Ixifi (infliximab-qbtx) is an approved treatment for the inflammatory bowel diseases Crohn’s and ulcerative colitis.

Pfizer developed it as a biosimilar to Remicade (infliximab) after Remicade’s patent protection ran out. A biosimilar has the properties of the original but is much cheaper.

In addition to bowel diseases, Ixifi can treat the other conditions that Remicade was approved for — the rheumatic diseases rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis) and plaque psoriasis.

The U.S. Food and Drug Administration approved Ixifi in December 2017.

How Ixifi works

It is a monoclonal antibody, or copy of an antibody produced in a lab. It blocks a cell-signaling protein known as tumor necrosis factor, or TNF.

Normally, TNF helps the immune system fight diseases and infections. The immune systems of people with an inflammatory bowel disease produce an excessive amount of TNF, causing gut inflammation. This leads to diarrhea, abdominal pain, cramping, fever and fatigue.

When Ixifi binds to TNF, it blocks its activity, reducing inflammation and improving patients’ symptoms.

Ixifi in clinical trials

The FDA based its approval of Ixifi on clinical trials showing that it had the properties of Remicade and worked as well.

Most of the evidence came from the Phase 3 REFLECTIONS B537-02 trial (NCT02222493). It compared Ixifi and Remicade’s safety, effectiveness and ability to trigger an immune response against moderate to severe rheumatoid arthritis in patients who stopped responding to methotrexate. Participants received injections of either Ixifi or Remicade plus methotrexate.

Ixifi was as effective as Remicade, results showed.

The yardstick researchers used was American College of Rheumatology 20 (ACR20) index scores after 14 weeks of treatment. The index measures improvements in tender or swollen joint conditions. It has five components. Three of them are a patient assessment, a doctor’s assessment, and a pain scale. Another is a  questionnaire on patients’ views of their function and disability. The fifth is an evaluation of acute phase reactants, or proteins whose plasma concentrations change in response to inflammation.

ACR20 measures whether a therapy helps a patient achieve at least a 20 percent improvement in tender or swollen joints. Ixifi met the test. Results after 30 weeks of treatment confirmed the initial findings.


IBD News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.