Evaluation of cost and infusion-related reactions among intravenous trastuzumab, subcutaneous trastuzumab, and trastuzumab biosimilars at an academic medical center.

INTRODUCTION: Trastuzumab is a vital treatment option for human epidermal growth factor 2 positive breast cancer. Since 2017, there have been 5 trastuzumab biosimilars approved for use. Despite hypotheses of infusion-related reactions among intravenous trastuzumab, subcutaneous trastuzumab, and trastuzumab biosimilars, there is minimal available literature comparing these agents. This evaluation will compare the rate of infusion-related reactions among these agents, evaluate our institution's utilization, and compare acquisition costs to determine if there is a potential cost savings by utilizing specific agents as our formulary preferred medication. METHODS: We retrospectively analyzed medical records to identify the incidence of infusion-related reaction after administration of intravenous or subcutaneous trastuzumab or trastuzumab biosimilars. Additionally, we conducted a cost analysis to identify potential cost savings by switching to an alternative institutional preferred agent. Infusion chair time was calculated to identify chair time savings with subcutaneous administration. RESULTS: There were 183 patients included in this study. Seven patients (3.8%) experienced an infusion-related reaction. The most utilized agent within our cohort was intravenous trastuzumab. During our study period, 181 patients received intravenous infusions, which could allow for substantial infusion chair savings by switching to trastuzumab/hyaluronidase, the subcutaneous formulation. Beyond the chair time, direct drug cost savings were also identified when comparing the costs of each of the evaluated medications. CONCLUSION: Subcutaneous trastuzumab or trastuzumab biosimilars do not pose a greater risk of infusion-related reactions compared to intravenous trastuzumab and may offer more affordable treatment options for breast cancer patients who qualify for trastuzumab therapy.

Applying a risk prediction model for bloodstream infection in a febrile, nonseverely neutropenic cohort of pediatric stem cell transplant patients.

BACKGROUND: The optimal management of febrile stem cell transplant (SCT) patients presenting without severe neutropenia (absolute neutrophil count [ANC] ≥ 500/µL) is unclear. The authors have developed iterative risk prediction models (Esbenshade Vanderbilt [EsVan] models) that reliably predict bloodstream infections (BSIs) in the febrile general pediatric oncology population without severe neutropenia, but SCT-specific data are limited. METHODS: All SCTs occurring from May 2005 to November 2019 at a single institution were identified. Episodes of fever with a central venous catheter and ANC values ≥ 500/µL were abstracted. All previous versions of the EsVan model were applied to the SCT data, and c-statistics were generated. The models were additionally applied to each type of transplant (autologous/allogeneic), and a new allogeneic model that further adjusted for metrics of immunosuppression, Esbenshade Vanderbilt Allogeneic SCT Model (EsVanAlloSCT), was developed and internally validated. RESULTS: For 429 SCT episodes (221 autologous and 208 allogeneic), the BSI incidence was 19.6% (84 of 429), and it was higher in allogeneic transplant patients (25.5%) than autologous transplant patients (14.0%; p < .01). All versions of the EsVan model performed well for the overall SCT cohort (c-statistics, 0.759-0.795). The EsVan models performed better for the autologous episodes (c-statistics, 0.869-0.881) than the allogeneic SCT episodes (c-statistics, 0.678-0.717). The new allogeneic transplant-specific model, EsVanAlloSCT, which added an adjustment for the extent of immunosuppression, yielded a c-statistic of 0.792 (bootstrap-corrected, 0.750). CONCLUSIONS: The EsVan models work exceptionally well when they are applied to autologous SCT, but they work less well for allogeneic SCT. EsVanAlloSCT appears to improve the predictive ability in allogeneic SCT, but it will need additional external validation.

Recent Advances in Pediatric Medulloblastoma.

