Renflexis is not a chemotherapy drug. It is a biologic medication that works by blocking a specific protein in the immune system called tumor necrosis factor-alpha (TNF-alpha). While it is given through an intravenous infusion, which can look and feel a lot like a chemotherapy session, the two types of medication work in completely different ways and treat different conditions.
How Renflexis Actually Works
Chemotherapy drugs kill rapidly dividing cells throughout the body, which is why they’re used against cancer and why they cause widespread side effects like hair loss. Renflexis does something fundamentally different. It’s a monoclonal antibody, a large Y-shaped protein with about 1,328 amino acids, designed to latch onto TNF-alpha with high precision. TNF-alpha is a chemical your immune system produces to trigger inflammation. In autoimmune diseases, the body overproduces it, causing chronic, damaging inflammation in joints, the digestive tract, or the skin.
By binding to TNF-alpha (both the free-floating form and the form attached to cell surfaces), Renflexis prevents it from activating its receptors. This dials down the overactive immune response rather than destroying cells. It’s a targeted therapy, not a broad-spectrum poison.
What Renflexis Treats
Renflexis is FDA-approved for a range of autoimmune and inflammatory conditions, not cancer. Its approved uses include rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, plaque psoriasis, ulcerative colitis, and Crohn’s disease in both adults and children. All of these involve the same underlying problem: an immune system attacking the body’s own tissues, driven in part by excess TNF-alpha.
Renflexis Is a Biosimilar to Remicade
Renflexis is technically a biosimilar, meaning it’s a near-identical copy of an older biologic called Remicade (infliximab), which has been used since the late 1990s. The FDA approved Renflexis through an abbreviated pathway created by the Affordable Care Act, which allows manufacturers to demonstrate that a new biologic is “highly similar” to an already-approved reference product. Renflexis was the second biosimilar approved for Remicade. It is manufactured by Samsung Bioepis and treats the same conditions at the same doses as the original.
Why People Confuse It With Chemo
The confusion is understandable. Renflexis is given as an intravenous infusion, typically in an infusion center where you sit in a chair with an IV line for a period of time. That setting often looks identical to a chemotherapy suite. Some patients even receive Renflexis alongside other immunosuppressive medications, which adds to the impression that they’re on a cancer-like regimen.
There’s also some overlap in side effects. The FDA prescribing information notes that Renflexis can, in rare cases, cause drops in white blood cells, red blood cells, or platelets, effects people commonly associate with chemotherapy. The label advises watching for signs like looking unusually pale, bruising easily, or bleeding more than normal. However, these blood-related side effects are uncommon with Renflexis, while they are expected and frequent with most chemotherapy drugs.
Side Effects to Expect
The most common side effects of Renflexis, occurring in more than 10% of patients, are infections (upper respiratory infections, sinus infections, sore throat), reactions during the infusion itself, headache, and abdominal pain. Hair loss, one of the hallmark side effects of chemotherapy, is not listed as a common or even notable adverse reaction.
The more serious concern with Renflexis is infection risk. Because the drug suppresses part of the immune system, it can make you more vulnerable to infections, including serious ones like tuberculosis. The FDA’s strongest safety warning on the label addresses this risk, along with a small increased risk of certain cancers, particularly lymphoma, in patients on long-term TNF blockers. This cancer warning is another reason some people associate the drug with chemotherapy, but the relationship runs in the opposite direction: the drug slightly raises cancer risk rather than treating it.
The Key Distinction
The simplest way to understand the difference: chemotherapy targets and kills cells, especially fast-growing ones, to fight cancer. Renflexis blocks a single inflammatory signal to calm an overactive immune system. They are administered in similar settings and both require medical supervision, but they belong to entirely different drug classes, treat different diseases, and affect the body in different ways.