Rolapitant, the lead product, recently completed Phase II clinical testing for prevention of nausea and vomiting related to cancer chemotherapy and surgery, and other indications. Phase 1 clinical testing has also been initiated for a second compound in the same class. It is anticipated that these compounds may have advantages over presently marketed products.

"We are pleased to acquire these assets from Schering-Plough," said Phillip Frost, M.D., OPKO's Chairman and Chief Executive Officer. "They will fit in well with our strategy to create a portfolio of important products that will bring significant value to patients and shareholders."

In connection with its pending merger with Merck & Co., Inc., Schering-Plough determined to divest its oral and intravenous formulations of rolapitant and other assets in its NK-1 program. Closing of the transaction between OPKO and Schering-Plough is subject to completion of the merger.

NK-1 receptors are highly concentrated in the brain and are also found in other tissues of the body. Activation of NK-1 receptors leads to the release of neurotransmitters and other signaling molecules that play a central role in controlling nausea and vomiting and other basic functions. Jamie Freedman, M.D., Ph.D., Executive Vice President of Research & Development at OPKO commented, "The profile of rolapitant and the positive clinical data generated so far are very promising. We believe rolapitant has the potential to be a best-in-class product for preventing nausea and vomiting in the post-surgical setting or induced by cancer chemotherapy drugs. We will also be exploring various other uses of rolapitant."