Ending a dispute over cancer therapy patents, Corixa Corp. and GlaxoSmithKline plc settled all outstanding lawsuits with Biogen Idec Inc.

At issue were patent infringement claims on the products and processes related to radioimmunotherapies, such as the non-Hodgkin's lymphoma drugs Bexxar and Zevalin.

"It's been a series of suits that have been ongoing, one dating back as far as September 2001, and a separate suit initiated last year," said Jim DeNike, senior director of corporate communications at Seattle-based Corixa. "So this is a settlement or a resolution of all of the suits."

The resolution means Corixa and its Bexxar partner, GlaxoSmithKline, of London, will receive a $20 million up-front settlement payment, as well as a one-time milestone payment based on future Zevalin sales performance. The companies also will receive royalties on Zevalin sales from Jan. 1, 2004, until the Bexxar patents expire in 2013.

Specific details on the milestone payment or the royalties were not disclosed.

The companies also have entered a worldwide, cross-license agreement related to each party's patents in the suit. Further financial or other details on that collaboration also are not being disclosed.

In any case, DeNike said Corixa is satisfied with the outcome.

"We're very pleased to have resolved this and are looking forward to focusing 100 percent of our efforts on promoting the sale of Bexxar," he told BioWorld Today.

Bexxar received FDA approval last summer and was launched in early fall. Initial sales of the product will be released next week, DeNike said. (See BioWorld Today, July 1, 2003.)

Corixa gained rights to Bexxar when it took over San Francisco-based Coulter Pharmaceuticals Inc. in 2000 in a stock swap. GSK gained its rights to the product when Glaxo merged with SmithKline Beecham plc, Coulter's partner.

Idec Pharmaceuticals Corp., which merged with Biogen in November, gained approval of Zevalin in February 2002. Zevalin was the first radioimmunotherapy approved for the treatment of cancer. (See BioWorld Today, Sept. 13, 2001, and Feb. 21, 2002.)

Zevalin sales for the first three quarters of 2003 were $15.1 million. Biogen Idec, of Cambridge, Mass., markets the drug alone in the U.S. It is partnered in Europe - in which it received approval in January - with Schering AG, of Berlin.

Radioimmunotherapies are made by linking monoclonal antibodies to radioactive isotopes. When infused into a patient, the antibodies locate and bind to the surface of specific tumor cells and then deliver their cytotoxic radiation directly to malignant cells.

With the approval of Zevalin in 2001, Idec filed two separate lawsuits in a California federal court for declaratory judgment for patent non-infringement and invalidity - one against Corixa, Coulter and the University of Michigan at Ann Arbor on six patents for products and processes related to radioimmunotherapy, and the other against GSK on two patents relating to cell-culture media.

A day later, Corixa and GSK said they filed a lawsuit against Idec for alleged patent infringement on Zevalin. They asked the court to declare that Idec was willfully infringing on Corixa's patents.

In January, the U.S. District Court for the Southern District of California vacated its October grant of a motion for summary judgment by Biogen Idec in which four U.S. Bexxar patents were held to be unenforceable. The court vacated the order after receiving new evidence and support for the patents.

Corixa's stock (NASDAQ:CRXA) rose 21 cents Monday to close at $6.30. Biogen Idec's stock (NASDAQ:BIIB) gained 66 cents to close at $56.11.