CTNI-07. LOMUSTINE/TEMOZOLOMIDE CHEMOTHERAPY FOR NEWLY DIAGNOSED MGMT-METHYLATED IDHWT GLIOBLASTOMA ACCORDING TO CETEG/NOA-09: REAL-WORLD EXPERIENCE IN A MULTICENTER COHORT

INTRODUCTION

The CeTeG/NOA-09 trial demonstrated superior median overall survival (mOS, 48.1 months) in MGMT-methylated glioblastoma treated with lomustine/temozolomide compared to temozolomide. We retrospectively analyzed an off-study cohort of patients treated with lomustine/temozolomide to gather real-world data on this new regimen.

METHODS

Adult patients from 20 centers in Germany, Austria and Switzerland were included. Inclusion criteria were MGMT-methylated IDHwt glioblastoma newly diagnosed prior to end of 2020, and lomustine/temozolomide treatment as part of first-line therapy.

RESULTS

321 patients with a median age of 57 years (range, 21-78) and a median follow-up of 19.9 months were included. In the whole cohort, mOS was 41.0 months (95%CI, 33.0 – not reached). In patients starting lomustine/temozolomide immediately upon initiation of radiotherapy strictly following the CeTeG protocol (88%), mOS was 52.8 months (35.8 – not reached) as compared to 24.6 months (17.6 – not reached) in patients starting lomustine/temozolomide after completion of radiotherapy/concomitant temozolomide (12%, logrank test: p = 0.06). Patients with a KPS < 80 had a shorter mOS of 19.7 months (95%CI, 16.6 – not reached) compared to 41.0 months (33.0 – not reached, p = 0.009) in KPS 80-100. Gross total resection (GTR, 53.9%) was associated with longer mOS (52.8 months, 95%CI 24.1 – not reached) compared to partial resection/biopsy (30.5 months, 95%CI 36.8 – not reached, p=0.004). Multivariable Cox regression analysis confirmed GTR (HR 0.66, p = 0.033) and younger age ( ≤ 50 years: HR 0.42, p = 0.001), but not KPS (80-100 vs. lower: HR 0.66, p = 0.12) as independent prognostic factors.

DISCUSSION

In this real-world multicenter cohort, survival was similar to the promising results of CeTeG/NOA-09. Further analyses should investigate a potentially reduced benefit from lomustine/temozolomide in patients with low KPS/no GTR and a possible detrimental effect from deferred lomustine/temozolomide initiation. The median follow-up is admittedly short, updated data will be presented.

NIMG-32. POSTPROGRESSION SURVIVAL AND MRI FEATURES AT PROGRESSION IN MGMT-METHYLATED GLIOBLASTOMA FOLLOWING TEMOZOLOMIDE (TMZ) OR CCNU/TMZ THERAPY - AN ANALYSIS OF THE CETEG/NOA-09-TRIAL

INTRODUCTION

In the randomized CeTeG/NOA-09 trial, combined CCNU/TMZ was superior to TMZ therapy regarding overall survival (OS) in newly diagnosed patients with MGMT-methylated glioblastoma. Using modified RANO criteria, however, progression-free survival (PFS) and pseudoprogression rates were similar in both arms. Exploring the hypothesis of undetected pseudoprogressions being accountable for this discrepancy, we analyzed patterns of postprogression survival (PPS) and MRI features at RANO-defined progression.

METHODS

86 CeTeG/NOA-09 patients with progression (modified RANO criteria) and MRI evaluable for standardized T1 and FLAIR volumetry at baseline and progression were included. Patients were further subdivided to short PPS (< 24 months) or long PPS (> 24 months) and a PPS/PFS ratio was calculated.

