Replay receives $1.5 million grant for its hypoimmunogenic technology platform

  • Replay developing uCell™, its universal, off-the-shelf, genomically rewritten, renewable cell source hypoimmunogenic technology, with support from the Bill & Melinda Gates Foundation
  • uCell™ has the potential to democratize cell therapy by reducing cost-of-goods, facilitating access to high-impact cell therapy products for underserved communities around the world
  • uCell™ forms part of Replay’s genomic medicine toolkit that encompasses a portfolio of potentially disruptive platform technologies, including a high payload capacity HSV delivery platform, synHSV™, and a proprietary genome writing platform
  • uCell™ applicable to cell therapy across a broad range of therapeutic areas including cancer, infectious diseases, neurodegenerative diseases, and regenerative medicine

San Diego, California and London, UK, November 28, 2022 – Replay, a genome writing company reprogramming biology by writing and delivering big DNA, today announced that it has received a $1.56 million grant from the Bill & Melinda Gates Foundation to accelerate the development of uCell™, a proprietary hypoimmunogenic technology platform.

Replay’s uCell™ platform is an off-the-shelf, genomically rewritten, hypoimmunogenic technology that allows allogeneic donor-derived primary cells and iPSCs (Induced Pluripotent Stem Cells) to be made immune silent. The technology is expected to substantially decrease the cost-of-goods of cell therapies, improve product volume and consistency, enable extensive genome engineering, and in the case of cancer cell therapy, enable deeper clinical responses and reduced relapse rates. uCell™ is anticipated to form the basis of several off-the-shelf iPSC-derived immune cell therapies applicable to a multiple therapeutic areas, including cancer and infectious diseases. The technology is relevant to both the developed and developing worlds, with the anticipated reduced cost-of-goods improving equity of access.

Adrian Woolfson, Executive Chairman, President, and Co-Founder of Replay, commented: “Hypoimmunogenic technology is the ‘holy grail’ of cell therapy and the non-dilutive funding received from the Bill & Melinda Gates Foundation will help accelerate the development of our uCell™ technology. It is expected to address many of the key challenges of cell therapy, including scalability, the ability to introduce extensive genomic modifications, and need to reduce cost-of-goods. We are immensely grateful to the foundation and our investors for supporting Replay’s vision for the future of genomic medicine, which includes a focus on the development of high-impact and affordable cell therapies that are accessible to both industrialized and rural communities.”

Lachlan MacKinnon, Chief Executive Officer, and Co-Founder of Replay, added: “Replay’s hypoimmunogenic technology is the result of a convergence of synthetic biology, computational design, and protein engineering with iPS cell technology. It will enable the Company to develop a universal off-the-shelf platform in a reliable, scalable, and cost-effective manner, and broaden the utility and accessibility of cell therapy, including regenerative medicine applications. The ability to reprogram hypoimmunogenic iPSCs with our high payload synHSV™ platform will unlock a differentiated set of opportunities. As is the case with synHSV™, and given the substantive opportunity in the space, we plan to progress our uCell™ technology through distinct therapeutic area-focused product companies.”

Professor Herman Waldmann, Co-inventor of uCELL™ and Emeritus Professor of Pathology at the Sir William Dunn School of Pathology at the University of Oxford, said: “As a physician scientist, it is encouraging to see Replay advance the uCell™ platform, which has the potential to overcome many of the current limitations of cell therapies. By making iPSCs immune silent to generate a universal cell with utility as a renewable source for cell therapies, uCell™ has the potential to bring the benefits of this important therapeutic modality to patients across the world.”


About Replay

Replay is a genome writing company, which aims to define the future of genomic medicine through reprogramming biology by writing and delivering big DNA. The Company has assembled a toolkit of disruptive platform technologies – including a high payload capacity HSV platform, a hypoimmunogenic platform, and a genome writing platform – to address the scientific challenges currently limiting clinical progress and preventing genomic medicine from realizing its full potential. The Company’s hub-and-spoke business model separates technology development within Replay from therapeutic development in product companies, which leverage the technology platforms. For example, Replay’s synHSV™ technology, a high payload capacity HSV vector capable of delivering up to 30 times the payload of AAV, is utilized by Replay’s four gene therapy product companies, bringing big DNA treatments to diseases affecting the skin, eye, brain, and muscle. The Company has, additionally, established an enzyme writing product company engaging its evolutionary inference machine learning and genome writing technology to optimize functionality. Replay is led by a world-class team of academics, entrepreneurs, and industry experts.

The Company raised $55 million in seed financing in July 2022 and is supported by an international syndicate of investors that includes KKR, OMX Ventures, ARTIS Ventures, and Lansdowne Partners.

Replay is headquartered in San Diego, California, and London, UK. For further information please visit and follow us on LinkedIn and Twitter.



Dr Adrian Woolfson/Lachlan MacKinnon

Consilium Strategic Communications – Media relations

Amber Fennell/Tracy Cheung/Melissa Gardiner

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