3D volume growth rate evaluation in the EORTC-BTG-1320 clinical trial for recurrent WHO grade 2 and 3 meningiomas

BACKGROUND

We previously reported that tumor 3D volume growth rate (3DVGR) classification could help in the assessment of drug activity in patients with meningioma using three main classes and a total of five subclasses: class 1: decrease; 2: stabilization or severe slowdown; 3: progression. The EORTC-BTG-1320 clinical trial was a randomized phase II trial evaluating the efficacy of trabectedin for recurrent WHO 2 or 3 meningioma. Our objective was to evaluate the discriminative value of 3DVGR classification in the EORTC-BTG-1320.

METHODS

All patients with at least one available MRI before trial inclusion were included. 3D volume was evaluated on consecutive MRI until progression. 2D imaging response was centrally assessed by MRI modified Macdonald criteria. Clinical benefit was defined as neurological or functional status improvement or steroid decrease or discontinuation.

RESULTS

Sixteen patients with a median age of 58.5 years were included. Best 3DVGR classes were: 1, 2A, 3A and 3B in 2 (16.7%), 4 (33.3%), 2 (16.7%) and 4 (33.3%) patients, respectively. All patients with progression-free survival longer than 6 months had best 3DVGR class 1 or 2. 3DVGR classes 1 and 2 (combined) had a median overall survival of 34.7 months versus 7.2 months for class 3 (p=0.061). All class 1 patients (2/2), 75% of class 2 patients (3/4) and only 10% of class 3 patients (1/10) had clinical benefit.

CONCLUSIONS

Tumor 3DVGR classification may be helpful to identify early signals of treatment activity in meningioma clinical trials.

Leptomeningeal metastasis from solid tumours: EANO-ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up

•This Clinical Practice Guideline provides recommendations for managing leptomeningeal metastases from solid tumours. •The guideline covers clinical, imaging and cytological diagnosis, staging and risk assessment, treatment and follow-up. •A treatment and management algorithm is provided. •The author panel encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion.

Secondary post-tonsillectomy haemorrhage: is there evidence of diurnal and monthly variation in haemorrhage rates?

BACKGROUND

Anecdotally, secondary post-tonsillectomy haemorrhage tends to occur out-of-hours. This study sought to establish whether there is a link between haemorrhage and time of day, and examined correlations with month and with monthly temperature.

METHODS

Data were obtained for patients in our hospital undergoing surgical arrest of secondary post-tonsillectomy haemorrhage between January 2002 and December 2020. Haemorrhage timing was categorised into daytime (07:00-18:00), evening (18:00-22:00) and overnight (22:00-07:00). The chi-square test was used to assess diurnal and monthly variation in haemorrhage rates (p < 0.05). Pearson's correlation test was used to analyse monthly haemorrhage rates and average monthly temperature.

RESULTS

Fifty per cent of patients suffered post-tonsillectomy haemorrhage overnight and 28.1 per cent haemorrhaged in the evening, representing a significant difference (p = 0.018). The highest rate of haemorrhage was in July (2.96 per cent), which was statistically significant (p = 0.0024). There was a positive correlation between average monthly temperature and haemorrhage rate (Pearson's correlation = 0.478, p = 0.116004), although this was not significant.

CONCLUSION

Most post-tonsillectomy haemorrhages occur out-of-hours (78.1 per cent), which could be conveyed during the consent process. The haemorrhage rate is lower in winter, which may influence planned operating theatre scheduling.

Association of pre-radiotherapy tumour burden and overall survival in newly diagnosed glioblastoma adjusted for MGMT promoter methylation status

PURPOSE

We retrospectively evaluated the association between postoperative pre-radiotherapy tumour burden and overall survival (OS) adjusted for the prognostic value of O6-methylguanine DNA methyltransferase (MGMT) promoter methylation in patients with newly diagnosed glioblastoma treated with radio-/chemotherapy with temozolomide.

MATERIALS AND METHODS

Patients were included from the CENTRIC (EORTC 26071-22072) and CORE trials if postoperative magnetic resonance imaging scans were available within a timeframe of up to 4weeks before radiotherapy, including both pre- and post-contrast T1w images and at least one T2w sequence (T2w or T2w-FLAIR). Postoperative (residual) pre-radiotherapy contrast-enhanced tumour (CET) volumes and non-enhanced T2w abnormalities (NT2A) tissue volumes were obtained by three-dimensional segmentation. Cox proportional hazard models and Kaplan Meier estimates were used to assess the association of pre-radiotherapy CET/NT2A volume with OS adjusted for known prognostic factors (age, performance status, MGMT status).

RESULTS

408 tumour (of which 270 MGMT methylated) segmentations were included. Median OS in patients with MGMT methylated tumours was 117 weeks versus 61weeks in MGMT unmethylated tumours (p < 0.001). When stratified for MGMT methylation status, higher CET volume (HR 1.020; 95% confidence interval CI [1.013-1.027]; p < 0.001) and older age (HR 1.664; 95% CI [1.214-2.281]; p = 0.002) were significantly associated with shorter OS while NT2A volume and performance status were not.

CONCLUSION

Pre-radiotherapy CET volume was strongly associated with OS in patients receiving radio-/chemotherapy for newly diagnosed glioblastoma stratified by MGMT promoter methylation status.

P11.65.B GBM AGILE: A global, phase 2/3 adaptive platform trial to evaluate multiple treatment regimens in newly diagnosed and recurrent glioblastoma

Background

GBM AGILE (Glioblastoma Adaptive, Global, Innovative Learning Environment) is a biomarker based, multi-arm, international, seamless Phase 2/3 Response Adaptive Randomization platform trial designed to rapidly identify experimental therapies that improve overall survival and confirm efficacious experimental therapies and associated biomarker signatures to support new drug approvals and registration. It is a collaboration between academic investigators, patient organizations and industry, under the sponsorship of the non-profit organization, Global Coalition for Adaptive Research, to support new drug applications for newly diagnosed and recurrent GBM.

Material and Methods

The primary objective of GBM AGILE is to identify therapies that effectively improve overall survival in patients with newly diagnosed or recurrent GBM. Bayesian response adaptive randomization is used within subtypes of the disease to assign participants to investigational arms based on their performance. Operating under a master protocol, GBM AGILE allows multiple drugs from different pharmaceutical companies to be evaluated simultaneously and/or over time against a common control arm. Based on performance, a drug may graduate and move to a Stage 2 (Phase 3) within the trial, and the totality of the data can be used for a new drug application and registration process. New experimental therapies are added as information about promising new drugs is identified while other therapies are removed as they complete their evaluation. The master protocol/ trial infrastructure includes efficiencies through an adaptive trial design, shared control arm and operational processes such as risk-based monitoring and enhanced remote activities. With its adaptable structure, GBM AGILE has continued trial activation, inclusion of new investigational therapies, and enrollment globally through the challenges of a global pandemic.GBM AGILE provides an efficient mechanism to screen and develop robust information regarding the efficacy of proposed novel therapeutics and associated biomarkers for GBM and to quickly move therapies and biomarkers into clinic. GBM AGILE received initial approval from the United States FDA in April 2019, and in Europe through the Voluntary Harmonization Procedure (VHP) in April, 2021. As of 2022, AGILE has screened over 1000 patients studying multiple investigational treatments. Enrollment rates are 3 to 4 times greater than traditional GBM trials, with active sites averaging 0.75 to 1 patients/site/month.

Currently, there are 41 sites activated in the US, 4 in Canada and 2 in Switzerland and an estimated 24 sites yet to open in Germany, France, Switzerland, Italy and Austria. In addition to the continued expansion in Europe, effort is undergoing to extend the trial to China and Australia as well. Clinical trial information: NCT03970447

P09.03.A Associations of levetiracetam use with the safety and tolerability of chemoradiotherapy for patients with newly diagnosed glioblastoma

Background

Levetiracetam (LEV) is one of the most frequently used antiepileptic drugs (AED) for brain tumor patients with seizures. We hypothesized that toxicity of LEV and temozolomide-based chemoradiotherapy may overlap.

Patients and Methods

In a retrospective analysis of individual patient data using a pooled cohort of patients with newly diagnosed glioblastoma included in clinical trials prior to chemoradiotherapy (CENTRIC, CORE, AVAglio) or prior to maintenance therapy (ACT-IV), we tested associations of hematologic toxicity, nausea or emesis, fatigue, and psychiatric adverse events during concomitant and maintenance treatment with the use of LEV alone or with other AED versus other AED alone or in combination versus no AED use at the start of chemoradiotherapy and of maintenance treatment.

Results

Of 1681 and 2020 patients who started concomitant chemoradiotherapy and maintenance temozolomide, respectively, 473 and 714 patients (28.1% and 35.3%) were treated with a LEV-containing regimen, 538 and 475 patients (32.0% and 23.5%) with other AED, and 670 and 831 patients (39.9% and 41.1%) had no AED. LEV was associated with higher risk of psychiatric adverse events during concomitant treatment in univariable and multivariable analyses (RR 1.86 and 1.88, p&lt;0.001) while there were no associations with hematologic toxicity, nausea or emesis, or fatigue. LEV was associated with reduced risk of nausea or emesis during maintenance treatment in multivariable analysis (HR=0.80, p=0.017) while there were no associations with hematologic toxicity, fatigue, or psychiatric adverse events.

