When a new drug is developed and marketed for a medical condition, it can be patented. In other words, it is protected from being developed or sold by other companies. Patents protect drugs for up to 20 years once the drug patent is filed with the government (Canadian Intellectual Property Office). Once a drug patent expires, other companies can develop and market generic or biosimilar versions of these drugs, which are typically available at a lower cost.
What is a generic drug?
Health Canada defines a generic drug as, a copy of a brand name drug. A generic drug is pharmaceutically equivalent to the brand name drug. This means it has the identical medicinal ingredients, present in the same amounts and in a similar dosage form. There may be many generic versions of the same brand name drug. Generic drugs are small molecules and are easier to manufacture.
Because a generic drug is made to act in the same way as the brand name drug, companies must prove that their generic drug is 'bioequivalent' to the brand name drug. When two drug products are bioequivalent, it means there is no significant difference in how quickly their medicinal ingredient is absorbed and achieves a certain level in the blood (bioavailability). Bioequivalent products should act the same way in the body and have the same safety and efficacy.
What is a biologic drug?
Biologic drugs come from living organisms, or from their cells and are often made using biotechnology. Biotechnology refers to the use of living organisms or their components to produce products, for example, novel medications used to treat diseases and medical conditions including multiple sclerosis. Biologic drugs are generally large molecule and more complex to manufacture than small molecule medications. Due to their complexity, they are usually more expensive to manufacture and therefore have a higher cost.
What is a biosimilar?
A biosimilar biologic drug, or biosimilar, is a drug that has demonstrated to be highly similar to a reference biologic drug (a drug that has already been approved for sale) in terms of safety and efficacy. Biosimilars are approved based on a thorough comparison to a reference drug.
Are biosimilars different from generic drugs?
Biosimilars are not the same as generic drugs. Generic drugs are small molecules that are produced chemically and contain identical medicinal ingredients to the brand name reference drugs. A biosimilar is modeled after its reference biologic drug, but they are not identical. Biologic drugs are more difficult to replicate due to their large molecular size, high complexity, and the natural variability of living cells or their components.
What is a non-biologic complex drug?
Non-biological complex drugs (NBCDs) is a large molecule drug and consists of different structures that cannot be fully characterized through laboratory analysis. Because NBCDs are so complex, even very small differences in the manufacturing process can significantly change the final pharmaceutical product.
Subsequent entry non-biologic complex drug (SENBCD): A subsequent-entry non-biologic complex drug is a copy of reference drug and is approved based on clinical trial evidence supporting its equivalence (establish that it contains identical medicinal ingredients) to the Canadian Reference Product.
What is an interchangeable drug?
An interchangeable drug refers to the ability of a pharmacist to change a patient’s prescription from one drug to an equivalent drug without consulting the prescribing clinician. The authority to declare two products interchangeable rests with each province and territory according to its own rules and regulations. Currently there is only one interchangeable disease modifying therapies in Canada: fingolimod.
What are the different MS drugs (disease modifying therapies, DMTs) in Canada?
Currently MS drugs in Canada fall under the following categories.
Small molecule: fingolimod (Gilenya®), siponimod (Mayzent®), ozanimod (Zeposia®), teriflunomide (Aubagio®), dimethyl fumarate (Tecfidera®), cladribine (Mavenclad®)
Generic: fingolimod (there are ten Health Canada approved generic 0.5mg fingolimod products)
Large molecule (biologic): interferon preparations (Avonex®, Rebif®, Plegridy®, Betaseron®, Extavia®), natalizumab (Tysabri®), alemtuzumab (Lemtrada®), ocrelizumab (Ocrevus®), ofatumumab (Kesimpta®), rituximab[i] (Rituxan®)
Biosimilar: rituximab (Truxima®, Riabni®, Riximyo®, Ruxience®)
Non-Biologic Complex Drug (reference drug): glatiramer acetate (Copaxone® 20mg, Copaxone® 40mg)
Subsequent Entry Non-Biologic Complex Drug: glatiramer acetate (Glatect®)
Some information on this webpage was adapted from Health Canada’s Biosimilar biologic drugs in Canada: Fact Sheet
Rituximab is prescribed off-label for treatment of multiple sclerosis in Canada.