The treatment of choice for rheumatic diseases has traditionally been the use of biological agents called bio-originators. These agents are derived from microorganisms, animals or humans. The increasing cost of these agents has put effective treatment out of the reach of many disease sufferers.

A group of international rheumatologists, patient representatives and specialists in related fields conducted a scientific review to determine if the use of “biosimilars” can help give patients greater access to treatment. Biosimilars are substances that have been approved by the FDA because they are so similar to bio-originators that are already in use.

The task force addressed three questions. The first was the matter of cost. Biosimilars introduce more competition in the market and are expected to result in lower prices. It was predicted that the savings would be about 35 percent. In the United States, for a product with only one biosimilar available, the savings was only about 15 percent. The task force hopes that as more biosimilars become available, the cost savings will be more fully realized.

The second question was in regard to extrapolation. An example is the best way to explain extrapolation. If a bio-originator is used to treat conditions A, B and C, full extrapolation would mean that as soon as the FDA approves the biosimilar for condition A, it could also be used to treat conditions B and C. The task force was in agreement that the more cautious route of doing additional testing for each condition should be followed.

The third question investigated by the task force looked at the implications of having a patient switch from the bio-originator to a biosimilar. The data regarding biosimilars for rheumatic diseases strongly suggest that this switch is safe and produces no drop in effectiveness. The decision to switch from one to the other, however, should only be made by the doctor in consultation with the patient.

One topic that still requires further research is the question of interchangeability. Interchangeability means that the biosimilar is truly equivalent in every meaningful way to the bio-originator. This can only be determined if patients are switched from one to the other and back at least three times. If there are no differences found regarding safety, effectiveness, reaction of the immune system, or side effects between a group that undergoes the switching and a group that only uses the bio-originator, the two products can be called interchangeable.