Provider Education: Understanding Biosimilar Differences

Most doctors and pharmacists know what a generic drug is. But when it comes to biosimilars, confusion is still widespread-even among experienced providers. A 2021 survey found that only 38% of U.S. physicians felt extremely familiar with the FDA’s definition of a biosimilar. That’s not because they’re untrained. It’s because biosimilars aren’t generics. They’re something entirely different-and understanding that difference is critical for patient safety and treatment success.

What Exactly Is a Biosimilar?

A biosimilar is a biological product that is highly similar to an already-approved reference biologic. It’s not an exact copy, but it must have no clinically meaningful differences in safety, purity, or potency. The FDA requires manufacturers to prove this through thousands of lab tests, animal studies, and at least one clinical trial in humans. Unlike generics, which are chemically identical to their brand-name counterparts, biosimilars are made from living cells-like yeast, bacteria, or mammalian cells. That means tiny variations in manufacturing can affect structure and behavior, even if the final product works the same way in the body.

Think of it like this: two handmade leather jackets might look identical, but one uses different stitching techniques or tanning methods. Both keep you warm. But if one causes an allergic reaction in someone with sensitive skin, you need to know why. That’s why biosimilars require more testing than generics. The FDA mandates up to 100 times more analytical data for biosimilars than for traditional generics.

Biosimilars vs Generics: The Key Differences

Biosimilars vs Generics: A Side-by-Side Comparison

Feature	Generic Drugs	Biosimilars
Chemical Structure	Small molecule, identical to brand	Large, complex protein, highly similar but not identical
Manufacturing Process	Chemical synthesis, easily replicated	Live cell culture, sensitive to changes
Testing Required	Bioequivalence study only	Analytical, non-clinical, and clinical studies
Interchangeability	Automatic substitution allowed	Requires extra FDA approval for substitution
Indication Extrapolation	Not applicable	Permitted with strong scientific justification

One major point of confusion is interchangeability. Not all biosimilars are interchangeable. Only those that have passed additional studies-proving that switching back and forth between the reference product and biosimilar doesn’t increase risk-can be substituted at the pharmacy without a prescriber’s permission. As of late 2023, only six biosimilars in the U.S. had received this designation. The rest require a specific prescription.

Why Provider Education Matters

A 2017 study of oncology staff showed that after just 12 training sessions over four months, provider confidence in biosimilar efficacy jumped from 40% to 92%. That’s not a small gain. That’s life-changing for patients who might otherwise delay treatment due to cost.

But education isn’t just about efficacy. It’s about trust. Many patients hear “biosimilar” and think “cheap version.” If providers don’t understand the science themselves, they can’t explain it clearly. A 2021 survey found that only 22% of U.S. pharmacists felt very confident explaining biosimilar differences to patients. That’s a problem. When patients are confused, they refuse treatment. At UCSF Medical Center, pharmacist-led education cut prescribing hesitancy among oncologists from 58% to 12% in six months.

Even more troubling: 57% of providers worry about using biosimilars for conditions not directly studied in trials. This is called extrapolation. For example, if a biosimilar is approved for rheumatoid arthritis based on one study, the FDA may allow it to be used for psoriatic arthritis too-if the mechanism of action is the same and the disease pathways are similar. It’s scientifically valid, but many providers still hesitate.

Where Adoption Stands Today

Biosimilars are saving money-real money. Medicare Part B data from 2022 shows biosimilars cost 28% less on average than their reference biologics. The Congressional Budget Office estimates they could save the U.S. healthcare system $150 billion over the next decade.

But adoption isn’t equal across specialties. Rheumatologists lead the way, with 68% using biosimilars regularly. Oncologists are close behind at 52%. But endocrinologists? Only 29%. And insulin biosimilars have been available since 2015. Why the lag?

Part of it is EHR issues. A 2022 survey found that 78% of U.S. hospitals struggle to document biosimilar use correctly in electronic health records. Some systems don’t even have a dropdown for biosimilars. Providers end up typing it manually, which leads to billing errors and tracking problems. At one major hospital, nurses reported spending up to 15 extra minutes per patient just to get the right code into Epic.

What Providers Need to Know

There are four core areas every provider should understand:

1. Immunogenicity - Biosimilars can trigger immune responses, just like the reference product. But differences in manufacturing mean the risk profile isn’t always identical. Monitoring for antibodies is still necessary.
2. Extrapolation - Just because a biosimilar works in one condition doesn’t mean it automatically works in all conditions the reference product treats. But the FDA approves extrapolation when the science supports it. Ask: Is the mechanism of action the same? Are the disease pathways similar?
3. Interchangeability - Know which biosimilars in your practice have this designation. Only those can be substituted without a new prescription. Check the FDA’s Purple Book regularly.
4. Documentation - Your EHR must accurately record which product was given. If you prescribe a biosimilar, don’t just write “adalimumab.” Write “adalimumab-atto” or “adalimumab-adaz.”

There’s also the issue of patient communication. A 2022 survey from the ArthritisPower registry found that 34% of rheumatology patients felt confused when switched to a biosimilar. Why? Because their provider didn’t explain it well. Patients need to hear: “This is not a cheaper version. It’s a scientifically proven alternative with the same results and safety profile.”

Where to Get Reliable Education

The FDA has created a free, comprehensive Teaching Resource Guide with 12 modules covering everything from manufacturing to billing. It’s available in nine languages and meets accessibility standards. Medical schools, pharmacy programs, and nursing schools across the country are starting to use it.

But education shouldn’t stop at the classroom. Hospitals that succeed have dedicated clinical pharmacists leading ongoing training. At the University of Pittsburgh Medical Center, they used a three-phase approach: four weeks of foundational learning, six weeks of specialty-specific application, and ongoing support. Within six months, 89% of providers reported high confidence in using biosimilars.

Don’t rely on manufacturer materials. The FDA’s resources are independent, evidence-based, and updated regularly. The Arthritis Foundation, the American College of Rheumatology, and the Alliance for Safe Biologic Medicines also offer free provider toolkits with case studies, FAQs, and patient handouts.

The Future Is Here-Are You Ready?

By 2027, biosimilars are projected to make up 45% of the biologics market. That’s not a distant forecast. It’s happening now. Insulin, Humira, Enbrel, Herceptin-all have biosimilar alternatives. And more are coming.

The biggest barrier isn’t cost. It’s knowledge. Providers who understand biosimilars aren’t just keeping up-they’re leading the charge toward more affordable, accessible care. Those who don’t? They risk misinformed patients, delayed treatments, and avoidable errors.

You don’t need to be a scientist to use biosimilars. But you do need to know the basics. Start with the FDA’s guide. Talk to your pharmacy team. Ask your hospital if they have a biosimilar education program. If they don’t, start one.

Patients are counting on you to get it right.