medwireNews: The adalimumab biosimilar BI 695501 is highly similar to its reference product, and switching between the two agents has no impact on efficacy, safety, and immunogenicity in patients with rheumatoid arthritis (RA), results of the phase III VOLTAIRE-RA study suggest.
“These data, together with the analytical and the phase I data, suggest that BI 695501 and [originator adalimumab] are biosimilar and thus therapeutically equivalent,” say Stanley Cohen (Metroplex Clinical Research Center, Dallas, Texas, USA) and study co-authors.
The investigators randomly assigned patients with moderate-to-severe active RA who were on stable methotrexate therapy to receive 24 weeks of treatment with subcutaneous BI 695501 or adalimumab at a dose of 40 mg every 2 weeks. After 24 weeks, participants receiving the originator were re-randomized to either continue with adalimumab or switch to the biosimilar for a further 24 weeks.
At the 12-week follow-up, a comparable proportion of the 324 patients receiving BI 695501 and the 321 patients given adalimumab achieved at least a 20% improvement in ACR criteria (ACR20), with rates of 67.0% and 61.1%. Similarly, the corresponding rates at week 24 were 69.0% and 64.5%.
The researchers report in the Annals of the Rheumatic Diseases that the differences in ACR20 response rates at weeks 12 and 24 were within the prespecified equivalence margins, demonstrating that the two drugs “are highly similar in terms of efficacy.”
At week 48, ACR 20, 50, and 70 response rates were similar among patients who switched from adalimumab to the biosimilar compared with those who continued with adalimumab, as was the mean change from baseline in Disease Activity Score at 28 joints based on C-reactive protein.
A comparable proportion of patients in the continuous BI 695501, continuous adalimumab, and switch groups experienced treatment-related adverse events (AEs), at 19.1%, 19.2%, and 22.9%. Rates of serious drug-related AEs were 0.6%, 0.7%, and 3.4%, respectively, and a corresponding 4.0%, 4.1%, and 6.9% of patients experienced AEs leading to discontinuation of the study drug.
Furthermore, a similar number of patients in the BI 695501 and adalimumab groups had antidrug antibodies at week 24, and whether or not patients transitioned from adalimumab to BI 695501 or continued with the originator “did not influence subsequent ADA frequency and titres,” say Cohen and team.
And they therefore conclude that “VOLTAIRE-RA completes the similarity assessment of the adalimumab biosimilar BI 695501.”
medwireNews is an independent medical news service provided by Springer Healthcare. © 2018 Springer Healthcare part of the Springer Nature group