inflammatory bowel disease

Stephen Hanauer, MD, on Biosimilars in Inflammatory Bowel Disease

Biosimilars are nearly identical to biologic agents in regard to pharmacokinetics, safety, and efficacy. They are a cheaper alternative to their biologic counterparts for the treatment of numerous chronic conditions.

Biosimilars of infliximab and adalimumab are approved for use by the US Food and Drug Administration (FDA) for the treatment of inflammatory bowel disease (IBD).

Gastroenterology Consultant caught up with Stephen Hanauer, MD, the medical director at the Digestive Health Center at Northwestern Medicine in Illinois, about what gastroenterologists should know about the use of biosimilars in the management of inflammatory bowel disease (IBD), a topic he will further discuss at the Advances in Inflammatory Bowel Diseases (AIBD) Regional Meeting in Chicago on July 20, 2019.

Gastroenterology Consultant: How should biosimilars be used in practice?

Stephen Hanauer: Biosimilars should be used the same way the original biologic agent is used. Biosimilars replicate the original medication. While they are not exactly generic, a biosimilar is as close to a generic as possible. It is not possible to make an identical copy of a biologic medication because it is a protein. Proteins go through a process of what is known as posttranslational carboxylation. The proteins form their shape by being coated with sugars. The sugars determine the shape of the protein, and the shape of the protein determines the function. All of the sugars are not exactly the same, but they are close enough that the biosimilar acts and performs the same way as the original compound.

GASTRO CON: Are there any safety concerns in switching a patient with active disease to a biosimilar?

SH: There is no fear here. The FDA developed a number of regulations and guidelines for the testing of biosimilars. These guidelines focus primarily on preclinical studies to demonstrate that a biosimilar is highly similar in the way it behaves in test tubes, animals, and in the development of antibodies. Once similarity between the biologic and biosimilar is achieved in the preclinical studies, the biosimilar is tested in a single indication. Once a single indication has been demonstrated to be similar, then the biosimilar can have all of the same indications for use as the originator. If a biosimilar is tested in rheumatoid arthritis (RA), you can extrapolate that data to Crohn disease or ulcerative colitis. If infliximab has 14 indications and similarity is demonstrated in 1 indication, the biosimilar can be used in any 1 of the 14 indications in the exact same manner as infliximab.

GASTRO CON: What do gastroenterologists need to know when a patient switches from treatment with a biologic agent to a biosimilar?

SH: Doctors usually do not switch patients to biosimilars. The switch in medications is typically initiated by a third-party insurance company that purchases the biosimilar at a lower cost than the originator. Again, it is very much like a generic in that the insurance company may wish to substitute the biosimilar for the original drug. The only difference in the medications is cost. One thing we do not recommend is switching back and forth. This is known as interchangeability. A patient can switch from infliximab to a biosimilar, but it is not recommended the patient switches back and forth between the 2 or switches to a separate biosimilar, due to a potential risk of developing antibodies. A single switch or substitution to a biosimilar has been tested and proven safe and effective.

GASTRO CON: Do you think interchangeability should be used in clinical practice?

SH: None of the biosimilars have been designated as interchangeable due to insufficient evidence. There is some research that has studied multiple switches of a biologic and biosimilar in RA. However, to this point, none of the medications have been designated as interchangeable by the FDA. I have no problem with a patient undergoing a single switch or substitution to a biosimilar, but there is a great amount of uncertainty for going back and forth between the original agent and biosimilar.