Double-blinded placebo-controlled trial measuring cartilage improvement in early Rheumatoid Arthritis under Adalimumab therapy using MRI

Background: To compare the effect of Adalimumab (ADA) plus Methotrexate (MTX) versus MTX monotherapy in patients with therapy naïve early rheumatoid arthritis (eRA) on cartilage quality measured by glycosaminoglycan (GAG) content in cartilage using gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). Methods: Prospective double-blinded, randomized clinical trial of cartilage integrity in finger joints of eRA patients according to American College of Rheumatology/ European League Against Rheumatism. Patients were examined therapy-naïve, 12 and 24 weeks after initiation of Adalimumab+MTX or placebo+MTX with 3T-MRI, recording dGEMRIC values of metacarpophalangeal joints of index and middle finger. Results: The study was prematurely terminated due to theoretical safety concerns regarding gadolinium deposition in the brain after MR contrast agent application. Instead of 30 planned patients, 10 patients could be included in the Adalimumab group (ADA+MTX: 6 females, 44.9y, range: 19-65), four in the control group (Placebo+MTX: 2 females, 46.7y, range: 24-64). Between treatment groups, cartilage composition did not change significantly (ADA+MTX: dGEMRIC mean change 85.8ms, range -156.2–346.5ms; Placebo+MTX: mean change-30.75ms, range-273.0–131.0ms; W=27, p=0.37). Neverthless a significant increase of the dGEMRIC values over time was observed in the Adalimumab group (median change 75.88 ms p=0.0117), but not in the placebo group (median change 9.50, p=0.878).Conclusions: In patients with eRA, Adalimumab+MTX leads to a significant dGEMRIC improvement, indicating a possible reduction of cartilage damage in the finger joints. The level of significance for the difference of change in cartilage quality between groups, was not met, potentially due to lower than expected number of patients which could be recruited. Trial registration: The cartilage in early Rheumatoid Arthritis (CAR-ERA)-Study was approved by the local ethics committee of the Heinrich-Heine University of Duesseldorf (reference number: MO-LKP-719) and was registered at clinicaltrials.gov under the number NCT02150473 / CAR-ERA 2013-004604-19 (EudraCT Number).