Abatacept shows comparable efficacy to Humira in year two data in patients with moderate to severe rheumatoid arthritis
Bristol-Myers Squibb ( BMS ) has announced the results of year two data from AMPLE ( Abatacept Versus Adalimumab Comparison in Biologic-Naïve rheumatoid arthritis (RA) Subjects With Background Methotrexate ), a first-of-its-kind trial of 646 patients comparing the subcutaneous ( SC ) formulation of Abatacept ( Orencia ) vs Adalimumab ( Humira ), each on a background of Methotrexate ( MTX ), in biologic naïve patients with moderate to severe rheumatoid arthritis.
AMPLE met its primary endpoint as measured by non-inferiority of ACR20 ( American College of Rheumatology 20 percent improvement ) at year one. The Abatacept regimen achieved comparable rates of efficacy versus the Adalimumab regimen ( 64.8% vs 63.4%, respectively ). Onset of response was also generally similar for the two groups.
Year two of the study remained investigator-blinded. At year two, the Abatacept regimen achieved the same rate of efficacy ( 60% ) as the Adalimumab regimen based on ACR20.
ACR50, 70, and 90, considered to be more stringent measures of efficacy, as well as DAS-28-CRP, were assessed over 24 months and were generally similar for the two arms.
Radiographic progression was also assessed at two years with 85% of patients on the Abatacept regimen and 84% of patients on the Adalimumab regimen achieving radiographic non-progression.
At 24 months, overall safety data were similar for both groups, including frequency of adverse events ( 92.8% and 91.5% ), serious adverse events ( 13.8% and 16.5% ), and malignancies ( 2.2% and 2.1% ) for the Abatacept regimen and the Adalimumab regimen, respectively.
Discontinuations due to adverse events were 3.8% for the Abatacept regimen and 9.5% for the Adalimumab regimen, while discontinuations due to serious adverse events were 1.6% for the Abatacept regimen and 4.9% for the Adalimumab regimen. Additionally, zero of the 12 patients who experienced serious infections in the Abatacept group discontinued, while nine of the 19 patients who experienced serious infections in the Adalimumab group discontinued.
Autoimmune events, of mild or moderate severity, were reported in 3.8% of patients in the Abatacept group and 1.8% of patients in the Adalimumab group.
Injection site reactions were reported in 4.1% of patients taking the Abatacept regimen and 10.4% of patients taking the Adalimumab regimen.
AMPLE is a phase IIIb randomized, investigator-blinded multinational study of 24 months duration with a 12 month efficacy primary endpoint ( non-inferiority for ACR20 ). The study included 646 adult biologic-naïve patients with active moderate to severe rheumatoid arthritis and inadequate response to Methotrexate; 318 in the Abatacept plus Methotrexate group and 328 in the Humira plus MTX group. Patients were stratified by disease activity and randomized to either 125 mg Abatacept SC weekly or 40 mg Humira every other week, both on background MTX. The primary endpoint was to determine non-inferiority of Abatacept plus Methotrexate to Humira plus Methotrexate based on ACR20 response at 12 months. Secondary endpoints included injection site reactions, radiographic non-progression as assessed using the van der Heijde modified total Sharp score ( mTSS ) method, safety and retention.
Source: European League Against Rheumatism ( EULAR ) Congress, 2013