Toward noninvasive assessment of stroke risk in pediatric cerebrovascular disease

Background and Purpose: Moyamoya disease (MMD) is a progressive steno-occlusive cerebrovascular disease leading to recurrent stroke. There is a lack of reliable biomarkers to identify unilateral stroke MMD patients who are likely to progress to bilateral disease and experience subsequent contralateral stroke(s). We hypothesized that local hemodynamics are predictive of future stroke and set out to noninvasively assess this stroke risk in pediatric MMD patients. Methods: MR and X-ray angiography imaging were utilized to reconstruct patient-specific models of the circle of Willis of 6 pediatric MMD patients who had previous strokes, along with a control subject. Blood flow simulations were performed by using a Navier-Stokes solver within an isogeometric analysis framework. Vascular regions with a wall shear rate (WSR) above the coagulation limit (> 5000 s-1) were identified to have a higher probability of thrombus formation, potentially leading to ischemic stroke(s). Two metrics, namely, ″critical WSR coverage″ and ″WSR score″, were derived to assess contralateral stroke risk and compared with clinical follow-up data. Results: In two patients that suffered a contralateral stroke within two months of the primary stroke, critical WSR coverages exceeding 50% of vessel surface and WSR scores greater than 6x the control were present in multiple contralateral vessels. These metrics were not as conclusive in two additional patients with 3-to-5-year gaps between primary and contralateral strokes. However, a longitudinal study of one of these two cases, where a subsequent timepoint was analyzed, accurately predicted disease stabilization on the primary stroke side and an elevated contralateral stroke risk, thus indicating that post-stroke follow-up at regular intervals might be warranted for secondary stroke prevention. Conclusions: WSR-based metrics could be predictive of future stroke risk after an initial stroke in MMD patients. In addition, more accurate predictions may be possible by performing patient-specific hemodynamic analysis at multiple timepoints during patient follow-up to monitor changes in the WSR-based metrics.

Targeting 11-beta hydroxylase with [ 131I]IMAZA – a novel approach for the treatment of advanced adrenocortical carcinoma

Introduction Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with limited treatment options. Theranostic approaches with adrenal specific radiotracers hold promise for improved diagnostics and treatment. Here, we report a new theranostic approach to advanced ACC applying (R)-1-[1-(4-[ 123I]Iodophenyl)ethyl]-1H-imidazole-5-carboxylic acid azetidinyl amide ([ 123I]IMAZA) for diagnostic imaging and [ 131I]IMAZA for radionuclide therapy. Patients and treatment 69 patients with non-resectable, metastatic ACC were screened, using a diagnostic [ 123I]IMAZA scan. Patients with significant uptake in all tumoral lesions were offered treatment with [ 131I]IMAZA. Tumor response was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST version 1.1), and adverse effects were assessed by Common Toxicity Criteria (version 5.0). Results After screening, 13 patients were treated with a median of 25.7 GBq [ 131I]IMAZA (range, 18.1–30.7 GBq). Five individuals received a second treatment course. Best response was a decrease in the RECIST target lesions of 26% in two patients. Five patients with disease stabilization experienced a median progression-free survival of 14.3 months (range, 8.321.9). Median overall survival in all patients was 14.1 months (4.056.5) after therapy. Treatment was well tolerated, i.e. no severe toxicities (CTCAE grade ≥3) were observed. Conclusion In patients with advanced ACC refractory to standard therapeutic regimens, [ 131I]IMAZA treatment was associated with disease stabilization and non-significant tumour size reduction in a significant patient fraction and only limited toxicities. High [ 131I]IMAZA-uptake in tumor lesions was observed in 38.5% of patients with advanced ACC, rendering [131I] IMAZA a potential treatment option in a limited, well-defined patient fraction. Further clinical trials will be necessary to evaluate the full potential of this novel theranostic approach.

