PolyMyalgia Rheumatica treatment with Methotrexate in Optimal Dose in an Early disease phase (PMR MODE): study protocol for a multicenter double-blind placebo controlled trial

BACKGROUND: Polymyalgia rheumatica (PMR) is an inflammatory rheumatic disease affecting people older than 50, resulting in pain and stiffness of the neck, shoulder, and pelvic girdle. To date, glucocorticoids (GC) remain the cornerstone of treatment, but these have several drawbacks. Firstly, a large proportion of patients do not achieve GC-free remission within either the first (over 70%) or second year of treatment (over 50%). Secondly, GC-related adverse events (AE) occur in up to 65% of patients and can be severe. The current EULAR/ACR guidelines for PMR recommend early introduction of methotrexate (MTX) as a GC sparing agent in patients at risk for worse prognosis. However, earlier trials of low to medium quality only studied MTX dosages of 7.5–10 mg/week with no to modest effect. These doses may be suboptimal as MTX is recommended in higher doses (25 mg/week) for other inflammatory rheumatic diseases. The exact role, timing, and dose of MTX in PMR remain unclear, and therefore, our objective is to study the efficacy of MTX 25 mg/week in recently diagnosed PMR patients. METHODS: We set up a double-blind, randomized, placebo-controlled superiority trial (PMR MODE) to assess the efficacy of MTX 25 mg/week versus placebo in a 1:1 ratio in 100 recently diagnosed PMR patients according to the 2012 EULAR/ACR criteria. All patients will receive prednisolone 15 mg/day, tapered to 0 mg over the course of 24 weeks. In case of primary non-response or disease relapse, prednisolone dose will be temporarily increased. Assessments will take place at baseline, 4, 12, 24, 32, and 52 weeks. The primary outcome is the difference in proportion of patients in GC-free remission at week 52. DISCUSSION: No relapsing PMR patients were chosen, since the possible benefits of MTX may not outweigh the risks at low doses and effect modification may occur. Accelerated tapering was chosen in order to more easily identify a GC-sparing effect if one exists. A composite endpoint of GC-free remission was chosen as a clinically relevant endpoint for both patients and rheumatologist and may reduce second order (treatment) effects. TRIAL REGISTRATION: Dutch Trial Registration, NL8366. Registered on 10 February 2020