, valid methodological approaches for cell death analyses applying flow cytometry, particularly in complex, large organoids, are lacking. Using glioblastoma organoids (GBOs), we developed a flow cytometry protocol to quantify cell death as an important readout in cancer research. Human GBOs were generated out of tumor material from six patients. Temozolomide (TMZ) and lomustine (CCNU) were used as cytotoxic agents commonly employed in glioblastoma therapy. After treatment for 144 and 288 hours, single cell suspensions from densely-packed GBOs were generated through a combined approach of enzymatic and mechanical dissociation. Cells were permeabilized with Triton X and subsequently stained with propidium iodide (PI). PI staining labels fragmented nuclear DNA, yielding a hypodiploid sub-G1 peak in flow cytometry that markes cell death. After treatment for 288 hours with physiologically-relevant concentrations of TMZ and CCNU cell death rates reached up to 63% in our GBO model. Across three GBO populations, the impact of CCNU at the given concentration was more pronounced compared to that observed with TMZ and the cell death rates of treatment for 288 hours surpassed that of the 144-hour treatment. Both biological and technical replicates showed low variability. Hoechst 33258 staining on the same samples confirmed trends in cell death rates obtained from PI-based analysis. We further validated the treatment-induced effect using a plate-based lactate dehydrogenase release assay and measurements of GBO diameter. Our single-stain flow-cytometry protocol scales to large, dense organoids and provides a practical balance of performance, hands-on time, cost, specificity, and throughput. This protocol could support development and evaluation of subtype-specific therapeutic strategies in translational cancer research.
L-RNA aptamer-based CXCL12 inhibition combined with radiotherapy and bevacizumab in newly-diagnosed glioblastoma: expansion of the phase I/II GLORIA trial
Rapid vascular recovery is a key feature preceding glioblastoma (GBM) recurrence after radiotherapy (RT). We performed spatial expression analyses, providing a rationale for dual inhibition of two non-redundant, spatially distinct acting factors, CXCL12 and VEGF. Subsequently, we expanded a multicentric phase 1/2 trial (NCT04121455), which initially combined RT and the CXCL12-neutralizing L-RNA-aptamer olaptesed pegol (NOX-A12) in patients with incompletely resected, newly-diagnosed GBM lacking MGMT promoter methylation. The primary endpoint was safety, secondary endpoints included maximum tolerable dose, recommended phase 2 dose, NOX-A12 plasma levels, topography of recurrence, tumor vascularization, neurologic assessment in neuro-oncology (NANO), quality of life, median progression-free survival (PFS), 6-months PFS and overall survival (OS). For the expansion arm, six patients were included that additionally received the VEGF-targeting antibody bevacizumab (BEV) to RT and NOX-A12. Combinatory treatment was well-tolerated and safe with no treatment-related deaths, resulting in abrogated tumor perfusion (rCBV, FTB high ) and delayed tumor regrowth as per mRANO. Median progression-free (PFS) and overall survival (OS) after RT + BEV + NOX-A12 were 9.1 and 19.9 months, respectively, significantly outperforming RT + NOX-A12 ( p  = 0.009; p  = 0.021) in a post-hoc comparative analysis, with two patients exceeding 2-year OS. These findings establish proof-of-principle for dual inhibition of CXCL12 and VEGF in patients with newly-diagnosed GBM following RT. Recently, the dose escalation stage of the GLORIA trial investigating NOX-A12 (L-RNA aptamer-based CXCL12 inhibitor) in combination with radiotherapy in patients with glioblastoma was reported. Here, the authors report the preclinical rationale and an expansion arm of the GLORIA trial combining NOX-A12, radiotherapy and bevacizumab (anti-VEGF) in patients with newly diagnosed glioblastoma.
