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

Study Overview
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Brief Summary
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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).

Official Title
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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

Conditions
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Giant Cell Arteritis

Intervention / Treatment
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* Drug: Tocilizumab


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: TCZ IV Q4W<br>Participants will receive up to 6 doses of Dose 1 of TCZ IV Q4W followed by up to 6 doses of Dose 2 of TCZ IV Q4W. | Drug: Tocilizumab<br>* TCZ will be administered by IV infusion at two dose levels Q4W. The maximum dose of TCZ that will be administered is 800 mg. The dose of TCZ infusion will be calculated on the basis of body weight measured prior to each infusion.<br>* Other names: RoActemra/Actemra;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum Serum Concentration (Cmax) of TCZ |  | Baseline; Weeks 4, 8, 12, 16-24 | 
| Trough Serum Concentration (Ctrough) of TCZ at Steady State |  | Baseline; Weeks 4, 8, 12, 16-24 | 
| Area Under the Concentration-Time Curve Over the Dosing Interval of 4 Weeks (AUC4weeks) of TCZ at Steady State |  | Baseline; Weeks 4, 8, 12, 16-24 | 
| Percentage of Participants With Adverse Events |  | Baseline - Day 151 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serum Concentration of Interleukin-6 (IL-6) |  | Baseline; Weeks 12, 16, 20, 24 | 
| Serum Concentration of Soluble Interleukin-6 Receptor (sIL-6R) |  | Baseline; Weeks 12, 16, 20, 24 | 
| Serum Concentration of C-Reactive Protein (CRP) |  | Baseline; Weeks 4, 8, 12, 16-24 | 
| Erythrocyte Sedimentation Rate (ESR) |  | Baseline; Weeks 4, 8, 12, 16-24 |