RESULTS

In the CCNU/TMZ arm, long PPS patients (n=10) tended to a shorter PFS (median 7.3 months) than short PPS patients in the same arm (n=33, 14 months, p=0.089, logrank test) and long PPS patients in the TMZ arm (n=9, 12.7 months, p=0.21). The mean PPS/PFS ratio in the long PPS group was markedly higher in the CCNU/TMZ arm (5.8) compared to the TMZ arm (3.3, p=0.043, Mann-Whitney test). Patients with long PPS of the CCNU/TMZ arm showed a nonsignificant tendency to a stronger volumetric increase in T1 enhancement (mean delta 6184,86 vs. 697.5 mm³) and FLAIR–T1-enhancement (mean delta 42671 vs 16860 mm³) at progression as compared to long PPS patients of the TMZ arm.

CONCLUSION

Combining a substantially increased PPS/PFS ratio (long OS despite particularly short PFS according to RANO) with indications for increased contrast enhancement and FLAIR volume at progression, the patients with long PPS in the CCNU/TMZ arm appear to differ from those in the TMZ arm. These observations support the hypothesis that this group (~25% of CCNU/TMZ-treated patients) contained patients with pseudoprogression undetected by modified RANO criteria.

Quantitative Signal Intensity in Fluid-Attenuated Inversion Recovery and Treatment Effect in the WAKE-UP Trial

Background and Purpose—

Relative signal intensity of acute ischemic stroke lesions in fluid-attenuated inversion recovery (fluid-attenuated inversion recovery relative signal intensity [FLAIR-rSI]) magnetic resonance imaging is associated with time elapsed since stroke onset with higher intensities signifying longer time intervals. In the randomized controlled WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke Trial), intravenous alteplase was effective in patients with unknown onset stroke selected by visual assessment of diffusion weighted imaging fluid-attenuated inversion recovery mismatch, that is, in those with no marked fluid-attenuated inversion recovery hyperintensity in the region of the acute diffusion weighted imaging lesion. In this post hoc analysis, we investigated whether quantitatively measured FLAIR-rSI modifies treatment effect of intravenous alteplase.

Methods—

FLAIR-rSI of stroke lesions was measured relative to signal intensity in a mirrored region in the contralesional hemisphere. The relationship between FLAIR-rSI and treatment effect on functional outcome assessed by the modified Rankin Scale (mRS) after 90 days was analyzed by binary logistic regression using different end points, that is, favorable outcome defined as mRS score of 0 to 1, independent outcome defined as mRS score of 0 to 2, ordinal analysis of mRS scores (shift analysis). All models were adjusted for National Institutes of Health Stroke Scale at symptom onset and stroke lesion volume.

Results—

FLAIR-rSI was successfully quantified in stroke lesions in 433 patients (86% of 503 patients included in WAKE-UP). Mean FLAIR-rSI was 1.06 (SD, 0.09). Interaction of FLAIR-rSI and treatment effect was not significant for mRS score of 0 to 1 ( P =0.169) and shift analysis ( P =0.086) but reached significance for mRS score of 0 to 2 ( P =0.004). We observed a smooth continuing trend of decreasing treatment effects in relation to clinical end points with increasing FLAIR-rSI.

Conclusions—

In patients in whom no marked parenchymal fluid-attenuated inversion recovery hyperintensity was detected by visual judgement in the WAKE-UP trial, higher FLAIR-rSI of diffusion weighted imaging lesions was associated with decreased treatment effects of intravenous thrombolysis. This parallels the known association of treatment effect and elapsing time of stroke onset.

Tumour necrosis factor receptor superfamily member 9 (TNFRSF9) is up-regulated in reactive astrocytes in human gliomas

AIMS

The prognosis of patients with malignant gliomas is still dismal despite maximum treatment. Novel therapeutic alternatives targeting tumorigenic pathways are, therefore, demanded. In murine glioma models, targeting of tumour necrosis factor receptor superfamily (TNFRSF) 9 led to complete tumour eradication. Thus, TNFRSF9 might also constitute a promising target in human diffuse gliomas. As there is a lack of data, we aimed to define the expression pattern and cellular source of TNFRSF9 in human gliomas.

