Clinical and out-of-pocket cost outcomes after switching to biosimilar adalimumab-atto in patients with rheumatoid arthritis.

BACKGROUND

Limited real-world studies have evaluated outcomes after switching treatment from a reference product (RP) to a biosimilar product. The objective of this real-world study was to assess the outcomes of switching from RP adalimumab to biosimilar adalimumab-atto in patients with rheumatoid arthritis (RA).

RESEARCH DESIGN AND

METHODS

This was a propensity score matched, non-inferiority study assessing adult patients with RA who switched from RP adalimumab to adalimumab-atto (Switchers) between or received RP adalimumab continuously (Non-Switchers). One-year disease worsening, serious adverse events, and patient out-of-pocket cost outcomes were evaluated. An upper limit of 5% for adalimumab-atto was set as the non-inferiority margin.

RESULTS

After matching, there were 1,172 patients in each group. 24.8% and 31.0% of patients in the Switcher and Non-Switcher groups, respectively, experienced the disease worsening (non-inferiority p < 0.01). The crude rates per 100 patient-years of the safety outcome and mean monthly changes in out-of-pocket costs were 5.6 (95% CI 4.2-7.5) and 7.2 (95% CI 5.2-9.2) (p = 0.21) and -$51 (±$164) and -$11 (±$152) (p < 0.01) in the Switcher and Non-Switcher groups, respectively.

CONCLUSIONS

These results provide evidence that switching from RP adalimumab to biosimilar adalimumab-atto did not result in disease worsening or increased adverse events but did deliver modestly lower patient out-of-pocket costs.