Baricitinib shows to lower biomarkers related to joint destruction

This study investigated the effect of baricitinib (Olumiant) on biomarkers in the blood, which indicate a state of joint destruction in patients with moderate to severe rheumatoid arthritis (RA).

The study showed that baricitinib reduced these biomarkers and resulted in decreased RA symptoms.

The inflammation caused by RA can lead to joint destruction, loss of cartilage, and destruction of bone tissue. This leads to symptoms like pain and impaired joint function. These limit the patients’ quality of daily life drastically. The state of joint destruction can be determined by an evaluation of special blood levels (biomarkers). Increased biomarkers indicate a progressed state of joint destruction, leading to increased symptoms (clinical response).

Certain biomarkers can indicate certain issues in patients with RA. High levels of biomarkers C1M, C3M, and C4M can indicate tissue inflammation, inflammation of the joint capsule's inner layer (synovial inflammation), and fibrosis (scar tissue). C2M can indicate cartilage destruction. CTX-I can indicate a reduction of bone tissue. Osteocalcin (OC) can indicate the forming of new bone tissue in response to the destruction. One goal of therapy for RA is to decrease the levels of biomarkers in the blood to ease the symptoms and improve life quality. 

Baricitinib works by blocking an enzyme called Janus kinase. It is known to lead to a decreased activity of the immune system and decreased symptoms. However, the effectiveness of baricitinib on joint destruction biomarkers and the resulting impact on the patients’ symptoms is unknown.

This study included 684 patients with moderate to severe RA overall. Participants received either 2mg baricitinib, 4 mg baricitinib, or a placebo daily for three months. The biomarkers of 240 patients were monitored for up to 12 weeks. Biomarkers evaluated included C1M, C3M, C4M, C2M, CTX-I, and OC. The clinical response was measured at 12 weeks using several assessment tools. 

Compared to the start of the study, levels of C1M, C3M, and C4M significantly dropped in both baricitinib-groups compared to placebo. A drop of these biomarkers was measured at both four and 12 weeks. In the 4mg-baricitinib-group, CTX-I was reduced significantly at four weeks compared to placebo. C2M and OC did not change significantly in the baricitinib-groups at either point of data collection compared to placebo. 

In both baricitinib-groups, blood levels indicating overall inflammation were significantly decreased at 12 weeks compared to placebo. Overall, the improvement of clinical response was significantly greater in both baricitinib-groups. The placebo-group showed less improvement in clinical response. 

The authors concluded that baricitinib reduced the biomarkers related to tissue inflammation and joint destruction. 

This study included a small number of participants and a short follow-up period. The long-term effects of baricitinib on joint destruction are necessary. The study was supported by pharmaceutical company Eli Lilly & Company, the producer of baricitinib.