Protein Design Labs Inc and Roche has obtained exclusive worldwide rights to market, develop manufacture and sell Zenapax (daclizumab) in all disease indications other than organ transplantation. Roche will continue to market Zenapax in transplantation indications until 2007. An earlier transfer of rights in transplantation to PDL could occur at Roche's election.

The PDL-Roche collaboration dates to 1989 when Roche acquired the rights to commercialize Zenapax worldwide. PDL began receiving royalties on sales of Zenapax following its commercial launch in 1997. In October 1999, under a revised agreement PDL assumed worldwide responsibility for the clinical development of daclizumab for the potential treatment of autoimmune diseases.

Roche retained exclusive worldwide rights to Zenapax for non-autoimmune diseases as well as commercialization rights worldwide, and continued to market Zenapax for the prevention of kidney transplant rejection.

Under the new agreement, PDL will immediately assume worldwide responsibility for the development and, if successful, sales and marketing of daclizumab in all indications other than transplantation. PDL also will have rights to manufacture the product. PDL currently is conducting a randomized, placebo-controlled Phase II clinical trial of Zenapax in patients with moderate-to-severe ulcerative colitis. A Phase II trial of daclizumab in severe asthma is fully enrolled, and PDL currently expects to report results of that study in the first quarter of 2004.