InFLIXimab-dyyb is the nonproprietary name for both Inflectra® and Zymfentra®.
This column was prepared by the Institute for Safe Medication Practices (ISMP), an ECRI affiliate.
Food and Drug Administration (FDA) has approved two brand-name biologics with the same nonproprietary name and four-letter suffix, inFLIXimab-dyyb; however, they are not biosimilars or interchangeable with each other. Inflectra is a biosimilar of the reference product Remicade®. As such, it is available as a 100 mg lyophilized powder, single-dose vial for reconstitution and dilution. It is approved for adults and pediatric patients six years of age and older with Crohn’s disease or ulcerative colitis. It is also approved for the treatment of rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and plaque psoriasis in adults.
Zymfentra is not a biosimilar of or interchangeable with Remicade. It is available in 120 mg/mL, single-dose prefilled syringes and prefilled pens. It is approved for adults as maintenance treatment for moderately to severely active Crohn’s disease or ulcerative colitis following treatment with an intravenously administered inFLIXimab product.
ISMP has previously alerted practitioners that there are branded and unbranded versions of adalimumab (eg, Hyrimoz® [adalimumab-adaz] and adalimumab-adaz) that share the same nonproprietary name and four-letter suffix. However, this is the first time ISMP has seen two brand-name products share the same nonproprietary name and four-letter suffix (ie, inFLIXimab-dyyb).
Specialty pharmacies may stock both drugs: Zymfentra, which is the subcutaneous injection that can be self-administered by the patient, and Inflectra, which is a lyophilized powder that requires preparation and intravenous administration by a provider but may be required to be “bagged” under the pharmacy benefit and dispensed to the patient or provider. If the lyophilized powder (Inflectra) is sent to the patient instead of the subcutaneous formulation (Zymfentra), there is a risk of misuse by the patient. Conversely, if a clinic received Zymfentra instead of Inflectra, they could potentially administer the subcutaneous injection to the patient via the incorrect route (intravenously) or administer it via the correct route, but it would be the incorrect formulation.
Safe Practice Recommendations
ISMP has notified FDA and Celltrion, Inc, the manufacturer of both products, about the potential for mix-up. However, per FDA-approved review documents, Zymfentra can have the same nonproprietary name and suffix as Inflectra because both are the same drug, only with a different strength, dosage form, and route of administration. To reduce the risk of errors, confirm with computer and drug information vendors that these are listed as separate products in electronic systems. Consider using the brand name when prescribing these medications. In electronic prescribing systems, ensure order sentences are associated with the correct product. In the pharmacy, verify that the dosage form and route of administration are appropriate for the prescribed and dispensed product. Educate staff about the product differences, noting that they are not interchangeable with each other, and about the potential to mix them up. At the point of sale, open the bag and have the patient check to make sure they are receiving the correct medication. If the medication is shipped to the patient, instruct them to carefully inspect the medication upon receipt, comparing the medication name and quantity to what is listed on the pharmacy label. Encourage patients to contact the pharmacy if they have any questions or concerns.