A Study to Evaluate the Pharmacokinetics, Pharmacodynamics, and Safety of Tocilizumab (TCZ) Administered to Participants With Giant Cell Arteritis (GCA).

A Phase Ib, Open-Label, Dose-Ranging Study to Evaluate the Pharmacokinetics, Pharmacodynamics, and Safety of Tocilizumab Administered by Intravenous Infusion to Patients With Giant Cell Arteritis

This study will evaluate the pharmacokinetics, pharmacodynamics, and safety of two dose levels of tocilizumab (TCZ) administered by intravenous (IV) infusion every 4 weeks (Q4W) to participants with giant cell arteritis (GCA).

Inclusion Criteria:

• Diagnosis of GCA as classified according to protocol-specified criteria;
• Participants entering Period 1 must be receiving treatment with TCZ 8 mg/kg IV Q4W.

Exclusion Criteria:

• Treatment with any other investigational agent besides TCZ within 12 weeks (or 5 half-lives of the investigational drug, whichever is longer) prior to screening;
• Evidence of serious uncontrolled disease;
• Known active current or history of recurrent bacterial, viral, fungal, mycobacterial, or other infections;
• Active TB requiring treatment within the previous 3 years.