Drug Firms to Team for New Products

Merck & Co. and Schering-Plough Corp., two large drug makers facing patent expirations on key medicines, have agreed to work together to develop new cholesterol and allergy pills.

The partnership will allow each company to find new uses for existing medications, including Schering-Plough’s top allergy drug, Claritin, and Merck’s top cholesterol fighter, Zocor.

The deal announced Tuesday will include the development of an allergy tablet that would combine Claritin and Merck’s Singulair asthma treatment. Several recent studies paid for by Merck already show that such a combination may be more effective than Claritin alone in reducing certain allergy symptoms. But Whitehouse Station, N.J.-based Merck could not pursue such a combination pill without a deal with Schering-Plough or waiting until Claritin loses patent protection in the next two or three years.

Madison, N.J.-based Schering-Plough is awaiting federal approval for its next generation of Claritin, which may be more potent and take effect quicker than the existing drug. It is unclear whether a combination Claritin-Singulair pill would compete with or complement it.

The second agreement in the partnership will have the companies develop a cholesterol-lowering drug that would combine Merck’s Zocor, the world’s top-selling cholesterol drug, with an experimental Schering-Plough pill called ezetimibe.

Schering-Plough shares rose $1.69 to close at $45.50, and Merck shares closed up $1.50 at $73.81, both on the New York Stock Exchange.