Merck & Co., Inc. (NYSE:MRK) is in advanced talks to acquire cancer drugmaker Harpoon Therapeutics, Inc. (NasdaqCM:HARP) for around $700 million, people familiar with the matter said. A deal could be announced within days assuming talks don?t fall apart, the people said, asking not to be identified because the information was private. Merck is discussing paying about $23 a share for South San Francisco-based Harpoon, the people said.

A representative for Merck declined to comment. A spokesperson for Harpoon didn?t immediately respond Sunday to a request for comment.