Rheumatoid arthritis occurs in approximately 1% of the adult population and is associated with progressive joint destruction, functional disability, and decreased life expectancy. Disease modifying antirheumatic drugs (DMARDs), such as methotrexate, sulfasalazine, and hydroxychloroquine, may retard disease progression. However, many patients do not achieve an adequate response, and many do not maintain a response because of toxicity or lack of efficacy.

Although the underlying cause of rheumatoid arthritis is unknown, tumor necrosis factor TNF-a, a proinflammatory cytokine produced by macrophages and T cell contributes to the pathogenesis of synovitis and joint destruction. Because of the involvement of TNF in the pathogenesis of rheumatoid arthritis, it was hypothesized that soluble recombinant human TNF receptors might be useful as therapy for this disease.

 Etanercept is a recombinant human TNF receptor Fc fusion protein, fused to the Fc portion of human IgG1. Previous trials in patients with active rheumatoid arthritis who had an inadequate response to DMARDs have shown etanercept to be safe, well tolerated, and able to produce significant dose-dependent improvements in disease activity.

The innovator product Enbrel marketed by Wyeth Limited has recently been approved by various regulatory including the US Food and Drug Administration (FDA), European and DCGI  for treatment of RA.

Intas Biopharmaceuticals Ltd (IBPL) has developed biosimilar product etanercept. IBPL had already conducted non-clinical studies of test product to prove safety profile of test product at human intended dose. The current study is planned to compare the safety and efficacy of etanercept manufactured by Intas Biopharmaceuticals Limited against the comparator product Enbrel for the treatment of Active Rheumatoid Arthritis patients.