US Patent 7582298 High affinity antibodies to human IL-6 receptor

A human antibody or an antigen-binding fragment which binds human IL-6 receptor (hIL-6R) with a KD of about 500 pM or less and blocks IL-6 activity with an IC50 of 200 pM or less. In preferred embodiments, the antibody the antibody or antigen-binding fragment binds hIL-6R with an affinity at least 2-fold higher relative to its binding monkey IL-6R.