Treatments based on the Nobel-prize winning Crispr gene-editing approach can make permanent changes to a genetic flaw— but those edits only amend a few letters of genetic code at a time. Like a chapter in the book of life, each gene in our genome comprises hundreds, or thousands, of such code letters.
A longstanding challenge in gene-editing is the ability to make big, gene-sized changes at spots of our choosing in the genome, says Harvard chemistry professor David Liu.
A group of MIT researchers described in November their use of prime editing to insert full length, working genes at targeted points in the DNA of a variety of human cells.
Nearby in Cambridge, Mass., the privately held Tessera Therapeutics is advancing an alternative way of rewriting faulty genes. Backed by the Flagship Pioneering venture group that launched Covid vaccine maker Moderna (MRNA), the scientists at Tessera are adapting a gene transfer phenomenon common in nature, called retrotransposons.
In November, Tessera and other Flagship startups joined the Cystic Fibrosis Foundation in a $110 million project to develop a single treatment that might fix the scattered mutations that cause CF.
