List of products in the National Drug Code with proprietary name . This medication is used to treat plaque psoriasis and certain types of arthritis (psoriatic arthritis, ankylosing spondylitis, axial spondyloarthritis). Ixekizumab belongs to a class of drugs known as monoclonal antibodies. It works by blocking a certain natural protein in your body (interleukin-17A) that may cause inflammation and swelling.