Biologic monotherapy – which drug is the most effective option in biologic-naïve rheumatoid arthritis?

This study investigated which biologic drugs improve rheumatoid arthritis (RA) management in patients who have not taken biologic drugs before. 

They found that interleukin-6 receptor inhibitors (IL6-Ri) drugs are most effective as a monotherapy (MT; single drug treatment). 

Rheumatoid arthritis (RA) is a chronic condition. It is caused by excessive inflammation in the joints. RA is treated with disease-modifying anti-rheumatic drugs (DMARDs). Biological DMARDs (bMDARDs) are one type of these. bDMARDs are antibodies that bind to or block chemicals and proteins that cause inflammation. 

There are many targets for bDMARDs. They include interleukin 6 receptor (IL6-R) and tumor necrosis factor (TNF). Another target is cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4). These targets are over-active in RA. Blocking these targets can improve RA symptoms. bDMARDs are used in combination with conventional DMARDs. They are sometimes prescribed alone as a monotherapy (MT). It is unclear if certain bDMARDs are more effective as a monotherapy (MT). 

This study included 126 patients with RA. No patient was treated with a bDMARD prior to this study. Patients were assigned to treatment as per their doctor’s instructions. TNF inhibitors (TNFi) included etanercept (Enbrel), adalimumab (Humira), certolizumab (Cimzia), and golimumab (Simponi). IL6-R inhibitors (IL6-Ri) such as tocilizumab (Actemra) and CTLA-4 inhibitors (CTLA-4i) such as abatacept (Orencia) were also used. RA activity was measured using the disease activity score (DAS28). 

78% of patients were treated with TNFi. At 6 and 12 months, patients in the IL6-Ri group had a lower DAS28 score compared to TNFi MT. More patients treated with IL6-Ri (54%) or CTLA-4i (50%) achieved disease remission at 18 months compared to TNFi (39%). 

Patients were more likely to continue taking their medication in the IL6-Ri (68%) and CTLA-4i (80%) groups after 18 months. This was compared to 55% in the TNFi group.

The authors concluded that Il-6Ri drugs are most effective as MT in patients with RA. The authors also suggested that CTLA-4is are a good option.

The number of patients in this study was relatively low. People on bDMARD MT would have less severe disease. The use of bDMARD MT in moderate-severe RA may be different. 

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