Conclusion

Any association of psychiatric adverse events with LEV did not persist beyond the concomitant treatment phase. Antiemetic properties of LEV may be beneficial during the maintenance temozolomide.

OS07.5.A Report from the pooled analysis of the randomized trials NORDIC, NOA-8 and CE.6 on elderly patients with glioblastoma

Background

The majority of patients diagnosed with glioblastoma are over 60 years old. Three randomized trials addressed the roles of radiotherapy (RT) and temozolomide (TMZ) for these patients. Two, the NORDIC and NOA-08 (N&N) compared RT versus TMZ head-to-head, the third, CE.6, randomized between hypofractionated RT and the combination of RT+TMZ. All showed significant benefit for the TMZ arms, especially for patients with MGMT promoter methylated tumors. An ongoing pooled analysis of these three trials focuses on identifying significant baseline prognostic factors and assess their value for predicting outcome in relation to treatment. The aim is improved selection of elderly patients with glioblastoma for their optimal treament; RT alone, TMZ with or without concomitant RT or palliative care.

Methods

The data of two phase 3 studies (N&N) were pooled to build a large dataset and findings are compared to CE.6 trial data. A re-assessment of the clinically most relevant MGMT cut-off is performed. The prognostic value of baseline clinical factors and quality of life scores, determined by the EORTC QLQ-30 and BN-20 questionnaires, are investigated. Data is also analysed to account for a possible impact of sex.

Results

The N&N dataset includes 715 and the comparative dataset (CE.6) 562 patients. Median age for N&N is 71 years and 73 for CE.6. In N&N and CE.6 respectively, 66.2% versus 70.5% underwent resection and 50.9% and 75.3% were on steroids at the time of study inclusion. In N&N, 401 patients received RT alone and 281 in CE.6, while 314 were randomized to TMZ alone in N&N and 281 to concomitant RT and TMZ in CE.6. For N&N MGMT promoter methylation status was successfully determined for 412 (57.6%) and 354 (63.0%) for CE.6. In a first report, patients with the combination of the comorbidities hypertension, diabetes and/or cerebrovascular insult had poorer prognosis when treated with TMZ.

Conclusion

An ongoing pooled analysis of the trials NORDIC, NOA-08 and CE.6 is expected to identify factors that will improve personalized medicine for elderly patients with glioblastoma. Reanalyzed MGMT promoter methylation data and the role of baseline quality of life for outcome will be reported.

P11.63.B Thrombocytopenia limits the feasibility of salvage lomustine chemotherapy in recurrent glioblastoma: a secondary analysis of EORTC 26101

Background

Chemotherapies used for the treatment of primary brain tumors frequently induce hematological toxicity. Thrombocytopenia represents the main cause of stopping chemotherapy for toxicity. Here we explored the incidence, and the consequences for treatment exposure and survival, of thrombocytopenia induced by lomustine chemotherapy at first recurrence of glioblastoma.

Methods

We performed a retrospective analysis of thrombocytopenia at first recurrence of glioblastoma, its consequences for treatment delivery, and associations with outcome in the phase II and III parts of EORTC 26101, a randomized trial designed to define the role of lomustine versus bevacizumab versus their combination in glioblastoma patients at first relapse.

Results

225 patients were treated with lomustine alone (median 1 cycle) (group 1) and 283 patients were treated with lomustine plus bevacizumab (median 3 lomustine cycles) (group 2). Among cycle delays and dose reductions of lomustine for toxicity, thrombocytopenia was the leading cause. Among 129 patients of group 1 and 187 patients of group 2 experiencing at least one episode of thrombocytopenia, 36 patients in group 1 and 93 in group 2 had their treatment modified because of thrombocytopenia. Lomustine was discontinued for thrombocytopenia in 16 patients (7.1%) in group 1 and in 38 patients (13.4%) in group 2. Patients with O6-methylguanine DNA methyltransferase (MGMT) promoter-methylated glioblastoma treated with lomustine alone experienced more interference with study treatment than patients with tumors without MGMT promoter methylation. On adjusted analysis accounting for major prognostic factors, treatment modification by thrombocytopenia was a positive prognostic factor for overall survival, and this effect was entirely driven by patients with tumors without MGMT promoter methylation only. Conversely, thrombocytopenia was associated with inferior progression-free survival in patients with MGMT promoter-methylated tumors, suggesting a link to insufficient lomustine exposure.

Conclusion

Drug-induced thrombocytopenia is a major limitation to adequate exposure to lomustine salvage chemotherapy in patients with recurrent glioblastoma. Its association with survival suggests that mitigating thrombocytopenia to allow enhanced drug exposure in patients with MGMT promoter methylated tumors might improve outcome.

OS08.8.A Integrin-specific CAR T cells for the treatment of glioblastoma

Background

Current standard of care for glioblastoma patients has limited therapeutic efficacy and novel innovative treatment strategies are urgently needed. One such strategy is chimeric antigen receptor (CAR) T cell therapy that has shown great success in hematological malignancies. αv integrins are overexpressed in several neoplasms and have already been used as therapeutic targets for small molecule inhibitors and antibodies, which did not cause major toxicities. Herein, we propose αv integrins as an ideal target for CAR T cell therapy in glioblastoma.

Material and Methods

CAR T cells targeting specific heterodimers (αvβ3, αvβ5 or αvβ8) were generated by transducing primary human T cells from healthy donors with a lentiviral vector expressing a second-generation CAR. Activity and specificity of CAR T cells was determined by co-culture assays with different glioma cells. Efficacy of CAR T cells to control tumor growth in vivo was investigated in clinically relevant orthotopic xenograft glioma mouse models. Additionally, we generated CAR T cells from T cells from a glioblastoma patient and measured their activity against the patient’s autologous tumor cells.

Results

All newly generated integrin-targeting CAR T cells exerted strong anti-glioma activity in vitro. Long-term and repetitive killing assays as well as cytokine-release measurements demonstrated highest activity of αvβ5 and αvβ8 integrin-specific CAR T cells. Antigen specificity of these cells was confirmed, as glioma cells with a CRISPR/Cas9-mediated knockout of the target antigen were resistant to CAR T cell-mediated cytotoxicity. Intratumoral injection of αvβ5 or αvβ8 CAR T cells significantly prolonged the survival and cured a substantial fraction of glioma-bearing mice in two different xenograft models. When used in a patient-derived setting, matched CAR T cells exerted strong anti-glioma activity.

Conclusion

We show strong and integrin-specific anti-glioma activity of CAR T cells developed from healthy donor T cells and glioblastoma-patient-derived T cells in vitro. αvβ5- and αvβ8-specific CAR T cells exerted the best therapeutic activity in two different xenograft glioma models in vivo. These data support the evaluation of integrin-specific CAR T cells as a therapeutic strategy in clinical neuro-oncology.

OS08.7.A Lomustine and the immunocytokine L19TNF are a promising treatment combination for recurrent glioblastoma

Background

Treatment options for recurrent glioblastoma are limited and with the possible exception of regorafenib, no agent has demonstrated superior activity to lomustine. Therefore, there is an urgent need for more effective treatment strategies for recurrent glioblastoma. Here, we investigated different treatment combinations based on the tumor-stroma targeting antibody-cytokine fusion protein L19TNF in preclinical glioma models and translated the most effective treatment combination to patients with recurrent glioblastoma.

Material and Methods

Orthotopic immunocompetent mouse glioma models were used to study the anti-glioma activity of L19TNF in combination with anti-PD1, bevacizumab or lomustine. Tumor growth was monitored by MRI. Flow cytometry and microscopy were used to characterize tumor-infiltrating-immune cells. MHC immunoaffinity purification and mass spectrometry were used to characterize the MHC immunopeptidome. Genetic mouse models were used to study immune-dependent effects. Subsequently, we translated the most efficient treatment combination to patients with recurrent glioblastoma within a phase I/II clinical trial (NCT04573192).

Results

The combination of L19TNF and lomustine demonstrated strong synergistic anti-tumor activity in two immunocompetent orthotopic glioma models and cured a majority of tumor-bearing mice. In contrast, combinations with anti-PD-1 or bevacizumab had only limited anti-glioma activity. Furthermore, compared to the monotherapies, the combination of L19TNF and lomustine led to the strongest increase in tumor-infiltrating lymphoid cells as demonstrated by flow cytometry and microsopy and to the highest number of peptides presented in the context of MHC-I. The treatment effect was abrograted in different genetic immunodeficient mouse models. The treatment combination of L19TNF and lomustine was well tolerated in the first patients treated within a phase I/II clinical trial and we observed partial tumor responses also in patients with an unmethylated MGMT promoter.

