MEDI-551 is a humanized monoclonal antibody that has high affinity (binding power) to a protein (CD19) expressed in B-cells. The therapy is being developed as a treatment for relapsing-remitting multiple sclerosis (MS).

The safety and tolerability results of a Phase 1 (NCT01585766) randomized and placebo-controlled, escalating intravenous and skin injected dose of MEDI-551 study in people with RRMS showed promising results. Two intravenous infusions with MEDI-551 (30 mg, 100 mg, or 600 mg) or a single skin injected dose (60 mg or 300 mg) led to a rapid, sustained depletion of B-cells. The number of new gadolinium-enhancing brain lesions at the end of the treatment was lower in the participants treated with MEDI-551 compared to the participants who received a placebo. The mean number of T2 lesions (hyperintense lesions) at the end of the treatment was also lower in the participants treated with the therapy compared to the participants who received a placebo.

Most of the adverse side effects of MEDI-551 in the Phase 1 study were fever, nasopharyngitis, oral herpes, and increased blood pressure.

In March 2016, MEDI-551 was granted Orphan Drug Designation by the U.S. Food and Drug Administration (FDA) for the treatment of neuromyelitus optica (NMO) and neuromyelitis optica spectrum disorders (NMOSD). It is currently in Phase 2b (NCT02200770). Research has shown that autoantibodies called NMO-IgG (or AQP4-Ab) and protein produced in a type of B-cell called plasmabasts, play a key role in NMO disease. MEDI-551 binds directly to the CD19 protein in the plasmabasts and depletes them.

Note: Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

 

  1. https://www.astrazeneca.com/media-centre/press-releases/2016/astrazenecas-potential-medicine-for-neuromyelitis-optica-receives-fda-orphan-drug-designation-09032016.html
  2. http://onlinelibrary.ectrims-congress.eu/ectrims/2015/31st/115379/mark.agius.safety.and.tolerability.of.medi-551.in.patients.with.relapsing.html