Despite several studies proving the efficacy and safety of biosimilars compared with original drugs, switching to a biosimilar remains challenging when the decision is at the discretion of physicians with mandatory consent from patients. Educating patients about biosimilars seems important to increase the prescription rate of biosimilars. This study aimed to evaluate the impact of a clinical pharmacist consultation on the switch to and retention rate of a biosimilar for patients with inflammatory rheumatic diseases.

This retrospective study compared 2 groups of adult patients receiving (intervention) or not (control) a consultation with a pharmacist right before the rheumatologist consultation. The primary outcome was the frequency of patients who switched to a biosimilar at the end of the rheumatologist visit.

We analysed 141 patients (50% women, 50±15years old, on original adalimumab (62%) or etanercept (38%)) who had never used biosimilars: 85 in the intervention group and 56 in the control group. The switch rate to a biosimilar significantly differed between the groups: 69.4% versus 41.1% in the intervention group versus the control group respectively (P<0.01). After a 1-year follow-up period, 72.5% versus 81.3% of patients who switched were still on biosimilar in the intervention versus control group respectively.

This study highlights the positive impact of a pharmacist consultation before the physician's one on switching to a biosimilar, but more studies are needed to assess the impact of this pharmacist consultation on preventing the nocebo effect and therefore on improving the retention rate of biosimilars.