An additional treatment choice for patients with inflammatory arthritis
Biosimilars describe a group of biologic medications that are administered by subcutaneous injection or intravenous infusion and are proven similar, but not identical, as their originator biologics (also referred to as “brand name” biologics).
Health Canada defines biosimilars as a “biologic drug that enters the market subsequent to a version previously authorized in Canada, and with demonstrated similarity to a reference biologic drug.”
While relatively new to Canada, biosimilars have been approved for use in Europe for a decade and for use in arthritis since 2013.
Biosimilars are not generics of their originator biologics
Biosimilars are similar, but not the same, as their originator biologics
Medications made with small, chemically manufactured molecules (e.g. acetylsalicylic acid, the active ingredient in aspirin) are made through a relatively simple process. After a manufacturer's patent for a particular medication, like aspirin, expires, other companies can easily make exact copies of the active ingredient of the brand name version. These are known as generics.
Biologics, however, are large molecule medicines made from living cells in a complex manufacturing process that can have a significant impact on the final drug product. It is impossible to make an exact copy of an originator biologic drug because the living cell structures cannot be the same.
Patient and healthcare professional groups have called for uniquely different brand naming for all biosimilars entering the Canadian marketplace to minimize confusion about which medication was being prescribed and filled at the pharmacy counter or infusion clinic, or taken by the patient. Unique naming is also very important when tracking adverse events at the population level.
Health Canada follows the non-proprietary naming protocol for biologics (including biosimilars) recommended by the World Health Organization (WHO). At the request of a number of regulatory jurisdictions, the WHO is working to address the issue of non-proprietary naming for biosimilars.
In late 2015, the WHO and the United States of America's Food and Drug Association (FDA) both released similar proposed guidance on naming - to add a unique identification code, consisting of four random consonants, to the existing non-proprietary name (e.g. infliximab wxyz). The WHO guidance also recommends that regulatory agencies like Health Canada, can add in two numerical digits as a “check-sum”. Health Canada is currently reviewing the WHO proposed guidance.
World-wide patient experience with effectively regulated biosimilars continues to grow and research-to-date shows their safety and efficacy profiles compared to their originator biologic (also referred as “brand name” biologic) to be very similar. Biosimilars have more pre-clinical data to inform physicians and patients making choices about medication therapy; however, biosimilars have less clinical trial data. Pre-clinical data for biosimilars is as, or more, robust than that for originators’, in order for biosimilar manufacturers to demonstrate to regulators that they are highly similar in structure and function to the originator biologic.
ACE wants to know what do you think about biologics?
What are your views about biologics?
Some of today’s important medications are biologic medications often referred to as “biologics.” They are made from living organisms. The material they are made from can come from many sources, including humans, animals and microorganisms such as bacteria or yeast. Biologic medications are manufactured through biotechnology, derived from natural sources or, in some cases, produced synthetically.
Biologics are among the medications used to treat diseases such as rheumatoid arthritis, anemia, low white blood cell counts, inflammatory bowel disease, skin conditions such as psoriasis and various forms of cancer.
Biologics are more complex in structure and have larger molecules or mixtures of molecules than conventional (small molecule) medications. Conventional medications are made of pure chemical substances and their structures can be identified. Most biologics, however, are complex mixtures that are more difficult to identify or characterize.
"Biosimilar" is the term used by Health Canada to describe "medications demonstrated to be highly similar to a biologic medication that was already approved for use (known as the "reference biologic" or "originator biologic") in specific disease indications. Biosimilars are approved based on rigorous scientific comparison to an originator biologic and may enter the market after the expiry of the originator biologic's patent and data protection period."
Biosimilars are made from the same basic building blocks as the originator. Biosimilars are not identical to their originator biologic because their chemical characteristics cannot be precisely duplicated during the manufacturing process because they are made from living cells. While there are concerns that biosimilars may have unique efficacy, immunogenicity, and safety profiles that are distinct from their originator biologics, the approval of biosimilars in Canada relies on the demonstration that these measures are equal between them. This is demonstrated through clinical (equivalence) trials in at least one originator biologic disease indication, such as rheumatoid arthritis.
