Evergreening: How Pharmaceutical Brands Stretch Patents to Block Generic Drugs

Every year, billions of dollars in drug sales hang on a single number: the expiration date of a patent. When that date passes, generic versions flood the market, prices drop by up to 85%, and patients finally get affordable access. But for many blockbuster drugs, that expiration date never really comes. Instead, companies use a legal maneuver called evergreening to keep generics out-long after the original patent should have expired.

What Evergreening Really Means

Evergreening isn’t about inventing new medicines. It’s about making tiny changes to old ones and filing new patents on those changes. Think of it like swapping out the battery in your phone and calling it a new model. The core function hasn’t changed, but now you get another 20 years of exclusive rights.

This isn’t some shady loophole-it’s built into the system. The 1984 Hatch-Waxman Act in the U.S. was meant to balance innovation with access. It gave brand-name drugmakers 20 years of patent protection, but also created a faster path for generics. The problem? Companies quickly learned how to game the rules. Instead of developing new drugs, they started extending the life of existing ones.

Take AstraZeneca’s Prilosec, a heartburn drug. When its patent was set to expire, the company launched Nexium-a slightly different version of the same molecule. Nexium wasn’t more effective. It didn’t work better for more people. But it had a new patent. And that patent delayed generics for over a decade. The result? Billions in extra revenue, while patients paid more for nearly the same pill.

The Playbook: How Companies Extend Patents

There’s no single way to evergreen a drug. There are dozens. Here are the most common tactics:

• New dosage forms: Switching from a pill to a capsule, liquid, or patch. Even if the active ingredient is identical.
• Combination products: Adding another drug to the mix-even if that second drug is old and off-patent. The combo gets a new patent.
• Extended-release versions: Making the drug last longer in the body. Often, this doesn’t improve outcomes, just changes how often you take it.
• Patent thickets: Filing dozens, even hundreds, of patents around one drug. AbbVie filed 247 patents on Humira, a drug for autoimmune diseases. Even if most are weak, the cost of fighting them deters generics.
• Product hopping: Pulling the original drug off the market while pushing the new version. Patients and doctors get nudged toward the new patent-protected version, even if it’s not better.
• Orphan drug designation: Repurposing a common drug for a rare disease to get seven years of exclusivity.
• Pediatric exclusivity: Running small studies on children to earn six extra months of protection.

These aren’t innovations. They’re legal maneuvers. The FDA doesn’t require proof that these changes make the drug safer or more effective. Only that they’re different.

Why This Matters for Patients

When generics enter the market, prices drop fast. Humira, for example, cost over $70,000 a year in the U.S. before generics. Now, with competition, it’s under $10,000. That’s life-changing for patients with rheumatoid arthritis, Crohn’s disease, or psoriasis.

But evergreening delays that drop. In some cases, it delays it for over a decade. During that time, patients pay hundreds or thousands of dollars a month. Some skip doses. Some go without. Some go bankrupt.

A 2023 study found that 78% of new patents on prescription drugs were for existing drugs-not new ones. That means most patent activity isn’t about innovation. It’s about profit.

And it’s not just the U.S. The World Health Organization calls evergreening a major barrier to affordable medicines in low- and middle-income countries. When a drug like insulin or HIV medication is locked behind patent thickets, people die because they can’t afford it.

The Cost of Evergreening-For Everyone

Developing a truly new drug costs about $2.6 billion and takes 10 to 15 years. Evergreening? It costs a fraction of that. A few million dollars for a new formulation, a small clinical trial, and a team of patent lawyers.

The return? Massive. AstraZeneca extended patent life on six drugs by more than 90 years combined. AbbVie made over $40 million a day from Humira during its patent monopoly. That’s not innovation. That’s rent-seeking.

And the cost doesn’t stop at patient wallets. Insurance companies pay more. Medicare pays more. Governments pay more. The entire healthcare system bears the burden.

Meanwhile, real innovation stalls. Why spend billions and a decade on a risky new drug when you can tweak an old one and lock in profits for years?

Who’s Fighting Back?

There’s growing pushback. In 2022, the U.S. Federal Trade Commission sued AbbVie over Humira’s patent strategy, calling it anticompetitive. Courts are starting to question whether minor changes deserve patent protection. The European Medicines Agency now requires proof of real clinical benefit for new formulations.

The Inflation Reduction Act of 2022 lets Medicare negotiate prices for the most expensive drugs. That cuts the profit motive behind evergreening. If the government won’t pay $70,000 for a drug, companies have less incentive to stretch patents.

Some generic manufacturers are fighting back too. They’re challenging patent clusters in court. It’s expensive and slow-but it’s working. In 2023, a court ruled against a patent on a version of the asthma drug Advair, opening the door for generics.

What’s Next?

Companies aren’t giving up. They’re just getting smarter. Now they’re moving into biologics-complex drugs made from living cells. These are harder to copy. Nanotechnology and pharmacogenomics (testing genes to predict drug response) are the next frontiers. Patenting a genetic test that says a patient will respond to a drug? That’s the new frontier.

But the tide is turning. Public pressure is rising. Politicians are talking. Courts are listening. And patients are demanding change.

The question isn’t whether evergreening will end. It’s how fast. Right now, the system rewards companies for delaying competition. The real innovation will come when it rewards them for creating drugs that actually help people-instead of just extending profits.

How to Spot Evergreening in Your Own Prescription

If you’re on a brand-name drug and notice:

• Your pharmacy suddenly stopped carrying the old version
• Your doctor switched you to a new form of the same drug
• You’re being told the new version is ‘better’ but can’t explain how
• The price didn’t drop even though the drug is old

You might be seeing evergreening in action. Ask your pharmacist: Is there a generic version available? Why isn’t it being offered? Sometimes, the answer is simple: the patent hasn’t expired yet. And sometimes, that’s because of a patent that shouldn’t have been granted in the first place.

What You Can Do

You don’t have to accept this system. Here’s how to push back:

• Ask your doctor if a generic version is available.
• Check GoodRx or other price-comparison tools before filling prescriptions.
• Support policy changes that limit patent extensions and require proof of real benefit.
• Share stories about drug costs. Public pressure drives change.

The next time you hear a drug company talk about innovation, ask: Is this a new medicine-or just a new patent?