Design and Characterization of a Novel Intravitreal Dual-Transgene Genetic Medicine for Neovascular Retinopathies.

Purpose: Intravitreal delivery of therapeutic transgenes to the retina via engineered viral vectors can provide sustained local concentrations of therapeutic proteins and thus potentially reduce the treatment burden and improve long-term vision outcomes for patients with neovascular (wet) age-related macular degeneration (AMD), diabetic macular edema (DME), and diabetic retinopathy.

Methods: We performed directed evolution in nonhuman primates (NHP) to invent an adeno-associated viral (AAV) variant (R100) with the capacity to cross vitreoretinal barriers and transduce all regions and layers of the retina following intravitreal injection. We then engineered 4D-150, an R100-based genetic medicine carrying 2 therapeutic transgenes: a codon-optimized sequence encoding aflibercept, a recombinant protein that inhibits VEGF-A, VEGF-B, and PlGF, and a microRNA sequence that inhibits expression of VEGF-C.

Multimodal evaluation of network activity and optogenetic interventions in human hippocampal slices.

Seizures are made up of the coordinated activity of networks of neurons, suggesting that control of neurons in the pathologic circuits of epilepsy could allow for control of the disease. Optogenetics has been effective at stopping seizure-like activity in non-human disease models by increasing inhibitory tone or decreasing excitation, although this effect has not been shown in human brain tissue. Many of the genetic means for achieving channelrhodopsin expression in non-human models are not possible in humans, and vector-mediated methods are susceptible to species-specific tropism that may affect translational potential.

Engineering novel adeno-associated viruses (AAVs) for improved delivery in the nervous system.

Harnessing adeno-associated virus (AAV) vectors for therapeutic gene delivery has emerged as a progressively promising strategy to treat disorders of both the central nervous system (CNS) and peripheral nervous system (PNS), and there are many ongoing clinical trials. However, unique physiological and molecular characteristics of the CNS and PNS pose obstacles to efficient vector delivery, ranging from the blood-brain barrier to the diverse nature of nervous system disorders. Engineering novel AAV capsids may help overcome these ongoing challenges and maximize therapeutic transgene delivery.