California-Based Genentech Sues Genzyme over Drug-Patent Royalties.

Byline: Ronald Rosenberg

Mar. 16--Genentech Inc. filed a lawsuit yesterday challenging Genzyme Corp.'s interpretation of a 9-year-old agreement under which Genzyme contends it would be owed royalties from Genentech's clot-busting agent TNKase.

"We are very surprised that they have sued us," said Thomas J. DesRosier, Genzyme's senior vice president and chief patent counsel. "TNKase is a second-generation drug that, under a 1992 settlement beween us, calls for them to pay us royalties. But I did not think they would sue us."

On Feb. 14, DesRosier sent a letter to Genentech, later followed up by a telephone call, claiming a Genzyme patent involved in the joint agreement obligates Genentech to pay $250,000 plus 2 percent royalties on sales of TNKase.

Genentech, in its lawsuit filed in US District Court in Delaware, disagrees. It is seeking a jury trial to prove that the technology in TNKase is different from technology covered by Genzyme's patent and does not violate the agreement.

"No thrombolytic agent manufactured or sold by Genentech, including TNKase, infringes any claim of the patent," the suit states, adding that Genentech has the right to make and sell the drug.

Genentech, based in South San Francisco, is also seeking to invalidate the Genzyme patent and ban Genzyme from countersuing to enforce it.