Health Canada approves Zinbryta™ for the management of relapsing-remitting MS
Health Canada has recently approved Biogen and AbbieVie’s newest disease modifying therapy, Zinbryta™ (daclizumab). Zinbryta is a humanized monoclonal antibody that binds to CD25, an interleukin-2 (IL-2) receptor subunit on the surface of T-cells. CD25 can be found at high levels on T-cells that become activated in people with MS. The antibody prevents activation and growth of disease-causing immune cells. Zinbryta also appears to increase the activity of certain beneficial immune cells called CD56(bright) natural killer cells which can regulate the immune system by destroying disease-causing T cells.
Zinbryta is the first monoclonal antibody to be available for self-administration once-monthly through subcutaneous injection (under the skin). Zinbryta is indicated for adults with active relapsing remitting multiple sclerosis (RRMS), who have had an inadequate response to, or are unable to tolerate, one or more therapies indicated for the treatment of relapsing forms of MS.
The most common adverse effects reported include fatigue, headache, nausea, rash, musculoskeletal disorders, allergic reactions, infections, elevated liver enzymes, heart problems, and reduced platelet number.
The Health Canada approval of Zinbryta is based on results from two clinical trials:
- DECIDE, a phase III trial with more than 1,800 participants from 28 countries, focused on comparing a once monthly subcutaneous injection of daclizumab to a once weekly intramuscular injection of interferon beta-1a in participants with RRMS over 144 weeks. Participants administered daclizumab showed a 45% reduction in annualized relapse rate compared to participants administered interferon beta-1a. Additional results revealed a 54% reduction in the number of new or enlarging brain lesions relative to interferon beta-1a at 96 weeks.
- The Phase IIb SELECT trial examined the effects of 150mg or 300mg daclizumab treatment compared to a dummy drug (placebo) over 52 weeks in over 600 participants. Participants treated with daclizumab had lower relapse rates compared to placebo treated participants (150mg showed a 54% reduction; 300mg showed a 50% reduction), and more relapse free patients compared to the control group (150mg 81%; 300mg 80%).
The approval of Zinbryta provides another second line option for people with active RRMS who have had an inadequate response to, or are unable to tolerate, one or more therapies indicated for the treatment of MS. Selecting an MS therapy should be done in consultation with a health care team. The MS Society of Canada will provide updates on availability and public coverage of Zinbryta™ as they become available.
Full drug information will be available on the MS Society website shortly.