Opko Health shares rise on Merck deal for experimental Epstein-Barr vaccine

(Reuters) -Opko Health Inc said on Wednesday it signed a deal with Merck & Co Inc potentially worth up to $922.5 million for its experimental Epstein-Barr virus vaccine.

Shares of Opko rose as much as 24%, before paring gains to trade 9.4% higher at $1.16.

Merck will take over the clinical and regulatory activities related to the vaccine, as well its commercialization once the drugmaker files a joint application with Opko unit ModeX Therapeutics to test it in humans, the company said.

Opko will receive an upfront payment of $50 million and is eligible for milestone payments of up to $872.5 million, plus royalties, on global sales.

There is currently no vaccine for the Epstein-Barr virus, which is the leading cause of mononucleosis, or mono, commonly called the “kissing disease”.