By 2028, the biggest drug in the world could lose its patent protection. That drug is Keytruda, Merck’s cancer immunotherapy that brought in $25.5 billion in sales in 2024 alone. When biosimilars finally arrive, they won’t just be cheaper alternatives-they’ll reshape how cancer care is paid for, prescribed, and accessed across the U.S. healthcare system.
What Exactly Are Biosimilars?
Biosimilars aren’t generics. Generics copy simple chemical drugs like ibuprofen or metformin. Biosimilars copy complex biological drugs-proteins made from living cells. Think of it like cloning a tree instead of copying a recipe. Even tiny changes in how the protein is folded, glycosylated, or stabilized can affect how it works in the body. The FDA requires biosimilars to prove they’re "highly similar" to the original biologic, with no clinically meaningful differences in safety, purity, or potency. That means years of lab testing, animal studies, and sometimes clinical trials. For example, a biosimilar for Keytruda must match the exact sugar patterns on its antibody structure. Get that wrong, and it might not trigger the immune system the same way to fight tumors.The Patent Cliff Is Here
Between 2025 and 2030, over $200 billion in annual global sales for biologics will lose patent protection. That’s not a small ripple-it’s a tsunami. The biggest targets:- Eylea (aflibercept) - $5.9 billion in U.S. sales in 2023. Patents expired in 2025. Three biosimilars launched in 2024.
- Humira (adalimumab) - Once the world’s top-selling drug. Biosimilars entered in 2023. Now, 80% of new prescriptions are for biosimilars.
- Keytruda (pembrolizumab) - $25.5 billion in 2024. Patent expires in 2028. Fourteen companies are already in late-stage trials.
- Enbrel (etanercept) - Biosimilar launched in 2023 at 35% discount. Now used in over 60% of new rheumatoid arthritis cases.
- Cosentyx (secukinumab) - Patent expires in 2029 in the U.S. But biosimilars already approved in Europe and entering the U.S. market early.
Why It’s Taking So Long to Get Here
You’d think once a patent expires, biosimilars flood the market. But that’s not what happened with Humira. Its patent was protected by over 100 patents filed in layers-some covering manufacturing methods, others covering dosing schedules, even packaging. These "patent thickets" delayed biosimilar entry by nine years. Originator companies also used legal tactics. Settlements between brand-name makers and biosimilar developers often included deals to delay market entry. The FDA’s 2025 rule changes now require real-time updates to the Purple Book, a public database of biologics and their patents. That’s meant to reduce these delays. There’s also the "product hopping" strategy. Companies tweak their drug slightly-change the delivery device, add a new indication-and get a new patent. Bristol Myers Squibb did this with Eliquis, pushing its exclusivity to 2029, even though the core patent expired earlier.Who’s Making These Biosimilars?
The leaders aren’t the big U.S. pharma giants. They’re specialized players with deep expertise in biologics manufacturing:- Sandoz (Novartis spinoff) - Market leader with 28% U.S. share after buying Biocon’s biosimilars business in 2024.
- Samsung Bioepis - South Korean company with $450 million invested in a single biosimilar manufacturing facility. Their versions of Enbrel and Humira are already in the U.S.
- Celltrion - Korean firm with biosimilars approved in over 70 countries. Their Remicade biosimilar is widely used in Europe.
- Alvotech - Icelandic startup that partnered with Regeneron in January 2025 to develop biosimilars for Eylea.
- Coherus BioSciences - U.S.-based company racing to be first with a Keytruda biosimilar.
Why Prices Are Still High-Even With Competition
Biosimilars launch at 15-35% discounts. That sounds good. But in the U.S., patients often don’t see those savings. Why? Medicare Part B pays providers based on the drug’s Average Sales Price (ASP). If a provider gives a $1,000 brand-name drug and gets reimbursed $1,050 (ASP + 6%), they make $50. If they give a $700 biosimilar, they get $742. That’s only $42 profit. So some doctors stick with the more expensive drug-because they make more money. Payers are trying to fix this. Cigna’s 2025 Medicare Advantage plans now charge $0 copay for biosimilars and $50 for the brand. Kaiser Permanente made biosimilars the default for new prescriptions. CVS Caremark saw a 22% drop in prior authorization denials for biosimilars in 2025. But hospitals still take months to update their electronic records to reflect biosimilar names. Some still list them as "alternative" drugs instead of interchangeable options.Real-World Results: Are They Safe?
For autoimmune diseases like rheumatoid arthritis or Crohn’s disease, the data is clear. Biosimilars work just like the originals. Dr. Laura Chow at the University of Washington reported no difference in outcomes for inflammatory bowel disease patients switching from Humira to its biosimilars. But oncology is trickier. In 2024, Dr. Richard Pazdur at the FDA’s Oncology Center documented cases where patients switching between different versions of rituximab (a lymphoma drug) had unexpected immune reactions. It’s not that biosimilars are unsafe-it’s that the immune system is more sensitive when fighting cancer. Even tiny differences in protein structure can matter. That’s why the FDA doesn’t yet approve many biosimilars as "interchangeable" for cancer drugs. Interchangeable means a pharmacist can swap them without the doctor’s approval. So far, only 12 biosimilars have that status in the U.S.-mostly for autoimmune conditions.Global Differences: Why Europe Is Ahead
In Europe, biosimilar adoption is over 70% for many drugs. Why? Simple: reimbursement rules favor cost savings. Health systems there pay a flat rate for a drug class, so hospitals and doctors are incentivized to pick the cheapest option. In the U.S., the system is broken. Insurance companies, pharmacy benefit managers (PBMs), and drug manufacturers have complex rebate deals. The lowest-priced drug doesn’t always win. Sometimes, the brand pays the PBM a bigger kickback to keep it on the formulary. The European Medicines Agency has approved 82 biosimilars. The FDA has approved 47. But the gap is closing. The FDA approved 17 biosimilars in 2024-up from just five in 2020.
