Efficacy of bortezomib in non-IgM type I cryoglobulinaemic vasculitis: a single-centre retrospective case series.

Introduction: Treatment of non-IgM type I cryoglobulinaemic vasculitis (CV) is challenging. Corticosteroids are first-line therapy, but relapses are frequent leading to therapeutic escalation. Bortezomib is a proteasome inhibitor with rapid effect on monoclonal component. However, its use in non-IgM type I CV has been barely reported.
Objective: To assess the efficacy of bortezomib in non-IgM type I CV.
Method: Single-centre case series of four patients with non-IgM type I CV treated with bortezomib monotherapy.
Results: Two men and two women, 60-84 years old, received bortezomib monotherapy. Monoclonal component was IgG-λ (n = 2), IgA-λ and IgG-κ. Clinical features were necrotic rash (n = 3), synovitis (n = 3) and sensitive neuropathy (n = 2). CV was refractory to corticosteroids (n = 4), cyclophosphamide (n = 3) and rituximab (n = 2). Three patients experienced dramatic clinical improvement with undetectable cryoglobulin after three cycles (bortezomib 1.3 mg/m ² weekly). Each patient relapsed 4-18 months after treatment discontinuation. Bortezomib was unsuccessful after four cycles in one patient. Bortezomib toxicity included one pneumonia and 1 case of worsening neuropathic pain.
Conclusion: Bortezomib in monotherapy should be considered as a valuable option in refractory non-IgM type I CV because of its swift efficacy and acceptable tolerance profile.
(© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)