From the Guidelines
Giant cell arteritis (GCA) is a medical emergency requiring immediate treatment with high-dose corticosteroids to prevent vision loss. The standard initial therapy is prednisone 40-60mg daily (or weight-based at 1mg/kg/day), which should be started as soon as GCA is suspected, even before biopsy confirmation 1. For patients with visual symptoms, methylprednisolone 0.25-1 g IV daily for up to 3 days may be given before transitioning to oral prednisone 1.
Key Considerations
- After 2-4 weeks at the initial dose, a slow taper should begin, typically reducing by 10% every 2 weeks until reaching 20mg daily, then more gradually afterward 1.
- Most patients require 12-24 months of therapy.
- Temporal artery biopsy should be performed within 1-2 weeks of starting steroids to confirm the diagnosis.
- For steroid-sparing, tocilizumab (162mg subcutaneously weekly) can be added 1.
- Patients should be monitored for steroid side effects with bone density testing, vitamin D and calcium supplementation, blood pressure checks, and blood glucose monitoring.
Diagnosis and Treatment
GCA is an inflammatory vasculitis affecting large and medium-sized arteries, particularly the branches of the carotid artery, and predominantly occurs in adults over 50 years old 1. The inflammation causes vessel wall thickening, leading to ischemic complications including the dreaded complication of permanent vision loss.
- Diagnosis is based on clinical presentation, pathologic abnormalities on temporal artery biopsy, and/or evidence of large vessel involvement on vascular imaging 1.
- Glucocorticoids are the mainstay treatment for GCA, but tocilizumab has been approved by the US Food and Drug Administration for the treatment of GCA 1.
Management
- The optimal duration of therapy with GCs for GCA is not well established and should be guided by the patient’s values and preferences 1.
- For patients with GCA who experience disease relapse while receiving moderate-to-high–dose GCs, a non-GC immunosuppressive drug can be added 1.
- For patients with GCA who experience disease relapse with symptoms of cranial ischemia, a non-GC immunosuppressive agent and increasing the dose of GCs can be considered 1.
From the FDA Drug Label
The safety of subcutaneous tocilizumab has been studied in one Phase III study (WA28119) with 251 GCA patients. The overall safety profile observed in the tocilizumab-SC treatment groups was generally consistent with the known safety profile of tocilizumab. There was an overall higher incidence of infections in GCA patients relative to RA patients.
The drug label provides information on the safety of tocilizumab in patients with Giant Cell Arteritis (GCA).
- The overall safety profile of tocilizumab in GCA patients was consistent with the known safety profile of the drug.
- There was a higher incidence of infections in GCA patients compared to RA patients.
- The rate of infection/serious infection events was higher in the tocilizumab-SC weekly and every other week groups compared to the placebo groups 2.
From the Research
Treatment of Giant Cell Arteritis
- The main treatment for giant cell arteritis (GCA) is corticosteroids (CS) 3, 4, 5, 6
- The choice of initial prednisone dosage takes into account the disease severity and comorbidities to reduce drug side effects 3
- Low-dose aspirin may benefit patients with ischemic complications or multiple cardiovascular risk factors 3
- Methotrexate has a moderate corticosteroid sparing effect, but it does not prevent cephalic complications 3, 7
- Tocilizumab is a promising treatment option, but its benefit-to-risk ratio in old people is largely unknown 3, 4, 6
- Hydroxychloroquine and infliximab or adalimumab did not prevent relapses in double-blind controlled trials 3
- High doses of intravenous methylprednisolone are often prescribed for severe ischemic complications, but there is no evidence that such doses are superior to classical doses 3
Corticosteroid-Sparing Agents
- Methotrexate is a safe alternative to corticosteroid therapy alone in patients with GCA and is more effective in controlling disease 7
- Tocilizumab is an approved substance for subcutaneous application as a GC-sparing treatment 6
- Methotrexate can be used as an off-label GC-sparing treatment alternative to tocilizumab 6