Biologics are therapies aimed to prevent, treat, and cure diseases. They are typically large complex molecules often derived from a living system. Biologics are managed differently than small molecules products by the FDA. The list of all currently approved biologics is available in the FDA’s Purple Book. With biologics, the initial product introduced into the market is labeled as the reference product. The reference product is approved based on a full complement of safety and effectiveness data.
From there, additional products can be developed and become approved as biosimilars. A biosimilar is a biological product that is highly similar to and has no clinically meaningful differences from the FDA-approved reference product. A biosimilar is compared directly to the reference product in terms of its structural make-up and its function.
A biosimilar can be dispensed when that particular biosimilar product name is written for by the prescriber. In addition to being a biosimilar, a product can also become an interchangeable biosimilar. An interchangeable biosimilar must meet additional requirements based on further evaluation and testing of the product. The FDA provides the following information on interchangeable products: “As part of fulfilling these additional requirements, information is needed to show that an interchangeable product is expected to produce the same clinical result as the reference product in any given patient. Also, for products administered to a patient more than once, the risk in terms of safety and reduced efficacy of switching back and forth between an interchangeable product and a reference product will have been evaluated.” Once a product is approved as interchangeable, it can be used in place of a reference product. The ability and procedure for pharmacies to substitute for a biologic are determined by state regulations.
Currently, there are two FDA-approved interchangeable biosimilar products. Semglee (insulin glargine-yfgn) was the first approved interchangeable biosimilar and is interchangeable for Lantus (insulin glargine). The original NDC of Semglee (insulin glargine) was approved as a biosimilar to Lantus in June 2020 under 351(a), the traditional pathway for an innovator biologic. The new Semglee (insulin glargine-yfgn) was approved in July 2021 under 351(k), the biosimilar pathway, which caused the assignment of a 4-character suffix (YFGN) to the chemical name, and which makes it a unique chemical name. This situation has presented challenges for the drug pricing compendia and with product selection at the pharmacy, because not all Semglee product NDCs have the interchangeable status. The second interchangeable biosimilar product is Cyltezo (adalimumab-adbm), the interchangeable for Humira (adalimumab), which is not currently on the market but is scheduled to launch in July 2023.
Wolters Kluwer’s Medi-Span drug compendium uses the generic product identifier (GPI) to link pharmaceutically equivalent products (i.e., products with the same active ingredient, strength, dosage form, and route of administration). A GPI will link a brand and all its available generics. However, the GPI will not work to link a biologic and its corresponding biosimilars, as each biosimilar has a unique 4-character suffix, and thus a unique chemical name/active ingredient. Therefore, the biosimilar will not link to its reference product and will instead have its own GPI. PHSL understands that interchangeability codes are included in a separate substitution file but are not accessible to subscribers of all Medi-Span platforms. Pharmacy systems relying on Medi-Span that do not have access to the substitution file for interchangeability will require additional data within the system or additional configuration efforts by the dispensing pharmacy staff to determine product interchangeability.
Drug pricing compendium First Databank (FDB) contains a similar linkage of brands and generics through their use of the Generic Code Number (GCN) and GCN Sequence Number. While Lantus and interchangeable biosimilar Semglee do not share the same GSN, FDB has introduced fields in which these products can be identified and used by stakeholders: Biologic Name Grouper and Biologic Association Type. Biologic Name Grouper represents a family name that groups reference biologics and their corresponding biosimilar and interchangeable NDCs. Biologic Association Type identifies a product as a reference, biosimilar, or interchangeable. As we referenced above, Semglee currently has NDCs that are considered biosimilars and additional NDCs that meet the criteria for interchangeable biosimilars. Within FDB, these fields may reduce the issues with Semglee NDCs by providing additional details on the interchangeable status to the reference product Lantus.
Data fields linking biologics, biosimilars, and interchangeable biosimilars are vital for stakeholders to identify and allow for proper substitution of interchangeable products. This can provide significant cost savings to health plans and patients. Providers may also be able to use this data to identify available interchangeable biosimilars for a particular product. On November 22, 2021, an article published in Drug Topics highlighted a policy change adopted by Mayo Clinic in which their prescribers were advised to utilize the lowest cost biosimilar. This policy change was reported to have saved Mayo Clinic approximately $23 million over the first twelve months, which demonstrates the potential for cost savings that can be realized in the biologic market. It will be up to stakeholders to utilize this additional information to create policy, automation, or other innovation to benefit from interchangeable biosimilars. What actions need to be taken by your organization to direct the use of biosimilars or interchangeable biosimilars?
Posted February 2, 2022