1. General Features
Biologic medicines, which are also known as biotechnology medicines, biopharmaceutical medicines or biotherapeutic medicinal products, are relatively new, with the first being approved for human use in 1982 (recombinant human insulin).
Today, biologic medicines are used for the diagnosis, treatment and prevention of numerous diseases, including cancer, diabetes mellitus, heart attack, stroke, rheumatoid arthritis and multiple sclerosis. They are usually prescribed by a specialist rather than a primary care physician or family doctor – and are commonly administered in a hospital setting. They are rarely available without a doctor’s prescription.
Biologic proteins are much larger and more complex molecules than traditional chemical medicines; this means they cannot be manufactured as a tablet, so they need to be administered via an injection.
Biologic medicines may come as a powder that needs to be dissolved in a solution before the injection is given or they may already be dissolved in an injectable solution, and may even come in a pre-filled syringe. Most biologic medicines need to be kept cold until they are given to the patient (during both transport and storage).
Some biologic medicines should be given at the same dose to all patients, whereas for others the dose varies according to the patient’s bodyweight. Injections can be administered by a doctor, but in some cases patients or family members may be trained to give the injection. The frequency of dosing depends on the disease and the particular type of biologic medicine administered; it can range from multiple injections per day to just a few injections per year. Similarly, the duration of treatment will also vary and may range from a single course of treatment (possibly comprising administration of multiple doses) to continued treatment for the remainder of a patient’s life.
Biologics are designed to have very specific effects and to interact with specific targets in the patient’s body, mainly on the outside of cells. A more targeted mechanism of action should lead to a greater chance of the medicine having the desired effect against the disease and should result in fewer side effects than traditional medicines. One common side effect of biologics, however, is the risk of immune reactions (immunogenicity), whereby the patient’s immune system recognises the biologic as a ‘foreign’ protein and tries to destroy it. This type of immune reaction may stop the biologic from working entirely or may just cause an irritation at the injection site.