A biosimilar is a replication of a biologic already on market (which is called 'the reference drug'). It cannot be a generic drug because biologics and biosimilars are made from living cells and grown in laboratories. Generic medicines, like an aspirin, are simple structures and can be replicated simply by a machine. The biosimilar has copied the active ingredient in the reference drug, but other non-active ingredients may differ in manufacturing.

In the United States, a biosimilar that earns the label "interchangeable" it means the biosimilar company has provided additional data to demonstrate that it a patient who is switched repeatedly between the reference product and the biosimilar can expect the same clinical result, without additional risks, relative to a patient who wasn’t switched. 

As of early 2024 in the USA, only interchangeable biosimilars can be substituted by pharmacies. But there are current efforts that may change this, where the pharmacist can switch a biologic with ANY biosimilar. This is the practice in Europe, where the word "interchangeable" is not associated with additional research - they feel all biosimilars, regardless of the additional research - are so close of a replica of the original there is no real difference. 

Other issues patients cite regarding labeling a biosimilar interchangeable would be that the biosimilar may have different modes of using it (harder to self-inject) or may not include the chemical that lessens the stinging sensation.

Yes. These medicines had to prove in clinical trials that they are just as safe and effective as the original biologic. At first, AiArthritis and other patient organizations and doctors were not sure if they were safe, but many studies have been done in patients to make sure if switched to the biosimilar that the patient would not have a reaction or lose efficacy. 

There are still some concerns around switching a patient who is stable. At this time, it is more accepted by doctors to switch a patient to a biologic if 1) they are biologic naive, meaning they've never used any biologic before, 2) if the patient is fairly controlled and would likely not lose efficacy if switched, and 3) if it's time to change biologics altogether. 

In Europe, the European Medicines Agency (EMA) in 2022 named biosimilars "interchangeable" with the brand name drug. That means the brand name drug ("reference drug") "can be replaced with the biosimilar without a patient experiencing any changes in clinical effect." Learn more  As of February 2023 in the United States, the FDA has not stated biosimilars are interchangeable. 

First, don't panic. Biosimilars have been tested in clinical trials and have demonstrated they are safe and as effective as their originator, reference drug.  However, most physicians do not wish to switch a patient to a new medicine when they are doing well on their current therapy. But if the switch saves the patient or healthcare system money, it may happen.  

In most of Western Europe, automatic substitution of biosimilars is rare – and banned in many jurisdictions. Throughout Eastern Europe, however, financial resources are often more limited. As a result, automatic substitution is commonplace. It is also common in Australia. In Canada it varies by province.

So where you live matters. Some countries in Europe respect the patient-doctor decision more than other countries, like the United States. 

If you live in the United States, are switched,  and your doctor has concern they will file an appeal. This is called "non-medical switching" by an insurance company, because they switched to save money and not because it was to better manage your disease. However, if you are doing well on a biologic, it is highly likely you will also do just as well on its biosimilar.

If a patient is not doing well on the original biologic, then they also will likely not do well on its biosimilar. So if you are not experiencing good outcomes from your biologic, you may want to talk to your doctor about switching to a new drug entirely.

Some patients have complex situations where the rheumatologist may be concerned switching could disrupt good health. For example, the biosimilar may have a different injection model that may make it more difficult for a person to use. Or it may not have a preservative that helps reduce sting. These non-active ingredients or design elements may impact adherence and, in turn, cause elevated disease activity.

Yes! In most countries, the use of biosimilars should lower costs to the healthcare system, which means more people with many conditions will have more access to the treatments they need. Patients may even see a discount. Savings has been demonstrated in Europe, but we will not know how much savings for patients - if any - will happen in the United States because of the healthcare system model and use of Pharmacy Benefit Managers (PBMs). 

We advise you to check the website of the manufacturer who makes your biosimilar for more information, as support programs may vary per country. These are common in the United States for patients who are not on government programs, like Medicare. 

Maybe. In European countries the use of biosimilars has made a difference in the funds available to the healthcare system (but it may not affect patients directly). In the United States, we have heard from some Medicare patients that biosimilars have helped them afford their medicines, as biologic/biosimilar manufacturer assistance plans are not available for those using this government program.

One reason some USA rheumatologists are reluctant to switch patients to biosimilars is because it is unclear there is any cost savings will be passed to them (or even to anyone other than the pharmacy benefit managers who negotiate prices and pocket the profits themselves).