Safety, Efficacy of Sarilumab in Relapsing Polymyalgia Rheumatica Assessed

Sarilumab demonstrates significant efficacy and is safe in the treatment of relapsing polymyalgia rheumatica (PMR), with clinically meaningful improvements in the quality of life of patients, according to study results presented at the American College of Rheumatology (ACR) Convergence 2022, held from November 10 to 14, in Philadelphia, Pennsylvania.

Sarilumab is a human anti-interleukin (IL)-6 receptor antagonist monoclonal antibody originally indicated to treat moderate to severe rheumatoid arthritis. Elevated levels of IL-6 may occur in active PMR that correlates with disease severity, relapse rate, and disease activity.

Researchers conducted a randomized double-blind placebo-controlled trial (SAPHYR; ClinicalTrials.gov Identifier: NCT03600818) to assess the safety and efficacy of sarilumab in patients with relapsing PMR.

Primary endpoint included percentage of patients with achievement of sustained PMR remission and successful adherence to decreased use of glucocorticoids at 52 weeks of treatment with 200 mg of sarilumab every 2 weeks plus a 14-week tapered glucocorticoid regimen.

The study ended early secondary to restrictions due to the COVID-19 pandemic.

A total of 78 patients completed treatment, with 42 in the treatment group and 36 in the placebo group.

The main reasons for treatment discontinuation included adverse events and lack of efficacy.

Adverse events occurred more frequently in the treatment group compared with the placebo group (94.9% vs 84.5%, respectively); however, serious adverse events occurred more frequently in the placebo vs treatment group (20.7% vs 13.6%, respectively). The most common treatment-related adverse events in the sarilumab group included neutropenia (15.3%) and arthralgia (15.3%), and in the placebo group, insomnia occurred most frequently (15.5%). No deaths were reported.

Patients in the sarilumab vs placebo group achieved sustained remission of PMR at higher rates (28.3% vs 10.3%, respectively; P =.0193), even after exclusion of C-reactive protein levels in the definition of sustained PMR remission (31.7% vs 13.8%, respectively; P =.0280).

Patients in the sarilumab vs placebo group had lesser flares during clinical remission (16.7% vs 29.3%; hazard ratio [HR], 0.56; 95% CI, 0.35-0.90; P =.0153). Researchers also noted that PMR activity scores improved with sarilumab vs placebo (least squares mean, -15.57 vs -10.27, respectively; P =.0002).

In addition to sustained PMR remission and decreased incidence of flares, patients in the sarilumab vs placebo group also required lesser treatment with additional glucocorticoids (0.0 vs 199.5 mg; P =.0189).

“[Sarilumab plus a 14-week glucocorticoid] taper demonstrated significant efficacy vs the comparator arm in [patients with] steroid-refractory PMR, including clinically meaningful improvement in quality of life,” the study authors said. “Safety was consistent with the known safety profile of [sarilumab],” they added.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.