EXTH-56. ZIKA VIRUS TREATMENT SIGNIFICANTLY PROLONGS SURVIVAL IN A GLIOBLASTOMA PATIENT DERIVED XENOGRAFT MODEL

The poor median survival for patients with glioblastoma (GBM) of 15 months has not budged for the past 15 years, when the current standard treatment was first approved. There is no standard of care chemotherapy for recurrent GBM. We previously showed that Zika virus (ZIKV) tropism for GBM cells is mediated through the receptor tyrosine kinase, AXL. This infection is cytotoxic. In this study we show that ZIKV is an effective oncolytic virus in a patient derived xenograft model. Fox N1 Nude homozygous female mice 6-8-weeks-old were grouped into 4 experimental arms: two patient derived cell lines, each with a ZIKV treated and a control group. There were 12 mice in each arm. Animals received subcutaneous flank injections of GBM 8049 or its AXL CRISPR knockout 8049 AXLKO (2x106 cells). When tumors reached 200 mm3, mice received intra-tumoral injection of 2.5x106 ZIKV particles or saline. ZIKV induced complete tumor remission in 22 of 24 animals (8049: 11/12; 8049 AXLKO: 11/12). There was no tumor remission in the saline treated animals. Median survival of 8049 and 8049 AXLKO ZIKV treated mice was 124 days and 125 days, respectively. This is compared to median survival of control animals 8049: 42 days; 8049 AXLKO: 46 days (P= 0.001). Among ZIKV treated mice, there were two recurrences: one in the 8049 tumor (24 days after significant tumor remission) and one 8049 AXLKO tumor (7 days after significant tumor remission). We conclude that ZIKV should be considered a candidate oncolytic virus for GBM.

Ten-Year Outcomes of Intravitreal Bevacizumab for Myopic Choroidal Neovascularization: Analysis of Prognostic Factors

The current standard treatment of myopic choroidal neovascularisation (mCNV) is intravitreal injection of VEGF antagonists. This study was proposed to assess efficacy and safety of intravitreal bevacizumab (IVB) for the treatment of mCNV across a 10-year follow-up. Thirty eyes of thirty patients with treatment-naïve mCNV who underwent IVB and were followed up with for a minimum of ten years were recruited for the present retrospective cohort study. All participants were treated with three monthly IVB at baseline and then evaluated and treated under pro re nata (PRN) schedule. Outcome measures were to determine BCVA changes over years and identify the predictive factors of both final visual outcome and need for retreatment. Analysis of the main involved prognostic factors with correlations among variables is reported. Visual acuity remained stable at 10-year follow-up (p = 0.001) with the greatest improvement at 2 years (p < 0.0001) in all CNV locations. Baseline BCVA correlated positively with final BCVA (β = 0.88, p < 0.0001, R2: 0.75). No predictive factors for the need of additional injections were identified. Retinal and choroidal thickness significantly reduced over time but without correlation with the number of injections. CNV max height and area significantly decreased at 10 years (p < 0.0001 and p = 0.003, respectively), with complete regression of mCNV lesion in 40% of subjects. Intravitreal bevacizumab resulted as long-term effective and safe therapy for mCNV with sustained results at 10 years.

Development of a CNS-permeable reactivator for nerve agent exposure: an iterative, multi-disciplinary approach

Nerve agents have experienced a resurgence in recent times with their use against civilian targets during the attacks in Syria (2012), the poisoning of Sergei and Yulia Skripal in the United Kingdom (2018) and Alexei Navalny in Russia (2020), strongly renewing the importance of antidote development against these lethal substances. The current standard treatment against their effects relies on the use of small molecule-based oximes that can efficiently restore acetylcholinesterase (AChE) activity. Despite their efficacy in reactivating AChE, the action of drugs like 2-pralidoxime (2-PAM) is primarily limited to the peripheral nervous system (PNS) and, thus, provides no significant protection to the central nervous system (CNS). This lack of action in the CNS stems from their ionic nature that, on one end makes them very powerful reactivators and on the other renders them ineffective at crossing the Blood Brain Barrier (BBB) to reach the CNS. In this report, we describe the use of an iterative approach composed of parallel chemical and in silico syntheses, computational modeling, and a battery of detailed in vitro and in vivo assays that resulted in the identification of a promising, novel CNS-permeable oxime reactivator. Additional experiments to determine acute and chronic toxicity are ongoing.

