What’s going on at Homology Medicines?

Back in 2016, a company called Homology Medicines came into the world with the claim that its scientists had built a better mousetrap for genome editing, using viruses to tinker with DNA in vivo instead of CRISPR’ing cells in a lab. That brought millions in venture dollars, a $144 million IPO, and a nearly $1 billion market cap.

At least until yesterday, which is when researchers at USC disclosed that they tried to reproduce Homology’s foundational paper and found themselves completely unable, casting doubt on the claims upon which the company is built. The USC paper was posted to a preprint server and has not been peer reviewed.

Homology lost about 20% of its value after the paper went live. In a statement, the company said it's confident in its science, which has been reviewed by third-party labs and by Novartis, Homology's research partner.

The company’s lead medicines are traditional gene therapies, not genome-editing projects. But Homology's promise is based in part on the idea that it could one day compete in genome editing with the efforts of biotech’s many CRISPR companies, a future that would require its baseline science actually working.