Settlement between Ligand and Burnham/SRI

In December 1999, the FDA approved Targretin (active ingredient: bexarotene) capsules for the treatment of cutaneous manifestations of cutaneous t-cell lymphoma in patients who are refractory to at least one prior systemic therapy. The European Commission granted marketing authorization for Targretin capsules in March 2001, and the product is currently marketed in many major European countries, including Germany, the United Kingdom, France, and Italy. Targretin is in continuing clinical trials in front-line, second-line, and third-line settings both in combination and as a monotherapy for non-small cell lung cancer.

A patent interference issue arose involving a patent application owned by Ligand and two patents owned by Burnham and SRI: U.S. Patent Numbers 5,466,861 and 5,837,725. These two patents previously were licensed exclusively to Ligand and now will be assigned to Ligand as part of the settlement.

SRI and Burnham will concede before the United States Patent and Trademark Office that Ligand has priority to all the disputed claims, i.e., the claims to bexarotene. SRI and Burnham also agreed not to challenge the validity and/or enforceability of any Ligand patents or applications that cover bexarotene, including certain retinoid X receptor related patents or applications that generically cover bexarotene and to cooperate in any Ligand enforcement actions involving any Ligand patents covering bexarotene.

Under the agreement, Burnham will have a research-only sublicense to conduct basic research under the assigned patents and Ligand will have an option on the resulting products and technology.