Recent Advances in Glioma Therapy: Combining Vascular Normalization and Immune Checkpoint Blockade

Glioblastoma (GBM) accounts for more than 50% of all primary malignancies of the brain. Current standard treatment regimen for GBM includes maximal surgical resection followed by radiation and adjuvant chemotherapy. However, due to the heterogeneity of the tumor cells, tumor recurrence is often inevitable. The prognosis of patients with glioma is, thus, dismal. Glioma is a highly angiogenic tumor yet immunologically cold. As such, evolving studies have focused on designing strategies that specifically target the tyrosine kinase receptors of angiokines and encourage immune infiltration. Recent promising results from immunotherapies on other cancer types have prompted further investigations of this therapy in GBM. In this article, we reviewed the pathological angiogenesis and immune reactivity in glioma, as well as its target for drug development, and we discussed future directions in glioma therapy.

Novel agents in a young patient with osteosarcoma: A short review

SummaryOsteosarcomas are rare malignant bone tumors, most frequently occurring in children as well as adolescents and young adults. Therapy of initially localized disease consists of neoadjuvant chemotherapy followed by surgical resection and adjuvant chemotherapy. Osteosarcomas often present relapses, most commonly lung metastases. Treatment of isolated lung metastasis most commonly includes surgical resection. The correct adjuvant treatment option is still under investigation. In this manuscript we describe the clinical course of an osteosarcoma patient and give a review of the literature regarding current standard treatment for localized as well as pulmonary metastatic disease.

Induction-phase treatment costs for cryptococcal meningitis in high HIV-burden African countries: New opportunities with lower costs

Introduction: Access to and the cost of induction treatment for cryptococcal meningitis (CM) is rapidly changing. The newly-announced price for flucytosine ($0.75 per 500 mg pill) and possibly lower prices for liposomal amphotericin B (AmB-L) create opportunities to reduce CM treatment costs compared to the current standard treatment in low- and middle-income countries. Methods: We developed an Excel-based cost model to estimate health system treatment costs for CM over a two-week induction phase for multiple treatment combinations, newly feasible with improved access to flucytosine and AmB-L. CM treatment costs include medications, laboratory tests and other hospital-based costs (bed-day costs and healthcare worker time). We report results from applying the model using country-specific information for South Africa, Uganda, Nigeria, and Botswana. Results: A 14-day induction-phase of seven days of inpatient AmB-D with flucytosine, followed by seven days of high-dose fluconazole as an outpatient, will cost health systems less than a 14-day hospital stay with AmB-D and fluconazole. If daily AmB-L replaces AmB-D for those with baseline renal dysfunction, with a cost of $50 or less per 50 mg vial, incremental costs would still be less than the AmB-D with fluconazole regimen. Simple oral combinations (e.g., seven days of flucytosine with fluconazole as an inpatient) are practical when AmB-D is not available, and treatment costs would remain less than the current standard treatment. Conclusions: Improved access to, and lower prices for flucytosine and AmB-L create opportunities for improving CM treatment regimens. An induction regimen of flucytosine and AmB-D for seven days is less costly than standard care in the settings studied here. As this regimen has also been shown to be more effective than current standard care, countries should prioritize scaling up flucytosine access. The cost of AmB-L based regimens is highly dependent on the price of AmB-L, which currently remains unclear.

The effect of Clofazimine Concentration on QT prolongation in patients treated for tuberculosis

Rationale Clofazimine is classified as a WHO group B drug for the treatment of rifampicin-resistant tuberculosis. QT prolongation, which is associated with fatal cardiac arrhythmias, is caused by several anti-tubercular drugs, including clofazimine, but there are no data quantifying the effect of clofazimine concentration on QT prolongation. Objectives To describe the effect of clofazimine exposure on QT prolongation Methods Fifteen adults drug-susceptible tuberculosis patients received clofazimine mono-therapy as 300 mg daily for three days followed by 100 mg daily in one arm of a 2-week, multi-arm early bactericidal activity trial in South Africa. Pre-treatment Fridericia-corrected QT (QTcF) (105 patients, 524 ECGs) and QTcF’s from the clofazimine-monotherapy arm matched with clofazimine plasma concentrations (199 ECGs) were interpreted with a nonlinear mixed-effects model. Measurements and Main Results Clofazimine was associated with significant QT prolongation described by an Emax function. We predicted clofazimine exposures using 100-mg daily doses and two-weeks loading with 200 and 300 mg daily, respectively. The expected proportions of patients with QTcF change from baseline above 30 ms (ΔQTcF>30) were 2.52%, 11.6%, and 23.0% for 100, 200, and 300-mg daily doses, respectively. At steady state, the expected proportion with ΔQTcF>30 ms was 23.7% and for absolute QTcF>450 ms was 3.42% for all simulated regimens. Conclusions The use of loading doses of 200 and 300 mg is not predicted to expose patients to increased risk of QT prolongation, compared to the current standard treatment, and is, therefore, an alternative option to achieve therapeutic concentrations faster.

