Zenapax® (daclizumab)

Parent companies: Biogen Idec, Inc and PDL BioPharma Administered via intravenous infusions every four weeks; also studied in subcutaneous injections.

Used to prevent rejection with organ transplants.

Works by targeting receptors on activated T-cells, limiting T-cell expansion, and reducing inflammation.

Two small, open-label studies showed positive results.

Another study was conducted with RRMS and SPMS patients who continued to experience worsening disease activity despite conventional MS drug therapies; study showed drug was well tolerated; reported to improve or stabilize 60 percent of patients; reduced number of active lesions in both RRMS and SPMS patients.

Ongoing CHOICE Phase II trial adds Zenapax (given subcutaneously biweekly) to interferon treatment in 30 patients with active MS; interim data show that the treated group experienced a significant reduction in new or enlarged enhancing lesions.

SELECT trial will study Zenapax versus placebo in patients with RRMS.