Comparative Study of Janus Kinase (JAK) Inhibitors Vs Tumor Necrosis Factor (TNF) Inhibitors in Rheumatoid Arthritis

Comparative Study of JAK Inhibitors Vs TNF Inhibitors in Patients With Rheumatoid Arthritis

Rheumatoid arthritis is a systemic autoimmune disease characterized by inflammatory synovitis and progressive joint destruction, which are associated with severe disability and increased mortality. It occurs at an incidence of 5 per 1000 with Women being 2 times more likely to be affected by Rheumatoid Arthritis than men. The peak incidence in both groups is in the sixth decade of life.

Management of RA has improved substantially in recent years. In addition to the reduction of signs and symptoms, improvement of physical function, and inhibition of structural damage, better patient outcomes, and clinical remission are now considered achievable goals. Therefore, the current recommended primary target for the treatment of RA should be a state of clinical remission.

Methotrexate (MTX) should be initiated, typically as monotherapy. If treatment response is inadequate, other Disease-modifying antirheumatic drugs (DMARDs) may be added to (rather than replacing) methotrexate to enhance efficacy and reduce the potential for the formation of anti-drug antibodies. TNF inhibitors are the first-line biologic therapies used in the event of incomplete response or adverse reaction to conventional DMARDs as TNF alpha is an important proinflammatory cytokine produced by macrophages and other cells, with myriad actions relevant to the pathogenesis of RA, including stimulation of other proinflammatory cytokine production, expression of endothelial cell adhesion molecules, production of metalloproteinases, and stimulation of osteoclasts. Activated Janus kinases (JAKs) play pivotal roles in intracellular signaling from cell-surface receptors for multiple cytokines implicated in the pathologic processes of rheumatoid arthritis. Baricitinib, an orally available small molecule, provides reversible inhibition of Janus Kinase 1 (JAK1) and Janus Kinase 2 (JAK2) and has shown clinical efficacy in studies involving patients with moderate to severely active Rheumatoid Arthritis who are either intolerant to MTX treatment or who have had an inadequate response to DMARDs, either conventional or biologic.

Aims of the Study:

• To determine the outcome of patients with moderate to severely active rheumatoid arthritis (RA) - despite methotrexate treatment - on JAK inhibitors (Baricitinib).
• To determine the outcome of patients with moderate to severely active rheumatoid arthritis (RA) - despite methotrexate treatment- on TNF inhibitors (Golimumab and Etanercept).
• To compare the outcome between these 2 groups of patients in terms of improvements in signs and symptoms, physical function, patient-reported outcomes, and progression of structural joint damage.
• Detection of any adverse effects that may emerge during the course of treatment.

Patients will be classified into 3 groups:

group (1): patients receiving Methotrexate group (2): patients receiving Methotrexate in addition to JAK inhibitors (Baricitinib at 4 mg once daily by oral route) group (3): patients receiving Methotrexate in addition to TNF inhibitors (Golimumab at 50 mg/month or Etanercept at 50mg/ week by subcutaneous injections)

Inclusion Criteria:

• Age: patients >18 years old.
• Patients with Rheumatoid arthritis diagnosed according to the 2010 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology Classification Criteria for RA.
• Patients with moderate to severely active RA as evaluated by DAS28-Score, who have never been treated with biologic DMARDs and who expressed a lack of adequate response or intolerability to conventional DMARDs.

Exclusion Criteria:

• Age < 18 years.
• Any autoimmune disease other than Rheumatoid arthritis.
• Previous treatment with biologic DMARDs.