The transaction could be announced as soon as Wednesday, said the people, who asked not to be identified because the discussions are private.
A final agreement hasn’t been reached and the talks could still end without one, the people said. Representatives for Merck and Terns didn’t immediately respond to requests for comment.
Shares of Terns rose as much as 15% in premarket trading. Through Tuesday’s close, the stock has risen 24% this year.
Terns, based in Foster City, California, ...