Evergreening: How Pharmaceutical Brands Delay Generic Drugs to Protect Profits

When a drug company spends billions to develop a new medicine, it makes sense they’d want to protect their investment. But what happens when that protection stretches for decades-not because of real innovation, but because of clever legal tweaks? That’s evergreening-a strategy used by big pharmaceutical companies to keep generics off the market long after a drug’s original patent should have expired.

What Exactly Is Evergreening?

Evergreening isn’t about inventing new drugs. It’s about making tiny changes to old ones-like switching from a pill to a liquid, changing the dosage, or combining it with another ingredient-and then filing a new patent. These aren’t breakthroughs. They’re tweaks. But under U.S. patent law, even minor modifications can trigger a fresh 20-year clock on exclusivity.

The system was designed to balance innovation and access. The 1984 Hatch-Waxman Act let generic manufacturers enter the market after patents expired, lowering prices dramatically. But drug companies quickly learned how to game it. Instead of waiting for generics to arrive, they started layering patents-like stacking bricks-to build a wall around their best-selling drugs.

How It Works: The Playbook

Here’s how it typically plays out:

• A drug gets approved. Its main patent lasts 20 years from filing.
• Five years before expiration, the company files for a new patent on a slightly different version-say, a slow-release pill instead of a regular one.
• The FDA grants three extra years of exclusivity because the company ran new clinical trials (even if they just tested absorption rates).
• Then they file another patent for a pediatric use, adding six more months.
• They launch a branded version of the generic they themselves own-called an “authorized generic”-to keep profits flowing while pretending to allow competition.
• By the time the original patent expires, the company has built a web of 10, 20, even 50+ overlapping patents.

This isn’t theory. It’s standard practice. AstraZeneca filed patent protections for six top drugs, extending their monopoly by over 90 years combined. Humira, AbbVie’s blockbuster drug for autoimmune diseases, has more than 247 patents attached to it. Over 100 have already been granted. That’s not innovation. That’s legal engineering.

The Real Cost: Patients Pay the Price

When generics enter the market, prices drop by 80-85% within a year. That’s the whole point of the system. But evergreening delays that drop-sometimes for a decade or more.

Take Humira. It was approved in 2002. The original patent expired in 2016. But because of patent stacking, generics didn’t hit the U.S. market until 2023. In the meantime, patients paid $7,000-$9,000 per month. AbbVie made over $40 million a day from it. That’s not luck. That’s strategy.

And it’s not just Humira. AstraZeneca’s Nexium, a reformulation of Prilosec, became the #1 best-selling drug in the world-not because it was better, but because the company convinced doctors and patients to switch. The new version had a slightly different chemical structure. It worked the same. But the patent clock reset. Patients didn’t save money. They paid more.

Why Do Companies Do This?

Because it works. And it’s cheap.

Developing a brand-new drug costs about $2.6 billion and takes 10-15 years. Evergreening? A fraction of that. A new formulation might cost $50 million to test. The return? Billions in extra revenue. And since the FDA and patent office often approve these minor changes without demanding real clinical improvement, companies have little incentive to stop.

Robin Feldman, a law professor who’s studied this for years, found that 78% of new patents on prescription drugs are for existing medications-not new ones. That’s the industry’s secret: innovation isn’t the business model. Profit protection is.

Regulators Are Starting to Push Back

But the tide is turning.

In 2022, the U.S. Federal Trade Commission sued AbbVie over Humira’s patent strategy, calling it an illegal monopoly. The Inflation Reduction Act of 2022 gave Medicare the power to negotiate prices for the most expensive drugs, cutting into the profits of evergreened products. The European Medicines Agency now requires proof of real clinical benefit before granting extra exclusivity.

Even the U.S. Patent Office is getting stricter. Examiners are now rejecting “obvious” patents-like changing a pill’s color or coating-more often than before. Courts are also starting to strike down patent thickets when they’re clearly designed to block competition.

Still, the system isn’t fixed. Generic manufacturers still face years of lawsuits, delays, and legal costs just to get their products approved. Many can’t afford the fight.

What’s Next? Biologics and Beyond

The next frontier for evergreening? Biologics-complex drugs made from living cells, like insulin or cancer treatments. These are harder to copy than pills, so companies are using that to their advantage.

Some are patenting genetic tests that predict who will respond to a drug. Others are creating nanotech versions that are nearly impossible for generics to replicate. A few are even using data exclusivity rules to block generic makers from using clinical trial data-even if they do their own studies.

These aren’t science fiction. They’re happening now. And without stronger oversight, they’ll become the new normal.

Who Gets Hurt?

Patients. Especially those without good insurance. People with diabetes, arthritis, Crohn’s disease, and other chronic conditions can’t choose between rent and their medication. Evergreening turns life-saving drugs into luxury items.

It also strains public health systems. Medicaid, Medicare, and VA hospitals pay billions more each year because generics are delayed. Taxpayers foot the bill. And in low-income countries, where these drugs are priced out of reach, the impact is even worse.

There’s no moral justification here. No public health benefit. Just profit.

Is There a Better Way?

Yes. And it’s simple: reward real innovation, not legal loopholes.

Instead of extending patents for minor changes, governments could offer cash prizes for breakthrough drugs. Or create a public fund that pays companies for developing truly new treatments-then let everyone make generics right away.

Some countries already do this. The U.K. and Canada have experimented with prize systems. They don’t rely on monopolies. They reward discovery, not delay.

Until the U.S. and other major markets adopt similar models, evergreening will keep thriving. And patients will keep paying the price.