
A George Church spinout fighting the viral vector bottleneck in cell and gene therapy lands $55M
A synthetic biology company spun out of George Church’s lab is set to tackle the gene therapy manufacturing bottleneck, and it just landed $55 million in a Series A financing round to do so.

64x Bio comes out of the Harvard Department of Genetics. CEO Lex Rovner and her team — which right now, sits around 10 people — are looking to tackle a key hurdle for major companies: manufacturing cell and gene therapies.
Rovner met Church while getting her PhD at Yale, and went on to do a postdoctoral research fellowship in his lab, and, when talking to folks in the industry, found a massive viral vector manufacturing bottleneck that wasn’t being talked about.
After a seed funding round and the company’s launch in 2020, it made some noise in the industry, particularly as Covid-19 made bottleneck issues more visible. There’s a waitlist to get a vector from manufacturers, and not much of a solution to the problem
“In a lot of cases, in-house vector manufacturing capacity is already exceeded for even the smallest disease populations. And once you get into the more widespread diseases, manufacturing capacity can be off by orders of magnitude,” Rovner said in an interview with Endpoints News. “It’s very likely going to be impossible to outsource that much manufacturing…It’s really no secret that this is a problem, that is and will continue to limit the therapies for each patient if this is left unsolved.”
Lifeforce Capital led the round, with Northpond Ventures, Future Ventures, the former Aldevron CEO Michael Chambers, First Round Capital, CEO of Recursion Chris Gibson and Alix Ventures all participating as well. The funds will go toward advancing VectorSelect, a platform that uses machine learning to test millions of different cells for how well viruses grow in them, making for a faster, and more effective process.
Once it’s tested millions of potential cell lines — all simultaneously — 64x screens for combinations of genes that make for highly productive cells. So far, there’s been success with adeno-associated viruses, the most common vector used in gene therapy, and Rovner and her team are looking to explore other markets too.
“The problem is more fundamental than physical infrastructure,” she said. “This is a genetics problem and the solutions are going to be in tailoring how a cell interacts with the viral components.”
Church said in a statement: “Until now, genetic tailoring of manufacturing cells has failed to deliver. Overcoming the cellular barriers to viral production will require many cellular mutations in combination, which means testing potentially trillions of mutant cells. Existing cell line engineering and screening technologies have not been up to the challenge.”
64x will “dramatically” grow its employee base, from 10 employees right now to about 50, Rovner said. That will start with the expansion of its management team. It’s also going to expand its partnerships with other biotechs, and while the company isn’t ready to announce anything just yet, news on that front could be coming in the near future.
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