PURPOSE OF REVIEW: Review recent advances in the understanding of pediatric medulloblastoma including etiology, biology, radiology, and management of pediatric medulloblastoma. RECENT FINDINGS: The classic four subgroups have been reclassified and further subdivided based on new molecular findings. Research is revealing the cell origins of the different subtypes of medulloblastoma. There has been continued personalization of management based on molecular parameters. While many advances have been made in the knowledge base of this most common malignant pediatric brain tumor, there has not yet been translation into more effective therapies to prolong survival in all subgroups with the possible exception of children with group 3 disease. Quality of life remains a major challenge for long-term survivors.

Infectious events in pediatric patients with acute lymphoblastic leukemia/lymphoma undergoing evaluation for fever without severe neutropenia.

BACKGROUND: Infections cause significant treatment-related morbidity during pediatric acute lymphoblastic leukemia/lymphoma (ALL/LLy) therapy. Fevers during periods without severe neutropenia are common, but etiologies are not well-described. This study sought to describe the bloodstream infection (BSI) and non-BSI risk in children undergoing therapy for ALL/LLy. METHODS: Demographic and clinical data were abstracted for febrile episodes without severe neutropenia at two children's hospitals. Treatment courses were stratified by intensity. Multivariate logistic regression evaluated characteristics associated with infection. RESULTS: There were 1591 febrile episodes experienced by 524 patients. Of these, 536 (34%) episodes had ≥1 infection; BSI occurred in 30 (1.9%) episodes. No BSIs occurred in episodes with a recent procedural sedation or cytarabine exposure. Presence of hypotension, chills/rigors, higher temperature, and infant phenotype were independently associated with BSI (p < .05). Of the 572 non-BSIs, the most common was upper respiratory infection (URI) (n = 381, 67%). Compared to episodes without infection, URI symptoms, higher temperature, absolute neutrophil count 500-999/µl, and evaluation during a low-intensity treatment course were more likely to be associated with a non-BSI (p < .05) and inpatient status was less likely to be associated with a non-BSI (p < .05). CONCLUSIONS: The BSI rate in pediatric patients with ALL/LLy and fever without severe neutropenia is low, but one-third of the time, patients have a non-BSI. Future research should test if the need for empiric antibiotics can be tailored based on the associations identified in this study.

Viral delivery of a microRNA to Gba to the mouse central nervous system models neuronopathic Gaucher disease.

Pathological mutations in GBA, encoding lysosomal glucocerebrosidase (GCase), cause Gaucher disease (GD). GD is a multi-system disease with great phenotypic variation between individuals. It has been classified into type 1 with primarily peripheral involvement and types 2 and 3 with varying degrees of neurological involvement. GD is characterized by decreased GCase activity and subsequent accumulation of its lipid substrates, glucosylceramide and glucosylsphingosine. Current murine models of neuronopathic GD mostly replicate the severe aspects of the neurological symptoms developing rapid progression and early lethality, thus presenting a short window for therapeutic testing. In order to develop a model of chronic neuronopathic GD, we reduced GCase in the central nervous system (CNS) of a mild GD mouse model (GbaD409V/D409V) via intracerebroventricular administration of an adeno-associated virus encoding a microRNA to Gba (AAV-GFP-miR-Gba). GbaD409V/D409V mice have significantly reduced GCase activity and increased substrate accumulation in the CNS. Phenotypically, these mice partially recapitulate features of mild type 1 GD. Their neurological examination reveals cognitive impairment with normal motor features. Administration of AAV-GFP-miR-Gba into GbaD409V/D409V pups in the CNS caused progressive lipid substrate accumulation. Phenotypically, AAV1-GFP-miR-Gba-treated mice were indistinguishable from their littermates until 10 weeks of age, when they started developing progressive neurological impairments, including hyperactivity, abnormal gait, and head retroflexion. Importantly, these impairments can be prevented by simultaneous administration of a miR-resistant GBA, demonstrating that the pathological effects are specifically due to Gba mRNA reduction. This novel model of neuronopathic GD offers several advantages over current models including slower progression of neurological complications and an increased lifespan, which make it more amenable for therapeutic testing.

