Crispr’s potential for curing inherited disease has made headlines, including at WIRED, for years. ( Here, here, here, and here.) Finally, at least for one family, the gene editing technology is turning out to deliver more hope than hype. A year after 34-year-old Victoria Gray received an infusion of billions of Crispr’d cells, NPR reported last week that those cells were still alive and alleviating the complications of her sickle cell disease. Researchers say it’s still too soon to call it a cure. But as the first person with a genetic disorder to be successfully treated with Crispr in the US, it’s a huge milestone. And with dozens more clinical trials currently in progress, Crispr is just getting started.
Yet for all its DNA-snipping precision, Crispr is best at breaking DNA. In Gray’s case, the gene editor built by Crispr Therapeutics intentionally crippled a regulatory gene in her bone marrow cells, boosting production of a dormant, fetal form of hemoglobin, and overcoming a mutation that leads to poor production of the adult form of the oxygen-carrying molecule. It’s a clever way around Crispr’s limitations. But it won’t work for a lot of other inherited conditions. If you want to replace a faulty gene with a healthy one, you need a different tool. And if you need to insert a lot of DNA, well, you’re kind of out of luck.
Not anymore, says Geoffrey von Maltzahn, the CEO of a new startup called Tessera Therapeutics. The company, which was founded in 2018 by Boston-based biotech investing powerhouse Flagship Pioneering where von Maltzahn is a general partner, emerged from stealth on Tuesday with $50 million in initial financing. Tessera has spent the last two years developing a new class of molecular manipulators capable of doing lots of things Crispr can do—and some that it can’t, including precisely plugging in long stretches of DNA. It’s not gene editing, says von Maltzahn. It’s “gene writing.”