A novel EGFRvIII-T cell bispecific antibody for the treatment of glioblastoma

T cell bispecific antibodies (TCBs) are engineered molecules that bind both the T cell receptor and tumor-specific antigens. Epidermal growth factor receptor variant III (EGFRvIII) mutation is a common event in glioblastoma (GBM) and is characterized by the deletion of exons 2-7, resulting in a constitutively active receptor that promotes cell proliferation, angiogenesis and invasion. EGFRvIII is expressed on the surface of tumor cells and is not expressed in normal tissues making EGFRvIII an ideal neoantigen target for TCBs. We designed and developed a novel 2+1 EGFRvIII-TCB with optimal pharmacological characteristics and potent anti-tumor activity. EGFRvIII-TCB showed specificity for EGFRvIII and promoted tumor cell killing as well as T cell activation and cytokine secretion only in patient-derived models expressing EGFRvIII. Moreover, EGFRvIII-TCB promoted T cell recruitment into intracranial tumors. EGFRvIII-TCB induced tumor regression in GBM animal models, including humanized orthotopic GBM patient-derived xenograft (PDX) models. Our results warrant the clinical testing of EGFRvIII-TCB for the treatment of EGFRvIII-expressing GBMs.

Identification of Tumor Antigens Among the HLA Peptidomes of Glioblastoma Tumors and Plasma

Glioblastoma multiforme (GBM) is the most aggressive brain tumor with poor prognosis to most patients. Immunotherapy of GBM is a potentially beneficial treatment option, whose optimal implementation may depend on familiarity with tumor specific antigens, presented as HLA peptides by the GBM cells. Further, early detection of GBM, such as by a routine blood test, may improve survival, even with the current treatment modalities. This study includes large-scale analyses of the HLA peptidome (immunopeptidome) of the plasma-soluble HLA molecules (sHLA) of 142 plasma samples, and the membranal HLA of GBM tumors of 10 of these patients' tumor samples. Tumor samples were fresh-frozen immediately after surgery and the plasma samples were collected before, and at multiple visits after surgery. In total, this HLA peptidome analysis involved 52 different HLA allotypes and resulted in the identification of more than 35,000 different HLA peptides. Strong correlations were observed in the signal intensities and in the repertoires of identified peptides between the tumors and plasma-soluble HLA peptidomes of the individual patients, whereas low correlations were observed between these HLA peptidomes and the tumors' proteomes. HLA peptides derived from Cancer/Testis Antigens (CTAs) were selected based on their presence among the HLA peptidomes of the patients and absence of expression of their source genes from any healthy and essential human tissues, except from immune-privileged sites. Additionally, peptides were selected as potential biomarkers if their levels in the plasma-sHLA peptidome were significantly reduced after the removal of tumor mass. The CTAs identified among the analyzed HLA peptidomes provide new opportunities for personalized immunotherapy and for early diagnosis of GBM.

Publisher Correction: Actively personalized vaccination trial for newly diagnosed glioblastoma

The additional author support information was erroneously omitted from the Supplementary Information. This has been corrected online.

Identification of Tumor Antigens Among the HLA Peptidomes of Glioblastoma Tumors and Plasma

Glioblastoma multiforme (GBM) is the most aggressive brain tumor with poor prognosis to most patients. Immunotherapy of GBM is a potentially beneficial treatment option, whose optimal implementation may depend on familiarity with tumor specific antigens, presented as HLA peptides by the GBM cells. Furthermore, early detection of GBM, such as by a routine blood test, may improve survival, even with the current treatment modalities. This study includes large-scale analyses of the HLA peptidome (immunopeptidome) of the plasma-soluble HLA molecules (sHLA) of 142 plasma samples, and the membranal HLA of GBM tumors of 10 of these patients' tumor samples. Tumor samples were fresh-frozen immediately after surgery and the plasma samples were collected before, and at multiple visits after surgery. In total, this HLA peptidome analysis involved 52 different HLA allotypes and resulted in the identification of more than 35,000 different HLA peptides. Strong correlations were observed in the signal intensities and in the repertoires of identified peptides between the tumors and plasma-soluble HLA peptidomes of the individual patients, whereas low correlations were observed between these HLA peptidomes and the tumors' proteomes. HLA peptides derived from Cancer/Testis Antigens (CTAs) were selected based on their presence among the HLA peptidomes of the patients and absence of expression of their source genes from any healthy and essential human tissues, except from immune-privileged sites. Additionally, peptides were selected as potential biomarkers if their levels in the plasma-sHLA peptidome were significantly reduced after the removal of tumor mass. The CTAs identified among the analyzed HLA peptidomes provide new opportunities for personalized immunotherapy and for early diagnosis of GBM.