METHODS

We investigated TNFRSF9 expression in normal human central nervous system (CNS) tissue and glioma specimens using immunohistochemistry, immunofluorescence and Western blotting techniques.

RESULTS

Our results show that TNFRSF9 is considerably up-regulated in human gliomas when compared with normal brain tissue. In addition, our data provides evidence for an immune cell-independent de novo expression pattern of TNFRSF9 in mainly non-neoplastic reactive astrocytes and excludes classic immunological cell types, namely lymphocytes and microglia as the source of TNFRSF9. Moreover, TNFRSF9 is predominantly expressed in a perivascular and peritumoural distribution with significantly higher expression in IDH-1 mutant gliomas.

CONCLUSIONS

Our findings provide a novel, TNFRSF9-positive, reactive astrocytic phenotype and challenge the therapeutic suitability of TNFRSF9 as a promising target for human gliomas.

ErbB2/HER2-Specific NK Cells for Targeted Therapy of Glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most common and malignant intracranial tumor in adults and currently incurable. To specifically target natural killer (NK) cell activity to GBM, we employed NK-92/5.28.z cells that are continuously expanding human NK cells expressing an ErbB2-specific chimeric antigen receptor (CAR).

METHODS

ErbB2 expression in 56 primary tumors, four primary cell cultures, and seven established cell lines was assessed by immunohistochemistry and flow cytometry. Cell killing activity of NK-92/5.28.z cells was analyzed in in vitro cytotoxicity assays. In vivo antitumor activity was evaluated in NOD-SCID IL2Rγ(null) (NSG) mice carrying orthotopic human GBM xenografts (6 to 11 mice per group) and C57BL/6 mice carrying subcutaneous and orthotopic ErbB2-expressing murine GBM tumors (5 to 8 mice per group). Statistical tests were two-sided.

RESULTS

We found elevated ErbB2 protein expression in 41% of primary GBM samples and in the majority of GBM cell lines investigated. In in vitro assays, NK-92/5.28.z in contrast to untargeted NK-92 cells lysed all ErbB2-positive established and primary GBM cells analyzed. Potent in vivo antitumor activity of NK-92/5.28.z was observed in orthotopic GBM xenograft models in NSG mice, leading to a marked extension of symptom-free survival upon repeated stereotactic injection of CAR NK cells into the tumor area (median survival of 200.5 days upon treatment with NK-92/5.28.z vs 73 days upon treatment with parental NK-92 cells, P < .001). In immunocompetent mice, local therapy with NK-92/5.28.z cells resulted in cures of transplanted syngeneic GBM in four of five mice carrying subcutaneous tumors and five of eight mice carrying intracranial tumors, induction of endogenous antitumor immunity, and long-term protection against tumor rechallenge at distant sites.

CONCLUSIONS

Our data demonstrate the potential of ErbB2-specific NK-92/5.28.z cells for adoptive immunotherapy of glioblastoma, justifying evaluation of this approach for the treatment of ErbB2-positive GBM in clinical studies.

Differential expression of vascular endothelial growth factor A, its receptors VEGFR-1, -2, and -3 and co-receptors neuropilin-1 and -2 does not predict bevacizumab response in human astrocytomas

BACKGROUND

A major hallmark of malignant progression in human astrocytomas is the formation of new blood vessels. Antiangiogenic therapy using the anti-vascular endothelial growth factor (VEGF)-antibody bevacizumab leads to increased progression-free survival in glioblastoma patients but does not influence their overall survival. To date, it is unclear why antiangiogenic therapy fails in many glioblastoma patients, while a small subpopulation profits considerably from this treatment.

METHODS

The aim of our study was to determine the expression of VEGF-A and its (co-) receptors by immunohistochemistry and to test the association with patient survival in 350 glioma patients. Additionally, VEGF-A expression was analyzed by in-situ hybridization. In 18 patients, the protein expression was compared with the bevacizumab response according to extended and modified RANO criteria.

