Viral Vector Therapy Research Articles

Technological advancements in viral vector designing and optimization for therapeutic applications.

Viral vector engineering is critical to the advancement of several sectors of biotechnology, gene therapy, and vaccine development. These vectors were produced from viruses, were employed to deliver therapeutic genes or to alter biological processes. The potential for viral vectors to improve the precision, safety, and efficiency of therapeutic interventions has boosted their demand. The dynamic interplay between technological advancements and computational tools in establishing the landscape of viral vector engineering and vector optimization for therapeutic reasons is discussed in this chapter. It also emphasizes the importance of in silico techniques in maximizing vector potential for therapeutics and many phases of viral vector engineering, from genomic analysis to computer modelling and advancements to improve precise gene delivery. High-throughput screening propels the expedited process of vector selection, and computational techniques to analyze complex omics data to further enhance vector capabilities have been discussed. As in silico models reveal insights into off-target effects and integration sites, vector safety (biodistribution and toxicity) remains a crucial part and bridges the gap between preclinical and clinical investigations. Despite the limitations, this chapter depicts a future in which technology and computing merge to catapult viral vector therapy into an era of boundless possibilities.

Research Progress in Immunotherapy of Gliomas.

Although some progress has been made in tumor treatment, gliomas remain one of the tumors that can still seriously threaten human life and health. Due to the particularity of the immune microenvironment of the central nervous system and the strong invasiveness of tumors, the treatment of gliomas remains a major challenge. Currently, researchers have explored a large number of immunotherapy programs to improve the survival and prognosis of glioma patients, including tumor vaccines, immune checkpoint inhibitors, adoptive cell transfer therapy, viral vector therapy, and genetic engineering therapy. The goal of these programs is to activate or change the immunosuppressive environment and target tumor cells through drugs, combined with surgical resection, radiotherapy, chemotherapy, and anti-angiogenesis drugs, to achieve the purpose of treating glioma. This review briefly describes the immunosuppressive microenvironment of gliomas and summarizes recent immunotherapeutic strategies and their progress. The aim is to summarize the latest immunotherapies for the treatment of gliomas and provide new research directions.

Interim Analysis of Treatment Outcomes of Young Children with 5q Spinal Muscular Atrophy on Gene Replacement Therapy with Onasemnogene Abeparvovec. Clinical Observations

Background. Onasemnogene abeparvovec is the first gene replacement therapy medication based on the adeno-associated viral vector (AAV9). One injection to a patient with 5q spinal muscular atrophy (SMA) leads to replacement of the missing or defective SMN1 gene with its functional copy. It leads to normalization of survival motor neuron protein (SMN) production.Objective. The aim of the study is to evaluate efficacy, safety, and causes of different responses to therapy after single administration of onasemnogene abeparvovec in 5 patients with 5q SMA (types I and II) comparing the baseline status with the results of continued monitoring in real clinical practice in Russian Federation.Methods. Interim results of continued follow-up of children with 5q SMA with 2–3 copies of the SMN2 gene are presented: 2 boys and 1 girl with type I who received single dose of onasemnogene abeparvovec at 4 and 7 months of age; and 2 girls with type II who received therapy at 11 and 16 months of age.Results. Short-term controlled fever was observed in 4 out of 5 patients during first 2 weeks after viral vector therapy administration (max in patient 5 — up to 38.5 ° C). All 5 children had transaminases increase, 1 patient — significant transaminases increase during the sensitisation period (> 10 from upper normal level (UNL)), 1 patient — delayed significant transaminases increase (> 20 UNL), 1 patient — transaminases increase (> 3 UNL) after discontinuation of longterm therapy with glucocorticosteroids (according to prescribing information). All patients had shown positive and sustained response to therapy over time at motor status assessment via CHOP INTEND / HFMSE scales. The more significant response was observed in patients with less aggressive baseline 5q SMA type II with 3 copies of the SMN2 gene.Conclusion. Onasemnogene abeparvovec is relatively safe medication for management of children with 5q SMA. Thus, the development of adverse events and their mechanisms should be further studied, as well as long-term follow-up of recipients is required to gather knowledge on this medication effects on human body.

