GC Therapeutics, a biotech startup that is writing the recipe book for turning a stem cell into nearly any natural human cell, formally launched Thursday with $75 million in financing.
The startup is based on research from George Church’s lab at Harvard Medical School and the Wyss Institute, led by his former graduate student Alex Ng and postdoc Parastoo Khoshakhlagh. The idea that helped found the company five years ago was built out of the duo’s frustrations with existing techniques for making therapies out of stem cells, which they thought were too slow, too piecemeal, and too complicated.
After founding the company with Church in 2019, a year later they reported a methodical way to search through nearly 1,600 transcription factors — proteins that control which sets of genes are turned on and off in a cell — to find ones that could quickly convert a stem cell into useful cells that make up blood vessels, the brain, connective tissues and more.
Called GCTx for short, the startup’s sweeping ambitions began attracting attention right away, even landing them a spot on the CBS show “60 Minutes” — but the company has tried to stay quiet since then and still has not shared details about many aspects of its work.
Khoshakhlagh, the startup’s CEO, told Endpoints News that GCTx recently closed a $65 million Series A financing led by Cormorant Asset Management on top of a previously unannounced $10 million seed investment led by Andreessen Horowitz (a16z) Bio + Health.
Ng, the startup’s chief scientific officer, said the 35-person company has been annotating and curating transcription factors, figuring out how to deliver those proteins to finicky and fragile stem cells, and developing ways to screen for the best combinations of the proteins. He said that the company is preparing to present and publish more details “in the near future.”
Khoshakhlagh said her company has an initial focus on gastrointestinal, neurological and immune diseases, which “are waiting to be transformed by cell therapy.” She also said that GCTx also plans to create so-called “SuperCell” therapies that combine the properties of two or more cells but didn’t give examples.
GCTx is focused on induced pluripotent stem cells, or iPSCs, which Japanese scientist Shinya Yamanaka discovered could be created from a cocktail of four transcription factors in 2006. In the nearly two decades since, biologists have been gradually working out how to turn those blank-slate cells into useful members of the human body.
To do so, scientists have tried to replicate the natural development paths that cells undergo from embryo to adulthood. The right mixture of transcription factors, nutrients, and other molecules given at just the right time over a period of weeks to months might create a brain cell, while another carefully administered concoction may create heart muscle.
Discovering those recipes, and following them to the letter, hasn’t been easy, but it is finally leading to some of the first clinical trials of stem cell-derived therapies for blindness, diabetes, Parkinson’s disease and more. (Some of these treatments currently in trials are still based on embryonic stem cells, but iPSC-derived ones are in the works.)
GCTx is hoping to dramatically simplify the creation of cell therapies by stripping complex and time-consuming recipes down to a small number of transcription factors that turn iPSCs into adult cells in just four days.
“We can use the same manufacturing process and only need to actually swap the transcription factors to give us a different cell product, which makes our process very streamlined and really much more straightforward,” Khoshakhlagh said.