Outcome assessment of intraoperative radiotherapy for brain metastases: results of a prospective observational study with comparative matched-pair analysis
Purpose Intraoperative radiation therapy (IORT) is an emerging alternative to adjuvant stereotactic external beam radiation therapy (EBRT) following resection of brain metastases (BM). Advantages of IORT include an instant prevention of tumor regrowth, optimized dose-sparing of adjacent healthy brain tissue and immediate completion of BM treatment, allowing an earlier admission to subsequent systemic treatments. However, prospective outcome data are limited. We sought to assess long-term outcome of IORT in comparison to EBRT. Methods A total of 35 consecutive patients, prospectively recruited within a study registry, who received IORT following BM resection at a single neuro-oncological center were evaluated for radiation necrosis (RN) incidence rates, local control rates (LCR), distant brain progression (DBP) and overall survival (OS) as long-term outcome parameters. The 1 year-estimated OS and survival rates were compared in a balanced comparative matched-pair analysis to those of our institutional database, encompassing 388 consecutive patients who underwent adjuvant EBRT after BM resection. Results The median IORT dose was 30 Gy prescribed to the applicator surface. A 2.9% RN rate was observed. The estimated 1 year-LCR was 97.1% and the 1 year-DBP-free survival 73.5%. Median time to DBP was 6.4 (range 1.7–24) months in the subgroup of patients experiencing intracerebral progression. The median OS was 17.5 (0.5-not reached) months with a 1 year-survival rate of 61.3%, which did not not significantly differ from the comparative cohort (p = 0.55 and p = 0.82, respectively). Conclusion IORT is a safe and effective fast-track approach following BM resection, with comparable long-term outcomes as adjuvant EBRT.
From bedside to bench: New insights in epilepsy‐associated tumors based on recent classification updates and animal models on brain tumor networks
Low‐grade neuroepithelial tumors (LGNTs), particularly those with glioneuronal histology, are highly associated with pharmacoresistant epilepsy. Increasing research focused on these neoplastic lesions did not translate into drug discovery; and anticonvulsant or antitumor therapies are not available yet. During the last years, animal modeling has improved, thereby leading to the possibility of generating brain tumors in mice mimicking crucial genetic, molecular and immunohistological features. Among them, intraventricular in utero electroporation (IUE) has been proven to be a valuable tool for the generation of animal models for LGNTs allowing endogenous tumor growth within the mouse brain parenchyma. Epileptogenicity is mostly determined by the slow‐growing patterns of these tumors, thus mirroring intrinsic interactions between tumor cells and surrounding neurons is crucial to investigate the mechanisms underlying convulsive activity. In this review, we provide an updated classification of the human LGNT and summarize the most recent data from human and animal models, with a focus on the crosstalk between brain tumors and neuronal function. Animal modeling based on data from studies on humans aims to recapitulate primary developmental brain tumor features and serve as a tool to study the pathogenesis of epilepsy‐associated tumor processes, particularly tumor progression and neuronal hyperexcitability. Thus, understanding the interaction between brain tumor cells and neurons is critical to infer the mechanisms involved in tumor progression and neuronal hyperexcitability.
Preclinical evidence for the use of anti‐Trop ‐2 antibody‐drug conjugate Sacituzumab govitecan in cerebral metastasized castration‐resistant prostate cancer
Improved survival rates have been observed in castration-resistant prostate cancer (CRPC) due to advancements in treatment options. However, individuals with brain metastases still have limited therapeutic options and an unfavorable prognosis. Therefore, there is an urgent need to explore new therapeutic avenues, such as antibody-drug conjugates (ADCs), which have demonstrated significant clinical activity against active brain metastases in solid tumors. Our objective was to determine the expression levels of the ADC targets Trop-2 and NECTIN-4 in cerebral metastasized CRPC (mCRPC). Immunohistochemical staining of Trop-2 and NECTIN-4 with evaluation of H-score was performed in CRPC brain metastases (n = 31). Additionally, we examined Trop-2 protein expression in prostate cancer cell lines and studied their responsiveness to the anti-Trop-2 ADC Sacituzumab govitecan (SG) in vitro. Our analysis revealed that most patients exhibited moderate to strong Trop-2 expression [n = 27/31 with H-score ≥100, median H-score 220 (IQR 180-280)], while NECTIN-4 was absent in all cerebral metastases. Mechanistically, we demonstrated that the efficacy of SG depends on Trop-2 expression levels in vitro. Overexpression of Trop-2 in Trop-2-negative PC-3 cells led to sensitization to SG, whereas CRISPR-Cas9-mediated knockdown of Trop-2 in Trop-2-expressing DU-145 cells conferred resistance to SG. The substantial expression of Trop-2 in cerebral metastases, along with our preclinical in vitro results, supports the efficacy of SG in treating cerebral mCRPC. Thus, our results extend the understanding of the potential of ADCs in prostate cancer treatment and provide an additional treatment strategy for the challenging subset of patients with cerebral metastases.