RESULTS

We found a heterogeneous expression pattern of VEGF and its receptors in glioblastoma patients with significantly lower levels in WHO grade II and III tumors and normal-appearing brain tissue (P < .001). Pilocytic astrocytomas (WHO grade I) showed significantly higher VEGFR-1, -2 and neuropilin-1 levels as compared to WHO grade II and III astrocytomas (P < .01) but at lower levels than glioblastomas. The expression of neuropilin-2 was low in all tumors. There was neither a significant correlation between protein expression and patient survival nor between protein levels and bevacizumab response after modified RANO criteria.

CONCLUSION

Since our data indicate that beneficial response to bevacizumab treatment is independent of the expression of VEGF-A and its (co-) receptors, further investigation is needed to decipher the underlying mechanisms of antiangiogenic treatment response.

[Glial fibrillary acidic protein in patients with symptoms of acute stroke: diagnostic marker of cerebral hemorrhage]

Glial fibrillary acidic protein (GFAP) is a highly brain-specific protein that is expressed in large quantities in astrocytes and has important functions in terms of maintaining and stabilizing the cytoskeleton. Acute intracerebral hemorrhage leads to an immediate mechanical destruction of astroglial cells with the subsequent release of GFAP into the extracellular space and the bloodstream. On the other hand, necrosis, cytolysis and GFAP release does not occur before 6-12 h after symptom onset in ischemic stroke. Thus, in the early hours after stroke increased GFAP values could indicate intracerebral hemorrhage. This review article describes the underlying pathophysiology of the test and guides the reader through the available data. Potential implications regarding the prehospital triage of acute stroke patients are discussed, including the possibility to initiate hyperacute treatment, such as blood pressure reduction in patients with intracerebral hemorrhage. Other areas of interest for a potential GFAP test include traumatic brain injury and malignant gliomas.

Macrophage migration inhibitory factor (MIF) expression in human malignant gliomas contributes to immune escape and tumour progression

Macrophage migration inhibitory factor (MIF), which inhibits apoptosis and promotes angiogenesis, is expressed in cancers suppressing immune surveillance. Its biological role in human glioblastoma is, however, only poorly understood. We examined in-vivo expression of MIF in 166 gliomas and 23 normal control brains by immunohistochemistry. MIF immunoreactivity was enhanced in neoplastic astrocytes in WHO grade II glioma and increased significantly in higher tumour grades (III-IV). MIF expression was further assessed in 12 glioma cell lines in vitro. Quantitative RT-PCR showed that MIF mRNA expression was elevated up to 800-fold in malignant glioma cells compared with normal brain. This translated into high protein levels as assessed by immunoblotting of total cell lysates and by ELISA-based measurement of secreted MIF. Wild-type p53-retaining glioma cell lines expressed higher levels of MIF, which may be connected with the previously described role of MIF as a negative regulator of wild-type p53 signalling in tumour cells. Stable knockdown of MIF by shRNA in glioma cells significantly increased tumour cell susceptibility towards NK cell-mediated cytotoxicity. Furthermore, supernatant from mock-transfected cells, but not from MIF knockdown cells, induced downregulation of the activating immune receptor NKG2D on NK and CD8+ T cells. We thus propose that human glioma cell-derived MIF contributes to the immune escape of malignant gliomas by counteracting NK and cytotoxic T-cell-mediated tumour immune surveillance. Considering its further cell-intrinsic and extrinsic tumour-promoting effects and the availability of small molecule inhibitors, MIF seems to be a promising candidate for future glioma therapy.

Notes on the normalizer of a finite subgroup of GL(n,d,Z) in GL(n,d,Z)

A finite algorithm for calculating a finite set of generators for the normalizer of a finite subgroup G of GL(n,d,Z) in GL(n,d,Z) is presented. It is based on an algorithm for the normalizer of a finite subgroup G in GL(n,Z), which has been developed recently by Opgenorth. The normalizer of G in GL(n,d,Z) plays a role for superspace groups analogous to the role that the normalizer of G in GL(n,Z) plays for n-dimensional space groups. It is important for calculating superspace groups with the Zassenhaus algorithm and is needed for testing equivalence of superspace groups.

