Biologic medications are made from living organisms and are used to treat a variety of medical conditions, including cancer. [1][2] In recent years, an increasing number of ‘biosimilar’ drugs have become available. These drugs are very similar to the reference biologic medications, with no significant differences in their safety or dosage, and can be used to treat the same conditions. [3][4]
Understanding biosimilar drugs
As patents begin to expire on many biologic medications, biosimilar drugs are becoming increasingly available. [3] These biosimilars are manufactured using the same processes and source materials as their reference biologic, which is the original medication they are designed to match. [1][4] While biosimilars are not identical copies, they are so highly similar that no clinically meaningful differences exist between them and the reference product. [1]
This close similarity allows biosimilars to treat the same conditions as their reference biologics with equivalent dosing, therapeutic benefits, and potential side effects. [2][4] The U.S. Food & Drug Administration (FDA) rigorously reviews each biosimilar to confirm it meets the same safety and efficacy standards as the original biologic. [2] This regulation ensures that patients and healthcare providers can trust biosimilars as reliable alternatives.
Biosimilars represent a unique category in pharmaceutical development, filling the gap between conventional generic medication and original biologic drugs. The development of more biosimilar drugs could increase medication availability for patients, potentially reducing the cost and increasing access. [4]
Are they the same as biologic generic drugs?
No, biosimilars are not the same as generic drugs. While generic drugs are identical copies of their reference medications, biosimilars are not identical to their reference biologics.
This distinction is a result of the complexity of biologic medications themselves. Unlike conventional drugs, biologics are manufactured through intricate processes involving living cells from animals, plants, or microorganisms. [3] The original pharmaceutical companies own proprietary rights to these specific manufacturing processes, preventing other manufacturers from replicating them. [3] Consequently, manufacturers must develop their own production methods, which inevitably produce slight variations from the reference biologic. [3]
This explains why true biologic generics don't exist; only biosimilars can be produced. As a result, biosimilars are sometimes considered the ‘generic’ versions of biologics, though this is not strictly accurate. Because they are biosimilar and not identical, biosimilar drugs still have to undergo FDA approval processes before being licensed for use.Â
Examples of biosimilar drugs currently in use
There are currently over 70 FDA-approved biosimilar drugs in use. [5] Some examples of these are below: [5]
| Biosimilar drug | Reference product |
|---|---|
| Inflectra | Remicade (infliximab) |
| Renflexis | Remicade (infliximab) |
| Erelzi | Enbrel (etanercept) |
| Amjevita | Humira (adalimumab) |
| Semglee | Lantus (insulin glargine) |
Why the FDA is pushing for biosimilar alternatives
The FDA has recently announced plans to streamline the manufacture of biosimilar drugs, allowing them to be produced quickly and more cost-effectively. [6] The main reason for this is to make them cheaper and more accessible to patients, in contrast to expensive biologic medications.Â
Recent data found that biologic drugs account for over half of total drug spending in the U.S, but only account for 5% of prescriptions. [6] This highlights the large financial burden of biologics, which could be significantly reduced if more biosimilars were available. For context, there are over 30,000 approved generic conventional drugs, but only 76 biosimilar medications, showing how far behind this area is in drug development. [6]
Biosimilar drugs are not only cheaper, but could also increase accessibility to medications for a huge patient population. For example, if someone usually takes a biologic medication but it becomes out of stock, they could switch to a biosimilar medication in the interim, keeping their condition under control. The more biosimilar drugs are available for each biologic reference drug, the further this accessibility will increase.
How much cheaper are biosimilars?
Biosimilars can be significantly cheaper than the biologic reference drug. In 2023, over $12 billion was saved by using a biosimilar alternative, with approximately $36 billion saved since 2015, when the first biosimilar drug was introduced. [7]
Typically, biosimilars are around 30% cheaper than their reference biologics. [8] Although this saving is a lot less than is seen in some conventional generic medications, it still represents a significant saving.
Are biosimilars as reliable as biologics?
Yes, biosimilars are just as reliable as their reference biologic medications. [4] The FDA's approval process for biosimilars is comprehensive and rigorous, requiring manufacturers to demonstrate that their biosimilar drug has no clinically meaningful differences compared to the reference product. [4] This means healthcare providers can prescribe biosimilars as an alternative to the biologic reference drug with confidence that it will provide the same benefit for their patient. [4]
Some biosimilar drugs go through further approval to be deemed an ‘interchangeable biosimilar’. [4] This recognizes that the biosimilar is an equivalent to the reference product, and could be substituted for the reference biologic at the pharmacy without the prescription being changed. [4] As the evidence supporting biosimilars continues to grow, so will both healthcare professionals' and patients' confidence in their therapeutic benefits.Â
How patients stand to benefit from the increased availability of biosimilar medications
There are several important benefits of biosimilar drugs for patients. Firstly, increased availability of biosimilar drugs will improve patient access to this type of medication. This is especially important for individuals who may otherwise have had delays due to medication shortages or insurance coverage limitations.
Additionally, for patients with chronic conditions requiring long-term biologic therapy, the lower cost of biosimilars can make treatment more financially sustainable while maintaining the same therapeutic benefits. [4]Â
Finally, the availability of multiple biosimilar drugs for a single reference biologic creates benefits in treatment planning. For example, if a patient has changes to their insurance coverage or experiences supply chain issues with their current medication, they can switch to an alternative biosimilar drug. This ensures their treatment continues without interruption.
Risks and criticisms
Despite the promise of biosimilars, they have had their share of criticisms. Much of this is related to both professional and patient unfamiliarity with biosimilars, subsequently leading to doubts about their benefits. One survey found that over half of U.S. physicians did not feel biosimilars were appropriate for patient use. [9] Similarly, patients who have been on biologics often share concerns that biosimilars won’t provide the same benefit or will produce unwanted side effects.Â
A further criticism is the complexity of the biosimilar approval pathway itself, something the FDA is attempting to improve. Currently, the process for biosimilar approval is time-consuming and costly, which could limit the number of manufacturers who are willing to pursue it.Â
Despite this, biosimilars do not carry any excess risks compared to their biologic reference counterparts. [3]
Final thought
Biosimilar drugs represent a significant advancement in making biologic treatments more accessible and affordable for patients. With FDA oversight ensuring their safety and efficacy, biosimilars offer a reliable alternative to expensive reference biologics without affecting therapeutic outcomes. As more biosimilars become available and awareness grows among healthcare providers and patients, these medications have the potential to transform treatment accessibility for millions of people managing chronic medical conditions.