What Comes Next?
The next wave includes more complex biologics: antibody-drug conjugates, fusion proteins, and even cell therapies. The FDA’s 2025 draft guidance aims to streamline approval for these next-generation products. That’s good news for patients-but it also means biosimilar makers will need even more advanced tech and bigger budgets. Payers are pushing harder. Centene Corporation now requires biosimilars for all new patients on tumor necrosis factor inhibitors. UnitedHealthcare signed value-based contracts with Sandoz: if the biosimilar doesn’t save 25%, they get a refund. The Congressional Budget Office estimates Medicare will save $51 billion from 2026 to 2035 because of these upcoming biosimilars. That’s money that could go to more patients, better care, or lower premiums. But the real question isn’t whether biosimilars will come. It’s whether the system is ready to use them.What Patients Should Know
If you’re on a biologic drug like Humira, Enbrel, or Eylea, you’ll likely be switched to a biosimilar soon. Here’s what to do:- Ask your doctor if a biosimilar is right for you. For autoimmune diseases, the answer is almost always yes.
- Check your insurance plan. Many now have $0 copays for biosimilars.
- Don’t panic if your drug name changes. It’s the same medicine, just cheaper.
- Report any new side effects-even small ones. While rare, switching between biosimilars can trigger reactions.
- Know your rights. In most states, pharmacists can substitute interchangeable biosimilars without telling you-but you can ask for the brand if you prefer.
Will Biosimilars Save the System?
They can. But only if the system changes. Right now, the biggest barrier isn’t science. It’s money. The same players who profit from high-priced biologics still control the flow of prescriptions, rebates, and payments. Until that changes, savings won’t reach patients fully. The data is clear: biosimilars work. They’re safe for most conditions. They’re cheaper. And they’re coming fast. The next five years will decide whether these drugs become a tool for equity-or just another layer in a broken pricing game.Are biosimilars the same as generics?
No. Generics are exact copies of simple chemical drugs like aspirin or metformin. Biosimilars are highly similar-but not identical-to complex biological drugs made from living cells, like antibodies or proteins. They require more testing because even tiny differences in structure can affect how they work in the body.
When will Keytruda biosimilars be available?
Keytruda’s main patent expires in 2028. Fourteen companies, including Coherus BioSciences and Merck’s own partner, are already in Phase 3 trials. The first biosimilars are expected to launch in late 2028 or early 2029, depending on FDA review speed and any legal delays.
Why are biosimilars cheaper if they’re so complex to make?
They’re not cheap to develop-companies spend $150-$250 million per biosimilar. But they don’t need to repeat the original clinical trials that proved the biologic works. They only need to prove they’re highly similar, which cuts development time and cost. Plus, once multiple biosimilars enter the market, competition drives prices down.
Can pharmacists switch me to a biosimilar without asking my doctor?
Only if the biosimilar is designated as "interchangeable" by the FDA. So far, only 12 out of 47 approved biosimilars have that status-and most are for autoimmune conditions, not cancer. For non-interchangeable biosimilars, your doctor must prescribe it by name. You can always ask your pharmacist if your drug is interchangeable.
Do biosimilars work as well as the original drugs?
For most conditions like rheumatoid arthritis, Crohn’s disease, and psoriasis, yes-multiple studies show no difference in effectiveness or safety. For cancer treatments, data is still being collected. Some patients have had unexpected reactions when switching between different biosimilars, so doctors monitor closely. The FDA requires strict testing before approval.
Why aren’t biosimilars more widely used in the U.S.?
Three main reasons: 1) Complex rebate systems that reward higher-priced drugs, 2) Slow adoption by hospitals and insurers who haven’t updated their systems, and 3) Legal delays from patent lawsuits. In Europe, where reimbursement favors cost savings, biosimilar use is over 70%. In the U.S., it’s still around 30-40% for most drugs.
Pawan Kumar
January 29, 2026 AT 11:50The entire biosimilar narrative is a carefully orchestrated illusion designed to pacify the public while Big Pharma consolidates control through regulatory capture and patent thickets disguised as innovation. The FDA’s ‘highly similar’ standard? A euphemism for ‘close enough to profit from.’ Look at the Korean firms-Sandoz, Samsung Bioepis-they’re not manufacturers, they’re Trojan horses for global biotech hegemony. And don’t be fooled by the ‘cost savings’ rhetoric-this is a Trojan horse for centralized healthcare control, where your treatment is dictated by algorithm, not physician discretion. The real question isn’t whether biosimilars work-it’s who benefits when you lose autonomy over your own biology.