Diffuse pediatric high-grade glioma of methylation-based RTK2A and RTK2B subclasses present distinct radiological and histomolecular features including Gliomatosis cerebri phenotype
Diffuse pediatric-type high-grade gliomas (pedHGG), H3- and IDH-wildtype, encompass three main DNA-methylation-based subtypes: pedHGG-MYCN, pedHGG-RTK1A/B/C, and pedHGG-RTK2A/B. Since their first description in 2017 tumors of pedHGG-RTK2A/B have not been comprehensively characterized and clinical correlates remain elusive. In a recent series of pedHGG with a Gliomatosis cerebri (GC) growth pattern, an increased incidence of pedHGG-RTK2A/B (n = 18) was observed. We added 14 epigenetically defined pedHGG-RTK2A/B tumors to this GC series and provided centrally reviewed radiological, histological, and molecular characterization. The final cohort of 32 pedHGG-RTK2A/B tumors consisted of 25 pedHGG-RTK2A (78%) and seven pedHGG-RTK2B (22%) cases. The median age was 11.6 years (range, 4–17) with a median overall survival of 16.0 months (range 10.9–28.2). Seven of 11 of the newly added cases with imaging available showed a GC phenotype at diagnosis or follow-up. PedHGG-RTK2B tumors exhibited frequent bithalamic involvement (6/7, 86%). Central neuropathology review confirmed a diffuse glial neoplasm in all tumors with prominent angiocentric features in both subclasses. Most tumors (24/27 with available data, 89%) diffusely expressed EGFR with focal angiocentric enhancement. PedHGG-RTK2A tumors lacked OLIG2 expression, whereas 43% (3/7) of pedHGG-RTK2B expressed this glial transcription factor. ATRX loss occurred in 3/6 pedHGG-RTK2B samples with available data (50%). DNA sequencing (pedHGG-RTK2A: n = 18, pedHGG-RTK2B: n = 5) found EGFR alterations (15/23, 65%; predominantly point mutations) in both subclasses. Mutations in BCOR (14/18, 78%), SETD2 (7/18, 39%), and the hTERT promoter (7/19, 37%) occurred exclusively in pedHGG-RTK2A tumors, while pedHGG-RTK2B tumors were enriched for TP53 alterations (4/5, 80%). In conclusion, pedHGG-RTK2A/B tumors are characterized by highly diffuse-infiltrating growth patterns and specific radiological and histo-molecular features. By comprehensively characterizing methylation-based tumors, the chance to develop specific and effective therapy concepts for these detrimental tumors increases.
Intraoperative or postoperative stereotactic radiotherapy for brain metastases: time to systemic treatment onset and other patient-relevant outcomes
Purpose Intraoperative radiotherapy (IORT) has become a viable treatment option for resectable brain metastases (BMs). As data on local control and radiation necrosis rates are maturing, we focus on meaningful secondary endpoints such as time to next treatment (TTNT), duration of postoperative corticosteroid treatment, and in-hospital time. Methods Patients prospectively recruited within an IORT study registry between November 2020 and June 2023 were compared with consecutive patients receiving adjuvant stereotactic radiotherapy (SRT) of the resection cavity within the same time frame. TTNT was defined as the number of days between BM resection and start of the next extracranial oncological therapy (systemic treatment, surgery, or radiotherapy) for each of the groups. Results Of 95 BM patients screened, IORT was feasible in 84 cases (88%) and ultimately performed in 64 (67%). The control collective consisted of 53 SRT patients. There were no relevant differences in clinical baseline features. Mean TTNT (range) was 36 (9 − 94) days for IORT patients versus 52 (11 − 126) days for SRT patients ( p  = 0.01). Mean duration of postoperative corticosteroid treatment was similar (8 days; p  = 0.83), as was mean postoperative in-hospital time (11 versus 12 days; p  = 0.97). Mean total in-hospital time for BM treatment (in- and out-patient days) was 11 days for IORT versus 19 days for SRT patients ( p  < 0.001). Conclusion IORT for BMs results in faster completion of interdisciplinary treatment when compared to adjuvant SRT, without increasing corticosteroid intake or prolonging in-hospital times. A randomised phase III trial will determine the clinical effects of shorter TTNT.