Outcome of cancer-related seizures in patients treated with lacosamide

OBJECTIVES

Lacosamide is an antiepileptic drug (AED), which has proven to be effective to control seizures, including acute conditions such as status epilepticus. The aim of this study is to describe the clinical experience with lacosamide in neuro-oncological patients.

MATERIALS AND METHODS

Multicenter retrospective study in patients with cancer-related seizures, who received lacosamide as an add-on therapy.

RESULTS

Forty-eight patients with benign and malignant tumors, including primary brain tumors, lymphomas, systemic cancer with central nervous system involvement, or paraneoplastic encephalitis, were included. Lacosamide was effective in the control of chronic seizures in patients with either benign or malignant tumors. The success rate was greater in malignant tumors, and drug-resistant epilepsies were more likely associated with benign tumors. Adverse events occurred in nearly 70% of patients, particularly in acute conditions and associated with the concomitant use of radio-/chemotherapy. Lacosamide-related adverse events were more likely somnolence and dizziness, which usually resolved after dose adjustment. After starting lacosamide, nearly half of the patients discontinued one of the baseline AEDs and decreased or discontinued dexamethasone. Fifteen patients with status epilepticus were treated with intravenous lacosamide, and 73% of them had their condition resolved without serious drug-related adverse events.

CONCLUSION

Lacosamide is an AED to consider in cases of cancer-related seizures. Lacosamide pharmacodynamics and pharmacokinetics allow the achievement of responder rates over 50% with no serious adverse effects, amelioration of side effects from other AEDs or radio-/chemotherapy, and no significant drug interactions. Furthermore, the intravenous formulation shows clear benefits in acute conditions such as status epilepticus.

Epileptic features and survival in glioblastomas presenting with seizures

INTRODUCTION

The prognostic value of seizures in patients with glioblastoma is currently under discussion. The objective of this research was to study the risk factors associated with seizures occurring at the diagnosis of glioblastoma and the role of seizures as a predictive factor for survival.

MATERIAL AND METHODS

We prospectively analyzed the clinical data over the course of the disease, baseline MR imaging, and histological characteristics (p53 overexpression, the Ki67 proliferation index, and presence of the IDH1 R132H mutation), in glioblastomas treated in a single hospital from November 2012 to July 2014. The study follow-up cutoff point was October 2015.

RESULTS

In total, 56 patients were recruited (57% men, mean age 57 years). Median baseline score on the Karnofsky performance scale was 80. Complete tumor debulking followed by radiochemotherapy was achieved in 58.9%. Mean survival was 13.6 months. Epileptic seizures were the presenting symptom in 26.6% of patients, and 44.6% experienced seizures at some point during the course of the disease. On multivariate analysis, the single factor predicting shorter survival was age older than 60 years (hazard ratio 3.565 (95%CI, 1.491-8.522), p=0.004). Seizures were associated with longer survival only in patients younger than 60 years (p=0.035). Younger age, the IDH1 R132H mutation, and p53 overexpression (>40%) were related to seizures at presentation. Baseline MRI findings, including tumor size, and the Ki67 proliferation index were not associated with the risk of epileptic seizures or with survival. Prophylactic antiepileptic drugs did not increase survival time.

CONCLUSIONS

Seizures as the presenting symptom of glioblastoma predicted longer survival in adults younger than 60 years. The IDH1 R132H mutation and p53 overexpression (>40%) were associated with seizures at presentation. Seizures showed no relationship with the tumor size or proliferation parameters.

Abstract 2654: GAPVAC-101 phase I trial: First data of an innovative actively personalized peptide vaccination trial in patients with newly diagnosed glioblastoma

The Glioma Actively Personalized Vaccine Consortium (GAPVAC; funded by the European Union Framework 7 Program) aims at treating newly diagnosed glioblastoma (GB) patients with two distinct actively personalized vaccines (APVACs).