Conclusion

The combination of L19TNF and lomustine demonstrated promising anti-glioma activity and patients are currently recruited within a phase I/II clinical trial for patients with recurrent glioblastoma.

P10.20.A Mechanisms of synergistic glioma growth suppression by radiotherapy and MET inhibition

Background

Glioblastoma remains to be one of the most lethal solid cancers. Despite multi-modal therapy including surgery as safely feasible, radiotherapy and chemotherapy with the alkylating agent temozolomide, the median survival of affected patients is still limited to approximately one year on a population level. Thus, novel therapies are urgently needed. There is increasing interest in the role of the HGF/MET pathway in the response of glioblastoma to radiotherapy since MET may be involved in radioresistance via proinvasive and DNA damage response pathways.

Material and Methods

Here we assessed the role of the MET pathway in the response to radiotherapy in vitro and in vivo in syngeneic mouse glioma models and explored potential modes of action responsible for the synergistic effects of MET pathway inhibition and irradiation on tumor growth in vivo.

Results

Murine glioma cells express HGF and MET and show increased MET phosphorylation upon exposure to exogenous HGF. In vitro, glioma cell viability and proliferation are not affected by pharmacological MET inhibition using tepotinib or genetic MET inhibition using CRISPR/Cas9-engineered Met gene knockout and sensitization to irradiation by MET inhibition is not seen. In vivo, the combination of MET inhibition with focal radiotherapy mediates prolonged survival of syngeneic orthotopic glioma-bearing mice compared with either treatment alone. Complementary studies demonstrate that synergy is lost when gliomas are established and treated in immunodeficient mice, but also if MET gene expression is disrupted in the tumor of wildtype mice. Combination therapy suppresses a set of pro-inflammatory mediators that are upregulated by radiotherapy alone and which are positively regulated by transforming growth factor (TGF)-β. In line with this data, ex vivo analysis of mouse brains reveal increased TGF-β pathway activity upon irradiation alone that is counteracted by concomitant MET inhibition.

Conclusion

In summary, we demonstrate synergistic suppression of syngeneic glioma growth by irradiation and MET inhibition that requires MET expression in the tumor as well as an intact immune system. Clinical evaluation of this combined treatment approach in newly diagnosed glioblastoma is warranted.

P11.51.B Initial temozolomide monotherapy without radiotherapy might be of limited benefit in the treatment of astrocytoma, IDH-mutant, CNS WHO grade 2 and 3

Background

The role of temozolomide chemotherapy alone in isocitrate dehydrogenase (IDH-) mutant astrocytomas has not been conclusively determined. Radiotherapy might be superior to temozolomide alone. Recent studies have linked temozolomide therapy with poor clinical course and induction of hypermutation in IDH-mutant gliomas.

Material and Methods

In this retrospective, single-center study, 183 patients with astrocytoma, IDH-mutant, CNS WHO grade 2 or 3 according to WHO 2021 and diagnosed between 2000 and 2019 were included. Patients initially monitored by means of a wait-and-scan strategy, or treated with radiotherapy alone, or receiving temozolomide alone after histological sampling through biopsy or tumor resection were studied. Patient-related, clinical and imaging data were correlated with progression-free and overall survival. A matched-pair analysis accounting for post-surgical tumor volume was conducted.

Results

No significant differences in median age and clinical status at diagnosis was seen. WHO grades were balanced between patients treated with radiotherapy and temozolomide, but the proportion of WHO grade 2 gliomas was higher in the wait-and-scan cohort. Radiotherapy was associated with significantly longer overall survival than temozolomide (in years, 14.4 vs 10.7; p=0.02) and longer progression-free survival than temozolomide (in years, 6.2 vs 3.4, p=0.02) and wait-and-scan strategies (in years, 6.2 vs 4; p=0.03). Comparing wait-and-scan with temozolomide, survival was significantly longer in the wait-and-scan cohort (in years, not reached vs 10.7, p&lt;0.0001). An analysis of WHO grade 2 astrocytomas only also showed superior survival in the wait-and-scan cohort as compared to temozolomide (p=0.02). Of note PFS was similar overall and in WHO grade 2 astrocytomas.

Conclusion

The results suggest superiority of radiotherapy alone over temozolomide alone or wait-and-scan strategies in IDH-mutant WHO grade 2 and 3. Recent study results indicating that temozolomide might compromise prognosis in some IDH-mutant gliomas might be supported by our data, although caution in interpretation of retrospective data is required. The potential negative effects may only be apparent in the long-term.

P10.19.B An immunotoxin targeting CD317 for the treatment of glioblastoma

Background

CD317 is an interferon-inducible cell surface receptor expressed in several solid cancer types. HM1.24-ETA’ is a small immunotoxin with a CD317 single-chain variable fragment (svFv) antibody fused to a truncated version of Pseudomonas aeruginosa exotoxin A (ETA’) that is explored as a novel therapeutic approach in CD317-expressing tumors.

Material and Methods

CD317 mRNA expression in human gliomas and its association with survival was analyzed using the database of the Cancer Genome Atlas (TCGA). CD317 protein levels in human gliomas were assessed by immunohistochemistry. CD317 mRNA expression was assessed by RT-PCR and CD317 protein levels by flow cytometry in 13 human glioma cell lines in vitro. Efficacy of HM1.24-ETA’ was analyzed in acute cytotoxicity assays in vitro. Finally, HM1.24-ETA’ was evaluated in the intracranial human LN-229 glioma xenograft nude mouse model after intravenous injection.

Results

Interrogation of the TCGA database showed that increased CD317 mRNA expression correlated with grade of malignancy among isocitrate dehydrogenase (IDH) wildtype and IDH-mutant gliomas. Enhanced CD317 mRNA expression was associated with inferior survival in glioblastoma and astrocytoma, IDH-mutant, WHO grade 4. Immunohistochemistry confirmed CD317 overexpression in human glioblastoma compared to lower grade astrocytomas. CD317 was expressed heterogeneously on mRNA and protein levels in glioma cell lines in vitro. HM1.24-ETA’ induced acute cytotoxicity in CD317-positive glioma cells in vitro. CD317 expression and susceptibility to HM1.24-ETA’-induced cell death were enhanced by interferon-β. HM1.24-ETA’ prolonged survival in the LN-229 xenograft nude mouse model.

Conclusion

These data define CD317 as a novel target for treatment of human gliomas with immunoconjugates.

OS10.4.A A macrophage-based drug delivery platform for glioma treatment

Background

There is an urgent need for more effective treatment strategies against gliomas. At present, even though various drugs have potent anti-tumor activity in vitro, their application in vivo is limited by ineffective delivery and systemic toxicity. Therefore, novel strategies are needed to deliver these drugs effectively and safely to the tumor site. Here, we developed an adoptive transfer strategy against malignant brain tumors utilizing macrophages that are loaded with ferritin-protein cages containing drugs or other proteins and transfer these nanocarriers to cancer cells in vitro and in vivo.

Material and Methods

Live-time imaging, microscopy and flow cytometry were utilized to investigate the transfer of ferritin cages from loaded macrophages to human or mouse glioma cells. Co-cultures of glioma cells and macrophages loaded with ferritin-drug cages were used to study the anti-glioma activity in vitro and orthotopic immunocompetent mouse glioma models were used to study the anti-glioma activity in vivo. Affinity purification-mass spectrometry (AP-MS) was used to elucidate the mechanisms of transfer by characterizing the interactome of ferritin cages within macrophages and cancer cells.

Results

We observed a high transfer efficiency of ferritin-cages from loaded macrophages into human and mouse glioma cells in vitro in co-culture assays and confirmed the transfer from macrophages to glioma cells also in vivo upon intravenous or intratumoral treatment of GL-261 or CT-2A glioma-bearing mice. To study the anti-glioma activity with therapeutically active payloads, we loaded murine/human macrophages with ferritin cages carrying cytotoxic payloads. Co-culture of these loaded macrophages with murine or human glioma cells in vitro revealed a time- and concentration-dependent cytotoxicity to glioma cells. In vivo, intravenous or intratumoral administration of ferritin-drug protein cages was tolerated without toxicities and conferred a survival benefit in two orthotopic murine glioma models (GL-261 and CT-2A). Interactome studies of ferritin-cage-binding proteins revealed phagocytic and cytoskeleton re-arrangement pathways to be involved in uptake and transfer of ferritin-cages from macrophages to glioma cells.

Conclusion

This ‘Trojan Horse’ approach constitutes a promising platform to deliver cytotoxic drugs effectively and safely to gliomas and provides a rationale for clinical translation.

P17.19.B Incidence of treatment-associated imaging changes in newly diagnosed MGMT promoter-methylated glioblastoma treated with cilengitide (EORTC 26071 - CENTRIC study): interim analysis

Background

In patients with glioblastoma, radiological recurrence of enhancing tissue after chemoradiotherapy can originate from progressive disease (PD) or from pseudoprogression/treatment-associated changes. There are no widely approved consensus criteria for treatment-associated changes. In the randomised EORTC-CENTRIC study (NCT00689221), patients with MGMT promoter-methylated glioblastoma were treated with chemoradiotherapy or chemoradiotherapy with cilengitide, an integrin inhibitor. We assessed the rate of treatment-associated changes in these groups according to the modified response assessment in neuro-oncology (RANO) criteria of 2017.

