Biologic medicines are complex drugs made using a biological source such as a cell and are many times larger than conventional small molecule drugs such as aspirin, for example. They can very accurately target specific molecules in the body that are critical in how diseases cause damage and have been a major advancement in the care of many conditions.
Infliximab (Remicade®) was the first biologic medicine in IBD, and has been used in Australia since 2001. It was also the first biologic to become available on the PBS for Crohn’s disease in 2007. Since then, adalimumab (Humira®) was listed in 2008 for Crohn’s disease, infliximab was also listed for ulcerative colitis and vedolizumab (Entyvio®) was listed for both Crohn’s disease and ulcerative colitis in November 2015. These medicines have made a significant difference in the treatment of inflammatory bowel disease in Australia.
The patents for the original biologic drugs are starting to expire, opening up the way for copies, known as biosimilars, to enter the market. Due to the large size and complexity of biologic agents, biosimlars are not identical copies like generic drugs that can be made for small molecules, but have highly similar effects both in the laboratory and in human trials on diseases.
Overall, biosimilars have been welcomed due to the high costs of biologic medicines. Biosimilars can result in cost savings for the Government due to price competition, but will be the same price to the patient.
Inflectra®, a biosimilar for infliximab, is now available on the PBS. Other biosimilars are expected to come onto the market in the coming years.
Currently, there is limited information on the effects of switching from one biologic drug to a biosimilar, and no trial data on the effects of switching back and forth multiple times between them.
Substitution at pharmacy level
The Australian government has decided that these drugs can be substituted at the point of dispensing in a pharmacy despite the opposition of the peak doctors and patient groups who use these drugs. This means that your pharmacist may be able to offer you the biosimilar brand instead of your usual brand of medicine, just as this can be done with other generic medicines. This would not require going back to your prescribing doctor.
Substitution at pharmacy level is a measure taken to encourage more people to use biosimilars. There are, however, still reasons to be wary about the implications for consumers.
What should we know about pharmacy level substitution of biologics?
CCA Board Director and Chair of the Australian IBD Association Dr Gregory Moore says Australia is the only jurisdiction in the world where repeated substitutions can be carried out in this way, despite a lack of long term safety and efficacy data for this strategy,
This is despite the Therapeutic Goods Association’s ruling that “it is not currently possible to determine a degree of similarity, between a biosimilar and an already registered biological medicine sufficient to support a designation by the TGA of ‘bioequivalence’.”
There are concerns the unknown safety and possible development of a patient’s own antibodies against the biologic drugs that can lead to loss of their effectiveness or infusion reactions, which could be a result of switching medication multiple times.
This needs to be discussed with your medical team.
Overall, Dr Moore recommends a patient who has started their treatment on one version of infliximab (either Remicade® or Inflectra®) to remain on that drug until we have more information on the long-term effects of switching.
At present, the best way to ensure consistent treatment for IBD patients is to list the drug by its generic name and its trade name, such as “infliximab Remicade” or “infliximab Inflectra” and to have the prescribing doctor tick the “Brand Substitution Not Permitted” box on prescriptions, Dr Moore says.
In cases where a patient is new to therapy, a full discussion with their treatment team is recommended on whether to use biosimilars that are available.
At present, only Remicade® (infliximab) is affected by these changes, but Humira® (adalimumab) will also be off patent in the near future..
How to make sure your medicine is the right one for you
Prescribers and patients both have the right to choose the brand of medicine they will receive at pharmacy level, but it is a choice that should be an informed one.
- Talk to your treatment team about your medication, and whether a biosimilar is available as an alternative to your current biologic treatment
- Decide in consultation with your gastroenterologist whether you should stay on your current biologic, or consider substituting it for a biosimilar
- If you will stay on your current biologic, ensure your doctor ticks the “Brand Substitution Not Permitted” box on your script. This will ensure no substitutions happen at pharmacy level
- Keep records of your medication, and immediately advise your treatment team if there is any change to the brand you receive from the pharmacy. This can simply be done by keeping the packaging, or taking photographs.
- Make sure you keep up to date on any changes to biologics or biosimilars available for the treatment of IBD by visiting crohnsandcolitis.com.au or following us on Facebook.