Head-to-head comparison of subcutaneous abatacept versus adalimumab for
rheumatoid arthritis: findings of a phase IIIb, multinational, prospective,
randomized study.
Author(s): Weinblatt ME(1), Schiff M, Valente R, van der Heijde D, Citera G, Zhao C,
Maldonado M, Fleischmann R.
Affiliation(s): Author information:
(1)Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
mweinblatt@partners.org
Publication date & source: 2013, Arthritis Rheum. , 65(1):28-38
OBJECTIVE: There is a need for comparative studies to provide evidence-based
treatment guidance for biologic agents in rheumatoid arthritis (RA). Therefore,
this study was undertaken as the first head-to-head comparison of subcutaneous
(SC) abatacept and SC adalimumab, both administered along with background
methotrexate (MTX), for the treatment of RA.
METHODS: Patients with active RA who were naive to treatment with biologic agents
and had an inadequate response to MTX were randomly assigned to receive 125 mg SC
abatacept weekly or 40 mg SC adalimumab biweekly, both given in combination with
MTX, in a 2-year study. The primary end point was treatment noninferiority,
assessed according to the American College of Rheumatology 20% improvement
response (ACR20) at 1 year.
RESULTS: Of the 646 patients who were randomized and treated, 86.2% receiving SC
abatacept and 82% receiving SC adalimumab completed 12 months of treatment. At 1
year, 64.8% of patients in the SC abatacept group and 63.4% in the SC adalimumab
group demonstrated an ACR20 response; the estimated difference between groups was
1.8% (95% confidence interval -5.6%, 9.2%), thus demonstrating the noninferiority
of abatacept compared to adalimumab. All efficacy measures showed similar results
and kinetics of response between treatments. The rate of radiographic
nonprogression (defined as a total modified Sharp/van der Heijde score [SHS] less
than or equal to the smallest detectable change) was 84.8% for SC
abatacept-treated patients and 88.6% for SC adalimumab-treated patients, while
the mean change from baseline in the total SHS was 0.58 and 0.38, respectively.
In the SC abatacept and SC adalimumab groups, the incidence of serious adverse
events (SAEs) was 10.1% and 9.1%, respectively, and the rate of serious
infections was 2.2% and 2.7%, respectively. In patients treated with SC
abatacept, the frequency of discontinuations due to AEs was 3.5% and
discontinuations due to SAEs was 1.3%, while in patients treated with SC
adalimumab, the frequencies were 6.1% and 3%, respectively. Injection site
reactions occurred in 3.8% of patients receiving SC abatacept compared to 9.1% of
patients receiving SC adalimumab (P=0.006).
CONCLUSION: The results demonstrate that SC abatacept and SC adalimumab have
comparable efficacy in patients with RA, as shown by similar kinetics of response
and comparable inhibition of radiographic progression over 1 year of treatment.
The safety was generally similar, other than the occurrence of significantly more
local injection site reactions in patients treated with SC adalimumab.
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