Interleukin-6 levels predict greater improvement of quality of life with sarilumab than with adalimumab in patients with RA

This study examined the effect of sarilumab (Kevzara) compared to adalimumab (Humira) on health-related quality of life (HRQoL) based on inflammatory marker levels in patients with rheumatoid arthritis (RA). 

The data showed that sarilumab has a higher effect on improving aspects of HRQoL in patients with higher levels of inflammation in the blood.

Interleukin-6 (IL-6) is a protein related to inflammation. High levels of IL-6 in patients with RA increase disease activity and joint destruction. This results in increased symptoms like pain, tiredness (fatigue), and painful morning stiffness (AM-stiffness). Inevitably, the physical function is limited. In addition, the patients’ mental health is very likely to be influenced negatively. All of these factors most likely lead to a heavily reduced HRQoL. 

Sarilumab is a medication used for the treatment of RA. It works by blocking IL-6, therefore reducing inflammation. Adalimumab is also used to treat RA symptoms. It blocks another inflammatory protein called tumor necrosis factor (TNF). The lowering effect of sarilumab and adalimumab on inflammation levels in the blood and symptoms previously led to their FDA-approval. However, the effectiveness of different aspects of HRQoL and how IL-6 blood levels influence this is unknown.

This study evaluated the data of 300 patients with RA. IL-6-levels were measured in all patients at the start of the study. IL-6 levels were categorized into 3 divisions: low (1.6-7.1 pg/ml), medium (7.2-39.5 pg/ml) and high (39.6-692.3 pg/ml). 152 patients received adalimumab (40mg every two weeks). 148 patients received sarilumab (200mg every two weeks). Patients completed HRQoL questionnaires and questions about AM-stiffness at the start of the study after 24 and 52 weeks. 

Patients in the high IL-6 group showed to have a heavier negative impact on HRQoL. After 24 weeks, HRQoL scores improved in all IL-6 group for both drugs. On average, the sarilumab group was 6 times more likely to show an improvement in HRQoL compared to the adalimumab group for patients in the high division compared to those in the low division. 

This study showed that sarilumab showed to be more effective in improving aspects of HRQoL. The benefits were seen especially in patients with high levels of IL-6.

The defined IL-6 levels cover uneven amounts of units and may not represent every important patient experience. The study was funded by Sanofi and Regeneron Pharmaceuticals, Inc. who produces sarilumab.

Ask your doctor about the relevance and compatibility of either drug for your treatment.