Cre-dependent AAV vectors for highly targeted expression of disease-related proteins and neurodegeneration in the substantia nigra.

Recombinant adeno-associated virus (AAV) vectors are a popular genetic approach in neuroscience because they confer such efficient transgene expression in the brain and spinal cord. A number of studies have used AAV to express pathological disease-related proteins in the dopaminergic neurons of the substantia nigra in situ ( e.g., α-synuclein to model aspects of Parkinson's disease). The neuropathology and neurodegeneration of Parkinson's disease occur in a circumscribed pattern in the brain, and one of the most important goals of any gene transfer study is accurate, pinpoint targeting. By combining Cre recombinase-dependent AAVs in Cre-driver rats in which Cre is expressed only in the tyrosine hydroxylase neurons, we have achieved more highly targeted expression of several disease-relevant neuropathological proteins in the substantia nigra pars compacta than using constitutive expression AAV vectors. Alpha-synuclein, tau, transactive response DNA-binding protein of 43 kDa, or the control fluorescent protein yellow fluorescent protein was individually expressed to induce highly targeted, dopaminergic neuron-specific neurodegeneration models. The refined targeting foreshadows a next-generation disease modeling system for expressing neurodegenerative disease-related proteins in a disease-relevant manner. We foresee specific utilities of this in vivo AAV vector targeting of pathological proteins to a well-defined and well-demarcated cell population.-Grames, M. S., Dayton, R. D., Jackson, K. L., Richard, A. D., Lu, X., Klein, R. L. Cre-dependent AAV vectors for highly targeted expression of disease-related proteins and neurodegeneration in the substantia nigra.

Gene Therapy Strategies to Restore ER Proteostasis in Disease.

Proteostasis alterations are proposed as a transversal hallmark of several pathological conditions, including metabolic disorders, mechanical injury, cardiac malfunction, neurodegeneration, and cancer. Strategies to improve proteostasis aim to reduce the accumulation of specific disease-related misfolded proteins or bolster the endogenous mechanisms to fold and degrade abnormal proteins. Endoplasmic reticulum (ER) stress is a common pathological signature of a variety of diseases, which engages the unfolded protein response (UPR) as a cellular reaction to mitigate ER stress. Pharmacological modulation of the UPR is challenging considering the physiological importance of the pathway in various organs. However, local targeting of ER stress responses in the affected tissue using gene therapy is emerging as a possible solution to overcome side effects. The delivery of ER chaperones or active UPR components using adeno-associated virus (AAV) has demonstrated outstanding beneficial effects in several disease models (e.g., neurodegenerative conditions, eye disorders, and metabolic diseases). Here, we discuss current efforts to design and optimize gene therapy strategies to improve ER proteostasis in different disease contexts.

A pilot study to assess the pharmacy impact of implementing a chemotherapy-induced nausea or vomiting collaborative disease therapy management in the outpatient oncology clinics.

