George Church launches stem cell programming start-up

GC Therapeutics (GCTx) has launched with $65 million in series A financing and a technology that promises to improve the speed and efficiency of stem cell differentiation for cell therapies.

The company was cofounded by Harvard University geneticist George Church, CEO Parastoo Khoshakhlagh, and chief scientific officer Alex Ng. According to Khoshakhlagh, the company had been operating in stealth mode for the past decade.

GCTx’s technology is built on something the company calls the TFome, a complete collection of human transcription factors that Khoshakhlagh and Ng worked on while they were members of Church’s lab group at Harvard (Nat. Biotechnol. 2020, DOI: 10.1038/s41587-020-0742-6. By screening the TFome, the team found transcription factors responsible for determining the cellular fates of induced pluripotent stem cells. “George donated his skin cells, which were reprogrammed into the stem cells that we use. So he surely has skin in the game,” Ng says.

By changing which transcription factors are delivered, GCTx scientists can create different cell types, an approach Khoshakhlagh calls a “plug-and-play model.” It’s a stark contrast to the traditional means of stem cell differentiation, which can take 60–180 days and have efficiencies as low as 4–5%. GCTx’s stem cell differentiation technology takes only 4 days and is up to 99% efficient, according to Khoshakhlagh. “That’s a huge game changer that can really revolutionize the field,” she says.

GCTx is set to use its new funding to assess the safety and efficacy of the cells built using their technology before the firm makes the cells available for clinical use. “Our dream is to have banks of all cell products and no patient who suffers due to lack of accessibility,” Khoshakhlagh says.