Biological medicines (or “biologics”) are not like medicines such as aspirin or paracetamol, which are made with chemicals. A biological medicine (commonly referred to as a “biologic” or “biopharmaceutical”) is a pharmaceutical drug whose active substance is made by or extracted from living organisms, tissues, or cells⁵. Scientists choose appropriate cells (animal or human cells are often used) and then modify them so that with skilful manufacturing they can be made to reproduce indefinitely. These cells become “factories” that endlessly produce a particular substance, usually a protein, which targets a specific illness⁸.

Biologic medicines have revolutionized the management of some of the most hard-to-treat diseases such as cancer, anemia, and autoimmune conditions such as multiple sclerosis, rheumatoid arthritis, psoriasis, and inflammatory bowel disease⁷.

One of the reasons biological medicines are so effective is that they are tailor-made to interact with specific targets in the body. This increases the potential that they will have the desired effect against the disease they are designed to treat.

A biosimilar is a successor to a biological medicine (known as the “reference medicine”) for which the patent has expired and exclusivity has been lost. Biosimilars have been shown to have equivalent efficacy and comparable safety and immunogenicity. Therefore, physicians and patients can expect the same clinical outcome^1,10,8,16-19.

Biosimilars have been shown to have matching efficacy and comparable safety and immunogenicity. Therefore, physicians and patients can expect the same clinical outcome^1,10,8,16-19.

All biological medicines are produced by living organisms, and all, be it the biologic reference medicine or the biosimilar, have a certain degree of inherent, natural variability (“microheterogeneity”). Therefore, not even two batches of the same biologic from the same manufacturing process at the same site are 100% identical; there is even variability within a single batch. ^1,8,14,15.  Each batch contains a distribution of biological molecules, either synthesized by the host organism or arising during downstream processing. This inherent variability can be detected and monitored using sensitive analytical tools and is tightly controlled during the manufacturing process, with limits and specifications agreed upon with the regulatory authorities to ensure the consistent safety and efficacy of the biologics being produced^1,10,20-22.

When considering product and manufacturing process quality, health authorities apply the same high standards to all biological medicines, irrespective of whether they are reference biologics or biosimilars¹. Approval of a biosimilar by the EMA (EU) or the US FDA is granted on the “totality of evidence”. This includes the extensive characterization of the reference molecule, to provide a full understanding of its structure–function relationship, and a stepwise comparability exercise with the proposed biosimilar. The comparability exercise involves a large battery of state-of-the-art physico-chemical, structural, and in vitro functional testing (also known as biological function tests), as well as preclinical and clinical studies^{1,16, 23-26}. 

Patents on some brands of biological medicines have run out or are reaching the end of their term, which is why different pharmaceutical companies are making biosimilars of these medicines.

In fact, biosimilars have been around for longer than 15 years. The first biosimilar was approved in Australia in 2004^9* and now biosimilars are in use in highly regulated countries such as those in Europe, as well as Canada, Japan and Australia, and the US^11,12,13. Many more biosimilars are in development globally and so they are likely to play a growing role in patient care⁴.
 

• Cause healthcare providers to reassess existing guidance about use of a particular biologic based on considerations around cost-effectiveness. 
• Make treatment more affordable for patients in certain countries who co-pay for their medicines.
• Allow health systems to redirect funds so that more patients can be treated.
• Allow some healthcare systems to introduce these innovative treatments to their citizens for the first time.
• Release resources to help healthcare systems keep pace with growing healthcare needs and fund new generations of innovative treatments so that access to treatments, patient care and patients’ lives can all be improved with a sustainable approach.
   

As with all decisions about managing their condition, patients should talk with their doctor (and healthcare team) about all available treatment options, including their safety, benefits and risks before coming to a decision about the treatment that suits them the best.