Patients diagnosed with esophageal cancer (EC) currently rely on treatments given at specialist care centers (surgery, chemotherapy, radiation), which despite their low cure rates are extremely life-disruptive, cause severe pain, and have strong side effects. In particular, dysphagia is one of the most distressing and debilitating symptoms in patients with cancer-related esophageal obstruction. There is clearly an urgent need for new effective and accessible therapies for EC patients that allow patients to continue normal activity as much as possible. Here, we describe a drinkable methylcellulose/xanthan gum-based gene therapy foam that coats the esophagus and accumulates an apoptosis-inducing gene therapy drug (mRNA lipid nanoparticles encoding Pseudomonas exotoxin A) at the tumorous esophageal stricture. In an in vitro EC tissue model, we show that gene therapy foam induces 110-fold higher tumor regression compared to suspension treatment. We also establish that gene therapy foam given prior to radiotherapy strongly enhances anti-tumor effects. Once implemented in the clinic, this treatment, which can be administered orally by a local family doctor or at home by the patient or caregiver, could maximize the time EC patients can live normal lives outside of the hospital and allow them to maintain their ability to swallow and eat.

Neovascular age-related macular degeneration (nAMD) is a major cause of irreversible vision loss in the elderly, driven by choroidal neovascularization and dysregulated vascular endothelial growth factor (VEGF) signaling. While anti-VEGF injections have transformed management, their frequent administration imposes a substantial burden on patients and limits adherence. Adeno-associated virus (AAV)-based gene therapy offers sustained intraocular delivery of anti-angiogenic agents with a single treatment, potentially overcoming these limitations. This review summarizes the rationale for AAV use in ocular gene therapy, compares major delivery routes, and highlights leading clinical candidates, including RGX-314, ADVM-022, 4D-150, and NG101. Advances in vector engineering, promoter optimization, and immune modulation are discussed alongside key challenges such as preexisting immunity and inflammation. Future directions include next-generation capsids, combination regimens, and precision patient selection. Collectively, these developments position AAV-based gene therapy as a promising strategy to redefine the therapeutic landscape of nAMD.

While recombinant adeno-associated virus (AAV) holds significant promise for effective and durable gene delivery for gene therapy, a thorough understanding of the critical quality attributes (CQAs) along with the degradation pathways of AAV under the various stresses that may occur during manufacturing, storage, and handling remains limited. To address this gap, we performed a comprehensive forced degradation study to elucidate the degradation pathways of AAV8 under a series of stress conditions, such as oxidation, extreme pH, high temperature, freeze-thaw, and agitation. Our results show that, under these stress conditions, distinct post-translational modifications (PTM), including methionine oxidation, asparagine deamidation, and aspartic acid isomerization, along with multiple physical degradation pathways, including capsid aggregation, viral protein fragmentation, and genome DNA leakage, could occur. Alterations in AAV8 biological activity were frequently attributed to the combination effect from chemical and physical degradation mechanisms. The results from this study provide a valuable insight into the establishment of stability-indicating methods and the identification of CQAs for AAV. It will also support the development of robust manufacturing process as well as stable and efficacious AAV gene therapy drug products.

Previously, we confirmed that BaEV-LVs outperformed VSV-G-LVs for gene delivery or correction of human T cells, B cells, NK cells and HSPCs correlating with high expression of its receptors, ASCT-1 and ASCT-2 on these cells. Since HERV-W gp uses the same entry receptors, we compared transduction efficiencies for BaEV-LVs and HERV-W-LVs in hematopoietic cells. HERV-W LV transduction was efficient but inferior to BaEV-LV in TCR-stimulated T cells (40% versus 80%) and this low efficiency was even more pronounced in IL-7/IL-15 pre-stimulated T cells. BaEV-LVs were significantly superior over HERV-W-LVs for the transduction of B cells and NK cells. High HERV-W-LV mediated transduction levels were achieved for pre-stimulated hCD34+ cells, which remained though lower than for the BaEV-LVs. Additionally, BaEV-LVs reached over 80% of transduction in severe combined immunodeficiency (SCID) repopulating cells (SRC) in 6/6 engrafted NBSGW mice. HERV-W-LVs reached this transduction level in 1/5 mice, while 3/5 engrafted NBSGW mice reached significantly lower transduction levels (20-50%). For both vectors the transduction levels were equivalent in the lymphoid and myeloid lineages in all hematopoietic tissues, suggesting transduction of immature HSPCs. Summarizing, BaEV-LVs outperformed HERV-W-LVs for transduction of important gene therapy target cells such as NK, B, T cells and CD34+ HSPCs.

