One of the biggest conversations in the pharmaceutical industry today is about the complex topic of bioequivalence. A biosimilar product can only receive FDA approval if it is highly similar to an already-approved biological product (called the reference product). While minor differences in clinically inactive components are allowable, it must have no clinically meaningful differences from the reference product, in terms of safety and effectiveness. The biosimilar must match its reference product’s mechanism(s) of action, route(s) of administration, dosage form(s), and strength(s) and will only be approved for the same indication(s) and condition(s). Even the manufacturing facilities for biosimilars must meet FDA standards.

If a biosimilar meets additional approval standards from the FDA, it can be identified as an interchangeable product. This designation means that the product is biosimilar to its reference product and that the same clinical outcomes can be expected in any given patient. Biosimilar and interchangeable products can be prescribed in the same manner as other medications, by writing out the proprietary name or the nonproprietary name. Pharmacists can substitute an interchangeable product for its reference product without needing to consult the prescriber. There are currently four* approved biosimilars in the United States, but so far, none of them has been approved as an interchangeable product. The available products are:

• Zarxio (filgrastim-sndz), biosimilar to Neupogen (filgrastim). Approved in March 2015.
• Inflectra (infliximab-dyyb), biosimilar to Remicade (infliximab). Approved in April 2016.
• Erelzi (etanercept-szzs), biosimilar to Enbrel (etanercept). Approved in August 2016.
• Amjevita (adalimumab-atto), biosimilar to Humira (adalimumab). Approved in September 2016.

As healthcare providers gain familiarity with them, prescribing biosimilars will likely become more commonplace. According to a recent survey of physicians across specialty areas, nearly half of those physicians queried indicated they expected to prescribe more biosimilars over the next few years. Some felt that biosimilars would become the norm and would replace biologics as time progresses, noting that a major advantage of prescribing biosimilars is the expected lower costs for patients. Many felt that the influence of payers and insurance firms would ultimately determine and possibly mandate the level of prescribing. Since industry experts view biosimilars as the pharmaceutical industry’s number one growth driver by increasing patient access and choice while driving down costs, we can expect a continued trend toward development and approval of more biologics.

Biosimilars are only approved for the indications and conditions of the reference biologic, but may be approved for fewer than all of them, so it is important for prescribers to review the FDA-approved drug labeling before prescribing. For informative labeling details on thousands of products, including biologics and biosimilars, visit PDR.net. Please update or register your PDR profile to receive alerts and other critical drug information from PDR via email. Also, look for information from PDR within your eRx workflow. Drug safety information, updates about dosing and formulary, patient support programs, and savings opportunities display on your screen as you prescribe, at no cost to you or your patients. To learn more about PDR services in your eRx/EMR/EHR workflow, email us at EHR-info@PDR.net.

Salvatore Volpe, MD, FAAP, FACP, CHCQM
Chief Medical Officer
PDR

*New approvals for biosimilars not mentioned in this article are anticipated for release in the near future. For daily updates on new approvals, please see www.FDA.gov.