BACKGROUND: Collaborative drug therapy management is a formal partnership between a pharmacist and physician to allow the pharmacist to manage a patient's drug therapy. Literature supports collaborative disease therapy management can improve patient outcomes, improve medication adherence, enhance medication safety, and positively influence healthcare expenditures. Chemotherapy induced nausea or vomiting is considered one of the most distressing and feared adverse events among patients receiving chemotherapy. Chemotherapy induced nausea or vomiting can impact a patient's quality of life and may affect compliance with the treatment plan. PURPOSE: The objective of this pilot study was to determine the pharmacy impact of implementing a chemotherapy induced nausea or vomiting collaborative disease therapy management protocol in the outpatient oncology clinics at a National Cancer Institute (NCI)-designated cancer center associated with an academic medical center. The primary endpoint was to determine the number and type of chemotherapy induced nausea or vomiting clinical interventions made by the oncology pharmacists. Secondary endpoints included comparing patient's Multinational Association for Supportive Care in Cancer scores and revenue of pharmacists' services. METHODS: The credentialed oncology pharmacists were consulted by an oncologist to manage chemotherapy induced nausea or vomiting. Patients were included in the chemotherapy induced nausea or vomiting collaborative disease therapy management if they were seen in an outpatient oncology clinic from October 2016 to January 2017 and had a referral from a qualified provider to help manage chemotherapy induced nausea or vomiting. Patients admitted to the hospital at the time of consult were excluded from the study. The pharmacists interviewed patients and provided recommendations. The pharmacists followed up with the patient via a telephone call or during the next scheduled clinic visit to assess their symptoms. RESULTS: The chemotherapy induced nausea or vomiting collaborative disease therapy management pilot study was implemented in October 2016. From October 2016 to January 2017, there were 45 consults for the management of chemotherapy induced nausea or vomiting. The pharmacists made 188 clinical interventions, which included addition of new medications (37%), patient education (34%), deletion of medications (10%), changing a dose/duration/frequency (8%), and other interventions (11%). Multinational Association for Supportive Care in Cancer symptom scores were available for 5 patients, in which all showed improvements from baseline with the pharmacists' clinical interventions. CONCLUSIONS: The implementation of our chemotherapy induced nausea or vomiting collaborative disease therapy management pilot study has shown favorable results after a 4-month evaluation period. The pharmacists have made a substantial number of clinical interventions and provided patient education to patients undergoing chemotherapy.

Severe respiratory changes at end stage in a FUS-induced disease state in adult rats.

BACKGROUND: Fused in sarcoma (FUS) is an RNA-binding protein associated with the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration. ALS manifests in patients as a progressive paralysis which leads to respiratory dysfunction and failure, the primary cause of death in ALS. We expressed human FUS in rats to determine if FUS would induce ALS relevant respiratory changes to serve as an early stage disease indicator. The FUS expression was initiated in adult rats by way of an intravenously administered adeno-associated virus vector serotype 9 (AAV9) providing an adult onset model. RESULTS: The rats developed progressive motor impairments observed as early as 2-3 weeks post gene transfer. Respiratory abnormalities manifested 4-7 weeks post gene transfer including increased respiratory frequency and decreased tidal volume. Rats with breathing abnormalities also had arterial blood acidosis. Similar detailed plethysmographic changes were found in adult rats injected with AAV9 TDP-43. FUS gene transfer to adult rats yielded a consistent pre-clinical model with relevant motor paralysis in the early to middle stages and respiratory dysfunction at the end stage. Both FUS and TDP-43 yielded a similar consistent disease state. CONCLUSIONS: This modeling method yields disease relevant motor and respiratory changes in adult rats. The reproducibility of the data supports the use of this method to study other disease related genes and their combinations as well as a platform for disease modifying interventional strategies.

Initial gene vector dosing for studying symptomatology of amyotrophic lateral sclerosis in non-human primates.

BACKGROUND: Most amyotrophic lateral sclerosis (ALS) research has focused on mice, but there are distinct differences in the functional neuroanatomy of the corticospinal pathway in primates vs. rodents. A non-human primate model may be more sensitive and more predictive for therapeutic efficacy. METHODS: Rhesus macaques received recombinant adeno-associated virus (AAV9) encoding either the ALS-related pathological protein TDP-43 or a green fluorescent protein (GFP) control by intravenous administration. Motor function and electromyography were assessed over a nine-month expression interval followed by post-mortem analyses. RESULTS: Recombinant TDP-43 or GFP was stably expressed long term. Although the TDP-43 subjects did not manifest severe paralysis and atrophy, there were trends of a partial disease state in the TDP-43 subjects relative to the control. CONCLUSIONS: These data indicate that a higher gene vector dose will likely be necessary for more robust effects, yet augur that a relevant primate model is feasible.

