If you are taking a specialty biologic drug, you may have heard the term “biosimilar” by now. If not, it’s important to learn more as these alternatives to expensive biologic drugs become more common and available.   

What is a Biosimilar? Is it a Generic?  

Biologic drugs like Keytruda®, Humira®, and Stelara® are used to treat serious medical conditions. They typically take longer and cost more to develop than conventional medications. The “active ingredients” are complex molecules formed from living organisms. That means biologics are more expensive to make, store and ship.  

Unlike drugs prescribed for common conditions like high cholesterol, hypertension and diabetes, there are no generics available for biologics. It is impossible to make an exact replica of a living organism. However, “highly similar” molecules can be approved for use in place of the original biologic (called the reference product¹). 

Reference products are patented, which means no other company can make or sell a biosimilar for 12 years. After that, manufacturers may develop and market a biosimilar if it meets Food and Drug Administration (FDA) requirements:  

1. No meaningful differences in effectiveness or safety  
2. Made with the same materials and methods as the reference product  
3. Available in the same dosage and strength  

Quick Recap:  

• Similar but not identical: Small differences allowed compared to the reference product.  
• Speed to market: Typically, 8-10 years compared to 12-15 years for reference products.   
• Cost savings: Less costly to develop, leading to reduced prices for health plans and patients.  

Why Do Biosimilars Matter?   

Compared to conventional drugs, biologics are a very small percentage of all prescriptions. But due to their high costs, they can account for 70% or more of total prescription drug spending.² Biosimilars can be more accessible and affordable for patients and the health plans that cover them.   

Which Biosimilars?   

Not long ago, Humira was the top-selling drug in the world. Today many providers and patients have shifted to Humira biosimilars. In 2024, they were the most common biologics switch for RxSS members with a savings opportunity identified in the RxSS engine.³

Stelara is the next “blockbuster” biologic to see competition from biosimilars. Four have launched in 2025.   

What Does Interchangeability Mean?  

In most cases, a generic version of a common drug can be substituted for the brand version by a pharmacist or at the patient’s request. Biosimilars require a new prescription from the prescriber—unless the biosimilar is interchangeable with the reference product.    

A biosimilar product must meet strict requirements to be interchangeable and can be subject to different state regulations.⁴ Interchangeability status can bring instant cost savings to patients and insurers. It may also help avoid questions or delays at the pharmacy or medical facility.   

What’s Next?  

Biosimilars represent a significant advancement in healthcare, offering a cost-effective and accessible alternative to high-cost biologic drugs. Nearly 120 biologic reference products are expected to lose patent protection in coming years.⁵ As more patients and doctors become familiar with them, biosimilars are bound to become a bigger part of healthcare in the future.   

Product and brand names are trademarks of their respective holders. Inclusion in this material does not imply affiliation or endorsement.  

Sources:  

1. United States Food and Drug Administration. “Biosimilars: The Basics for Patients.” FDA, U.S. Department of Health and Human Services, www.fda.gov/drugs/biosimilars/biosimilars-basics-patients. Accessed February 2025. 
2. “Biosimilars: Why Biosimilars?” Biosimilars Forum, biosimilarsforum.org/why-biosimilars/#:~:text=A%20biosimilar%20is%20a%20biologic,drugs%20in%20our%20healthcare%20system. Accessed February 2025.   
3. RxSS data; eligible members with identified biologics savings opportunities; 2024. Accessed February 2025.   
4. United States Food and Drug Administration. “Biosimilar and Interchangeable Products.” FDA, July 2021, www.fda.gov/media/151094/download. PDF. Accessed February 2025. 
5. IQVIA Institute for Human Data Science: Assessing the Biosimilar Void in the U.S., Achieving Sustainable Levels of Biosimilar Competition. Accessed February 2025.