LINDA A. JOHNSON AP Business Writer TRENTON, N.J. (AP) — Merck & Co. and Portola Pharmaceuticals Inc. said Thursday they have signed an exclusive deal to develop and market an experimental drug to prevent strokes in people with a dangerous irregular heart rhythm. Merck, the world’s eighth-biggest drugmaker, will pay Portola $50 million initially to license the drug, called betrixaban, and a possible total of $470 million, if all further research and development goes well. Betrixaban prevents blood clots by blocking a clotting protein called Factor Xa. The pill would be taken daily by people with atrial fibrillation, a sometimes deadly abnormal heart rhythm affecting roughly 7 million people in the U.S. and Europe. The companies said drugs that block Factor Xa might overcome limitations of the most frequently prescribed anticlotting drug in North America, warfarin. Getting the dosage of warfarin correct is tricky, so patients must have frequent follow-up blood tests to prevent bleeding or other problems. Warfarin also can cause serious interactions with other drugs. Betrixaban, now in midstage testing, might offer a couple other advantages: It could be good for patients with severe kidney disease because it is mostly excreted through other mechanisms and it may produce fewer drug interactions than other anticlotting treatments. Under the deal, Merck would cover costs of future testing and marketing of the drug. If the drug is approved for sale, Portola could earn up to $420 million more in payments from Merck. Portola also would be eligible for royalties worth more than 10 percent on future worldwide sales of betrixaban, according to the company’s chief financial officer, Mardi Dier. Portola has kept an option to help fund final-stage human testing in exchange for additional royalties. “Betrixaban represents an important addition to our late-stage portfolio,” Dr. Luciano Rossetti, a senior vice president at Merck Research Laboratories, said in a statement. “This agreement reinforces Merck’s focus on developing an innovative portfolio of products for the treatment and management of multiple aspects of cardiovascular disease.” Merck already sells several blockbuster heart drugs, including blood pressure treatments Cozaar and Hyzaar and two cholesterol drugs it jointly sells with Schering-Plough Corp., Vytorin and Zetia. Merck, of Whitehouse Station, N.J., is in the process of acquiring Schering-Plough, of Kenilworth, N.J., for $41.1 billion. Portola, which has no products on the market, is developing treatments for heart disease, cancer and inflammatory diseases. The South San Francisco, Calif.-based company also has a partnership with Swiss drugmaker Novartis AG to develop a drug called elinogrel that potentially could compete with the blockbuster anticlotting drug Plavix.
