Switching from Intravenous to Subcutaneous Formulation of Abatacept: Different Results in a Series of 21 Patients.

OBJECTIVE Subcutaneous (SC) abatacept (ABA) is comparable to intravenous (IV) formulation in terms of efficacy and safety profile. Our work analyzed the switch to SC formulation from IV administration in patients with rheumatoid arthritis. METHODS Fifty-one patients treated with SC ABA were included. Clinical data were obtained from clinical charts. RESULTS Fourteen patients relapsed and needed to return to the IV administration. Neither clinical and laboratory features nor the previous therapies were identified as risk factors for SC formulation inefficacy. Disease activity decreased after the return to IV infusions. CONCLUSION SC ABA showed a risk of relapse in 27% of cases. The reinsertion of the IV administration quickly reinstated disease control.