Information for Patients

When patents expire on medicines made with chemicals (such as aspirin, paracetamol or prednisone) it is straightforward for different pharmaceutical companies to make identical versions (generics) of the original brand. This is because these medicines are made by combining specific chemical ingredients in a defined and ordered process, making them relatively simple to duplicate: Chemical A + Chemical B = Drug C.

Because biological medicines are made in living cells and the manufacturing process is extensive it isn’t possible to make generics of these medicines. Think of it like making bread, cheese, wine or beer all of which are produced using fermentation, a natural process involving living cells. It is normal that even two batches of the same biologic from the same company that deliver the same therapeutic effect, are not identical and have inherent natural variability (called “microheterogeneity”).⁷

To manage this natural variability in a particular biological medicine, any variations have to stay within precise ranges to maintain clinical efficacy and safety. These ranges are set and tightly controlled by both the regulatory authorities and the pharmaceutical company, to ensure that all batches of any one biologic are similar.^1,2,3

When patents expire on branded biologics different pharmaceutical companies are allowed to make these medicines, which have become known as biosimilars. Biosimilars have essentially the same active ingredient as an existing, approved biologic.³ To gain approval for use by regulatory authorities, every batch has to stay within the same precise ranges for variation as the existing, branded biological medicine; the ball has to go between the same goal posts.^1,2,3

In fact, the term biosimilar can only be used to describe a biological medicine that has gone through a thorough process of laboratory analysis, pre-clinical testing and clinical study comparing the biosimilar to the original brand. This process is designed to demonstrate that the biosimilar is expected to deliver the same safety and beneficial effects in patients as an existing biological medicine.^1,8 A product is designated a “biosimilar” by the regulatory authority, so this term is a validation of its quality and comparability. And of course, once approved, biosimilars are as closely monitored as existing biological medicines to ensure their continuing safety and efficacy.³

Even though it takes many years to develop and gain approval for use of a biosimilar it is likely that there will be a difference in price between them and existing biologics. This means that once they are approved for use, depending on the approaches of different healthcare authorities, biosimilar medicines have the potential to:^1,4

• 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 use these innovative treatments for their citizens for the first time.
• Release resources so that healthcare systems can keep pace with growing healthcare needs, and funding new generations of innovative treatments brought about by advances in medical science.