Methods

CENTRIC patients from both study arms with ≥3 follow-up MRIs were included. Preliminary PD (PPD) was defined as a ≥25% increase of the sum of perpendicular diameter (SPD) of a new or increasing lesion compared to baseline or nadir on the T1-MRI with gadolinium. Subsequent PD was defined as a second ≥25% increase of the SPD, at least 4 weeks later, or as a new lesion outside the radiation field. Treatment-associated changes were defined as stabilisation on ≥2 follow-up MRIs after PPD, each one 4 weeks later, or partial/complete regression on ≥1 follow-up MRI 4 weeks later.

Results

In total, 4,051 MRIs from 584 patients were available. This interim analysis included data on 462 patients with similar proportions in the cilengitide and control arm (50.9% and 49.1%). Due to missing MRIs or values, 128 were excluded. Of the remaining 334 patients, 157 (47%) patients showed RANO measurable disease at baseline or nadir (median SPD, 0mm2; interquartile range (IQR) 552.1 (0-552.1). After chemoradiotherapy with or without cilengitide, PPD occurred in 214 patients (64.1%) after a median time of 6.08 months after finishing radiation (IQR 11.4 (2.4-13.8), and 3.65 months after baseline or nadir (IQR 6.4 (2.1-8.5). After follow-up of these 214 patients, treatment-associated changes were diagnosed in 62 (18.6%) and PD was diagnosed in 48 (14.4%). The remaining 104 (31.1%) patients had no further follow-up MRI after PPD, mostly because a clinical decision to call PD was made. In the cilengitide group of 178 patients, 37 (20.8%) patients developed treatment-associated changes, and 23 (12.9%) patients developed PD, whereas in the control group of 156 patients, 25 (16%) patients developed treatment-associated changes, and 25 (16%) patients PD.

Conclusion

With the modified RANO criteria, the rate of treatment-associated changes was low compared to previous studies in newly diagnosed MGMT promoter-methylated glioblastoma. This rate did not change with addition of cilengitide. RANO-recommended radiological follow-up was not always awaited, which reflects clinical practice. Full data will be presented.

Ultrafast temporal evolution of interatomic Coulombic decay in NeKr dimers

We investigate interatomic Coulombic decay in NeKr dimers after neon inner-valence photoionization [Ne⁺(2s^-1)] using a synchrotron light source. We measure with high energy resolution the two singly charged ions of the Coulomb-exploding dimer dication and the photoelectron in coincidence. By carefully tracing the post-collision interaction between the photoelectron and the emitted ICD electron we are able to probe the temporal evolution of the state as it decays. Although the ionizing light pulses are 80 picoseconds long, we determine the lifetime of the intermediate dimer cation state and visualize the contraction of the nuclear structure on the femtosecond time scale.

Ion and Electron Momentum Distributions from Single and Double Ionization of Helium Induced by Compton Scattering

We present the momentum distributions of the nucleus and of the electrons from double ionization of the helium atom by Compton scattering of photons with hν=40  keV. We find that the doubly charged ion momentum distribution is very close to the Compton profile of the nucleus in the ground state of the helium atom, and the momentum distribution of the singly charged ion to give a precise image of the electron Compton profile. To reproduce these results, nonrelativistic calculations require the use of highly correlated initial- and final-state wave functions.

Investigating charge-up and fragmentation dynamics of oxygen molecules after interaction with strong X-ray free-electron laser pulses

The X-ray-induced charge-up and fragmentation process of a small molecule is examined in great detail by measuring the molecular-frame photoelectron interference pattern in conjunction with other observables in coincidence.

My Baby's Movements: a stepped-wedge cluster-randomised controlled trial of a fetal movement awareness intervention to reduce stillbirths

OBJECTIVE

The My Baby's Movements (MBM) trial aimed to evaluate the impact on stillbirth rates of a multifaceted awareness package (the MBM intervention).

DESIGN

Stepped-wedge cluster-randomised controlled trial.

SETTING

Twenty-seven maternity hospitals in Australia and New Zealand.

POPULATION

Women with a singleton pregnancy without major fetal anomaly at ≥28 weeks of gestation from August 2016 to May 2019.

METHODS

The MBM intervention was implemented at randomly assigned time points, with the sequential introduction of eight groups of between three and five hospitals at 4-monthly intervals. Using generalised linear mixed models, the stillbirth rate was compared in the control and the intervention periods, adjusting for calendar time, study population characteristics and hospital effects.

MAIN OUTCOME MEASURES

Stillbirth at ≥28 weeks of gestation.

RESULTS

There were 304 850 births with 290 105 births meeting the inclusion criteria: 150 053 in the control and 140 052 in the intervention periods. The stillbirth rate was lower (although not statistically significantly so) during the intervention compared with the control period (2.2/1000 versus 2.4/1000 births; aOR 1.18, 95% CI 0.93-1.50; P = 0.18). The decrease in stillbirth rate was greater across calendar time: 2.7/1000 in the first versus 2.0/1000 in the last 18 months. No increase in secondary outcomes, including obstetric intervention or adverse neonatal outcome, was evident.

CONCLUSIONS

The MBM intervention did not reduce stillbirths beyond the downward trend over time. As a result of low uptake, the role of the intervention remains unclear, although the downward trend across time suggests some benefit in lowering the stillbirth rate. In this study setting, an awareness of the importance of fetal movements may have reached pregnant women and clinicians prior to the implementation of the intervention.

TWEETABLE ABSTRACT

The My Baby's Movements intervention to raise awareness of decreased fetal movement did not significantly reduce stillbirth rates.

OS12.7.A Characterization of intra-tumoral heterogeneity and differential immune activation during malignant progression of meningiomas on single cell level

BACKGROUND

As the most common intracranial tumor, meningiomas have caused increasing interest in the field of medical research. Based on their mutational profile, meningiomas can be separated into two main groups: NF2 altered meningiomas, which can occur at WHO grades 1 to 3, and non-NF2 mutant meningiomas with mutations in other genes, such as TRAF7, AKT1, KLF4, and SMO, which are usually of WHO grade 1. While this means that non-NF2 mutant meningiomas usually follow a benign course, risk stratification for NF2 mutant meningiomas remains difficult. As of now, the underlying mechanisms contributing to the malignant phenotype of some NF2 mutant meningiomas remained unknown, even though some molecular markers have been associated with an increased risk of recurrence. Here, we sought to characterize robust molecular subgroups for meningiomas and identify the critical steps in malignant progression of these tumors.

MATERIAL AND METHODS

We applied bulk RNA sequencing and proteomic analyses for 44 meningioma samples as well as single nuclei RNA sequencing analyses for an additional set of 26 meningiomas with a total of 46,002 nuclei. Both datasets comprised samples across the molecular landscape of meningiomas and WHO grades 1, 2, and 3.

RESULTS

The meningioma subgroups previously identified on epigenomic level were found consistently also on transcriptomic, proteomic, and phospho-proteomic levels. In addition, strong differences in numbers and types of infiltrating immune cells between subgroups became apparent. A decreased number of infiltrating macrophages and an activation to a more proinflammatory phenotype was observed for WHO grade 3 tumors. This observation correlated with lower expression levels of CSF1 in tumor cells of WHO grade 3 meningiomas, which was predicted to stimulate macrophages in WHO grade 1 and 2 tumors. Moreover, we identified several tumor cell subpopulations, each defined by a distinct phenotype, shared across samples. Their proportions in the tumor strongly depended on tumor grade. Especially a subpopulation characterized by an elevated stress response and TGFβ signaling activity was found specifically in WHO grade 3 cases.

CONCLUSION

Our findings establish molecular subgroups for meningiomas that are robust across multiple levels with characteristic differences in pathway activities and demonstrate a subtype-specific immune activation, both of which may be basis for novel treatment strategies.

OS05.3.A Temporal muscle thickness as surrogate parameter of sarcopenia in newly diagnosed glioblastoma patients:translational imaging analysis of the CENTRIC EORTC 26071-22072 and CORE trials

BACKGROUND

Temporal muscle thickness (TMT) was described as surrogate parameter of skeletal muscle mass. This study aimed to investigate the prognostic relevance of TMT in patients with newly diagnosed glioblastoma.

MATERIAL AND METHODS

TMT was assessed in cranial magnetic resonance images (MRI) of 755 pts enrolled in the CENTRIC EORTC 26071-22072 study (n=508) and CORE study (n=247). Predefined sex-specific TMT cutoff values were used to categorize “patients at risk of sarcopenia” and “patients with normal muscle status” at baseline. Furthermore, patients were categorized according to the extent of TMT loss over time. Cox models adjusted for other explanatory variables were used to evaluate the associations with progression-free survival (PFS) and overall survival (OS).

