Molecular Therapy最新文献

Hemophilia B gene therapy treatments have not addressed the need for predictable, durable, active, and redosable factor IX (FIX). Unlike conventional gene therapy, engineered B cell medicines (BCMs) are durable, redosable, and titratable and thus have the potential to address significant unmet needs in the hemophilia B treatment paradigm. BE-101 is an autologous BCM comprising expanded and differentiated B lymphocyte lineage cells genetically engineered ex vivo to secrete factor IX (FIX)-Padua. CRISPR-Cas9-mediated gene editing at the C-C chemokine receptor type 5 (CCR5) locus was used to facilitate transgene insertion of an adeno-associated virus 6-encoded DNA template via homology-directed repair. Transgene insertion did not alter B cell biology, viability, or differentiation into plasma cells. Appreciable levels of BE-101-derived FIX-Padua were detected within 1 day after IV administration in mice, and steady state was reached within 2 weeks and persisted for over 184 days. Redosing produced an increase in FIX-Padua production close to linear dose proportionality. Comprehensive genotoxicity analysis found no off-target issues of concern. No safety signals were observed in animal tolerability and Good Laboratory Practice toxicology studies. In conclusion, BE-101 produces sustained levels of active FIX-Padua with the ability to engraft without host preconditioning and with the potential for redosing and titratability.

Age-related tissue changes lead to reduced oxygen delivery to photoreceptors and the retinal pigment epithelium (RPE) and contribute to the pathology of age-related macular degeneration (AMD). The implication of hypoxia-inducible factors (HIFs) in this process makes them good candidates as therapeutic targets for AMD. We developed a multiplex dual-acting therapy utilizing the shRNAmir system, delivered by a single adeno-associated virus, that reduces mRNA levels of Hif1a in photoreceptors and Hif2a in the RPE. This RNA interference (RNAi)-based strategy demonstrated a strong therapeutic effect, potently preserving photoreceptors and the RPE in two models of pseudo- and true hypoxia up to 61 weeks post-injection. The efficacy of our dual-acting virus proved superior to single-acting viruses targeting only Hif1a in photoreceptors or Hif2a in the RPE. By targeting a common, conserved disease pathway, this gene-agnostic RNAi therapy shows significant potential to protect tissues from chronic hypoxic insults in complex diseases such as AMD.

Epigenome editing is emerging as a transformative approach in clinical treatment, enabling precise modifications to gene expression without altering the underlying DNA sequence. The ongoing transition of epigenome editing techniques from foundational research to clinical applications highlights several key strategies. These include targeted DNA methylation/demethylation, histone modification, and transcriptional regulation. These approaches offer the potential for durable and reversible gene expression modulation, paving the way for precisely tailored therapies for genetic and complex diseases. Here, we review pioneering research, technological advancements, granted patents, and clinical trials that have been reported during the past decade. By synthesizing current research and development efforts, this review aims to provide insights into the promising landscape of epigenome editing and its potential to promote therapeutic interventions.

Increased vascular leakage and endothelial cell (EC) dysfunction are major features of neurodegenerative diseases. Here, we investigated the mechanisms leading to EC dysregulation and asked whether altered mitochondrial dynamics in ECs impinge on vascular barrier integrity and neurodegeneration. We show that ocular hypertension, a major risk factor for developing glaucoma, induced mitochondrial fragmentation in retinal capillary ECs, accompanied by increased oxidative stress and ultrastructural defects. Analysis of EC mitochondrial components revealed overactivation of dynamin-related protein 1 (DRP1), a central regulator of mitochondrial fission, during glaucomatous damage. Pharmacological DRP1 inhibition or EC-specific in vivo gene delivery of a dominant-negative DRP1 mutant was sufficient to rescue mitochondrial volume, reduce vascular leakage, and increase expression of the tight junction claudin-5 (CLDN5). We further demonstrate that EC-targeted CLDN5 gene augmentation restored blood-retinal barrier integrity, promoted neuronal survival, and improved light-evoked visual behaviors in glaucomatous mice. Our findings reveal that preserving mitochondrial homeostasis and EC function are valuable strategies to enhance neuroprotection and improve vision in glaucoma.

Duchenne muscular dystrophy (DMD) is a fatal muscle degenerating disease caused by dystrophin deficiency. Adeno-associated virus (AAV)-based gene therapy holds promise for restoring missing dystrophin and improving quality of life. Many clinical trials have been conducted or are ongoing. Despite compelling preclinical data, the full potential of AAV gene therapy remains to be established in DMD patients. Importantly, high-dose intravenous AAV administration has resulted in hospitalizations and several deaths in patients afflicted by DMD and other inherited diseases due to innate and adaptive immune responses to the vectors. Although fatal outcomes are rare, a critical analysis of these cases may provide insights to refine systemic AAV gene therapy for DMD and other inherited diseases. Here, we review the clinical findings of the reported deaths and related cases in AAV gene therapy for DMD and other diseases. We also evaluate the underlying mechanisms and discuss mitigating strategies and future directions.