Refractory cytokine release reaction to Nivolumab: Following desensitization algorithms to optimize the management of drug hypersensitivity

Introduction Nivolumab is a fully human IgG4 monoclonal antibody (moAb) against programmed cell death protein 1, approved for the treatment of over ten types of cancer. The use of this and other moAbs has augmented considerably in recent years and this in turn has caused an increase of hypersensitivity reactions (HSR). Case report We present the case of a patient with metastatic renal cell cancer (RCC) who developed a grade 3 cytokine release reaction (CRR) to nivolumab. The maintenance of the symptoms despite of the administration of symptomatic treatment and slowing down the infusion rate of nivolumab during the 1st and 2nd reaction required an allergy evaluation of our patient. Management and outcome Skin testing to Nivolumab with negative results and baseline tryptase within the normal range were observed during the allergy workout. A desensitization protocol with specific premedication was applied to reintroduce the moAb, with no further issues. Moreover, a follow up of the patient in the oncology setting was done showing disease stabilization. Discussion The CRR should be treated by desensitization, in contrast to infusion reactions. The diagnosis of CRR phenotype is based on the clinical presentation and recently, and elevation of IL-6 levels has been shown to be a useful biomarker along with negative skin testing. We can conclude that after a HSR and an appropriate allergy diagnosis of CRR, nivolumab can be safely reintroduced by desensitization without reducing the target dose or the appropriate dilution concentration.

Results of combined nivolumab and ipilimumab therapy in patients with cancer

Introduction. The discovery of immune checkpoints and immune checkpoint inhibitors (ICI) became a breakthrough in medical oncology. Currently a search for most effective and safe schemes of ICI therapy for different cancers is ongoing.Aim. To evaluate the efficacy and tolerability of a combination of nivolumab and ipilimumab in cancer patients in real-life clinical practice.Materials and methods. The study included 30 patients: 13 patients with melanoma, 10 patients with renal cell carcinoma (RCC) and 7 patients with colorectal cancer (CRC). All patients underwent 4 courses of combined immune therapy (melanoma - nivolumab 1 mg/kg + ipilimumab 3 mg/kg; RCC, CRC – nivolumab 3 mg/kg + ipilimumab 1 mg/kg once per 21 days). Nivolumab monotherapy was continued after the achievement of disease control. Objective tumor response was registered in cases of partial or complete tumor regression. Treatment response was determined using iRECIST criteria.Results. Treatment effect assessment was performed in 91 patients. Complete response (CR) was registered in 1 (5%) patient, partial response (PR) – in 3 (16%) patients, disease stabilization – in 8 (42%) patients, unconfirmed progression – in 7 (37%) patients. No cases of disease progression were registered. Thus, objective response rate was 21%; disease control was achieved in 63% of patients. The most significant immune-mediated adverse effects (imAEs) were gastric toxicity (20%), 1–2 grade fatigue (13%) and 2–3 grade hepatotoxicity (10%).Conclusions. Combined nivolumab and ipilimumab therapy in patients with melanoma, CRC and RCC is associated with a high rate of disease control with acceptable toxicity profile.

Experience in treatment of glial tumors using the CyberKnife device

The study objective is to determine the effectiveness of stereotactic radiotherapy in treatment of glial cerebral tumors.Materials and methods. Results of using stereotactic radiotherapy in treatment of recurrent cerebral gliomas in 30 patients and primary glial tumor in 1 patient who couldn’t receive traditional radiotherapy were analyzed. Treatment was administered both to adults (n = 22) and children (n = 9). Prior to treatment all patients underwent pre-radiotherapy preparation in the form of contrast-enhanced magnetic resonance topometry of the brain, computed tomography with topometry, as well as positron emission tomography/computed tomography with amino acids (n = 21).Results. During treatment 2 patient developed grade II toxic reactions requiring emergency medical help. In 29 patients, treatment did not cause any complications. At the time of article preparation, 7 patients were alive; maximal follow-up period was 55 months, median follow-up duration was 8 months.Conclusion. Stereotactic radiotherapy can be used for disease stabilization. The results show effectiveness and safety of stereotactic radiotherapy as a salvage method of local treatment in patients with recurrent glial tumors of the brain.