RESULTS

Overall, 510/755 (67.6%) patients were categorized as “at risk of sarcopenia” and 245/755 (32.4%) patients had normal muscle status at baseline. In both study cohorts patient at risk of sarcopenia at baseline had significantly higher risk of progression and death than patients with normal muscle status (CENTRIC: PFS = HR 0.16, 95% CI: 0.12, 0.21, p&lt;0.001; OS = HR 0.341, 95% CI: 0.27, 0.44, p &lt; 0.001; CORE: PFS = HR 0.29, 95% CI: 0.21, 0.39, p&lt;0.001; OS = HR 0.365, 95% CI: 0.27, 0.49, p&lt;0.001). In multivariate Cox models adjusted for other important prognostic parameters similar results were obtained. In patients at risk for sarcopenia the extent of TMT loss over time showed a significant inverse correlation with median OS times (CENTRIC: p &lt; 0.001, CORE: p = 0.005, log-rank test), but not in patients with normal baseline muscle mass in both study cohorts (CENTRIC: p = 0.538, CORE: p = 0.28, log-rank test).

CONCLUSION

TMT identifies patients with newly diagnosed glioblastoma at risk for progressive sarcopenia and adverse outcomes. Early intervention for muscle mass preservation including exercise and resistance training as well as nutritional support may prevent skeletal muscle loss and improve patient outcome in this group of patients.

PL03.3.A Development and characterization of CD317-specific CAR T cells as an innovative immunotherapeutic strategy against glioblastoma

BACKGROUND

Due to the limited success of existing therapies for gliomas, innovative therapeutic options are urgently needed. Chimeric antigen receptor (CAR) T cell therapy has been successful in patients with hematological malignancies. However, using this treatment against solid tumors such as glioblastomas is more challenging. Here, we generated CAR T cells targeting the transmembrane protein CD317 (BST-2, HM1.24) which is overexpressed in glioma cells and may therefore serve as a novel target antigen for CAR T cell-based immunotherapy.

MATERIAL AND METHODS

CAR T cells targeting CD317 were generated by lentiviral transduction of human T cells from healthy donors. The anti-glioma activity of CD317-CAR T cells was determined in lysis assays using different glioma target cell lines with varying CD317 expression levels. The efficiency of CD317-CAR T cells to control tumor growth in vivo was evaluated in clinically relevant orthotopic xenograft glioma mouse models.

RESULTS

We created a second-generation CAR construct targeting CD317 and observed strong anti-glioma activity of CD317-CAR T cells in vitro. Glioma cells with a CRISPR/Cas9-mediated CD317 knockout were resistant to CD317-specific CAR T cells, demonstrating their target antigen-specificity. Since CD317 is also expressed by T cells, transduction with a CD317-directed CAR resulted in fratricide of the transduced T cells. Silencing of CD317 in CAR T cells by integrating a specific shRNA into the CAR vector significantly increased the viability, proliferation and cytotoxic function of the CAR T cells. Importantly, intratumoral treatment with CD317-CAR T cells prolonged the survival and cured a significant fraction of glioma-bearing nude mice.

CONCLUSION

We demonstrate strong CD317-specific anti-tumor activity of CD317-CAR T cells against various glioma cell lines in vitro and in xenograft glioma models in vivo. These data lay a scientific basis for the subsequent evaluation of this therapeutic strategy in clinical neuro-oncology.

P13.17 CD95 gene silencing affects growth and invasiveness of glioma-initiating cells in a CD95L-independent manner

BACKGROUND

CD95 (Fas/APO-1) holds a dual role of potential relevance in tumor development. CD95-CD95 ligand (CD95L) signaling regulates apoptotic cell death in CD95-expressing cells, but non-apoptotic, tumor-promoting CD95-CD95L signaling has been likewise described. Therapeutic stimulation of apoptotic CD95 signaling is associated with major clinical side effects. However, inhibition of tumor-promoting CD95 signaling may represent a promising treatment strategy for human cancers where potential tumor-promoting CD95 functions include invasiveness and cancer cell stemness, including glioblastoma.

MATERIAL AND METHODS

In this study, CD95 and CD95L expression was characterized in human glioma-initiating cells (GIC) in vitro and in vivo. CD95 and CD95L gene knockout (KO) GIC were generated by means of CRISPR-Cas9 and the effects of gene silencing were evaluated by assessing growth, clonogenicity, invasiveness and tumorigenicity in nude mice.

RESULTS

CD95 expression and sensitivity to exogenous CD95L-induced apoptosis were confirmed in selected GIC in vitro. CD95L expression was not detected. Upon CD95 KO, all GIC acquired resistance to CD95L-induced apoptosis. Furthermore, despite the confirmed absence of CD95L expression in vitro, CD95 KO S-24 GIC revealed decreased cell growth, inferior sphere forming capacity and decreased invasiveness. These data suggested a CD95L-independent tumor-promoting role of CD95 in S-24 GIC. In vivo, however, CD95 KO did not prolong the survival of glioma-bearing mice. Analyses of further GIC models are ongoing.

CONCLUSION

These data demonstrate that, unlike CD95, CD95L is not expressed in cultured human GIC and that CD95-CD95L interactions are not required for tumor-promoting CD95 signaling. Although CD95 KO is detrimental for S-24 GIC in vitro, CD95 KO alone does not affect survival in S-24 human GIC xenograft-bearing mice.

OS06.7A METPlatform identifies brain metastasis vulnerabilities and predicts patient response to therapy

BACKGROUND

The diagnosis of brain metastasis involves high morbidity and mortality and remains an unmet clinical need in spite of being the most common tumor in the brain. Exclusion of these cancer patients from clinical trials is a major cause of their limited therapeutic options.

MATERIAL AND METHODS

We report a novel drug-screening platform (METPlatform) based on organotypic cultures which allows identifying effective anti-metastasis agents in the presence of the organ microenvironment. We have applied this approach to clinically relevant stages of brain metastasis using both experimental models and human tumor tissue (by performing patient-derived organotypic cultures - PDOCs -). We have also used METPlatform to perform unbiased proteomics of brain metastases in situ to identify potential novel mediators of this disease and explore resistance mechanisms to targeted therapy. Finally, we have exploited METPlatform as “avatars” to predict response to therapy in patients with primary brain tumors.

RESULTS

We identified heat shock protein 90 (HSP90) as a promising therapeutic target for brain metastasis. DEBIO-0932, a blood-brain barrier permeable HSP90 inhibitor, shows high potency against mouse and human brain metastases from different primary origin and oncogenomic profile at clinically relevant stages of the disease, including a novel model of local relapse after neurosurgery. Furthermore, in situ proteomic analysis of brain metastases treated with the chaperone inhibitor revealed non-canonical clients of HSP90 as potential novel mediators of brain metastasis and actionable mechanisms of resistance driven by autophagy. Combined therapy using HSP90 and autophagy inhibitors showed synergistic effects compared to sublethal concentrations of each monotherapy, demonstrating the potential of METPlatform to design and test rationale combination therapies to target metastasis more effectively. Finally, we show that brain tumor PDOCs predict the response of the corresponding patient to standard of care, thus proving the potential of METPlatform for improving personalized care in cancer.

CONCLUSION

Our work validates METPlatform as a potent resource for metastasis research integrating drug-screening and unbiased omic approaches that is fully compatible with human samples and questions the rationale of excluding patients with brain metastasis from clinical trials. We envision that METPlatform will be established as a clinically relevant strategy to personalize the management of metastatic disease in the brain and elsewhere.

Fourfold Differential Photoelectron Circular Dichroism

We report on a joint experimental and theoretical study of photoelectron circular dichroism (PECD) in methyloxirane. By detecting O 1s photoelectrons in coincidence with fragment ions, we deduce the molecule's orientation and photoelectron emission direction in the laboratory frame. Thereby, we retrieve a fourfold differential PECD clearly beyond 50%. This strong chiral asymmetry is reproduced by ab initio electronic structure calculations. Providing such a pronounced contrast makes PECD of fixed-in-space chiral molecules an even more sensitive tool for chiral recognition in the gas phase.

Prognostic significance of genome-wide DNA methylation profiles within the randomised, phase 3, EORTC CATNON trial on non-1p/19q deleted anaplastic glioma

Background

Survival in patients with IDH1/2-mutant (mt) anaplastic astrocytomas is highly variable. We have used the prospective phase 3 CATNON trial to identify molecular factors related to outcome in IDH1/2mt anaplastic astrocytoma patients.

Methods

The CATNON trial randomized 751 adult patients with newly diagnosed 1p/19q non-codeleted anaplastic glioma to 59.4 Gy radiotherapy +/− concurrent and/or adjuvant temozolomide. The presence of necrosis and/or microvascular proliferation was scored at central pathology review. Infinium MethylationEPIC BeadChip arrays were used for genome-wide DNA methylation analysis and the determination of copy number variations (CNV). Two DNA methylation-based tumor classifiers were used for risk stratification. Next-generation sequencing (NGS) was performed using 1 of the 2 glioma-tailored NGS panels. The primary endpoint was overall survival measured from the date of randomization.

