Treatment of refractory polymyalgia rheumatica with infliximab: A pilot study

Objective. To investigate whether infliximab has a steroid-sparing effect in the treatment of patients with polymyalgia rheumatica (PMR) who are resistant to corticosteroid (CS) therapy and have had CS-related side effects. Methods. In a pilot study, infliximab 3 mg/kg was administered at weeks 0, 2, and 6 in 4 patients with relapsing PMR who were not able to reduce their prednisone dose below 7.5-12.5 mg/day and who had experienced multiple vertebral fractures. The patients were regularly monitored for clinical signs/symptoms and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and interleukin-6 (IL-6) during the one-year followup period. Results. Two patients had a complete response to infliximab with clinical remission 2 weeks after the first infusion. At this time ESR and IL-6 values were normal and the patients were able to suspend prednisone. Normal ESR, CRP, and IL-6 levels persisted after the suspension of infliximab and prednisone during the followup period, paralleling the clinical remission. The third patient had a complete and persistent clinical remission 2 weeks after the first infusion, although IL-6 levels remained elevated during the followup period despite the normalization of ESR values. These 3 patients were symptom-free with normal ESR and CRP at the end of 1-year of followup. The fourth patient had continuous clinical activity associated with persistently elevated acute phase reactants, although IL-6 levels measured during followup were lower compared to baseline values and the patient was able to reduce prednisone dosage to 5 mg/day. Conclusion. Our encouraging results suggest that a controlled study may assess the efficacy of infliximab as CS-sparing drug in PMR.