The adalimumab biosimilar PF-06410293 showed similar efficacy, safety, and immunogenicity as the adalimumab reference product for the treatment of active rheumatoid arthritis (RA), according to results published in Arthritis Research & Therapy.
The study included participants with active RA (n=597). Participants were randomly assigned 1:1 to receive either PF-06410293 or an adalimumab reference product while continuing treatment with methotrexate. The primary end point was American College of Rheumatology 20% improvement (ACR20) at 12 weeks. Secondary end points included ACR20/50/70, change from baseline 28-joint Disease Activity Score based on high-sensitivity C-reactive protein (DAS28-4[CRP]), European League Against Rheumatism (EULAR) response, DAS28-4(CRP) score <2.6, and ACR/EULAR remission through 26 weeks.
The researchers determined therapeutic equivalence if the 2-sided 95% CI for the ACR20 difference between the groups was entirely contained within the symmetric equivalence margin (±14%). Participants had mean baseline DAS28-4(CRP) values of 5.9 in the biosimilar group and 6.1 in the reference product group.
At 12 weeks, 68.7% of participants in the biosimilar group achieved ACR20 compared with 72.7% of participants in the reference product group.
After nonresponder imputation, the researchers found that the treatment difference in 12-week ACR20 was −2.98%. The 95% CI (−10.38% to 4.44%) and 90% CI (−9.25% to 3.28%) were both entirely contained within the equivalence margins.
In the biosimilar group, 1.7% of participants had injection-site reactions, 4.4% had hypersensitivity events, 0.7% developed pneumonia, and 2.4% developed opportunistic infections compared with 2.0%, 8.4%, 2.0%, and 1.7% of participants in the reference product group, respectively. In the reference product group, 1 participant died as a result of myocardial infarction.
“Upcoming data from the subsequent 6 months of the trial will provide additional efficacy, safety, and immunogenicity information, including data on patients after a blinded transition from adalimumab [reference product] to PF-06410293 and on those who receive a total of 1 year of treatment with either PF-06410293 or adalimumab [reference product],” the researchers wrote.
This study was sponsored by Pfizer Inc.
Fleischmann RM, Alten R, Pileckyte M, et al. A comparative clinical study of PF-06410293, a candidate adalimumab biosimilar, and adalimumab reference product (Humira®) in the treatment of active rheumatoid arthritis. Arthritis Res Ther. 2018;20:178.