Resected tumor material is analyzed for multiple biomarkers to characterize the tumor in depth and to enable the design of APVACs tailored to each individual patient: Tumor-specific mutations, the HLA peptidome and gene expression profile are assessed by next-generation sequencing, mass spectrometry and RNA microarray analysis, respectively. Further, the patient-individual immune status is investigated by assessment of leukapheresis samples utilizing an in vitro immunogenicity platform. Data are integrated to define two distinct APVACs for each patient: APVAC1 is composed of up to ten peptides selected from a pre-manufactured “warehouse”. The warehouse contains 59 HLA class I-binding and three class II-binding tumor-associated peptides frequently over-presented in GB. APVAC2 is composed of one or two peptides that are de novo synthesized for a given patient and preferentially represent mutation-bearing neo-epitopes.

After a preparation phase in which the warehouse was generated and setup of APVAC selection and manufacturing processes took place, the GAPVAC-101 phase I clinical trial was initiated. Primary endpoints of the study are assessment of safety, feasibility of APVAC manufacturing and biological activity.

The trial is conducted at six European centers and recruits HLA-A*02:01 or A*24:02-positive patients with newly diagnosed GB after gross total resection. Patients receive APVAC1 and APVAC2 vaccinations plus immunomodulators (poly-ICLC and GM-CSF) three and six months post study enrolment, respectively, and concurrent to maintenance temozolomide (TMZ).

As of November 2015, 11 patients have been enrolled, of whom six already received APVAC vaccines. Composition and manufacturing are ongoing for four patients. All APVACs were generated in time without ultimate failures. APVAC1 vaccines differ substantially with 31 out of 59 warehouse peptides have been selected at least once, indicating the need for personalization due to tumor heterogeneity even for non-mutated epitopes. In patients’ tumor samples an average of 40 non-synonymous mutations (including known driver mutations) were identified. Injection site reactions were the most frequent toxicities so far. One brain edema (Grade 3) and one allergic reaction (Grade 4)were observed, both potentially related to the vaccinations. First data on biological activity of APVACs and updated clinical data will be presented at the Annual Meeting.

In conclusion, the GAPVAC concept has been successfully translated into the clinics and so far demonstrated to be safe and feasible with its level of personalization matching the observed tumor heterogeneity.

Citation Format: Norbert Hilf, Katrin Frenzel, Sabrina Kuttruff-Coqui, Sandra Heesch, Sebastian Kreiter, Arie Admon, Valesca Bukur, Sjoerd van der Burg, Cecile Gouttefangeas, Judith R. Kroep, Marij Schoenmaekers-Welters, Jordi Piro, Berta Ponsati, Hans Skovgaard Poulsen, Ulrik Lassen, Francisco Martinez-Ricarte, Jordi Rodon, Juan Sahuquillo, Monika Stieglbauer, Stefan Stevanovic, Per thor Straten, Marco Skardelly, Ghazaleh Tabatabai, Michael Platten, David Capper, Andreas von Deimling, Valérie Dutoit, Hideho Okada, Christian Ottensmeier, Randi Kristina Feist, Jens Fritsche, Karoline Laske, Peter Lewandrowski, Martin Löwer, Regina Mendryzk, Miriam Meyer, Carsten Reinhardt, Bernhard Rössler, Anna Paruzynski, Nina Pawlowski, Colette Song, Stevermann Lea, Toni Weinschenk, Christoph Huber, Hans-Georg Rammensee, Pierre-Yves Dietrich, Wick Wolfgang, Ugur Sahin, Harpreet Singh-Jasuja. GAPVAC-101 phase I trial: First data of an innovative actively personalized peptide vaccination trial in patients with newly diagnosed glioblastoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2654.

Combined pleomorphic xanthoastrocytoma-ganglioglioma with BRAF V600E mutation: case report

Combined pleomorphic xanthoastrocytoma (PXA) and ganglioglioma (GG) is an extremely rare tumor, with fewer than 20 cases reported. The authors report a case of combined PXA-GG in an 18-year-old man with a history of seizures. The tumor showed necrosis and the BRAF V600E mutation on histological examination, with no evidence of tumor recurrence 1 year after gross-total resection. The BRAF V600E mutation was present, which suggests that both cell lineages may share a common cellular origin.