Adoptive Cell Therapies based on cytokine-induced killer cells (CIKs) can address the heterogeneity of solid tumors due to their multiple mechanisms of cancer cell recognition. However, tumor trafficking is one of the main limitations. In this work, we describe that a high proportion of CIKs obtained from pancreatic ductal adenocarcinoma patients express the CXCR3 and CCR5 receptors, and they migrate towards their corresponding chemokines CXCL10 and CCL5 in vitro. Using an immune competent orthotopic PDAC mouse model, we have investigated the ability of different clinically compatible interventions to increase the expression of these chemokines. No significant elevation was obtained with chemotherapy (5-fluorouracil, irinotecan, oxaliplatin, paclitaxel, gemcitabine or temozolomide), tyrosine kinase inhibitors sorafenib and sunitinib, or the immunostimulatory agents polyinosinic:polycytidylic acid, Mycobacterium tuberculosis antigens and diphtheria/pertussis/tetanus vaccine. In contrast, CXCL10 and CCL5 expression was stimulated by local administration of an adenoviral vector equipped with a drug-inducible expression system for interleukin-12 (IL-12). Combination of the vector and CIKs obtained a strong antitumor effect in the PDAC model, although it was mainly due to vector-mediated recruitment of endogenous immune cells. We conclude that additional barriers beyond chemokine expression should be overcome in order to unleash the full potential of CIKs on solid tumors.

Immune responses against recombinant adeno-associated virus (rAAV) are one of the major obstacles in gene therapy. We investigated the potential of Programmed Death 1 ligands 1 and 2 (PD-L1/2) to protect AAV-transduced cells from immunological clearance. Ligand compatibility for co-delivery was first evaluated using two transgenes, VEGF-B186 and muSEAP, separated from PD-L1/2 by a self-cleaving P2A peptide. After proper cleavage and biological activity of the co-produced proteins were demonstrated in vitro, the effect of PD-L1/2 co-expression on muSEAP production and persistence was studied in naïve and vector pre-immunized mice. Vectors (rAAV6-muSEAP, rAAV6-muSEAP-PD-L1, or rAAV6-muSEAP-PD-L2) were injected into two sites of the gastrocnemius muscle at a total dose of 1×1010 vg. Co-delivery of PD-L1, particularly, significantly enhanced muSEAP secretion into the bloodstream up to 12 weeks despite elevated anti-AAV6 responses in pre-immunized mice. muSEAP secretion increased 33.3- and 31.4-fold with the co-delivery of PD-L1, while the increase was only 5.6- and 9.3-fold in the muSEAP control group at 5 and 12 weeks, respectively. Ligand-treated pre-immunized animals also had less T-cell infiltration into the treated muscle compared to naïve animals. In summary, co-delivery of PD-L1/2 alongside a transgene represents a promising strategy for achieving sustained gene expression in individuals pre-exposed to AAV.

Adeno-associated virus (AAV)-based gene therapies have garnered significant attention and investment due to their clinical success and potential to address underlying causes of many diseases. AAV vectors provide effective delivery of therapeutic genetic material to disease-relevant tissues. When evaluating safety and efficacy of recombinant AAV vectors, biodistribution profiles play a critical role in novel therapy development. Herein, a biodistribution metadata analysis was performed on ten studies involving 51 cynomolgus macaques (Macaca fascicularis). The macaques received a self-complementary or single-stranded AAV9 vector containing chicken ß-actin (CBA) or cytomegalovirus (CMV173) promoters expressing fluorescent reporters or a human SMN1 gene. These studies covered various routes of administration (ROA) including intravenous (IV), intracisternal magna (ICM), and lumbar puncture intrathecal (IT) injection. Metadata analysis of AAV9 biodistribution showed relatively uniform vector genome delivery throughout spinal cord tissues over multiple timepoints and ROAs. Moreover, decreased expression efficiency of viral DNA in liver was observed regardless of the ROA, macaque age, or viral construct used. To understand this trend, epigenetic profiling of tissue-localized AAV9 vector genome DNA was performed. Experimental evidence supports partial silencing and repression of transgene expression in macaque liver. These findings point to plausible strategies to consider in preclinical development of AAV9 mediated gene therapies.

