AC-CUTE: An Open-Label Study to Evaluate Progression of Structural Joint Damage and Inflammation in Subjects with Moderate to Severe Rheumatoid Arthritis.

Aim: Examine the efficacy of once-weekly subcutaneous tocilizumab (SC-TCZ) on joint damage at 24 weeks based on radiography of the hands and feet and magnetic resonance imaging (MRI) of the hand in subjects with moderate to severe rheumatoid arthritis (RA).

Methods: In this Australian open-label, multicentre, prospective, single-arm study, subjects received 162 mg SC-TCZ weekly. Primary endpoint was change in radiographic Genant-modified Total Sharp Score (TSS) between baseline and Week 24. Secondary endpoints included change from baseline to Week 24 in RA MRI scoring (RAMRIS) of erosions, synovitis, and osteitis and Cartilage Loss Score (CARLOS) in the dominant hand and disease activity score 28 (DAS28).

Results: 52 subjects were enrolled (80% female, mean (SD) age 57  (12) years). Radiography showed mild but not significant progression of joint damage (mean (SD) change in TSS 0.46 (1.29)). Synovitis reduced significantly on MRI; however, osteitis, erosion, and cartilage loss did not change significantly. DAS28 improved significantly by Week 24; 78% of subjects achieved DAS28 remission. SC-TCZ was generally well tolerated.

Conclusion: Synovitis and DAS28 decreased significantly; however, no significant change in osteitis or joint damage was observed at Week 24.

Trial registration: This trial is registered with Clinicaltrials.gov registration number NCT01951170 (ML28703).