The move raises privacy concerns as the drugmaker takes control of the genetic data of millions of clients of the once-sizzling DNA-testing startup.

Biotechnology company Regeneron Pharmaceuticals is buying 23andMe for $256 million, two months after the genetic testing company filed for Chapter 11 bankruptcy protection. In March 23andMe said that it was looking to sell “substantially all of its assets” through a court-approved reorganization plan.