The US Food and Drug Administration (FDA) has approved sarilumab (Kevzara), an injectable interleukin-6 (IL-6) receptor blocker, as the first and only biologic to treat adult patients with polymyalgia rheumatica who had inadequate response to corticosteroids or could not tolerate a corticosteroid taper.

Polymyalgia rheumatica, an inflammatory rheumatic disease, commonly presents with pain and stiffness around the hip, shoulder, and neck, fatigue, weight loss, and low-grade fever. These patients, who are usually aged 50 years and older, have difficulty performing activities of daily living, including standing up from a chair, getting out of bed, and lifting their arms

The drug was previously approved to treat moderate-to-severe rheumatoid arthritis (RA) after inadequate response or intolerance to at least 1 disease-modifying antirheumatic drug (DMARD).

The Trial

The Phase 3 SAPHYR trial evaluated the safety and efficacy of sarilumab in patients with active, steroid resistant polymyalgia rheumatica who experienced flares on ≥7.5 mg/day of prednisone, or an equivalent medication, during the tapering period. Patients were randomized to receive sarilumab 200 mg every 2 weeks coupled with a 14-week tapering of corticosteroids (n = 60) or placebo every 2 weeks combined with a 52-week steroid tapering period (n = 58).

The primary endpoint was sustained remission, as defined by disease remission by week 12, adherence to steroid tapering protocol from weeks 12 to 52, C-reactive protein normalization from weeks 12 to 52, and the absence of disease flare.

At week 52, 28% of patients treated with sarilumab achieved sustained remission, compared with only 10% in the placebo cohort. A sensitivity analysis confirmed the findings. Additionally, the cumulative corticosteroid dose was 777 mg for patients in the sarilumab group compared with 2044 mg in the placebo group.

The most common side effects reported included neutropenia (15%), leukopenia (7%), myalgia (7%), and constipation (7%). Serious adverse reaction of neutropenia was reported in 3% of patients receiving sarilumab, which was resolved after discontinuation.

“Corticosteroids have been the primary treatment to date, but many patients do not adequately respond to steroids or cannot be tapered off steroids, which puts such patients at risk of complications from long-term steroid therapy,” George D. Yancopolous, MD, PhD, President and Chief Scientific Officer at Regeneron, said in a statement. “With the approval of Kevzara for polymyalgia rheumatica, patients now have an FDA-approved treatment to help offer relief from the disabling symptoms of this disease and long-term dependence on steroids.”