Results

Full analysis (genome-wide DNA methylation and NGS) was successfully performed on 654 tumors. Of these, 432 tumors were IDH1/2mt anaplastic astrocytomas. Both epigenetic classifiers identified poor prognosis patients that partially overlapped. A predictive prognostic Cox proportional hazard model identified that independent prognostic factors for IDH1/2mt anaplastic astrocytoma patients included; age, mini-mental state examination score, treatment with concurrent and/or adjuvant temozolomide, the epigenetic classifiers, PDGFRA amplification, CDKN2A/B homozygous deletion, PI3K mutations, and total CNV load. Independent recursive partitioning analysis highlights the importance of these factors for patient prognostication.

Conclusion

Both clinical and molecular factors identify IDH1/2mt anaplastic astrocytoma patients with worse outcome. These results will further refine the current WHO criteria for glioma classification.

Strong Differential Photoion Circular Dichroism in Strong-Field Ionization of Chiral Molecules

We investigate the differential ionization probability of chiral molecules in the strong-field regime as a function of the helicity of the incident light. To this end, we analyze the fourfold ionization of bromochlorofluoromethane (CHBrClF) with subsequent fragmentation into four charged fragments and different dissociation channels of the singly ionized methyloxirane. By resolving for the molecular orientation, we show that the photoion circular dichroism signal strength is increased by 2 orders of magnitude.

From first symptoms to diagnosis: Initial clinical presentation of primary brain tumors

Background:

Despite modern imaging methods, a long symptom-to-diagnosis interval can be observed in patients with primary brain tumors.

Objective:

The study evaluated the initial and subsequent clinical presentation of patients with brain tumors in the context of time to diagnosis, localization, histology, and tumor grading.

Methods:

In this retrospective analysis of 85 consecutive patients with primary brain tumors, we assessed the presenting symptoms and signs. The analyses were based on entries from medical records at the Department of Neurology of Zurich University Hospital between 2005 and 2010.

Results:

A total of 54 men and 31 women with a mean age at diagnosis of 48 years were included. 60% of the patients present with a malignant tumor (World Health Organization grading III–IV), 24.7% with a benign tumor (I–II), and 15.3% were not classified. The interval between symptom onset and diagnosis varied from 1 day to 96 months (median: 39 days). High-grade tumors (III–IV) were diagnosed significantly earlier than low-grade tumors (II) after the first symptoms occurred (median: 26 vs. 138 days; z = −3.847, p < 0.001).

Conclusions:

Symptoms with a short symptom-to-diagnosis interval such as nausea/vomiting, seizures, as well as of personality change are assumed to contribute to a faster diagnosis in high-grade tumors. Visual disturbances and headaches, although occurring relatively seldom, did not contribute to a decrease in time to diagnosis and should therefore be considered for further diagnostic workup.

Addressing a national crisis: the spine hospital and department's response to the COVID-19 pandemic in New York City

In a very brief period, the COVID-19 pandemic has swept across the planet leaving governments, societies, and healthcare systems unprepared and under-resourced. New York City now represents the global viral epicenter with roughly one-third of all mortalities in the United States. To date, our hospital has treated thousands of COVID-19 positive patients and sits at the forefront of the United States response to this pandemic. The goal of this paper is to share the lessons learned by our spine division during a crisis when hospital resources and personnel are stretched thin. Such experiences include management of elective and emergent cases, outpatient clinics, physician redeployment, and general health and wellness. As peak infections spread across the United States, we hope this article will serve as a resource for other spine departments on how to manage patient care and healthcare worker deployment during the COVID-19 crisis.

Fampridine-induced changes in walking kinetics are associated with clinical improvements in patients with multiple sclerosis

Gait dysfunction is common in patients with multiple sclerosis (PwMS). Treatment with prolonged-release fampridine (PR-fampridine) improves walking ability in some PwMS. Associated fampridine-induced changes in the walking pattern are still poorly understood but may provide a better understanding of the mechanisms underlying the beneficial drug effects. 61 PwMS were treated with PR-fampridine in a randomized, monocentric, double-blind and placebo-controlled clinical trial with crossover design (FAMPKIN). Drug-induced improvements in walking speed (Timed-25-Foot Walk; T25FW) and endurance (6-Minute Walk Test; 6MWT) were quantified. In this sub-study of the FAMPKIN trial, fampridine-induced changes in kinetic gait patterns were analyzed by pressure-based foot print analysis during treadmill walking. Vertical ground reaction forces were analyzed during different gait phases. Kinetic data of 44 PwMS was eligible for analysis. During double-blind treatment with PR-fampridine, patients performed significantly better in the T25FW and 6MWT than during placebo treatment (p < 0.0001 for both). At the group level (n = 44), there were no significant changes of gait kinetics under PR-fampridine vs. placebo. However, we found relevant changes of walking kinetics regarding forces during loading, single limb and pre-swing phase in a patient sub-group (n = 8). Interestingly, this sub-group demonstrated superior responsiveness to PR-fampridine in the clinical walking tests compared to those patients without any fampridine-induced changes in kinetics (n = 36). Our results demonstrate fampridine-induced changes in gait kinetics in a sub-group of PwMS. These gait pattern changes were accompanied by improved clinical walking performance under PR-fampridine. These results shed some light on the biomechanical changes in walking patterns underlying enhanced fampridine-induced gait performance.

Embolization of tumor cells is rare in patients with systemic cancer and cerebral large vessel occlusion

BACKGROUND AND PURPOSE

Stroke is a dreaded complication in patients with cancer. Besides paraneoplastic coagulopathy, chemotherapy, radiotherapy and tumor-directed invasive procedures, circulating cancer cells may contribute to thrombus formation and embolic stroke. However, the incidence of tumor cells within the blood clots of cancer patients with stroke is unknown and the role of circulating tumor cells in the formation of cerebrovascular thrombi remains unclear.

METHODS

All patients who had undergone cerebrovascular thrombectomy at the University Hospital Zurich between 2014 and 2017 were screened for history of cancer. Clinical information was retrieved from the local stroke registry and the electronic charts and thrombi underwent a thorough histopathological re-review.

RESULTS

Thirty-two of 182 patients (18%) with thrombectomy had a history of cancer. The majority of patients had advanced stage cancer. However, even after extensive histopathological re-review, only one specimen revealed tumor cells in the thrombus: a 75-year-old patient with acute occlusion of the middle cerebral artery who had been diagnosed with non-small-cell lung cancer 8.1 months prior to stroke.

CONCLUSIONS

The presence of cancer cells in clots from cerebrovascular thrombectomy, indicative of a direct involvement of circulating tumor cells in the causation of stroke, is rare.

My Baby's Movements: a stepped wedge cluster randomised controlled trial to raise maternal awareness of fetal movements during pregnancy study protocol

Background

Stillbirth is a devastating pregnancy outcome that has a profound and lasting impact on women and families. Globally, there are over 2.6 million stillbirths annually and progress in reducing these deaths has been slow. Maternal perception of decreased fetal movements (DFM) is strongly associated with stillbirth. However, maternal awareness of DFM and clinical management of women reporting DFM is often suboptimal. The My Baby’s Movements trial aims to evaluate an intervention package for maternity services including a mobile phone application for women and clinician education (MBM intervention) in reducing late gestation stillbirth rates.

Methods/design

This is a stepped wedge cluster randomised controlled trial with sequential introduction of the MBM intervention to 8 groups of 3–5 hospitals at four-monthly intervals over 3 years.

The target population is women with a singleton pregnancy, without lethal fetal abnormality, attending for antenatal care and clinicians providing maternity care at 26 maternity services in Australia and New Zealand. The primary outcome is stillbirth from 28 weeks’ gestation. Secondary outcomes address: a) neonatal morbidity and mortality; b) maternal psychosocial outcomes and health-seeking behaviour; c) health services utilisation; d) women’s and clinicians’ knowledge of fetal movements; and e) cost. 256,700 births (average of 3170 per hospital) will detect a 30% reduction in stillbirth rates from 3/1000 births to 2/1000 births, assuming a significance level of 5%. Analysis will utilise generalised linear mixed models.

Discussion

Maternal perception of DFM is a marker of an at-risk pregnancy and commonly precedes a stillbirth. MBM offers a simple, inexpensive resource to reduce the number of stillborn babies, and families suffering the distressing consequences of such a loss. This large pragmatic trial will provide evidence on benefits and potential harms of raising awareness of DFM using a mobile phone app.

Trial registration

ACTRN12614000291684. Registered 19 March 2014.

Version

Protocol Version 6.1, February 2018.

Bevacizumab plus hypofractionated radiotherapy versus radiotherapy alone in elderly patients with glioblastoma: the randomized, open-label, phase II ARTE trial

Background

The addition of bevacizumab to temozolomide-based chemoradiotherapy (TMZ/RT → TMZ) did not prolong overall survival (OS) in patients with newly diagnosed glioblastoma in phase III trials. Elderly and frail patients are underrepresented in clinical trials, but early reports suggested preferential benefit in this population.

