Biologics 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.
Biosimilars, or subsequent entry biologics, describe a group of biologic medications that are administered by subcutaneous injection or intravenous infusion and are similar, but not the same, as their originator biologics (also referred to as “brand name” biologics).
Health Canada defines a biosimilar as a “biologic product that would enter the market subsequent to, and similar to, an approved innovator biologic, which would rely in part, on prior information regarding safety and efficacy that is deemed relevant due to the demonstration of similarity to a reference biologic product (originator biologic).”
According to Health Canada, “authorization of a biosimilar is not a declaration of pharmaceutical equivalence, bioequivalence or therapeutic equivalence to the originator biologic.” Biosimilars are highly similar to the originator biologic they were compared to, but have allowable differences because they are made from living organisms. Biosimilars also have no clinically meaningful differences in terms of safety, purity, and strength from the originator biologic. Health Canada also states: “the demonstration of similarity does not signify that the quality attributes of the two products being compared are identical, but that they are highly similar with two consequences:
1) that the existing knowledge of both products is sufficient to predict that any differences in quality attributes should have no adverse impact upon safety or efficacy of the biosimilars; and
2) that non-clinical and clinical data previously generated with the reference biologic drug are relevant to the biosimilar.”
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 studied with the originator product. This 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.
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.
Interchangeability is a process that allows a pharmacist to automatically substitute one product for another when it has been deemed interchangeable by a Provincial or Territorial regulatory body. For instance, this is a common practice for drugs that are off patent and have been deemed interchangeable with their generic equivalent.
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.
New starts are patients who have been newly prescribed a biologic medicine. Infliximab (Inflectra) has been approved for patients newly prescribed infliximab (“new starts”) on public drug plans across Canada.
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.
Arthritis medication naming system
In light of the recent arrival of new classes of medicines for certain types of inflammatory arthritis, such as biosimilars and Janus kinase (JAK) inhibitors, a new naming system for disease-modifying anti-rheumatic drugs (DMARDs) is being adopted in Europe and North America.
Essentially, there are two categories of medications: a group that treats disease symptoms and a group that treats the underlying disease process.
1. Medications to treat symptoms
- non-steroid anti-inflammatories (NSAIDs)
- pain relievers, like acetaminophen (Tylenol®)
- opioids (narcotics)
Glucocorticoids (GC such as steroids like prednisone): steroids are often used as a “bridging therapy” or to treat life-threatening or organ-threatening complications of rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, systemic lupus erythematosus, and vasculitis.
Non-steroidal anti-inflammatory drugs (NSAIDs such as aspirin, naproxen and celecoxib): these medications help to reduce the inflammation and pain caused by rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis and osteoarthritis. Some NSAIDs are available over the counter like ibuprofen (e.g. Motrin or Advil) or naproxen (Aleve) while others require a prescription.
2. Medications to treat the underlying disease
The term “disease-modifying anti-rheumatic drugs” (DMARDs) is used to categorize certain medicines that suppress the disease process that causes the worsening of rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis, among many other types of inflammatory arthritis. They alter the natural course of the disease. DMARDs suppress the inflammation, slow joint damage, decrease autoantibody levels and have positive effects on long-term functional outcome.
DMARDs now come in all “shapes and sizes” and can be taken by pill, self-injection and infusion (IV). Each DMARD works in a unique way and the decision about which one(s) is best for you is perhaps the most important conversation you can have with your rheumatologist.
In the new naming system for disease-modifying anti-rheumatic drugs (DMARDs), there are classifications for:
Synthetic (or chemical) DMARDs are now divided into:
csDMARDs: Conventional synthetic DMARDs include traditional medications such as methotrexate, sulfasalazine, leflunomide, hydroxychloroquine, gold salts and others.
tsDMARDs: Targeted synthetic DMARDs include only those medications that were specifically developed to target a particular molecular structure such as tofacitinib, baricitinib or apremilast, or agents not focused primarily on rheumatic diseases, such as imatinib or ibrutinib.
Biological DMARDs are now divided into:
boDMARDs: Biological original DMARDs include abatacept, adalimumab, anakinra, certolizumab peogl, etanercept, golimumab, infliximab-Remicade, rituximab or tocilizumab
bsDMARDs: SEB or Biosimilar DMARDs include infliximab-Inflectra