MSH2, MSH6, MLH1, and PMS2 immunohistochemistry as highly sensitive screening method for DNA mismatch repair deficiency syndromes in pediatric high-grade glioma
Pediatric high-grade glioma (pedHGG) can occur as first manifestation of cancer predisposition syndromes resulting from pathogenic germline variants in the DNA mismatch repair (MMR) genes MSH2 , MSH6 , MLH1 , and PMS2 . The aim of this study was to establish a generalized screening for Lynch syndrome and constitutional MMR deficiency (CMMRD) in pedHGG patients, as the detection of MMR deficiencies (MMRD) may enable the upfront therapeutic use of checkpoint inhibitors and identification of variant carriers in the patients’ families. We prospectively enrolled 155 centrally reviewed primary pedHGG patients for MMR-immunohistochemistry (IHC) as part of the HIT-HGG-2013 trial protocol. MMR-IHC results were subsequently compared to independently collected germline sequencing data (whole exome sequencing or pan-cancer DNA panel next-generation sequencing) available in the HIT-HGG-2013, INFORM, and MNP2.0 trials. MMR-IHC could be successfully performed in 127/155 tumor tissues. The screening identified all present cases with Lynch syndrome or CMMRD (5.5%). In addition, MMR-IHC also detected cases with exclusive somatic MMR gene alterations (2.3%), including MSH2 hypermethylation as an alternative epigenetic silencing mechanism. Most of the identified pedHGG MMRD patients had no family history of MMRD, and thus, they represented index patients in their families. Cases with regular protein expression in MMR-IHC never showed evidence for MMRD in DNA sequencing. In conclusion, MMR-IHC presents a cost-effective, relatively widely available, and fast screening method for germline MMRD in pedHGG with high sensitivity (100%) and specificity (96%). Given the relatively high prevalence of previously undetected MMRD cases among pedHGG patients, we strongly recommend incorporating MMR-IHC into routine diagnostics.
Transient MRI changes and neurological deterioration in glioblastoma upon SARS-CoV-2 infection
Purpose Little is known about the effect of SARS-CoV-2 infection on glioblastoma (GBM) growth, metabolism, and prognosis. Immunological changes within GBM tissue are potentially symptomatic, underlining the urgent need for a better understanding of this phenomenon. To date, the complex underlying biology has not been fully elucidated. A decisive role of the tumor microenvironment (TME) and the components of the immune system acting within it is assumed. Methods Immunohistochemical staining of SARS-CoV-2 spike protein and immune cell infiltration of TME was performed on the tumor tissue of one patient. This patient developed hemiparesis 14 days after symptomatic SARS-CoV-2 infection, leading to tumor diagnosis. Subsequently and after biopsy, there was an unexpectedly good response to chemotherapy only. In looking for further evidence of the potential of SARS-CoV-2 to influence the course of GBM, two additional adult patients that had transient MRI changes and neurological deterioration following SARS-CoV-2 infection were evaluated. Results In the patient for whom neurological deterioration in the course of SARS-CoV-2 led to GBM diagnosis, immunohistochemistry revealed virus-specific protein accumulation in the tumor cells, microglial activation, and the formation of T-cell nodules. In the other two patients, the findings were compatible with symptomatic pseudoprogression that occurred in a temporal relationship with SARS-CoV-2 infection. Conclusion The results indicate a possible association between clinically relevant changes in GBM biology and SARS-CoV-2 infection, with histological confirmation of SARS-CoV-2-associated changes within the tumor tissue. The exact pathomechanism and underlying inflammatory pathways require further investigation.