Biologic medicines are used to treat millions of patients with serious illnesses like cancer, arthritis, and psoriasis. The patents for many biologic therapies are expiring over the coming years, and biosimilars will be entering the marketplace. Regulatory authorities around the world have put policies in place to ensure that biosimilars have been appropriately tested, and are safe and effective for patients.
What is a biologic medicine?
Most people are familiar with small molecule medicines, like aspirin or oral antibiotics. These are produced via a series of chemical reactions, and their exact structure is simple and easily identified.
In contrast, biologic medicines are very large, and very complex. Biologic medicines are made in living cells, grown in a laboratory. By way of comparison, if you think of a small molecule as a small house, a biologic medicine could be compared to the Empire State Building, in relative size and complexity.
What is a biosimilar medicine?
When the patents for medicines expire, other companies are free to make copies of them. For small molecule medicines, these copies are known as generics. Because it is easy to determine their exact structure and how they are made, IDENTICAL copies can be made by following a series of chemical reactions.
For biologics, it’s not as easy. To begin with, because of their size and complexity, it is not possible to exactly determine the structure. Second, the living cells and manufacturing processes used to make the biologic are unique and proprietary to each manufacturer; a different company will not make the biologic in exactly the same way. Copies of biologics and SIMILAR but not identical to the original biologic, hence the name: biosimilars. Clinical testing is important to identify if any of the small differences between the two have an effect in the body.
What do I need to know about biosimilars?
Because biologics are large complex molecules that have the potential to cause immune reactions in the body, there are a number of factors that are important in ensuring patient safety.
For a biosimilar to be approved as an interchangeable biosimilar, it must produce the same effects in a patient when substituted for the originator product without any additional risks. If a biosimilar receives an interchangeability designation, it can be substituted at the pharmacy without the intervention of the prescribing physician. The specific data requirements to receive regulatory approval for interchangeability are still being determined.
This is the substitution of the originator biologic with the biosimilar by the pharmacist. This is only appropriate for interchangeable biologics, or those that determined to produce the same effects when substituted for the originator product, without any additional risks. It is important that physician who prescribed the biologic is notified of the switch. This allows for the appropriate monitoring of a patient’s response to treatment, as well as close tracking of adverse events.
All biologics, including biosimilars, should have unique, distinguishable names to ensure robust safety surveillance and adverse event reporting. One approach for this is the use of a meaningful, user friendly, suffix related to the company manufacturing the biologic, added to the end of a shared root name.
The product label should contain all the information to enable a physician to make an informed treatment choice, including:
- That the product is a biosimilar
- Name of the biosimilar’s reference product
- Analytical and clinical data used to demonstrate biosimilarity
- Indications for which the biosimilar is approved, including whether or not these were studied
- Indications for which the originator is approved, but the biosimilar is not
- Whether the biosimilar is interchangeable with the originator product. (This means the FDA has decided the biosimilar can be safely switched back and forth with the originator product)
- Post marketing surveillance data