PDL BioPharma, Inc and Alexion Pharmaceuticals, Inc has entered into a definitive license agreement and settlement agreement that resolve the legal disputes between them relating to Alexion's humanized antibody, Soliris (eculizumab) and PDL's patents known as the Queen et al. patents.

Under the agreements announced, PDL has granted Alexion a license under certain claims in the Queen patent portfolio, and provided Alexion a covenant not to sue in respect of other claims in the Queen patent portfolio, thus permitting Alexion to commercialize Soliris for all indications under the Queen patents. In consideration of this license, Alexion will pay PDL $25 million. No additional payments will be owed by Alexion to PDL under the Queen patents in respect of Soliris sales for any indication. As part of the settlement, Alexion has confirmed that the Queen patent claims are valid and that Soliris employs technology covered under the Queen patents. Further, Alexion has agreed not to challenge or assist other parties in challenging the validity of the Queen patents in the future.

PDL's Queen patents are related to the humanization of antibodies. Soliris was approved in the US and European Union in 2007 as a treatment for patients with paroxysmal nocturnal hemoglobinuria (PNH), a rare, debilitating and life-threatening blood disease. The use of Soliris as a treatment for other rare and severe disorders is in early stages of investigation.

Under the license agreement announced, PDL has separately granted Alexion the right to take a royalty-bearing license under PDL's Queen patents to commercialize additional Alexion humanized antibodies that may be covered by the Queen patents in the future. In the event that Alexion takes such a license, Alexion will pay PDL a royalty of 4 per cent of net sales of such non-Soliris products. Additional terms of the agreements were not disclosed.

"PDL helped revolutionize the development of therapeutic antibodies to treat patients with previously untreatable and devastating conditions," said Leonard Bell, chief executive officer of Alexion.

John P McLaughlin, president and chief executive officer of PDL said, "We appreciate Alexion's efforts to resolve the dispute and its acknowledgement about our patents' strength. Soliris is an important therapeutic product, and it serves a critical - and otherwise underserved - market."

With the closing of these agreements, the previously announced claims filed by PDL and counterclaims filed by Alexion in the US District Court for the District of Delaware will be dismissed.

Soliris is the first product approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) in the US and Europe.

Alexion Pharma is a biopharmaceutical company working to develop and deliver life-changing drug therapies for patients with serious and life-threatening medical conditions.

PDL BioPharma was a leader in the humanization of monoclonal antibodies and enabled the discovery of a new generation of targeted treatments for cancer and autoimmune diseases.