What Is A Biosimilar?
The FDA approved RENFLEXIS as biosimilar to Remicade® (infliximab)

What are biosimilars?

Biosimilars are approved by the FDA as being highly similar to an already approved biologic medicine. The already approved biologic medicine is known as the reference product or originator biologic product.

Manufacturers must show that biosimilars have no clinically meaningful differences in safety, purity, or potency (safety and effectiveness) compared to the originator biologic product.

How is a biosimilar approved by the FDA?

A biosimilar must show that it has no clinically meaningful differences in effectiveness and safety from the originator biologic product. To demonstrate this, the FDA requires a biosimilar to be tested to prove the medicine is similar in several ways, including:

  • Similar effectiveness and safety: A biosimilar must prove it is highly similar in efficacy and safety.
  • Similar in how it works: A biosimilar works in the body in a similar way to the originator biologic product.
  • Similar structure: A biosimilar is developed in a way that ensures that it is similar in structure to the originator biologic product.

Biosimilars are the same as originator biologic product in the following ways:

  • Same dosage.
  • Taken the same way (for example, given as an infusion).

Why do biosimilars exist?

In the United States, biosimilars are approved under the Biologics Price Competition and Innovation Act. One of the goals of this act is to help more people get access to certain medicines.

Learn about The Merck Access Program

Important Safety Information

Only your doctor can recommend a course of treatment after checking your health condition. RENFLEXIS can cause serious side effects such as lowering your ability to fight infections. Some patients, especially those 65 years and older, have had serious infections caused by viruses, fungi, or bacteria that have spread throughout the body, including tuberculosis (TB) and histoplasmosis. Some of these infections have been fatal. Your doctor should monitor you closely for signs and symptoms of TB during treatment with RENFLEXIS.

Unusual cancers have been reported in children and teenage patients taking TNF-blocker medicines. Hepatosplenic T-cell lymphoma, a rare form of fatal lymphoma, has occurred mostly in teenage or young adult males with Crohn’s disease or ulcerative colitis who were taking infliximab products and azathioprine or 6-mercaptopurine. For children and adults taking TNF blockers, including RENFLEXIS, the chances of getting lymphoma or other cancers may increase.

You should discuss any concerns about your health and medical care with your doctor.

What should I tell my doctor before I take RENFLEXIS?

You should let your doctor know if you have or ever had any of the following:
  • Tuberculosis (TB) or have been near someone who has TB. Your doctor will check you for TB with a skin test. If you have latent (inactive) TB, you will begin TB treatment before you start RENFLEXIS. If your doctor feels that you are at risk for TB, you may be treated with medicine for TB before you begin treatment with, and during treatment with, RENFLEXIS. Even if your TB test is negative, your doctor should carefully monitor you for TB infections while you are taking RENFLEXIS. Patients who had a negative TB skin test before receiving infliximab products have developed active TB.
  • Lived in a region where certain fungal infections like histoplasmosis, coccidioidomycosis, or blastomycosis are common. These infections may develop or become more severe if you take RENFLEXIS. If you do not know if you have lived in an area where histoplasmosis, coccidioidomycosis, or blastomycosis is common, ask your doctor.
  • Infections that keep coming back, diabetes, or an immune system problem.
  • Any type of cancer or a risk factor for developing cancer, for example, chronic obstructive pulmonary disease (COPD) or had phototherapy for psoriasis.
  • Heart failure or any heart condition. Many people with heart failure should not take RENFLEXIS.
  • Hepatitis B virus (HBV) infection or think you may be a carrier of HBV. Your doctor will test you for HBV.
  • Nervous system disorders (like multiple sclerosis or Guillain-Barré syndrome).
Also tell your doctor if you:
  • Use the medicines Kineret® (anakinra), Orencia® (abatacept), or Actemra® (tocilizumab) or other medicines called biologics used to treat the same problems as RENFLEXIS.
  • Are pregnant, plan to become pregnant, are breast-feeding, or have a baby and were using RENFLEXIS during your pregnancy. Tell your baby's doctor about your RENFLEXIS use. If your baby receives a live vaccine within 6 months after birth, your baby may develop infections with serious complications that can lead to death.
  • Recently received or are scheduled to receive a vaccine. Adults and children taking RENFLEXIS should not receive live vaccines or treatment with a weakened bacteria (such as Bacille Calmette-Guérin [BCG] for bladder cancer) while taking RENFLEXIS.

