Abatacept Treatment in Polymyositis and Dermatomyositis — ARTEMIS  

Dermatomyositis Clinical Trial

Official title: Abatacept Treatment in Polymyositis and Dermatomyositis

Status Completed

Clinical Trial Summary

The aim of this study is to investigate the efficacy and safety of abatacept in patients with Dermatomyositis (DM) and polymyositis (PM) refractory to conventional treatment using a randomised trial design with delayed start in one arm. Abatacept will be administered intravenously to participants at a dose based on body weight at the screening visit followed by six follow-up treatments (Active treatment arm). Abatacept will also be administered intravenously to participants at a dose based on body weight starting at 3 months followed by six follow-up treatments (Delayed-onset treatment arm). The International Myositis Assessment and Clinical Studies Group (IMACS) preliminary definition of improvement (DOI) will be used for assessment.

Clinical Trial Description

This is a phase IIb pilot study with a randomised delayed treatment design. Half of the patients will be randomised to treatment with abatacept from week 0 (Active treatment arm) and half to start active treatment after 3 months (Delayed-onset treatment arm). The open-label study will not include placebo, but the efficacy outcome assessors will be blinded to treatment arm. The study will be conducted at three sites (Karolinska University Hospital Stockholm, Sweden; King's College Hospital National Health Service (NHS), London, United Kingdom (UK); and the Institute of Rheumatology Prague, Prague, Czech Republic).

Patients will be eligible between ages 18 and 80 years and must have active disease after treatment with glucocorticoids (≥0.5 mg/kg/day for ≥1 month), in combination with at least one other immunosuppressive drug, methotrexate (minimum dose 15 mg/week) or azathioprine (minimum dose 100 mg/day) for at least 3 months. Concomitant methotrexate or azathioprine will be allowed, with stable doses for ≥1 month prior to inclusion in the study. Active disease is defined as persisting or worsening muscle weakness (Manual Muscle Test (MMT)-8 bilaterally <150) or low endurance measured by Functional Index for myositis (FI-2) <20% of upper value,15 together with at least one other sign of active disease: elevated (above upper limit of normal) serum levels of muscle enzymes, inflammation in a recent muscle biopsy (<1 month) or on Magnetic resonance imaging (MRI) findings consistent with inflammation, or active extramuscular disease.

The primary endpoint will be the number of responders, defined according to the International Myositis Assessment and Clinical Studies Group (IMACS) preliminary definition of improvement (DOI),16 after treatment with abatacept for 6 months. IMACS DOI is defined as relative improvement by ≥20% in three of any six core set measures, with no more than two core set measures worsening by ≥25%, which cannot be MMT.

Secondary objectives will include the number of responders in the delayed-onset arm compared with active treatment arm at 3 and 6 months, and the change in individual components of the IMACS core set measures for disease activity and in the muscle endurance as tested by FI-2, in the delayed-onset arm compared with active treatment arm at 3 and 6 months. ;

Related Conditions & MeSH terms

• Dermatomyositis
• Polymyositis

• NCT number: NCT01315938
• Study type: Interventional
• Source: Karolinska Institutet
• Status: Completed
• Phase: Phase 2
• Start date: January 2011
• Completion date: November 28, 2013