Acceptance rate and sociological factors involved in the switch from originator to biosimilar etanercept (SB4).

OBJECTIVE: To study acceptance rate and factors influencing acceptance of the switch from originator etanercept (Enbrel©) to biosimilar etanercept (SB4, Bénépali©) in patients with rheumatic disease.

METHODS: Patients with a well-controlled rheumatic disease consulting in our rheumatology department were offered the switch for SB4. After oral and written information concerning biosimilar, free choice to accept the switch was left to the patients. The main outcome was primary switch acceptance rate defined by switch acceptance during the initial consult. Real switch adherence, socio-cultural factors and beliefs influencing switch acceptance rate were retrieved during a telephonic interview at distance from the consultation.

RESULTS: Fifty-two patients were eligible for the switch: 32 (62%) with spondyloarthritis and 20 (38%) with rheumatoid arthritis. The primary acceptance rate was 92% (48/52). Patients refusing the switch were more likely to report a bad opinion on generic drugs (100% vs 11%, p < 0.001). Other patient characteristics were roughly identical except for a statistical trend in the refusal group toward older age (61.4 vs 50.7 years, p = 0.08) and longer disease duration (26 vs 12.1 years, p = 0.05). Despite initial acceptance, two patients did not begin SB4 after receiving negative information by their regular pharmacist. Real SB4 switch rate was 85% (44/52) and 86% (38/44) of patients reported a good experience of the switch.

CONCLUSIONS: Acceptance rate of the switch from originator to biosimilar etanercept is high. Patient information, physician and pharmacist knowledge on biosimilars should be taken into account in order to improve their diffusion.