Impact of Time-to-Antibiotic Delivery in Pediatric Patients With Cancer Presenting With Febrile Neutropenia.

PURPOSE: Febrile neutropenia (FN) in pediatric patients with cancer can cause severe infections, and prompt antibiotics are warranted. Extrapolated from other populations, a time-to-antibiotic (TTA) metric of <60 minutes after medical center presentation was established, with compliance data factoring into pediatric oncology program national rankings. METHODS: All FN episodes occurring at Vanderbilt Children's Hospital (2007-February 2022) and a sample of episodes from Colorado Children's Hospital (2012-2019) were abstracted, capturing TTA and clinical outcomes including major complications (intensive care unit [ICU] admission, vasopressors, intubation, or infection-related mortality). Odds ratios (ORs) were adjusted for age, treatment center, absolute neutrophil count, hypotension presence, stem-cell transplant status, and central line type. RESULTS: A total of 2,349 episodes were identified from Vanderbilt (1,920) and Colorado (429). Only 0.6% (n = 14) episodes required immediate ICU management, with a median TTA of 28 minutes (IQR, 20-37). For the remaining patients, the median TTA was 56 minutes (IQR, 37-90), and 54.3% received antibiotics in <60 minutes. There were no significant associations between TTA (<60 or ≥60 minutes) and major complications (adjusted OR, 0.99 [95% CI, 0.62 to 1.59]; P = .98), and a TTA ≥60 minutes was not associated with any type of complication. Similarly, TTA, when evaluated as a continuous variable, was not associated with a major (OR, 0.99 [95% CI, 0.94 to 1.04]; P = .69) nor any other complication in adjusted analysis. CONCLUSION: There is no clear evidence that a reduced TTA improves clinical outcomes in pediatric oncology FN and thus it should not be used as a primary quality measure.

Nanoparticle-Encapsulated Bryostatin-1 Activates α-Secretase and PKC Isoforms In vitro and Facilitates Acquisition and Retention of Spatial Learning in an Alzheimer's Disease Mouse Model.

BACKGROUND: Alzheimer's disease (AD) animal models have revealed neuroprotective actions of Bryostatin-1 mediated by activation of novel PKC isoforms, suppression of beta-amyloid and downregulation of inflammatory and angiogenic events, making Bryostatin-1 an attractive candidate for attenuating AD-associated neural, vascular, and cognitive disturbances. OBJECTIVE: To further enhance Bryostatin-1 efficacy, nanoparticle-encapsulated Bryostatin-1 formulations were prepared. METHODS: We compared nano-encapsulated and unmodified Bryostatin-1 in in vitro models of neuronal PKC-d, PKC-e isoforms, α-secretase and studied nano-encapsulated Bryostatin-1 in an AD mouse model of spatial memory (BC3-Tg (APPswe, PSEN1 dE9) 85Dbo/J mice). RESULTS: We found that nanoencapsulated Bryostatin-1 formulations displayed activity greater or equal to that of unmodified Bryostatin-1 in PKC-δ and -ε and α-secretase activation assays. We next evaluated how treatment with a nanoencapsulated Bryostatin-1 formulation facilitated spatial learning in the Morris water maze. AD transgenic mice (6.5 to 8 months of age) were treated with nanoparticle encapsulated Bryostatin-1 formulation (1, 2.5, or 5 µg/mouse) three times the week before testing and then daily for each of the 5 days of testing. Across the acquisition phase, mice treated with nanoencapsulated Bryostatin-1 had shorter latencies, increased % time in the target zone and decreased % time in the opposite quadrant. The mice were given retention testing after a 2-week period without drug treatment. Mice treated with nanoencapsulated Bryostatin-1 had shorter latencies to find the escape platform, indicating retention of spatial memory. CONCLUSION: These data suggest that cognitive deficits associated with AD could be treated using highly potent nanoparticle-encapsulated formulations of Bryostatin-1.

Spinal cord astrocytoma: a unique presentation of abdominal pain.