While relatively new to Canada, biosimilars have been reviewed and approved for use in Europe for a decade and for use in arthritis since 2013.
What is an originator biologic (also referred to as “reference biologic” or “brand name” biologic) medication?
An “originator biologic” is a biologic drug authorized on the basis of a complete quality, non-clinical, and clinical data package, to which a biosimilar is compared in studies to demonstrate similarity.
A biosimilar needs to have the same mechanism of action as the originator biologic it was compared to, which means it should work in a similar way.
Health Canada will only approve a biosimilar if it has the same mechanism of action, route of administration, dosage form, and strength as the originator biologic. Additionally, a biosimilar can only be approved for the indications and conditions of use that have been previously approved for the originator biologic.
Once a biosimilar has been approved by Health Canada, patients and health care providers will be able to rely upon the safety and effectiveness of a Health Canada approved biosimilar just as they would for the originator biologic that it was compared to.
A generic medication is chemically identical to a brand name drug in dosage, safety, strength, route of administration, quality, performance and intended use.
No, biosimilars are not "generic biologics" and many characteristics associated with the authorization process and marketed use for generic pharmaceutical medications do not apply. Generic medications are copies of brand-name medications, have the same active ingredient, and are the same as those brand name medications in dosage form, safety, strength, route of administration, quality, performance characteristics and intended use. That means the brand name and the generic are "bioequivalent".
According to Health Canada: "Due to the size, complexity and natural variability of biologic drugs, and because biologic drugs are made from living cells rather than with chemicals, a biosimilar and its originator biologic can be shown to be similar, but not identical."
Unlike generic medications, biosimilars are not identical to their originator biologics. Every biologic is made from living cells. To ensure that any minor structural differences of a biosimilar will not result in differences in the body, multiple tests called “assays” are conducted in the lab.
When those tests prove the biosimilar’s similarity to its originator biologic, it is then studied “head-to-head” against its originator biologic in clinical trials. Only then can it be confirmed as highly similar.
After the originator biologic patent expires, a biosimilar can enter the marketplace if it meets all Health Canada safety and efficacy requirements. Makers of biosimilars use the same building blocks (or “amino acid” sequence) as the originator biologic, but will use a different manufacturing process to form the final medication. In ACE surveys conducted across Canada, physicians and patients considered patient safety a primary concern in the use of biosimilars, or any marketed medication. They felt strongly that biosimilars be effectively tracked in the marketplace and that information should be made available for external review, as it is for their originator biologics.
Immunogenicity is the ability to stimulate an immune response in the body of a human or animal. This ability generally protects people against pathogens by recognizing and reacting to foreign proteins. It is a specific concern for biologic medications because they are primarily protein medicines that may be seen as being foreign. An immune response to a biologic medication can range from development of detectable but not clinically significant antibodies to an immune response with significant impact on patient safety. A patient's immune response may also affect a treatment's effectiveness.
There are a number of ongoing studies, including “real world” tracking of patients, to monitor for any increase in immunogenicity when transitioning from an originator biologic to a biosimilar. This will help determine if transitioning patients can be considered a safe practice before it can be medically recommended or mandated through reimbursement policy.
Health Canada is addressing immunogenicity as part of the comparative clinical trials required for approval of biosimilars. In addition, biosimilar manufacturers are responsible to monitor the immunogenicity potential of the biosimilar after it is on the Canadian market.
Originator biologics and biosimilars have their own regulatory review pathways. For biosimilars, Health Canada reviews the manufacturing process, data on the comparability of the biosimilar to the originator biologic and non-clinical and clinical data supplied by the biosimilar manufacturer, to establish whether it is similar enough to its originator biologic.