Stepping foot into a successful partnership to support your viral vector therapy through commercialization

<p class="p2"><span class="s1"><span class="Apple-converted-space">&nbsp;</span></span><span class="s2"><b>Charlotte Barker, </b></span>Editor, <span class="s2"><i>Cell and Gene Therapy Insights</i></span>, <span class="s2"><b>speaks to Minh Hong, </b></span>Head of Commercial, Viral Gene Therapy, Merck, <span class="s2"><b>and Marc Gaal, </b></span>Director, Program Management at the Life Sciences Business Sector, Merck<span class="Apple-converted-space">&nbsp;</span> <div class="authors authors-lg"><div class="author"><div class="author-img"><img src="https://cdn.insights.bio/uploads/Minh Hong copy.png" data-image="1"></div><div class="author-det"> <b>Minh Hong</b> leads the commercial team for Viral Gene Therapy contract manufacturing services within the Life Sciences Business Sector of Merck. He is responsible for account management, business development, and out-licensing activities of innovative viral vector manufacturing tools. </div></div></div><div class="authors authors-lg"><div class="author"><div class="author-img"><img src="https://cdn.insights.bio/uploads/MAG Profile pic small - Copy copy.jpg" data-image="1"></div><div class="author-det"> <b>Marc Gaal</b> heads Merck’s Commercial Project Management Office and is responsible for contract administration and project management of customer programs throughout the entire life cycle of the program. </div></div></div>

Modern approaches in gene therapy of motor neuron diseases.

Motor neuron disorders are a group of neurodegenerative diseases characterized by muscle weakness, loss of ambulation, respiratory insufficiency, leading to an early death. Spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis are the most common and fatal motor neuron diseases. The last 3 years became very successful for novel gene therapy approaches in SMA in infants. Two innovative drugs-nusinersen (Spinraza) and onasemnogene abeparvovec (Zolgensma) have been approved by health authorities. The numerous molecular and genetic overlaps between different neurodegenerative diseases are of great importance in the development of innovative therapeutic strategies, including viral vector therapy and RNA modulating approaches.

Evaluation of a novel cyclic olefin polymer container system for cryopreservation of adeno-associated virus

Background & Aim One of the most effective vehicles for delivery of therapeutic nucleic acids are viral vectors, demonstrated by their utility in many commercial cell and gene therapies. Despite success, gaps remain in the optimization of viral vector storage. Traditional polypropylene snap- and screw-cap vials used in academic and research settings do not have the closure integrity or inert properties required for storage of a commercial drug product. Further, glass vials commonly used for protein biologic drug products have not been fully characterized in the context of viral vectors, which have a need for colder storage temperatures and an associated need for increased break resistance. In the present work, two vial types used for biologic drug product storage, cyclic olefin polymer (COP) and glass, were evaluated for preservation of adeno-associated virus (AAV) during low-temperature storage. Methods, Results & Conclusion Preservation of AAV was evaluated using an AAV2 serotype GFP expression vector that was stored frozen at -80°C in either COP or glass vials. Different storage volumes were investigated in both vial types to determine if surface area-to-volume ratio would have any effect on viral recovery. A quantitative viral titer assay was used to measure any loss of nucleic acid content during the freeze-thaw process and HEK293 transduction efficiency was evaluated as a functional readout using flow cytometry. Overall, viral recovery was greater for larger volume samples, indicating that surface area-to-volume ratio of the storage container may be an important consideration during viral gene therapy formulation. Further, AAV recovery was greater after storage in COP as compared to storage in glass. The results provide baseline data indicating that the storage container used for a viral vector therapy can affect product quality, and that the COP vial may serve as a preferred container for commercial viral vector storage.

