Evergreening: How Pharmaceutical Brands Stretch Patents to Block Generic Drugs

When a drug hits the market, the clock starts ticking. After 20 years, the patent expires - and suddenly, cheaper generics can flood in. But for many big pharma companies, that 20-year window isn’t enough. That’s where evergreening comes in: a legal strategy to delay generic competition by filing new patents on tiny changes to old drugs. It’s not about innovation. It’s about keeping prices high.

What Evergreening Actually Looks Like

Evergreening isn’t a single tactic. It’s a playbook. Companies take a drug that’s about to lose patent protection and make small tweaks - a new dosage form, a different release timing, a combination with another ingredient - then file a new patent. These aren’t breakthroughs. They’re tweaks. But under patent law, even minor changes can qualify for a fresh 20-year monopoly.

Take AstraZeneca’s Prilosec to Nexium switch. Prilosec, a heartburn drug, was set to lose patent protection. So AstraZeneca tweaked the molecule slightly and launched Nexium - marketed as a "better" version. The problem? Studies showed Nexium wasn’t more effective. But because it had a new patent, generics couldn’t enter. That one move added over a decade of exclusivity. And that’s just one example.

The U.S. patent office has granted over 247 patents for Humira, a drug used for arthritis and Crohn’s disease. AbbVie, the maker, didn’t invent 247 new treatments. They filed patents on things like dosing schedules, packaging, and minor chemical variations. The result? Humira stayed exclusive for nearly 20 years beyond its original patent, generating about $40 million a day in revenue.

The Five Common Evergreening Tactics

There are five main ways companies stretch patent life:

• New formulations: Switching from a pill to a liquid, or from immediate-release to extended-release. Even if the active ingredient is identical, the new form gets a new patent.
• Combination drugs: Adding a second, often unrelated, drug to the original. The combo gets its own patent, even if the original drug is about to expire.
• Pediatric extensions: Companies run small studies on children to earn an extra six months of exclusivity - even if the drug isn’t used in kids.
• Orphan drug status: Repurposing a common drug for a rare disease to qualify for seven years of exclusivity under orphan drug laws.
• Product hopping: Phasing out the original drug and pushing patients onto the new, patented version. Then, they stop making the old version - forcing patients to pay more.

These aren’t accidental. They’re planned years in advance. Teams of patent lawyers and chemists work five to seven years before a patent expires, hunting for any possible modification that can trigger a new exclusivity period.

Why This Hurts Patients and Systems

Generic drugs cut prices by 80-85% within a year of launch. That’s not theory - it’s data. When a drug like Lipitor or Plavix went generic, millions of patients suddenly paid a fraction of what they did before.

Evergreening blocks that. When companies delay generics, patients pay hundreds or thousands more per month. For chronic conditions like diabetes or autoimmune diseases, that’s not a minor cost - it’s life or death. A 2023 report from Strathmore University found that in low-income countries, evergreening practices directly prevent access to life-saving medications.

In the U.S., Medicare spends billions annually on drugs kept off the market by evergreening. The Inflation Reduction Act of 2022 tried to fix this by letting Medicare negotiate prices for the most expensive drugs. But if a drug is still under patent, Medicare can’t touch it. Evergreening turns patents into financial shields.

Is It Legal? Yes. Is It Right? That’s the Question

Legally, most evergreening tactics are allowed - for now. The Hatch-Waxman Act of 1984 was meant to balance innovation with access. It gave brand-name companies exclusivity to recoup R&D costs, then opened the door for generics. But it didn’t foresee how companies would exploit loopholes.

The U.S. Patent and Trademark Office (USPTO) has started pushing back. In 2022, the Federal Trade Commission sued AbbVie over Humira’s 247 patents, calling it an "anticompetitive patent thicket." Courts are beginning to question whether some patents are even valid. In one case, a judge ruled that a patent on a slightly altered version of a blood thinner was "obvious" - and therefore unenforceable.

But the system is still stacked. Challenging a patent costs millions. Most generic manufacturers can’t afford to fight 10 or 20 patents at once. So they wait - and patients pay.

What’s Changing? And What’s Next

Regulators are waking up. The European Medicines Agency now requires proof of "significant clinical benefit" before granting extra exclusivity for modified drugs. Canada and Australia have tightened rules on product hopping. In 2023, the World Health Organization called evergreening a "barrier to global health equity." But pharma companies aren’t standing still. They’re moving into harder-to-copy territory: biologics, nanotech formulations, and pharmacogenomic tests. These aren’t pills you can easily copy. They’re complex therapies that require advanced labs to replicate. That’s the next frontier of evergreening.

Some experts argue we need a new system - one that rewards real innovation, not legal gymnastics. Ideas include: patent buyouts, prize funds for breakthroughs, or direct government funding for R&D. But until then, the game continues.

What You Can Do

If you’re on a brand-name drug that’s about to go generic, ask your doctor or pharmacist: "Is there a generic version available?" Sometimes, it’s there - but your doctor hasn’t been told because the brand still controls prescriptions.

If you’re paying over $500 a month for a drug that’s been on the market for 15+ years, you’re likely paying for evergreening - not innovation. Ask for alternatives. File a complaint with your state’s attorney general. Support policy efforts to reform patent law.

The truth? Most drugs aren’t expensive because they’re hard to make. They’re expensive because someone decided to keep the door closed.

Final Thoughts

Evergreening isn’t a glitch in the system. It’s a feature. The rules were written to protect innovation - but they’ve been turned into a tool for profit. The result? Millions of people pay more than they should for drugs that have been around for decades. The solution isn’t to stop drug development. It’s to reward real breakthroughs - not legal tricks.