A biosimilar is a biological agent that is very much like another previously FDA-approved biological agent, called the reference drug. Biosimilars and their reference drugs are both made from living organisms, but they may be made in different ways and of slightly different substances. A biosimilar must demonstrate the same safety and efficacy and work in the same way as the reference drug, and it must also be used in the same way, at the same dose, and for the same condition.

There are currently several FDA-approved biosimilars of agents used in oncology, including filgrastim-sndz (Zarxio®, Sandoz), pegfilgrastim-jmdb (Fulphila™, Mylan and Biocon), filgrastim-aafi (Nivestym™, Pfizer), and pegfilgrastim-cbqv (Udenyca®, Coherus BioSciences, Inc.) for the treatment of chemotherapy-induced neutropenia; trastuzumab-dkst (Ogivri®, Mylan), for breast cancer; trastuzumab-pkrb (Herzuma®, Celltrion Inc.) for HER2-overexpressing breast cancer; trastuzumab-dttb (Onruzant®, Merck) for early breast cancer, metastatic breast cancer, and metastatic gastric cancer; trastuzumab-qyyp (Trazimera®, Pfizer) for HER2-overexpressing breast cancer and HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma; rituximab-abbs (Truxima™, Teva and Celltrion) for CD20-positive, B-cell non-Hodgkin lymphoma; and bevacizumab-awwb (Mvasi®, Amgen, Inc.) for certain colorectal, lung, brain, kidney, and cervical cancers.

At the Oncology Nursing Society (ONS) 44th Annual Congress in Anaheim, California, in April 2019, i3 Health conducted a survey of 24 oncology nurses to assess nurses' familiarity with these agents. Results showed that around one-third of oncology nursing professionals were very familiar with filgrastim-sndz, but the same amount had never heard of rituximab biosimilars or trastuzumab biosimilars. In addition, one-quarter of oncology nursing professionals had never heard of bevacizumab biosimilars.

When asked about the bevacizumab biosimilar, 8.3% of respondents indicated they were "very familiar" with it, and 8.3% indicated they had "an understanding of clinical trial data." About twenty percent of respondents "know basic information," 12.5% "know the name," and 29.2% had "never heard of" filgrastim-sndz. Only 16.7% and 12.5% were "very familiar" with rituximab biosimilars and trastuzumab biosimilars, respectively. Only 4.2% indicated they had "an understanding of clinical trial data" on (peg)filgrastim biosimilars, and no respondents indicated an understanding of clinical trial data for trastuzumab biosimilars.

"Highly engaged oncology nurses attend this conference and represent a variety of practice settings: from urban to rural, from inpatient to ambulatory. Nursing feedback from ONS Congress has provided a worldview of current practice," said Sandra Ruesch, MSN, RN, CEN, SPEN, SANE-A, Lead Nurse Planner at i3 Health. "These oncology nurses have identified a gap in knowledge, skills, and practice surrounding the topic of biosimiliars."

The majority of respondents (79.2%) indicated they would like to receive education on biosimilars to enhance their oncology nursing practice.