2298. Infections in Patients Receiving TVEC Therapy

BackgroundOncolytic viral immunotherapy is an emerging cancer treatment, but the infectious complications are not well described outside of clinical trials. Genetically engineered replication competent herpes simplex virus (HSV-1), commercially known as IMLGYIC® (AmGen) or talimogene laherparepvec (TVEC) was the first FDA approved agent in this class and is used for the local intralesional treatment (of unresectable melanoma. TVEC is derived from a wild-type(WT) strain of HSV-1 (JS—1), which is modified to attenuate off-target effects and promote selective proliferation within cancer cells. Despite these changes local and systemic infection with HSV have been reported from trials and is the subject of an FDA mandated post-marketing review. Here we review the infectious complications of the first cohort of patients treated at our institution post-FDA approval.MethodsDemographic and clinical information for 52 adult patients treated for unresectable melanoma with TVEC following FDA approval in 2015 was extracted from the EMR for the period October 1, 2015–June 30, 2018. EMR and microbiologic data were reviewed for evidence of local site reaction and disseminated infection.ResultsNo cases of disseminated HSV infection were identified during the study period. Of cutaneous reactions, none were documented as greater than severity grade 2, based on standard adverse event reporting criteria. 3 (50%) grade 1–2 cutaneous reactions were deemed probable or definitely related to TVEC and described as pruritis or rash. 12 (23%) patients had any microbiologically confirmed infection identified following TVEC therapy; 6 were bacterial (3 UTI, 1BSI, 2 wound). 8 episodes of viral infections occurred (5 respiratory and 3 GI). A single patient was noted to have localized HSV dermal lesions more than one year after the final TVEC.ConclusionNo local or disseminated HSV infections were encountered in the study cohort. Bacterial skin and soft-tissue infection were uncommon. Most other infections were unrelated to TVEC therapy. Real-world review of the use of an HSV-derived oncolytic viral vector therapy mimics reported infectious complications from clinical trials.Disclosures All authors: No reported disclosures.

First-in-human phase I trial of the combination of two adenoviral vectors expressing HSV1-TK and FLT3L for the treatment of newly diagnosed resectable malignant glioma: Initial results from the therapeutic reprogramming of the brain immune system.

2019 Background: This is the initial report on a first in human Phase I dose escalation trial of the combination of two adenoviral vectors expressing HSV1-TK or Flt3L for the treatment of newly diagnosed, resectable malignant gliomas. The absence of functional dendritic cells from the brain precludes anti-brain tumor immune responses. We combined tumor cytotoxicity (Ad-HSV1TK) with recruitment of dendritic cells to the brain (Ad-Flt3L) to induce an effective anti-tumor immune response. This strategy induced an efficacious, cytotoxic CD8 and CD4 T-dependent immune response in many animal models of glioma. This immune response also generated anti-tumor memory, and the capacity for neoantigen recognition. Methods: The trial was approved by FDA and all institutional cttees. Treatment was administered intraoperatively following complete glioma resection in newly diagnosed tumors. The trial consisted of vector dose escalation, starting at 1x10^9 i.u., and increasing to 1x10^11 i.u. of each vector. Dose escalation proceeded by increasing the vector dose through a total of 6 combinations administered to 6 cohorts of 3 patients each. Two cycles of 14 days each of valacyclovir were administered to activate HSV1-TK cytotoxicity. Cycle 1 starts on Day 1-3 post surgery for 14 days, and Cycle 2 on Week 8-12. Standard radiation, i.e., 60 Gy in 2 Gy fractions over 6 weeks, with concurrent temozolomide, was followed by cyclic temozolomide. Results: Examination of tumor samples at primary resection and first recurrence show an increase in the infiltration of inflammatory cells. The experimental treatment was well tolerated. At this time the MTD has not been reached. There were approx. 248 AEs, and 26 SAEs; these have not been linked to treatment. At this time the MTD has not been reached. A secondary outcome is overall survival. Preliminary analysis of partial data may suggest that the combined viral vector therapy may provide a clinically significant survival. Conclusions: Our results show for the first time that reprogramming of the host’s brain immune system to recognize gliomas reveals a new approach for the treatment of highly malignant brain tumors. Clinical trial information: NCT01811992.

Disease Modification Through Trophic Factor Delivery.

Huntington's disease (HD) is characterized by a significant loss of striatal neurons that project to the globus pallidus and substantia nigra, together with loss of cortical projection neurons in varying regions. Mutant huntingtin is suggested to drive the pathogenesis partially by downregulating corticostriatal brain-derived neurotrophic factor (BDNF) levels and signaling. Neurotrophic factors are endogenous peptides that promote the survival and maintenance of neurons. BDNF and other neurotrophic factors have shown neuroprotective benefits in various animal models of neurodegeneration, and are interesting candidates to protect the cell populations that are destined to die in HD. In an attempt to enhance the delivery of neurotrophic factors, several methods have been established to deliver long-term neurotrophic factor gene therapy to human target tissues. This chapter discusses two alternative approaches that have been shown to have potential to deliver neurotrophic factors as a neuroprotective gene therapy for HD. The methods are (1) ex vivo approach where encapsulated cells engineered to express neurotrophic factor are inserted into brain parenchyma or ventricle, and (2) in vivo viral vector therapy, in which viral vector is injected into desired brain area to express gene of interest in the host cells.