Health Canada may approve a biosimilar to treat a disease without any clinical trial data to support its use in that disease. Once “biosimilarity” to the originator has been demonstrated, it is no longer a requirement to re-study the biosimilar in all indications previously conducted with the originator product. This is called "indication extrapolation." Health Canada approval of a biosimilar is not a declaration of bioequivalence with the originator biologic. Post-approval, biosimilars are regulated like any new biologic medicine.
Interchangeability is a policy process that allows a pharmacist to automatically substitute one medication for another when it has been deemed interchangeable by a Provincial or Territorial regulatory body. This is a common practice for medications that are off patent and have been deemed interchangeable with their generic equivalent. This is not the case for originator biologics and biosimilars.
Currently, Health Canada declares biosimilars not to be interchangeable with their originator biologic. However, provincial governments in Canada govern rules around the determination of interchangeability between an originator biologic and a biosimilar. They also regulate pharmacy substitution practices. Health Canada states: “Health Canada's authorization of a biosimilar is not a declaration of equivalence to the reference biologic drug. There are varying definitions of interchangeability. In Canada, the term often refers to the ability for a patient to be changed from one drug to another equivalent drug by a pharmacist, without the intervention of the doctor who wrote the prescription. In Canada, the authority to declare two products interchangeable rests with each province and territory according to its own rules and regulations." Health Canada has expressed caution to the Provinces on the issue of interchangeability and states that physicians make only well-informed decisions on alternating or interchanging therapies.
Therapeutic substitution, also referred to as “drug switching” or “therapeutic interchange”, is the practice of replacing the prescribed medication with a chemically different medication in the same class that is expected to have the same clinical effect. Therapeutic substitution usually occurs when the prescribed medication is substituted at the pharmacy counter with another due to cost differences, without consulting the patient's prescribing physician.
The authority to declare two products automatically substitutable by a pharmacist rests with provincial governments. At this time, no provincial government in Canada has declared interchangeability between an originator biologic and a biosimilar and, therefore, there have been no cases of substititution in pharmacy practices across Canada.
According to Health Canada: "Switching generally refers to a one-time change from a reference biologic drug to a biosimilar. Health Canada recommends that a decision to switch a patient being treated with a reference biologic (innovator product) to a biosimilar should be made by the treating physician in consultation with the patient and taking into account available clinical evidence and any policies of the relevant jurisdiction. For questions related to changing from one biologic drug to another, patients should speak to their doctor."
ACE uses the term "transitioning" rather than "switching" and provides the following definition in the case of biosimilars:
Policy transitions (referred to as non-medical switching) necessitate patients to change their medicine of choice to another, typically less expensive, medicine, not for a medical reason.
In the case of a patient not doing well on their current originator biologic or biosimilar of choice, a transition to another originator biologic or biosimilar, or other non-biologic medicine, with a different molecular action is then considered by the patient and their rheumatologist. Transitioning when medically required is important to achieving the best disease control and outcomes.
Can a biosimilar be used to effectively treat the same diseases/conditions that its originator biologic drug treats?
A biosimilar may be granted any indication(s) held in Canada by its originator biologic, but only if all the required data is provided to Health Canada to support the claim. A biosimilar can also be granted indications different from those of the originator biologic if a full clinical data package is submitted for those indications.
Once "biosimilarity" to the originator biologic has been demonstrated and approved by Health Canada, it is not required to re-study its biosimilar in all indications previously studied with the originator product. This aspect of the biosimilar regulatory pathway is called "indication extrapolation." Approval of a biosimilar is not a declaration of bioequivalence with the originator biologic. Post-approval, biosimilars are regulated like any new biologic medicine.
Questions? We’ll find the answers for you.
As biosimilars research is published and policies regulating them evolve, ACE will continue to provide information updates applicable to the arthritis community and other chronic diseases, such as diabetes, oncology and gastrointestinal diseases. As part of that commitment, we encourage you to send us questions. We will provide answers to you and add that content to our website. That’s what the Biosim•Exchange is all about.