Positive Results Announced from Phase 2 Trial of Daclizumab
August 10, 2011
Biogen Idec and Abbott Pharmaceuticals announced in a press release that DAC HYP – a liquid formulation of the monoclonal antibody daclizumab delivered via monthly injection under the skin – reduced the average annual relapse rate significantly in a study of 600 people with relapsing-remitting MS over a one-year trial. Full data from the “SELECT Study” are to be presented at an upcoming medical meeting.
Background: Daclizumab is a laboratory-created monoclonal antibody that blocks the activity of interleukin-2 receptor-alpha, a key immune activator in MS. A form of this drug is approved for use in organ transplant rejection. Results of a previous study called the CHOICE study – in which 230 people with relapsing MS taking interferon beta and having disease activity were administered one of two doses of daclizumab or placebo – showed that the higher dose reduced disease activity on MRI scans by 72%. (Lancet Neurology 2010;9:381-390). Facet Biotech (acquired by Abbott) developed a highly concentrated liquid formulation for daclizumab – daclizumab high yield process, or DAC HYP – which is injected under the skin.
The Study: Six hundred people with relapsing-remitting MS were randomly assigned to receive DAC HYP 150 mg, DAC HYP 300 mg or inactive placebo every four weeks for 48 weeks. The primary endpoint was the reduction in the average annual relapse rate at one year. Secondary endpoints included the reduction in disease activity observed on MRI, the reduction in the proportion of people who had relapses, and improvements in quality of life measures. Additional endpoints assessed the effect on disability progression (as measured by the EDSS disease activity scale) and safety and tolerability.
According to the press release, both doses of DAC HYP significantly reduced the average annual relapse rate (150 mg by 54%, and 300 mg by 50%) compared with placebo. Most secondary endpoints were met as well.
Safety: Two deaths occurred in the study, and the role of DAC HYP could not be ruled out; one person died from a complication while recovering from a serious skin-related adverse event and another from autoimmune hepatitis. Serious infections, serious skin events and liver function test abnormalities occurred more frequently in the DAC HYP groups than in the placebo group.
Further Study: DAC HYP also is being studied in a phase 3 trial called DECIDE, which is enrolling 1500 people at 250 sites worldwide with relapsing-remitting MS. DECIDE is evaluating the efficacy and safety of DAC HYP compared with interferon beta1-a. This trial is necessary before the companies can submit an application to the FDA for approval of this therapy as a treatment for MS. Read more.
This is one of 17 large phase 3 studies ongoing in people with MS; read more in a table in Clinical Trials for MS 2011 (PDF).