A previously healthy male presented at age 5 years with recurrent abdominal pain that occurred diffusely. The pain was severe enough to cause episodic screaming, especially at night with spontaneous resolution. The patient was initially treated for constipation but when motor symptoms began to develop, imaging revealed the cause of his pain to be a spinal cord mass. The tumor was treated with steroids, and biopsy confirmed a grade II spinal cord astrocytoma. We describe this unusual presentation of a pediatric spinal cord astrocytoma and review the literature.

TDP43 nuclear export and neurodegeneration in models of amyotrophic lateral sclerosis and frontotemporal dementia.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are progressive neurodegenerative disorders marked in most cases by the nuclear exclusion and cytoplasmic deposition of the RNA binding protein TDP43. We previously demonstrated that ALS-associated mutant TDP43 accumulates within the cytoplasm, and that TDP43 mislocalization predicts neurodegeneration. Here, we sought to prevent neurodegeneration in ALS/FTD models using selective inhibitor of nuclear export (SINE) compounds that target exportin-1 (XPO1). SINE compounds modestly extend cellular survival in neuronal ALS/FTD models and mitigate motor symptoms in an in vivo rat ALS model. At high doses, SINE compounds block nuclear egress of an XPO1 cargo reporter, but not at lower concentrations that were associated with neuroprotection. Neither SINE compounds nor leptomycin B, a separate XPO1 inhibitor, enhanced nuclear TDP43 levels, while depletion of XPO1 or other exportins had little effect on TDP43 localization, suggesting that no single exporter is necessary for TDP43 export. Supporting this hypothesis, we find overexpression of XPO1, XPO7 and NXF1 are each sufficient to promote nuclear TDP43 egress. Taken together, our results indicate that redundant pathways regulate TDP43 nuclear export, and that therapeutic prevention of cytoplasmic TDP43 accumulation in ALS/FTD may be enhanced by targeting several overlapping mechanisms.

Methods and Tips for Intravenous Administration of Adeno-associated Virus to Rats and Evaluation of Central Nervous System Transduction.

Adeno-associated virus (AAV) vectors are a key reagent in the neurosciences for clustered regularly interspaced short palindromic repeats (CRISPR), optogenetics, cre-lox targeting, etc. The purpose of this manuscript is to aid the investigator attempting expansive central nervous system (CNS) gene transfer in the rat via tail vein injection of AAV. Wide-scale expression is relevant for conditions with widespread pathology, and a rat model is significant due to its greater size and physiologic similarities to humans compared to mice. In this example application, a wide-scale neuronal transduction is used to mimic a neurodegenerative disease that affects the entire spinal cord, amyotrophic lateral sclerosis (ALS). The efficient wide-scale CNS transduction can also be used to deliver therapeutic protein factors in pre-clinical studies. After a post-injection expression interval of several weeks, the effects of the transduction are evaluated. For a green fluorescent protein (GFP) control vector, the amount of GFP in the cerebellum is estimated quickly and reliably by a basic imaging program. For motor disease phenotypes that are induced by the ALS related protein transactive response DNA-binding protein of 43 kDa (TDP-43), the deficits are scored by escape reflex and rotarod. Beyond disease modeling and gene therapy, there are diverse potential applications for the wide-scale gene targeting described here. The expanded use of this method will aid in expediting hypothesis testing in the neurosciences and neurogenetics.

p62 Pathology Model in the Rat Substantia Nigra with Filamentous Inclusions and Progressive Neurodegeneration.