Patients and methods

ARTE was a 2 : 1 randomized, multi-center, open-label, non-comparative phase II trial of hypofractionated RT (40 Gy in 15 fractions) with bevacizumab (10 mg/kg×14 days) (arm A, N = 50) or without bevacizumab (arm B, N = 25) in patients with newly diagnosed glioblastoma aged ≥65 years. The primary objective was to obtain evidence for prolongation of median OS by the addition of bevacizumab to RT. Response was assessed by RANO criteria. Quality of life (QoL) was monitored by the EORTC QLQ-C30/BN20 modules. Exploratory studies included molecular subtyping by 450k whole methylome and gene expression analyses.

Results

Median PFS was longer in arm A than in arm B (7.6 and 4.8 months, P = 0.003), but OS was similar (12.1 and 12.2 months, P = 0.77). Clinical deterioration was delayed and more patients came off steroids in arm A. Prolonged PFS in arm A was confined to tumors with the receptor tyrosine kinase (RTK) I methylation subtype (HR 0.25, P = 0.014) and proneural gene expression (HR 0.29, P = 0.025). In a Cox model of OS controlling for established prognostic factors, associations with more favorable outcome were identified for age <70 years (HR 0.52, P = 0.018) and Karnofsky performance score 90%-100% (HR 0.51, P = 0.026). Including molecular subtypes into that model identified an association of the RTK II gene methylation subtype with inferior OS (HR 1.73, P = 0.076).

Conclusion

Efficacy outcomes and exploratory analyses of ARTE do not support the hypothesis that the addition of bevacizumab to RT generally prolongs survival in elderly glioblastoma patients. Molecular biomarkers may identify patients with preferential benefit from bevacizumab.

Clinical trial registration number

NCT01443676.

P11.45 Synergistic growth inhibition mediated by dual PI3K/mTOR pathway targeting and genetic or direct pharmacological AKT inhibition in human glioblastoma models

BACKGROUND

Molecular genetic aberrations in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway are common in human cancers including glioblastoma, yet, novel therapeutic approaches targeting this pathway in glioblastoma have had limited success to date.

MATERIAL AND METHODS

Here we analyzed the molecular mechanisms determining sensitivity to PI3K/mTOR inhibition using gene silencing or pharmacological target inhibition, and effects on proliferation, and clonogenicity or spherogenicity as readouts, in an extended panel of human long-term glioma cell (LTC) lines and glioma-initiating cells (GIC).

RESULTS

Glioma cells, including GIC in particular, were universally sensitive to growth inhibition induced by PQR309, a novel, dual pan-PI3K/mTOR antagonist in vitro. Cells exhibited profound growth arrest, but little apoptotic or necrotic cell death as confirmed by electron microscopy; yet, there was evidence of senescence. In vivo studies confirmed the anti-glioma activity of PQR309 in the orthotopic LN-229 glioma model. Cell lines with high basal levels of phosphorylated (active) AKT, low levels of phosphorylated (inactive) protein translation repressor eukaryotic initiation factor (eIF) 4E-binding protein 1 (p4E-BP1), and high levels of Ser9-phosphorylated (inactive) glycogen synthase kinase 3 beta (pGSK3ß) were more sensitive to PQR309. Accordingly, the activity of PQR309 was synergistically enhanced by AKT gene silencing or direct pharmacological AKT inhibition.

CONCLUSION

These data justify to explore combined targeted therapy approaches in glioblastoma that aim at down-regulating AKT function to enhance the therapeutic potential of dual PI3K/mTOR inhibitors.

PL3.3 Second interim and first molecular analysis of the EORTC randomized phase III intergroup CATNON trial on concurrent and adjuvant temozolomide in anaplastic glioma without 1p/19q codeletion

BACKGROUND

The 1st interim analysis of the CATNON trial showed benefit from adjuvant (adj) temozolomide (TMZ) on overall survival (OS) but remained inconclusive about concurrent (conc) TMZ. A 2nd interim analysis was planned after 356 events.

MATERIAL AND METHODS

The 2x2 factorial design phase III CATNON trial randomized 751 adult patients with newly diagnosed non-codeleted anaplastic glioma to either 59.4 Gy radiotherapy (RT) alone; the same RT with concTMZ; the same RT and 12 cycles of adjTMZ or the same RT with both concTMZ and adjTMZ (doi: 10.1016/S0140-6736(17)31442-3). MGMT promoter methylation (MGMTmeth) status was re-assessed with the Infinium Methylation EPIC Beadchip using the MGMT_STP27 model. Isocitrate dehydrogenase 1 and 2 (IDH) mutation (mt) status was assessed with glioma targeted Agilent SureSelect baits sequence using an Illumina HiSeq2500 Rapid PE100.

RESULTS

With a median follow-up of 56 months and 356 events, the hazard ratio (HR) for OS adjusted for stratification factors after concTMZ was 0.968 (99.1% CI 0.73, 1.28). 5-year OS was 50.2% with and 52.7% without concTMZ (95% CI [44.4, 55.7] and [46.9, 58.1]). An IDHmt was found in 335 of 480 assessed cases (70%). Median OS was 19 mo (95% CI 16.3, 22.3) in IDHwt tumors and 116 mo (95% CI 82.0, 116.6) in IDHmt tumors. The interaction test based on IDH status was significant (p=0.016) in the univariate HR analysis for OS after concTMZ (IDHwt, n=145, events=120, HR = 1.27, 95% CI 0.89, 1.82, p=0.19; IDHmt, n=335, events=92, HR= 0.67, 95% CI 0.44, 1.03, p=0.06). IDHmt was predictive of benefit from adjTMZ (IDHmt HR: 0.41, 95% CI 0.27, 0.64; IDHwt: HR 1.05, 95% CI 0.73, 1.52; interaction test p = 0.001). In IDHmt patients that received adjTMZ, the HR for OS after concTMZ was 0.71 (95% CI 0.35, 1.42, p=0.32). MGMTmeth was found in 288 of 410 assessed cases (70%), interaction test for concTMZ (p = 0.092) and adjTMZ (p = 0.166) did not reach statistical significance.

CONCLUSION

In the entire study cohort, concTMZ did not increase OS. However, in IDHmt tumors a trend towards benefit of concTMZ is present. AdjTMZ increased OS in IDHmt but not in IDHwt tumors. Further analyses and follow-up will allow full assessment of efficacy in the molecular subgroups.

PL3.2 Trabectedin for recurrent WHO grade II or III meningioma: a randomized phase II study of the EORTC Brain Tumor Group (EORTC-1320-BTG)

BACKGROUND

EORTC-1320-BTG investigated the activity, safety and quality of life of therapy with the tetrahydroisoquinoline alkaloid trabectedin (Yondelis®) in patients with recurrent higher-grade meningiomas. Trabectedin was originally derived from the Caribbean sea squirt, Ecteinascidia turbinata, and currently is manufactured by total synthesis.

METHODS

Adult patients with histological diagnosis of WHO grade II or III meningioma and radiologically documented progression after maximal feasible surgery and radiotherapy were randomly assigned in a 2:1 ratio to receive intravenous trabectedin (1.5 mg/m2every three weeks) or local standard of care (LOC). The primary endpoint was progression-free survival (PFS).

RESULTS

Within 22.1 months, we randomized a total of 90 patients (n=29 in LOC arm, n=61 in trabectedin arm) in 35 institutions and nine countries. In the LOC arm, the following treatments were administered: hydroxyurea (n=11), bevacizumab (n=9), none (n=4), chemotherapy (n=3), somatostatin analogue (n=1), combined chemotherapy and somatostatin analogue (n=1). With 71 PFS events, median PFS was 4.17 months in the LOC and 2.43 months in the trabectedin arm (hazard ratio [HR] for progression, 1.42; 80% CI, 1.00–2.03; p=0.204) with a PFS-6 rate of 29.1% (95% CI, 11.9%-48.8%) in the LOC and 21.1% (95% CI, 11.3%-32.9%) in the trabectedin arm. Median OS was 10.61 months in the LOC and 11.37 months in the trabectedin arm (HR for death, 0.98; 95% CI, 0.54–1.76; p=0.94).Grade 3 to 5 adverse events occurred in 44.4% (18.5% related, 4 serious adverse events, 0 lethal events) of the patients in the LOC and 59% (32.8% related, 57 serious adverse events and 2 toxic deaths) of patient in the trabectedin arm.

CONCLUSIONS

In this first prospective randomized trial performed in recurrent grade II or III meningioma, trabectedin did not improve PFS and OS and was associated with significantly higher toxicity as compared to LOC treatment. The data collected in this study may serve as benchmark for future clinical trials in this setting.

P14.108 Bevacizumab versus alkylating chemotherapy in recurrent glioblastoma

BACKGROUND

The use of alkylating chemotherapy versus bevacizumab for recurrent glioblastoma remains controversial. Here we tested the hypothesis that the activity of alkylators, but not that of bevacizumab, would be associated with the O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status

PATIENTS AND METHODS

We analyzed a cohort of patients treated at centers of the German Glioma Network or the University Hospital Zurich with alkylating agent-based chemotherapy (n=260) or bevacizumab without or with irinotecan (n=84) for first recurrence of glioblastoma. Outcome was stratified for MGMT status and cross-over to bevacizumab or alkylators at further tumor progression.

