Evergreening: How Pharmaceutical Brands Stretch Patents to Block Generic Drugs

When a drug’s patent expires, generic versions should flood the market-lowering prices, increasing access, and saving patients thousands. But in many cases, they don’t. Instead, brand-name drugmakers use a tactic called evergreening to delay generics for years, sometimes decades. It’s not illegal. It’s not always obvious. But it’s everywhere-and it’s driving up drug costs for millions.

What Evergreening Really Means

Evergreening isn’t about inventing new medicines. It’s about tweaking old ones just enough to get a new patent. Think of it like changing the color of your car and calling it a new model. The engine? Same. The performance? Nearly identical. But now you get another 20 years of monopoly pricing.

The practice took off after the 1984 Hatch-Waxman Act in the U.S., which created a path for generic drugs to enter the market. In theory, this balanced innovation with affordability. In practice, drugmakers found loopholes. They started filing patent after patent-not for breakthroughs, but for minor changes: a new pill coating, a slightly different dose, a once-daily version instead of twice-daily. These aren’t improvements that help patients. They’re legal maneuvers to keep generics out.

How It Works: The Playbook

Pharmaceutical companies don’t wait until their patent is about to expire. They start planning five to seven years in advance. Their teams-comprised of chemists, patent lawyers, and regulatory specialists-look for any small change that could qualify for a new patent. Here are the most common tactics:

• New formulations: Switching from a tablet to a capsule, or from immediate-release to extended-release. Example: AstraZeneca’s shift from Prilosec to Nexium, a drug with nearly identical active ingredients but a new patent.
• Combination drugs: Adding a second, already-approved drug to the original. This creates a new patentable product-even if the original drug was already off-patent.
• Patent thickets: Filing dozens, even hundreds, of patents around one drug. AbbVie filed 247 patents on Humira, a biologic used for rheumatoid arthritis. Over 100 were granted. This creates a legal maze that generic makers can’t afford to navigate.
• Product hopping: Pulling the original drug off the market while pushing the new version. Patients are forced to switch, even if the old version worked fine. Insurers often won’t cover the old drug anymore, making generics the only affordable option-except they’re not allowed yet.
• Orphan drug and pediatric extensions: Getting extra exclusivity by testing a drug on children or for rare diseases-even if the drug was already widely used for common conditions.

The Real Cost: Patients Pay the Price

When generics enter the market, prices typically drop by 80% to 85% within the first year. That’s the power of competition. But evergreening blocks that. Take Humira: AbbVie’s drug generated over $40 million a day in revenue at its peak, thanks to patent extensions that delayed generics until 2023. Before then, patients paid up to $5,000 a month for a drug that could have cost $300.

AstraZeneca’s strategy on six top-selling drugs-like those for diabetes and acid reflux-extended their patent life by over 90 years combined. That’s not innovation. That’s financial engineering.

In Canada, the U.S., and Europe, patients with chronic conditions-diabetes, Crohn’s, psoriasis-are forced to choose between their medication and rent. A 2023 WHO report called evergreening a barrier to medicine access in low- and middle-income countries. In the U.S., the Federal Trade Commission sued AbbVie in 2022, calling Humira’s patent strategy “anticompetitive.” The case is ongoing.

Is This Really Innovation?

Developing a brand-new drug takes about 10 to 15 years and costs $2.6 billion on average. Evergreening? A fraction of that. A new formulation might cost $50 million to develop. The return? Billions in extra revenue.

Harvard researchers found that 78% of new patents for prescription drugs were on existing drugs-not new ones. That means the patent system, meant to reward innovation, is now being used to protect profits. The same companies that claim they need patent protection to fund research are spending more on legal teams than on R&D for new molecules.

Critics say the system is broken. Supporters argue that even small improvements deserve protection. But when the improvement is a coating that lasts 12 hours instead of 8, and the patient doesn’t feel any difference, is that really worth a decade of monopoly pricing?

Regulators Are Fighting Back

The U.S. Patent Office has started rejecting obvious patent applications. The FDA has streamlined generic approval. The European Medicines Agency now requires proof of “significant clinical benefit” before granting extra exclusivity.

The Inflation Reduction Act of 2022 gave Medicare the power to negotiate prices for the most expensive drugs. That’s a direct hit to evergreening’s profit model. If the government can cap prices, the financial incentive to stretch patents weakens.

Still, companies adapt. Now they’re moving into biologics-complex drugs made from living cells. These are harder to copy. And they’re using nanotechnology and pharmacogenomics to patent genetic tests that predict who responds to a drug. If you need the test to get the drug, and the test is patented, you’re stuck with the brand.

What Can Be Done?

There’s no single fix, but progress is happening:

• Patent reform: Limiting secondary patents to only those with clear clinical benefits.
• Transparency: Making all patent filings public and subject to independent review.
• Fast-tracking generics: Reducing legal barriers for generic makers to challenge weak patents.
• Public pressure: Patient advocacy groups are pushing lawmakers to act. In Canada, provinces are negotiating bulk drug purchases to bypass brand monopolies.

The goal isn’t to kill innovation. It’s to stop pretending that tweaking a pill is the same as discovering a cure.

What Patients Should Know

If you’re on a brand-name drug that’s been on the market for over 10 years, ask your pharmacist: Is there a generic? If not, ask why. Check if the drug has been reformulated recently. Look up the patent status on the U.S. FDA’s Orange Book or Health Canada’s Drug Product Database.

Sometimes, switching to a different drug in the same class can save hundreds or thousands. Don’t assume your doctor’s prescription is the only option. Ask about alternatives. Ask about cost. And don’t be afraid to push back.

What’s Next?

Evergreening won’t disappear overnight. But the tide is turning. With more lawsuits, tighter regulations, and growing public outrage, the days of unchecked patent stretching are numbered. The next five years will decide whether the system serves patients-or just profits.