OBJECTIVES: To describe the effectiveness and safety of biologics for the treatment of relapsing and/or refractory polyarteritis nodosa (PAN). METHODS: A retrospective European collaborative study was conducted in patients with PAN who received biologics for relapsing and/or refractory disease. RESULTS: Forty-two patients with PAN received a total of 53 biological courses, including TNF-alpha blockers in 15 cases, rituximab (RTX) in 18 cases, tocilizumab (TCZ) in 10 cases, and other biologics in 10 cases. TNF-alpha blockers and TCZ were mainly used for refractory diseases whereas RTX was mainly initiated for relapsing disease. After a median follow-up of 29 (8-50) months, remission occurred in 40%, partial response in 13%, treatment failure in 40% and treatment discontinuation due to severe adverse events in 7% of patients receiving TNF-alpha blockers, 50%, none, 30% and 20% of TCZ recipients, and 33%, 11%, 56% and none of the RTX recipients, respectively. No remission was noted in patients treated with other biologics. Severe adverse events were observed in 14 (28%) patients without significant differences between the 3 biologics, leading to early biologics discontinuation in only 3 cases. CONCLUSION: These results suggest that TCZ may be effective in relapsing and/or refractory PAN. Our data warrant further study to confirm these findings.Read less <