Amjevita Similar to Humira in Efficacy, Safety, and Immunogenicity in RA

A recently published study shows that Amgen’s ABP 501 (Amjevita), the first adalimumab biosimilar referenced on Humira to be approved by the FDA for the treatment of multiple inflammatory diseases, shows that the product has similar clinical efficacy, safety, and immunogenicity to its reference in patients with moderate to severe rheumatoid arthritis (RA).

Previous phase 1 clinical studies of ABP 501 have demonstrated its pharmacokinetic (PK) equivalence to adalimumab as well as its similarity in clinical efficacy, safety, and immunogenicity compared with reference adalimumab. Two phase 3 studies were undertaken comparing ABP 501 with reference adalimumab, 1 in patients with moderate to severe plaque psoriasis, and 1 in patients with moderate to severe RA. The latter study, by Stanley Cohen, MD, and colleagues, was published online in the Annals of Rheumatologic Disease. The authors report that the phase 3 study, funded by Amgen, demonstrates that ABP 501 is similar to reference adalimumab in clinical efficacy, safety, and immunogenicity in patients with moderate to severe RA.

The randomized, double-blind, active comparator—controlled, 26-week equivalence study enrolled adalimumab-naïve patients, with moderate to severe RA despite methotrexate treatment, who were randomized 1:1 to receive ABP 501 or reference adalimumab. Patients received 40  mg of the biosimilar or reference adalimumab subcutaneously on day 1, and then every 2 weeks until week 22.

The primary endpoint was risk ratio (RR) of the American College of Rheumatology’s (ACR) ACR20 measurement of symptoms (20% improvement in tender and swollen joint counts, patient assessments of pain, global disease activity and physical function, physician global assessment of disease activity, and acute phase reactant) between groups at week 24.

Secondary endpoints included another measure of RA disease activity, the Disease Activity Score 28-joint count-C reactive protein (DAS28-CRP). Safety was assessed by adverse events (AEs) and laboratory evaluations. Immunogenicity was assessed by monitoring antidrug antibodies (ADAs).

Of the 526 randomized patients—264 in the ABP 501 arm and 262 in the adalimumab arm—494 completed the study. At week 24, the ACR20 response was 74.6% for the ABP 501 group and 72.4% for the adalimumab group. The RR of ACR20 between groups was 1.039, confirming the primary hypothesis that the 2 treatments were equivalent.

Changes from baseline on all measurements were similar. There were no clinically meaningful differences in AEs and laboratory abnormalities, and 38.3% (ABP 501) and 38.2% (reference adalimumab) of patients tested positive for binding ADAs. The researchers concluded that ABP 501 and reference adalimumab have similar safety profiles. “No new safety signals were detected in this study compared with other adalimumab clinical trials in patients with RA,” they noted. “Hypersensitivity reactions were reported infrequently and occurred at a generally similar frequency in both treatment groups.”

In conclusion, the researchers say that data from this study show that the clinical efficacy, safety, and immunogenicity of ABP 501 are similar to that of reference adalimumab in patients with moderate to severe RA. Analytical, biofunctional, and PK properties of ABP 501 have previously been shown to be highly similar to those of reference adalimumab. Thus, taken together, these data contribute to the totality-of-evidence—based requirements to demonstrate that ABP 501 is similar to reference adalimumab. The FDA’s approval of ABP 501 (Amjevita) adalimumab biosimilar has provided a valuable new therapeutic option for the treatment of moderate to severe RA.