What should I watch for and talk to my doctor about before or while taking RENFLEXIS?

The following serious (sometimes fatal) side effects have been reported in people taking RENFLEXIS.

You should tell your doctor right away if you have any of the signs listed below:

  • Infections (like TB, blood infections, pneumonia)—fever, tiredness, cough, flu, or warm, red, or painful skin or any open sores. RENFLEXIS can make you more likely to get an infection or make any infection that you have worse.
  • Lymphoma, or any other cancers in adults and children.
  • Skin Cancer—any changes in or growths on your skin.
  • Heart Failure—new or worsening symptoms, such as shortness of breath, swelling of your ankles or feet, or sudden weight gain.
  • Reactivation of HBV—feeling unwell, poor appetite, tiredness, fever, skin rash, and/or joint pain.
  • Liver Injury—jaundice (yellow skin and eyes), dark brown urine, right-sided abdominal pain, fever, or severe tiredness.
  • Blood Problems—in some patients taking infliximab products, the body may not make enough of the blood cells that help fight infections or help stop bleeding. Tell your doctor if you have a fever that does not go away, bruising, bleeding, or severe paleness.
  • Nervous System Disorders—numbness, weakness, tingling, changes in your vision, or seizures.
  • Allergic Reactions (some severe) during or after the infusion—hives, difficulty breathing, chest pain, high or low blood pressure, swelling of face and hands, and fever or chills.
  • Lupus-like Syndrome—chest discomfort or pain that does not go away, shortness of breath, joint pain, rash on the cheeks or arms that gets worse in the sun.
  • Psoriasis—new or worsening psoriasis such as red scaly patches or raised bumps on the skin that are filled with pus.

The more common side effects with infliximab products are respiratory infections (that may include sinus infections and sore throat), headache, rash, coughing, and stomach pain.

What conditions is RENFLEXIS used to treat?
RENFLEXIS is a prescription medication used to treat: Crohn's Disease
  • Can reduce signs and symptoms and induce and maintain remission in adult patients with moderately to severely active Crohn’s disease who haven’t responded well to other therapies
Pediatric Crohn's Disease
  • Can reduce signs and symptoms and induce and maintain remission in children (ages 6–17) with moderately to severely active Crohn’s disease who haven’t responded well to other therapies
Ulcerative Colitis
  • Can reduce signs and symptoms, induce and maintain remission, promote intestinal healing, and reduce or stop the need for steroids in adult patients with moderately to severely active ulcerative colitis who haven’t responded well to other therapies
Rheumatoid Arthritis
  • Can reduce signs and symptoms, help stop further joint damage, and improve physical function in patients with moderately to severely active rheumatoid arthritis, in combination with methotrexate
Psoriatic Arthritis
  • Can reduce signs and symptoms of active arthritis, help stop further joint damage, and improve physical function in patients with psoriatic arthritis
Ankylosing Spondylitis
  • Can reduce signs and symptoms in patients with active ankylosing spondylitis
Plaque Psoriasis
  • Approved for the treatment of adult patients with chronic (doesn’t go away) severe (extensive and/or disabling) plaque psoriasis under the care of a physician who will determine if RENFLEXIS is appropriate considering other available therapies



You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

Please read the accompanying Medication Guide for RENFLEXIS, including the information about serious infections and cancers, and discuss it with your doctor. The physician Prescribing Information also is available.

This site is intended only for residents of the United States, its territories and Puerto Rico.

Brands mentioned are trademarks of their respective owners.

Copyright © 2018 Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc. All rights reserved. BIOS-1206420-0004 08/18

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Please read the accompanying Medication Guide for RENFLEXIS, including the information about serious infections and cancers, and discuss it with your doctor. The physician Prescribing Information also is available.