Anti-CD20 B-Cell Depletion for Inducing Remission in IgG4-RD

"Anti-CD20 B-Cell Depletion for Inducing Remission in IgG4-RD" takes up the question of when anti-CD20 therapy belongs at the start of treatment.

Dr. Culver notes that rituximab, an anti-CD20 antibody, is used off-label because neither the FDA nor the European Medicines Agency has approved it for IgG4-related disease. She asks Dr. Della Torre about his experience. He calls it a very effective drug. After colleagues published their phase 2 trial, centers across Europe began using it with satisfactory results. Given its efficacy, his team now uses rituximab in most patients.

The key question, he explains, is whether to use B-cell depletion to induce remission or to maintain it. His team uses it for induction in patients with contraindications to glucocorticoids. He also uses it in patients whose disease is not suitable for medium- to high-dose glucocorticoids. These include patients with multi-organ disease and relapse risk factors, such as high serum IgG4, who are almost certain to relapse within a year.

When such patients also have comorbidities, his team starts with B-cell depletion. Examples include uncontrolled blood pressure, uncontrolled diabetes, and a high fracture risk from osteoporosis. He estimates that 20% to 30% of patients fall into this group and receive rituximab first-line. Other patients receive a short glucocorticoid course for diagnostic purposes and to quickly switch off disease activity. In those with relapse risk factors, rituximab follows as soon as remission is achieved to reinforce disease control.

His protocol is two 1-g infusions given 15 days apart. His team then observes how the disease behaves. Responses vary widely. Some patients maintain remission for a long time after a single course. Others relapse early despite treatment. His team prefers to learn each patient's response before deciding on maintenance therapy.

Our next episode, "Monitoring and Safety Considerations With Anti-CD20 Therapy in IgG4-RD," turns to how Dr. Della Torre tracks disease activity between infusions and which safety issues he discusses with patients.