[Atypical ganglioglioma with BRAF V600E mutation: a case report and review of the literature]

INTRODUCTION

Gangliogliomas are rare tumours that affect young patients, appear predominantly in the temporal lobe and usually begin with epileptic seizures. Histologically they have a grade I of malignancy, with an anaplastic form that is catalogued as grade III in the 2007 WHO classification. Yet, there are tumours that do not meet the criteria of either grade and which offer clear prognostic differences with respect to those of grade I. These tumours would be atypical gangliogliomas (grade II), which are not considered in this classification. From the molecular point of view, the best known alteration in gangliogliomas is the BRAF V600E mutation, which worsens the prognosis of the lesion. The possible use of treatments targeted towards this mutated protein is especially relevant in this disorder.

CASE REPORT

A 21-year-old male, who had undergone surgery due to a ganglioglioma on two occasions. The neuro-pathological examination revealed histological features consistent with an intermediate grade of malignancy (grade II), with positive BRAF mutation.

CONCLUSIONS

The case presented here, together with those previously reported in the literature, reopens the debate on the definition of gangliogliomas in the 2007 WHO classification, and lends support to the fact that the next classification should again include atypical gangliogliomas (grade II), together with possible genetic mutations and molecular disorders.

Prognostic implications of epilepsy in glioblastomas

OBJECTIVES

The role of seizures and antiepileptic treatments associated with glioblastoma is a current topic of discussion. The objective of this study is to characterize and establish implications of epilepsy associated with glioblastoma.

PATIENTS AND METHODS

We retrospectively analyzed the medical history, focused on epileptic features of 134 histologically diagnosed glioblastoma over a period of 4 years.

RESULTS

The sample group had an average age of 56 years and 66% were male. Complete tumor resection was performed in 66% and 64.2% received further radio-oncologic treatment. The average survival rate was 12.4 months and 11.5% survived to 5 years. Epileptic seizures were the presentation symptom in 27% of cases and 51% suffered seizures during the disease, 26% become drug-resistant. Focal evolving to a bilateral convulsive seizures were the most frequent type. Epileptic seizures at presentation independently predicted longer survival (p<0.001). Furthermore, a history of epilepsy or seizures during disease improved survival. Late onset seizures, recurrences or status epilepticus during the course of the disease indicated tumor progression or the final stages of life. Prophylactic antiepileptic drugs did not prevent seizures. Similarly, there was no difference in survival between patients who did not use antiepileptic drugs and those using valproate or levetiracetam. Patients under 60 years, full oncologic treatment and secondary glioblastomas were factors that improved survival (p<0.001).

CONCLUSION

Previous history of epilepsy or the onset of seizures as a presentation symptom in glioblastomas predict longer survival. Half of patients have seizures during the course of the disease. Antiepileptic drugs alone do not increase survival in glioblastoma patients.

Intra-abdominal pressure: the neglected variable in selecting the ventriculoperitoneal shunt for treating hydrocephalus

OBJECTIVE

In the selection of a ventriculoperitoneal cerebrospinal fluid shunt, the intra-abdominal pressure (IAP) is traditionally neglected as a result of the idea that its value is close to 0 mmHg. Our aim was to explore the relationship between body mass index (BMI) and IAP with the goal of providing clinically relevant data that could help neurosurgeons to estimate IAP and select the appropriate shunt for patients with hydrocephalus and especially those with normal-pressure hydrocephalus syndrome.

METHODS

Sixty patients requiring the placement of a ventriculoperitoneal shunt were included in the study. We determined weight, BMI, and IAP. IAP was measured through an intraperitoneal catheter during the shunt surgery. To determine whether a linear relationship existed between quantitative variables, linear regression analysis was used.

RESULTS

BMI was 28.1 +/- 4.8 kg/m2. Eighteen patients (30%) had normal weight, 21 (35%) were moderately overweight, and 21 (35%) were obese. IAP was related to patient BMI. A significant positive linear correlation was identified between BMI and IAP (r = 0.52; P = 0.018) with a slope of 0.31 (P < 0.001) and an intercept of -5.5.

CONCLUSION

In our study, we determined that IAP had a strong positive linear relationship with BMI. This correlation was independent of sex. An IAP of 0 mmHg can, therefore, only be assumed for patients with a normal BMI who are recumbent. In obese or overweight patients, neurosurgeons should take IAP into account when selecting both the most adequate differential pressure valve to be implanted and in which distal cavity to place the distal catheter to avoid shunt underdrainage induced by high IAP.