The Role of Irinotecan-Bevacizumab as Rescue Regimen in Children With Low-Grade Gliomas: A Retrospective Nationwide Study in 72 Patients

Introduction. At least half of children with low-grade glioma (LGG) treated with first line chemotherapy experience a relapse/progression and may therefore need a second-line chemotherapy. Irinotecan-bevacizumab has been recommended in this setting in France after encouraging results of pilot studies. We performed a retrospective analysis to define the efficacy, toxicity and predictors for response to the combination on a larger cohort. Methods. We reviewed the files from children < 19 years of age with progressive or refractory LGG treated between 2009 and 2016 in 7 French centers with this combination. Results. 72 patients (median age 7.8 years [range, 1-19]) received a median of 16 courses (range, 3-30). The median duration of treatment was 9 months (range, 1.4-16.2). 96% of patients experienced at least disease stabilization. The 6-month and 2-year progression-free survivals (PFS) were 91.7% [IC 95% 85.5-98.3] and 38.2% [IC 95% 28.2-51.8] respectively. No progression occurred after treatment in 18 patients with a median follow-up of 35.6 months (range, 7.6-75.9 months). Younger patients had a worse PFS (p=0.005). Prior chemoresistance, NF1 status, duration of treatment, histopathology or radiologic response did not predict response. The most frequent toxicities related to bevacizumab included grades 1-2 proteinuria in 21, epistaxis in 10, fatigue in 12 and hypertension in 8 while gastro-intestinal toxicity was the most frequent side effect related to irinotecan. Conclusion. Bevacizumab-irinotecan is highly effective for children with recurrent LGG who have failed standard chemotherapy regimens whatever their clinical characteristics, only younger children had a worse PFS.

Leptomeningeal Dissemination of Low-Grade Neuroepithelial Tumor with FGFR1_TACC1 Fusion with Clinical and Radiographic Response to Pazopanib and Topotecan

<b><i>Introduction:</i></b> Low-grade neuroepithelial tumors are a heterogeneous group of central nervous system tumors that are generally indolent in nature but in rare instances can progress to include leptomeningeal dissemination. <b><i>Case Presentation:</i></b> We present a case of a patient with a low-grade neuroepithelial tumor of indeterminate type with symptomatic leptomeningeal dissemination despite 3 chemotherapy regimens and radiotherapy. Somatic targetable mutation testing showed an FGFR1_TACC1 fusion. Therapy with pazopanib/topotecan was initiated, and disease stabilization was achieved. He received pazopanib/topotecan for a total of 2 years and is now &#x3e;2 years from completion of treatment and continues to do well with no evidence of disease. <b><i>Discussion:</i></b> This case highlights the utility of targetable mutation testing in therapeutic decision-making and the novel use of systemic pazopanib/topotecan therapy for refractory low-grade neuroepithelial tumor within the context of this clinical situation and specific mutation profile.

INNV-17. RESPONSE TO AVAPRITINIB IN A PEDIATRIC SPINAL CORD H3K27M-MUTANT GLIOMA PATIENT

H3K27M-mutated diffuse midline glioma (H3K27M-DMG) may arise in the pons, thalamus and spinal cord generally having a dismal prognosis. Notably, H3K27M-DMG are driven by oligodendrocyte precursor-like cells which are partly sustained by PDGFRA signaling. Co-mutations including TP53, ACVR1, PDGFRA, KIT and PI3K pathway alterations are present in a subset of cases, and molecular profiling may allow detection of additional targetable alterations. However, small-molecule inhibitors often have limited efficacy associated with low blood-brain-barrier (BBB) penetration. Here, we report on a patient with spinal, leptomeningeal disseminated H3K27M-DMG treated with avapritinib, an orally administered, BBB-penetrant and highly selective KIT and PDGFR inhibitor, provided through a compassionate-use program. Initial therapy consisted of subtotal resection, focal radiotherapy and temozolomide (TMZ) resulting in disease stabilization. Ten months after diagnosis, leptomeningeal metastases were detected, biopsied and treated with local irradiation and TMZ. The patient subsequently received systemic and intrathecal chemotherapy augmented with dasatinib. Molecular analyses of the biopsy revealed the H3F3A and TP53 mutations present in the primary tumor, as well as de novo PDGFRA and KIT amplifications with gene copy numbers of 25 and 21, respectively. Upon further disease progression, therapy with avapritinib was initiated. Assessment of treatment response according to RANO criteria after four months revealed stable disease of the target lesion in the cerebellum and partial response of all non-target lesions. Avapritinib was generally well tolerated with lower limb edema (Grade 2), small intratumoral bleeding (Grade 1) and unrelated hydrocephalus (Grade 3) as reported adverse events. As precaution, treatment was interrupted and re-initiated after one week as the bleeding was stable. A ventriculoperitoneal shunt was implanted resolving the hydrocephalus. Pharmacokinetic analyses revealed up to 65% avapritinib plasma exposure and clinically relevant levels in cerebrospinal fluid. In summary, we report on first effective therapy of treatment-resistant H3K27M-DMG with avapritinib as clinical proof of concept.

