Sarilumab in rheumatoid arthritis – an update on safety and effectiveness

This study investigated the safety and effectiveness of sarilumab (Kevzara) added to methotrexate in rheumatoid arthritis (RA).

They found that sarilumab was clinically effective and well-tolerated. 

Rheumatoid arthritis (RA) is a long-term condition. It is caused by an excess of inflammation in the joints. Disease-modifying anti-rheumatic drugs (DMARDs) are the first line of treatment for RA. Methotrexate (MTX) is a DMARD. It works by blocking pathways involved in inflammation. Many patients with RA do not respond to MTX. DMARDs with specific targets can help manage RA symptoms in combination with MTX. 

Sarilumab (SRB) is a biological DMARD. It is an antibody that attaches to the interleukin (Il-6) receptor. This prevents the chemical Il-6 from attaching to it. Il-6 leads to increased inflammation in RA. Blocking its action can improve RA symptoms. Studies have shown that SRB combined with MTX is an effective RA treatment in non-Asian patients. Some drugs act differently in Asian populations. It is unclear if the same scenario exists in Japanese patients. 

This study included 243 Japanese patients with RA. The trial lasted 52 weeks and there were two phases. In the first phase, patients were assigned to either SRB (150 mg or 200 mg) or placebo (inactive drug). After 24 weeks, patients in the placebo group switched to either 150 mg or 200 mg SRB. This continued for 28 weeks. All patients were also taking MTX. Disease activity was measured using the ACR20 as an endpoint. ACR20 is an improvement of 20% in RA symptoms. 

At week 24, ACR20 rates were higher in SRB + MTX patients than MTX alone (57.5-67.9% vs 14.8%).

Serious side effects were reported in patients taking 150 mg SRB (0 – 9.9%) and 200 mg SRB (6.3 – 13.3%). No deaths were recorded from SRB treatment. Infection was reported in 52.5 – 67.9% of patients.  Low white blood cell count (neutropenia) was reported in SRB-treated patients. This was not associated with infection rates. 

The authors concluded that SRB was clinically effective and well-tolerated.

This study included patients with a long history of RA. The effectiveness of SRB + MTX may differ in other categories of patients with RA. 

If you have any concerns regarding RA treatment, please consult with your physician.