109. Replicating Oncolytic Chimeric Adenovirus Expressing shRNA Improves Inhibition of Human Colorectal Carcinoma (CRC) Growth

RNAi combined with oncolytic viral vector therapy may provide a new approach to control malignant disease since allele specific shRNA to a retrogene that modulates stemness will inhibit growth of human CRC in vivo. Our original delivery vector was nonreplicating Lentiviral vectors (LV) but now oncolytic adenovirus is the vector. We have created a conditionally replicating chimeric oncolytic adenovirus (CRAd) expressing a shRNA to inhibit growth of established tumors in preclinical models. shRNA is directed to NANOGP8, a retrogene that differs from parental NANOG primarily in a single nucleotide variant: c.759G>C, p.Gln253His. Oncolytic adenoviruses were generated with a 5/3 fiber with either a control (Ad5/3-wtE1a-shNEG (Ad5/3shNEG)) or an anti-NANOGP8 shRNA (Ad5/3-wtE1a-shNp8 (Ad5/3shNp8)). LV shNEG or LV shNp8 were added 24 hr after creation of 3-D organoid cultures of human CRC cells (Clone A, CX-1 or LS174T) in serum-free medium. LV transduced 45 – 90% of cells in culture and shNp8 inhibited organoids by ~50% compared to either shNEG or untreated CRC organoids. In addition, LV injected into 7 -9 mm diameter CX-1 tumors in NOD/SCID mice reduced tumor growth in vivo by 40% for 11 days, but then tumors grew at an accelerated rate. NMF cluster analysis reveals that LVshNp8 affects a gene expression profile that is distinct from that of either LVshNEG or untreated controls. In contrast, Ad5/3shNp8 inhibited organoid growth by more than 70% and controlled growth of CX-1 and LS174T in vivo. Infection of cells in vitro was over 90%. Thus, shNp8 alters gene expression and replicating oncolytic virus with shNp8 has a more persistent inhibitory effect than that achieved with non-replicating LV-delivered shRNA.

Modulation of taste responsiveness by the satiation hormone peptide YY

It has been hypothesized that the peripheral taste system may be modulated in the context of an animal's metabolic state. One purported mechanism for this phenomenon is that circulating gastrointestinal peptides modulate the functioning of the peripheral gustatory system. Recent evidence suggests endocrine signaling in the oral cavity can influence food intake (FI) and satiety. We hypothesized that these hormones may be affecting FI by influencing taste perception. We used immunohistochemistry along with genetic knockout models and the specific reconstitution of peptide YY (PYY) in saliva using gene therapy protocols to identify a role for PYY signaling in taste. We show that PYY is expressed in subsets of taste cells in murine taste buds. We also show, using brief-access testing with PYY knockouts, that PYY signaling modulates responsiveness to bitter-tasting stimuli, as well as to lipid emulsions. We show that salivary PYY augmentation, via viral vector therapy, rescues behavioral responsiveness to a lipid emulsion but not to bitter stimuli and that this response is likely mediated via activation of Y2 receptors localized apically in taste cells. Our findings suggest distinct functions for PYY produced locally in taste cells vs. that circulating systemically.

The role of natural killer cells in combinatorial anti-cancer therapy using Sindbis viral vectors and irinotecan

Oncolytic viruses (OVs) have shown great anti-cancer potential in animal models, but only modest success in early clinical trials. A better understanding of the mechanisms underlining OV efficacy is needed to resolve this discrepancy. In the clinic, OV therapy will likely be combined with traditional chemotherapy, underscoring the need to also evaluate the interactions between these therapeutic modalities. Here we show that combining Sindbis viral vector therapy with the topoisomerase inhibitor irinotecan (CPT-11) results in the long-term survival of about 35% of SCID mice bearing aggressively growing ES2 human ovarian cancer. Single-agent treatments did not result in long-term survival. Flow cytometry analysis, bioluminescent imaging and survival experiments revealed that Sindbis and CPT-11 utilize non-overlapping natural killer (NK)-cell-dependent and -independent anti-cancer mechanisms, respectively. Notably, the combinatorial therapy was only effective in the presence of NK cells. These results highlight the hidden role of immune cell activation in combinatorial cancer therapy involving OVs and provide a potential method for tackling tumor cell resistance to cancer therapy while limiting treatment-related side effects.