VCN-01 disrupts pancreatic cancer stroma and exerts antitumor effects

BackgroundPancreatic ductal adenocarcinoma (PDAC) is characterized by dense desmoplastic stroma that limits the delivery of anticancer agents. VCN-01 is an oncolytic adenovirus designed to replicate in cancer cells with a dysfunctional RB1 pathway and express hyaluronidase. Here, we evaluated the mechanism of action of VCN-01 in preclinical models and in patients with pancreatic cancer.MethodsVCN-01 replication and antitumor efficacy were evaluated alone and in combination with standard chemotherapy in immunodeficient and immunocompetent preclinical models using intravenous or intratumoral administration. Hyaluronidase activity was evaluated by histochemical staining and by measuring drug delivery into tumors. In a proof-of-concept clinical trial, VCN-01 was administered intratumorally to patients with PDAC at doses up to 1×1011 viral particles in combination with chemotherapy. Hyaluronidase expression was measured in serum by an ELISA and its activity within tumors by endoscopic ultrasound elastography.ResultsVCN-01 replicated in PDAC models and exerted antitumor effects which were improved when combined with chemotherapy. Hyaluronidase expression by VCN-01 degraded tumor stroma and facilitated delivery of a variety of therapeutic agents such as chemotherapy and therapeutic antibodies. Clinically, treatment was generally well-tolerated and resulted in disease stabilization of injected lesions. VCN-01 was detected in blood as secondary peaks and in post-treatment tumor biopsies, indicating virus replication. Patients had increasing levels of hyaluronidase in sera over time and decreased tumor stiffness, suggesting stromal disruption.ConclusionsVCN-01 is an oncolytic adenovirus with direct antitumor effects and stromal disruption capabilities, representing a new therapeutic agent for cancers with dense stroma.Trial registration numberEudraCT number: 2012-005556-42 and NCT02045589.

Systemic chemotherapy of pediatric recurrent ependymomas: results from the German HIT-REZ studies

Purpose Survival in recurrent ependymoma (EPN) depends mainly on the extent of resection achieved. When complete resection is not feasible, chemotherapy is often used to extend progression-free and overall survival. However, no consistent effect of chemotherapy on survival has been found in patients with recurrent EPN. Methods Systemic chemotherapeutic treatment of 138 patients enrolled in the German HIT-REZ-studies was analyzed. Survival depending on the use of chemotherapy, disease-stabilization rates (RR), duration of response (DOR) and time to progression (TTP) were estimated. Results Median age at first recurrence was 7.6 years (IQR: 4.0–13.6). At first recurrence, median PFS and OS were 15.3 (CI 13.3–20.0) and 36.9 months (CI 29.7–53.4), respectively. The Hazard Ratio for the use of chemotherapy in local recurrences in a time-dependent Cox-regression analysis was 0.99 (CI 0.74–1.33). Evaluable responses for 140 applied chemotherapies were analyzed, of which sirolimus showed the best RR (50%) and longest median TTP [11.51 (CI 3.98; 14.0) months] in nine patients, with the strongest impact found when sirolimus was used as a monotherapy. Seven patients with progression-free survival > 12 months after subtotal/no-resection facilitated by chemotherapy were found. No definitive survival advantage for any drug in a specific molecularly defined EPN type was found. Conclusion No survival advantage for the general use of chemotherapy in recurrent EPN was found. In cases with incomplete resection, chemotherapy was able to extend survival in individual cases. Sirolimus showed the best RR, DOR and TTP out of all drugs analyzed and may warrant further investigation.