The use of immunotherapy treatment in malignant pheochromocytomas/paragangliomas: a case report

Background Pheochromocytomas are a subset of paragangliomas, which are a rare group of neural crest cell-derived tumors. Malignant cases of both pheochromocytomas and paragangliomas are even rarer, and currently there is no standard of care. This case report details the use of off-label immunotherapy and its efficacy in the management of the aforementioned tumor. Case presentation Herein is presented a case of a 60-year-old Caucasian female with a rare malignant pheochromocytoma. The tumor was determined to be unresectable because of involvement of surrounding organs. Radiation therapy was also not a viable option because of concerns over appreciable toxicity in relation to mass size. As there is no standard of care for malignant cases, the patient was started on chemotherapeutic agents but was soon shown to be intolerant to this treatment. As she was ineligible for several clinical trials, the patient was started on the off-label immunotherapeutic agents nivolumab and ipilimumab. Immunotherapy use resulted in decreased tumor size, improved quality of life, and reconsideration for radiation therapy. Conclusions The use of immunotherapy in pheochromocytoma in this patient clearly demonstrated substantial benefit, as she was able to be reconsidered for radiation therapy. Not only has the patient been tolerant of this treatment, but she has exhibited progression-free survival of over 20 months. As there is no current standard treatment for malignant pheochromocytomas, the success of its use in this patient lends support to the ongoing clinical trials regarding the use of immunotherapy in rare tumors, including pheochromocytomas.

Development of a CNS-permeable reactivator for nerve agent exposure: An iterative, multi-disciplinary approach

Nerve agents have experienced a resurgence in recent times with their use against civilian targets during the attacks in Syria (2012), the poisoning of Sergei and Yulia Skripal in the United Kingdom (2018) and Alexei Navalny in Russia (2020), strongly renewing the importance of antidote development against these lethal substances. The current standard treatment against their effects relies on the use of small molecule-based oximes that can efficiently restore acetylcholinesterase (AChE) activity. Despite their efficacy in reactivating AChE, the action of drugs like 2-pralidoxime (2-PAM) is primarily limited to the peripheral nervous system (PNS) and, thus, provides no significant protection to the central nervous system (CNS). This lack of action in the CNS stems from their ionic nature that, on one end makes them very powerful reactivators and on the other renders them ineffective at crossing the Blood Brain Barrier (BBB) to reach the CNS. In this report, we describe the use of an iterative approach composed of parallel chemical and in silico syntheses, computational modeling, and a battery of detailed in vitro and in vivo assays that resulted in the identification of a promising, novel CNS-permeable oxime reactivator. Additional experiments to determine acute and chronic toxicity are ongoing.

Nanotechnology and Nanocarrier-Based Drug Delivery as the Potential Therapeutic Strategy for Glioblastoma Multiforme: An Update

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor with poor prognosis. The heterogeneous and aggressive nature of GBMs increases the difficulty of current standard treatment. The presence of GBM stem cells and the blood brain barrier (BBB) further contribute to the most important compromise of chemotherapy and radiation therapy. Current suggestions to optimize GBM patients’ outcomes favor controlled targeted delivery of chemotherapeutic agents to GBM cells through the BBB using nanoparticles and monoclonal antibodies. Nanotechnology and nanocarrier-based drug delivery have recently gained attention due to the characteristics of biosafety, sustained drug release, increased solubility, and enhanced drug bioactivity and BBB penetrability. In this review, we focused on recently developed nanoparticles and emerging strategies using nanocarriers for the treatment of GBMs. Current studies using nanoparticles or nanocarrier-based drug delivery system for treatment of GBMs in clinical trials, as well as the advantages and limitations, were also reviewed.