Response to methylphenidate in boys with attention-deficit hyperactivity disorder

The response to methylphenidate was examined in 36 boys, aged 7-11 y, with attention-deficit hyperactivity disorder (ADHD) in a double-blind, placebo-controlled, crossover design. Hyperactivity and conduct problems were significantly reduced during methylphenidate treatment. Stimulant medication was associated with improvements on tests of sustained attention, working memory and motor steadiness. When individual changes were studied, it was found that 83% showed a significant improvement in their hyperactivity at home or at school, and for 60% their levels of hyperactive behaviour were within the normal range. High levels of hyperactivity at school and relatively low age were significant predictors of normalization of hyperactivity in at least one setting. However, these predictors could only classify correctly 71% of the children. In clinical practice a trial with stimulants is indicated in ADHD children who show symptoms that are sufficiently severe to cause impairment at home and at school.

Altered reinforcement mechanisms in attention-deficit/hyperactivity disorder

The present study tested eight boys with attention-deficit/hyperactivity disorder (ADHD) and 12 normal boys (comparison group), aged 7-12 years, to investigate the hypothesis that ADHD is associated with a steeper and shorter delay-of-reinforcement gradient than is normal. A two-component schedule of reinforcement was used to deliver trinkets or coins as reinforcers in a game-like test. One component was marked by a signal. During this period reinforcers (coins or trinkets) were delivered every 30 s. This component is called a 30-s fixed interval (FI) schedule of reinforcement and measures changes in reactivity to reinforcers. The other component was in effect when the signal was turned off. Then no reinforcer was ever delivered. This is called an extinction (EXT) component and measures primarily sustained attention. The ADHD children gradually developed hyperactivity to a large extent consisting of bursts of responses with short interresponse times (IRTs) during both schedule components. The response bursts not only constituted a substantial portion of the ADHD overactivity, but may well be a key component of the behaviour commonly described as impulsiveness, the key behavioural characteristic of ADHD. In addition, the ADHD children showed behaviour during the extinction component that may well be described as a sustained-attention deficit: initially stopping when the signal was turned off and then resuming responding some time thereafter as if the signal had been turned on again. The comparison group ceased responding during extinction and did not show impulsiveness. The findings were in accordance with a steeper and shorter delay gradient in ADHD.

No vigilance deficit found in either young schizophrenic or ADHD subjects

Vigilance deficits have been found in both schizophrenic and ADHD subjects. The two patient groups have never been directly compared on any vigilance measure, however. In the present study 20 early-onset schizophrenics were compared to 20 ADHD adolescents on a Degraded Stimulus Continuous Performance Test (DS-CPT). A comparison group of 30 normal adolescents was also included. Results showed no significant differences between the three groups on any of the DS-CPT measures. Different hypotheses are put forth to explain the findings, among them that the task may be insensitive to identifying sustained attention deficits in adolescent populations.

Parent-reported symptoms of hyperactivity and attention deficits predict teacher-reported symptoms

The object of the study was to examine whether symptoms of attention problems and hyperactivity reported by parents predicted teacher-reported symptoms in a referred sample of boys with the DSM-III-R diagnosis of Attention-deficit Hyperactivity Disorder (ADHD). Data from 48 boys, 7-12 years, were gathered independently from parents and teachers using the Child Behavior Checklist, Teacher's Report Form and the ADHD Rating Scale. Base rate, positive predictive power and negative predictive power were calculated for each symptom and for clusters of symptoms. The positive predictive power for individual symptoms was reasonably high with a mean score of 80%, while the parent-teacher agreement (measured by phi correlations) was low. Our results indicate that in most children referred because of hyperactivity, inattention and impulsivity, parent reports are sufficient to make a diagnostic evaluation. However, when multiple informants are available, data should be obtained from different sources.