RESULTS

Median post-recurrence survival-1 (PRS-1) for patients receiving alkylating agent chemotherapy at first recurrence was longer than for patients receiving bevacizumab (11.1 versus 7.4 months, p<0.001). The use of alkylating agents was associated with longer PRS-1 for patients with a methylated versus an unmethylated MGMT promoter (p=0.017). For patients receiving bevacizumab, PRS-1 was not different with or without MGMT promoter methylation. PRS-1 was longer in the group receiving alkylating chemotherapy compared to bevacizumab for patients with a methylated (p<0.001) or unmethylated MGMT promoter (p=0.034). For patients with alkylators at first recurrence receiving bevacizumab at any further recurrence, PRS-1 was longer than in patients receiving bevacizumab first and alkylators thereafter (p=0.002).

CONCLUSION

This study confirms limited value of bevacizumab in recurrent glioblastoma independent of MGMT status. Alkylating agents have activity in recurrent glioblastoma, especially in the context of a methylated MGMT promoter.

OS7.2 Measuring change in health-related quality of life: the added value of analysis on the individual patient level in glioma patients in clinical decision making

BACKGROUND

Health-related quality of life (HRQoL) is often used as an outcome in glioma research, reflecting the impact of disease and treatment on a patient’s functioning and wellbeing. Data on changes in HRQoL scores may provide important information for clinical decision-making, but different analytical methods may lead to different interpretations of the impact of treatment on HRQoL. This study aimed to examine three different methods to evaluate change in HRQoL, and to study whether these methods result in different interpretations.

MATERIAL AND METHODS

HRQoL and sociodemographical/clinical data from 15 randomized clinical trials were combined. Change in HRQoL scores was analyzed in three ways: (1) at the group level, comparing mean changes in scale/item scores between treatment arms over time, (2) at the patient level per scale/item by calculating the percentage of patients that deteriorated, improved or remained stable on a scale/item per scale/item, and (3) at the individual patient level combining all scales/items.

RESULTS

Baseline and first follow-up HRQoL data were available for 3727 patients. At the group scale/item level (method 1), only the item ‘hair loss’ showed a significant and clinically relevant change (i.e. ≥10 points) over time, whereas change scores on the other scales/items showed a statistically significant change only (all p<.001, range in change score: 0.1–6.2). Analyses on the patient level per scale (method 2) indicated that, while a large proportion of patients had stable HRQoL over time (range 27–84%), many patients deteriorated (range: 6–43%) or improved (range: 8–32%) on a specific scale/item. At the individual patient level (method 3), the majority of patients (86%) showed both deterioration and improvement, while only 1% of the patients remained stable on all scales. Clustering on clinical characteristics (WHO performance status, sex, tumor type, type of resection, newly diagnosed versus recurrent tumor and age) did not identify subgroups of patients with a specific pattern of change in their HRQoL score.

CONCLUSION

Different analytical methods of changes in HRQoL result in distinct interpretations of treatment effects, all of which may be relevant for clinical decision-making. Additional information about the joint impact of treatment on all outcomes, showing that most patients experience both deterioration and improvement, may help patients and physicians to make the best treatment decision.

P12.08 Immunocytokines are a novel immunotherapeutic approach against glioblastoma

BACKGROUND

Glioblastoma is the most common malignant primary brain tumor in adults with an urgent need for novel treatment options. The administration of pro-inflammatory cytokines could be a potent immunotherapeutic approach to shift the balance between tumor-associated immunosuppression and immune activation. However, the systemic administration of therapeutically active doses of pro-inflammatory cytokines is not feasible due to toxic side effects and there is a need for strategies that enable a targeted delivery of pro-inflammatory cytokines to the tumor site.

METHODS

We investigated different antibody-cytokine fusion products that enable a targeted delivery of interleukin (IL)-2, IL-12 or tumor necrosis factor (TNF)-α to the tumor site by binding to a tumor-specific epitope of fibronectin. We investigated the expression of this tumor-specific epitope ex vivo in tumor-bearing mouse brains and human glioblastoma samples. Subsequently, we assessed the anti-tumor activity of IL-2, IL-12 or TNF-α fused to an antibody targeting this tumor-specific epitope in orthotopic syngeneic mouse glioma models.

RESULTS

The tumor-specfic extra domain B of fibronectin is expressed in murine glioma models and human glioblastoma samples. A fluorochrome-labeled antibody targeting this tumor-specific epitope accumulated at the tumor site in the brain in vivo upon systemic administration. IL-2, IL-12, or TNF-α fused to this antibody conferred a survival benefit in orthotopic tumor-bearing mice and cured a fraction of tumor-bearing mice. Mechanistically, antibody-fused TNF-α induced tumor necrosis and increased the activation of tumor-infiltrating natural killer (NK) cells, whereas antibody-fused IL-12 mainly boosted an anti-tumor immune response mediated by NK cells and T cells.

CONCLUSION

We demonstrate the expression of a tumor-specific epitope of fibronectin in glioblastoma and exploit this for the targeted delivery of IL-2, IL-12 or TNF-α to the tumor site. Our preclinical assessments indicate potent anti-tumor activity in orthotopic, syngneic glioma mouse models and reveal the mode of action for the different immunocytokines. Based on these findings, we initiated a phase I/II clinical trial in patients with recurrent glioma to investigate the targeted delivery of TNF-α (ClinicalTrials.gov identifier NCT03779230).

P14.124 EORTC 1709/CCTG CE.8: A phase III trial of marizomib in combination with standard temozolomide-based radiochemotherapy versus standard temozolomide-based radiochemotherapy alone in patients with newly diagnosed glioblastoma

BACKGROUND

The standard of care for patients with newly diagnosed glioblastoma includes maximal debulking surgery followed by radiotherapy (RT), and concomitant as well as maintenance therapy with the alkylating agent, temozolomide (TMZ). However, the prognosis remains poor and novel treatment strategies are urgently needed. Targeting the proteasome has been considered a promising anti-cancer approach for several years. Marizomib is a novel, irreversible and pan-proteasome inhibitor, which crosses the blood-brain barrier and has been assessed in phase I trials in patients with newly diagnosed or recurrent glioblastoma.

MATERIAL AND METHODS

EORTC 1709/CCTG CE.8 is a randomized, controlled, open label phase III superiority trial. Patients with histologically confirmed newly diagnosed glioblastoma and a performance status >70 are eligible. Patients are randomized in a 1:1 ratio to receive standard of care (TMZ/RT→TMZ) alone or TMZ/RT→TMZ plus marizomib. The study aims at enrolling 750 patients. Stratification factors include study site, age, performance status and extent of resection. The primary objective of this trial is to compare overall survival in patients receiving marizomib in addition to standard of care with those receiving standard treatment only. The testing strategy specifies the determination of this objective in the intent-to-treat population as well as the subgroup of patients with MGMT-unmethylated tumors. Secondary endpoints include progression-free survival, safety, neurocognitive function and quality of life. A translational research program has been set up. The study will be activated at approximately 50 EORTC sites across Europe, 25 sites in Canada and additional sites in the US. Patient recruitment started in June 2018 and as of April 29, 2019, a total of 164 patients have been randomized. An update on the enrolment status will be provided at the EANO meeting. ClinicalTrials.gov Identifier: NCT03345095

P11.08 Defining EGFR amplification status for clinical trial inclusion

BACKGROUND

Precision medicine trials targeting the epidermal growth factor receptor (EGFR) in glioblastoma patients require selection for EGFR-amplified tumors. However, there is currently no golden standard in determining the amplification status of EGFR or EGFRvIII expression. Here, we aimed to determine which technique and which cut-offs are suitable to determine EGFR amplification status.

MATERIAL AND METHODS

We compared fluorescent in-situ hybridization (FISH) and RT-qPCR data from patients screened for trial inclusion into the Intellance 2 clinical trial, with data from a panel-based next generation sequencing (NGS) platform (both DNA and RNA).

RESULTS

By using data from >1000 samples, we show which cut-offs are optimal to determine EGFR gene amplification by FISH. Our data also show that gene amplification (as determined by FISH) correlates with EGFR expression levels (as determined by RT-qPCR) with ROC analysis showing an under the curve area of up to 0.902. EGFR expression as assessed by RT-qPCR therefore may function as a surrogate marker for EGFR amplification. Our NGS data shows that EGFR copy numbers can strongly vary between tumors with levels ranging from 2 to more than 100 copies per cell. Levels exceeding 5 gene copies can be used to define EGFR-amplification by NGS; below this level FISH detects very few (if any) EGFR amplified nuclei and none of the samples express EGFRvIII.

CONCLUSION

Our data from central laboratories and diagnostic sequencing facilities, using material from patients eligible for clinical trial inclusion, help defining the optimal cut-off for various techniques to determine EGFR amplification for diagnostic purposes.