Technology and product development have different talent requirements, timelines, costs, and cultures. We created a model to accommodate these differences. Replay owns and develops core platform technologies, developed in a disease area agnostic manner. When we identify a product opportunity that can be addressed by one or more of our platforms, we create a product company with a specific focus in a defined area.

Separating technology development from product development


Delivering big DNA

synHSV™ is capable of delivering up to 30x the payload of AAV. We can deliver big genes, genomic genes, and multiple genes, unlocking the promise of polygenic medicine.

HSV: 150kb vs. AVV: 4.8kb
HSV: 150kb vs. AVV: 4.8kb
HSV: 150kb vs. AAV: 5kb

83% of genes are too big for AAV

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Graph showing 6 squares, connected by the Replay logo
Products housed within product companies

Big DNA gene therapies leveraging synHSV™

Product Company Founders - EyePCF - Eye

Retinitis pigmentosa is a group of rare eye diseases that affect the retina. RP causes progressive disfunction of rod photoreceptors with subsequent degeneration of cone photoreceptors and the retinal pigment epithelium, resulting in vision loss. Symptoms start in childhood and most individuals eventually lose the majority of their sight.

Construct 1: 7kb
Construct 2: 9kb
Replay Bio Construct Illustration
Construct 1: 7kb
Construct 2: 9kb

Rewritten enzymes, leveraging DropSynth™ and LASR™

Product Company Founders - EnzymesPCF - Enzymes


TET and APOBEC are key enzymes in DNA methylation analysis. Methylation analysis is increasingly the approach of choice for early cancer detection (ECDx), as it has high sensitivity and provides tissue of origin information.

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Help us to author the future of genomic medicine