This article provides a regulatory perspective on secondary malignancy of T-cell origin as a rare adverse reaction to the currently marketed CD19- or BCMA-directed chimeric antigen receptor (CAR) T-cell therapies. To assess the risk, causality between reported suspected adverse reactions and CAR T-cell therapy was assessed applying the principles of the World Health Organization-Uppsala Monitoring Centre causality categories, alongside a review of scientific publications and data from registries/ databases. By 11 April 2024, 38 cases of T-cell malignancy after CAR T-cell therapy were reported in patients aged 29-80 years. In 19 patients, tumour samples were tested for the presence of CAR transgene, which was detected in seven cases. Most of the T-cell malignancies were diagnosed within 12 months of treatment (22/33; 67%). The reporting rate is approximately one case per 1000 patients treated. An overall causal relationship was established with at least a reasonable possibility. Regulatory measures included updates to the product information, risk management plan, and educational materials. An additional pharmacovigilance activity was requested from the marketing authorisation holders (MAHs) to strengthen the process of genetic testing of residual tumour samples. To further characterise this risk and understand underlying mechanisms, continued efforts from healthcare professionals, MAHs and regulators are essential. Well-documented case reports, including information on genetic testing of tumour samples, are considered crucial elements.

Retinitis pigmentosa (RP) associated with mutations in the rhodopsin gene (RHO) is a significant cause of blindness. Here we report on the application of adenine base editing of the c.1030C>T (p.Q344X) RHO mutation linked to RP. Using a fluorescence reporter cell system, we optimized editing by exploring base editors, sgRNA, and delivery methods. Flow cytometry, western blotting, and immunofluorescence microscopy confirmed the restoration of full-length rhodopsin after editing. DNA sequencing verified editing at the target nucleotide and the absence of bystander edits within the editing window. Polyethylenimine cationic polymer transfection of cells with a plasmid containing the NG-ABE8e adenine base editor and A6 guide RNA that placed the targeted adenine in position 6 of the editing window resulted in 31.0% gDNA sequence correction and 26.3% rhodopsin protein correction as determined by flow cytometry. Purified NG-ABE8e protein complexed with A6-sgRNA showed 32.2% gDNA editing and 44.5% rhodopsin correction. Plasmid NG-ABE8e and A6-sgRNA co-encapsulated into lipid nanoparticles (LNPs) and transfected into the reporter cell system resulted in the highest editing (42.6% gDNA editing and 65.9% rhodopsin correction). These results demonstrate the successful correction of the c.1030C>T RHO mutation and provide the foundation for base editing as a treatment for RP.

Adeno-associated viruses (AAVs) hold significant promise for gene therapy targeting the central nervous system (CNS). However, current delivery methods are either invasive or cause significant systemic exposure. Intranasal (IN) delivery presents a promising noninvasive alternative for direct CNS targeting, though its efficacy in delivering AAVs to the brain has seldom been explored. Here, we quantitatively assessed AAV transduction in the brain and peripheral organs of Swiss, BALB/c, and C57BL/6 J mice following IN administration, using intravenous (IV) injection as a benchmark for comparison. Our findings revealed that IN administration of the AAV9 vector achieved approximately 15% of the transduction efficiency and 9% of the gene expression levels observed with IV delivery. Importantly, IN delivery significantly reduced systemic exposure to most major peripheral organs by up to 1.34 × 104-fold compared to IV injection. The ratios of gene transduction between the brain and various peripheral tissues were calculated, revealing that for key organs such as the liver, stomach, kidney, and spleen, IN delivery achieved higher brain-to-peripheral transduction ratios than IV delivery. These findings underscore the potential of IN delivery for noninvasive brain-targeted gene delivery with significant reductions in peripheral exposure.