Generic, bioidentical, and biosimilar are terms used to identify a drug that has a comparable chemical structure and intended effect as the original patented drug. However, the terms are not necessarily interchangeable. The differences between these can impact the way you practice.

The term biosimilar refers to new formulations of a drug that is produced by a living organism (e.g., bacteria, yeast, plant). Biologically engineered drugs include monoclonal antibodies (e.g., trastuzumab, cetuximab, panitumumab) and growth factor stimulators (e.g., pegfilgrastim, filgrastim). When a drug patent expires, less expensive drugs can come to market.

What Is a Biosimilar Drug?

Biosimilar drugs are similar to the generic version of a standard drug—but with a catch. A biosimilar drug is created by a different microorganism than the original drug. Strains of microorganisms vary, so a biosimilar drug will be somewhat different from the original biologic drug.

Is a Biosimiar Drug as Effective as the Original Formula?

The U.S. Food and Drug Administration requires biosimilars to be comparable in chemical structure and produce the desired effect in the body. If these criteria are met, the extensive testing used to approve the original patented drug is not required. Therefore, the efficacy of the original formula compared to the biosimilar model is less known. Time will tell how well a biosimilar works when compared to the original drug.

Is There a Financial Advantage to Using a Biosimilar?

Because pharmaceutical companies do not have to incur the expense of extensively testing biosimilars, the cost savings can be passed on to the patient.

Are New Biosimilars Coming to Market?

Biosimilar versions of trastuzumab and rituximab could be available within the next two years. Filgrastim-sndz, a biosimilar version of filgrastim, was approved and released in 2015.

Oncology nurses who are aware of new treatment options will be better educated when patients ask questions about the availability and use of biosimilar drugs. Learn more about biosimilars to stay abreast on current and emerging trends in treatment options for your patients.