One of the proteins most frequently found in neuropathological lesions is the ubiquitin binding protein p62 (sequestosome 1). Post-mortem analysis of p62 is a defining diagnostic marker in several neurodegenerative diseases including amyotrophic lateral sclerosis and inclusion body myositis. Since p62 functions in protein degradation pathways including autophagy, the build-up of p62-positive inclusions suggests defects in protein clearance. p62 was expressed unilaterally in the rat substantia nigra with an adeno-associated virus vector (AAV9) in order to study p62 neuropathology. Inclusions formed within neurons from several days to several weeks after gene transfer. By electron microscopy, the inclusions were found to contain packed 10 nm thick filaments, and mitochondria cristae structure was disrupted, resulting in the formation of empty spaces. In corollary cell culture transfections, p62 clearly impaired mitochondrial function. To probe for potential effects on macroautophagy, we co-expressed p62 with a double fluorescent tagged reporter for the autophagosome protein LC3 in the rat. p62 induced a dramatic and specific dissociation of the two tags. By 12 weeks, a rotational behavior phenotype manifested, consistent with a significant loss of dopaminergic neurons analyzed post-mortem. p62 overexpression resulted in a progressive and robust pathology model with neuronal inclusions and neurodegeneration. p62 gene transfer could be a novel methodological probe to disrupt mitochondrial function or autophagy in the brain and other tissues in vivo.

Corrigendum: Better Targeting, Better Efficiency for Wide-Scale Neuronal Transduction with the Synapsin Promoter and AAV-PHP.B.

[This corrects the article on p. 116 in vol. 9, PMID: 27867348.].

Better Targeting, Better Efficiency for Wide-Scale Neuronal Transduction with the Synapsin Promoter and AAV-PHP.B.

Widespread genetic modification of cells in the central nervous system (CNS) with a viral vector has become possible and increasingly more efficient. We previously applied an AAV9 vector with the cytomegalovirus/chicken beta-actin (CBA) hybrid promoter and achieved wide-scale CNS transduction in neonatal and adult rats. However, this method transduces a variety of tissues in addition to the CNS. Thus we studied intravenous AAV9 gene transfer with a synapsin promoter to better target the neurons. We noted in systematic comparisons that the synapsin promoter drives lower level expression than does the CBA promoter. The engineered adeno-associated virus (AAV)-PHP.B serotype was compared with AAV9, and AAV-PHP.B did enhance the efficiency of expression. Combining the synapsin promoter with AAV-PHP.B could therefore be advantageous in terms of combining two refinements of targeting and efficiency. Wide-scale expression was used to model a disease with widespread pathology. Vectors encoding the amyotrophic lateral sclerosis (ALS)-related protein transactive response DNA-binding protein, 43 kDa (TDP-43) with the synapsin promoter and AAV-PHP.B were used for efficient CNS-targeted TDP-43 expression. Intracerebroventricular injections were also explored to limit TDP-43 expression to the CNS. The neuron-selective promoter and the AAV-PHP.B enhanced gene transfer and ALS disease modeling in adult rats.

AAV9 supports wide-scale transduction of the CNS and TDP-43 disease modeling in adult rats.

AAV9 has emerged as an efficient adeno-associated virus (AAV) serotype for gene transfer to the central nervous system. We have used this technique to study aspects of amyotrophic lateral sclerosis (ALS) by administering AAV encoding the ALS-related gene transactive response DNA binding protein of 43 kDa (TDP-43) to neonatal rats. However, inducing the expression in adult subjects would be preferable to mimic the adult onset of symptoms in ALS. We expressed either green fluorescent protein (GFP) or TDP-43 in adult rats after an intravenous (i.v.) route of administration to attempt wide-scale transduction of the spinal cord for disease modeling. In order to optimize the gene transfer, we made comparisons of efficiency by age, gender, and across several AAV serotypes (AAV1, AAV8, AAV9, and AAV10). The data indicate more efficient neuronal transduction in neonates, with little evidence of glial transduction at either age, no gender-related differences in transduction, and that AAV9 was efficient in adults relative to the other serotypes tested. Based on these data, AAV9 TDP-43 was expressed at three vector doses in adult female rats yielding highly consistent, dose-dependent motor deficits. AAV9 can be delivered i.v. to adult rats to achieve consistent pathophysiological changes and a relevant adult-onset system for disease modeling.