Dyno eCap 1 capsid: an optimized IVT delivered AAV capsid with improved retinal cell targeting for wetAMD, GA, glaucoma and IRD gene therapies

Abstract

Purpose : We hypothesize that safer and more effective intravitreally (IVT) delivered ocular gene therapies may be enabled by engineering AAV capsids for highly efficient transduction of the retina at low doses. Higher transduction can improve biofactory-based gene therapy approaches for wetAMD and GA, while higher cell-specific targeting of cells like photoreceptors and bipolar cells can advance inherited retinal disease (IRD) and optogenetic-based therapies. Here we characterize the Dyno eCap 1 capsid, a novel capsid designed with generative AI leveraging in vivo data from multiplexed measurements of capsid libraries.

Methods : Retinal transduction of Dyno eCap 1 was evaluated in multiplexed capsid library studies from IVT injected Cynomolgus monkey eyes by NGS of expressed variant associated barcodes from bulk tissue samples and by single-nucleus RNA sequencing (snRNA-seq). In separate studies Dyno eCap 1 was co-injected with an external engineered capsid at doses of ~1e11 vg/eye, and transduction was quantified from immunofluorescent (IF) staining of histological sections. Tropism was confirmed by co-staining for cell-type specific markers.

Results : Bulk NGS measurements showed that Dyno eCap 1 outperformed AAV2 ~80-fold and an external engineered capsid ~2-fold in the neural retina. Similarly, through histology quantification, Dyno eCap 1 outperformed the external engineered capsid, with 2.6-fold higher transduction across the entire retina, and between 2-3-fold higher transduction across ganglion cells, inner nuclear layer cells including bipolar cells, and photoreceptors in the central retina. Cell-specific immunostaining also demonstrated high transduction in ganglion cells of the macula, and rod and bipolar cells throughout the retina. snRNA-seq confirmed these results, also demonstrating delivery of Dyno eCap 1 delivery to all major NHP retinal cell types. Dyno eCap 1 showed 2-3 fold higher transduction across these cell types compared to the external engineered capsid, closely matching histology results. Similar results were observed when quantifying transduction of the macula by snRNA-seq.

Conclusions : These results demonstrate the potential of the Dyno eCap 1 capsid as the field-leading capsid for IVT delivered gene therapies, opening new opportunities to treat a wider range of ocular diseases including glaucoma, wetAMD, GA and IRDs.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.