Comparing the safety and effectiveness of etanercept with HD203 in rheumatoid arthritis

This study compared the safety and effectiveness of etanercept (ETN, Ebrel) versus HD203 when combined with methotrexate (Trexall) in rheumatoid arthritis (RA) patients. The study concluded that HD203 was as effective and as safe as ETN.

RA causes joint pain and damage and increases disability levels the longer the disease is active. Early aggressive treatment is better for maintaining the joints and keeping joint mobility. Remission (a reduction in disease symptoms) is the main target in treatment.

One category of drugs used to treat RA is called tumor necrosis factor inhibitors (TNFi), such as ETN. ETN combined with MTX is successful in reducing symptoms of RA. ETN is also used alone in patients who cannot tolerate MTX. A biosimilar is a drug that is similar to another already approved drug, with no difference in safety or effectiveness. HD203 is a biosimilar of ETN. Whether HD203 combined with MTX is as effective as ETN combined with MTX is unclear. 

In this study, 233 patients were randomly assigned to one of two groups. One group received 25 mg of HD203 by injection twice weekly (115 patients). The other group received 25 mg of ETN by injection twice weekly (118 patients). All patients also received MTX.

By week 24, 83.48% of the HD203 group and 81.36% of the ETN group had achieved a greater than 20% improvement in RA disease activity. The number of patients who showed improvement of over 50% was higher in the HD203 group over the course of the study (48 weeks). There were no other significant differences in disease activity improvement.

HD203 was well tolerated by the patients and adverse events were similar for the two groups. The most common adverse event was infection. The most common serious adverse event was pneumonia.

The study concluded that HD203 was as effective and safe as ETN. 

The patients in this study were all Korean. This treatment is not yet approved by the US Food and Drug Administration (FDA).