Polymyalgia rheumatica (PMR) is prevalent among elderly. Untreated, it leads to major reduction in quality of life. Glucocorticoids are the cornerstone of treatment, but have drawbacks, warranting glucocorticoid sparing treatment. A proof of concept study on Rituximab (RTX) vs placebo showed efficacy in 48 vs 21%(p=0.049) in glucocorticoid free remission after 21 weeks (Marsman et al. 2021). Though promising, the short study duration, small sample size and only few relapsing patients included in this study require further confirmation. Therefore a larger randomised controlled trial with longer follow up will be performed on RTX efficacy on glucocorticoid free remission in relapsing PMR patients during glucocorticoid taper.

Inclusion Criteria:

• Polymyalgia rheumatica (PMR) diagnosis fulfilling the 2012 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria
• Experiencing a PMR relapse, defined as recurring of symptoms and increase in erythrocyte sedimentation rate (ESR)/ C reactive protein (CRP)
• Unable to reduce glucocorticoid dose below 5mg/day prednisolone or equivalent
• Informed consent

Exclusion Criteria:

• Treatment with systemic immunosuppressants (other than GC, MTX, leflunomide and azathioprine) 3 months prior to inclusion;
• (clinical) suspect concomitant giant cell arteritis or other rheumatic inflammatory diseases;
• concomitant conditions that might significantly interfere with PMR pain or movement evaluation as judged by the investigator;
• previous hypersensitivity for RTX or contra-indications to RTX.