Zenapax® (daclizumab)

Parent companies: Biogen Idec, Inc and PDL BioPharma.

Administered via intravenous infusion every four weeks; also studied in subcutaneous injections.

This drug is used to prevent renal (kidney) transplant rejection. It is a genetically engineered antibody against interleukin-2, a substance necessary for the growth of T cells, limiting their growth and reducing inflammation.

A study in RRMS and SPMS patients (who continued to experience worsening disease activity with interferon-beta therapy) showed the drug was well tolerated; reported to improve or stabilize 60 percent of patients; and reduced the 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.