Litigation in Generic Markets: How Patent Disputes Delay Affordable Medicines

When a brand-name drug’s patent expires, you’d expect cheaper generic versions to hit the market quickly. But in reality, many generics face legal roadblocks that delay their arrival for years-even after the original patent runs out. This isn’t random. It’s a system built into U.S. drug law, and it’s costing patients billions.

How the Hatch-Waxman Act Created a Legal Battleground

The Drug Price Competition and Patent Term Restoration Act of 1984, better known as the Hatch-Waxman Act, was meant to balance two goals: rewarding innovation and speeding up access to affordable drugs. It gave generic manufacturers a clear path to approval through Abbreviated New Drug Applications (ANDAs). But it also gave brand-name companies a powerful tool: the ability to sue when a generic company challenges their patents.

Here’s how it works. Generic companies file an ANDA and include a Paragraph IV certification, saying they believe the brand’s patent is invalid or won’t be infringed. That’s a direct challenge. The brand company then has 45 days to sue. If they do, the FDA can’t approve the generic for up to 30 months. That’s not a review delay-it’s a legal freeze.

This 30-month stay was designed to give courts time to resolve disputes. But in practice, it’s become a strategic pause button. Some brand companies have used it to delay generic entry for over a decade, even when the core patent has expired.

The Orange Book: A List That’s Being Abused

The FDA’s Orange Book is supposed to be a transparent list of patents tied to brand-name drugs. Only patents covering the active ingredient, formulation, method of use, or manufacturing process should be listed. But that’s not always what happens.

In 2025, a federal judge in New Jersey ruled that six patents listed for ProAir® HFA-an asthma inhaler-were improperly included. The patents covered the dose counter on the inhaler, not the drug itself (albuterol sulfate). Judge Chesler made it clear: “The drug for which Teva submitted its application was albuterol sulfate inhalation aerosol.” Patents on the device don’t count.

That ruling is a big deal. Skadden’s September 2025 analysis estimates that 15-20% of all Orange Book listings could be invalid under this standard. Yet brand companies keep listing patents on packaging, delivery devices, and even software used with the drug. These aren’t protecting the medicine-they’re protecting profits.

The Association for Accessible Medicines (AAM) found that brand companies often use this tactic to launch a series of lawsuits-each with a new patent, each triggering a new 30-month stay. One drug saw generic entry delayed by nearly 10 years because of this serial litigation strategy.

Where Lawsuits Are Fought: The Eastern District of Texas

Not all courts are created equal when it comes to patent cases. In 2024, the Eastern District of Texas became the most active venue for pharmaceutical patent litigation, handling 38% of all cases. That’s up from just 12% a decade ago.

Why? Because it’s known for being favorable to patent holders. Judges there have deep experience with complex pharmaceutical cases. The procedures are predictable. And the jury pool is seen as more likely to side with innovators. That’s why companies like Teva, Amgen, and Pfizer file their lawsuits there.

The Western District of Texas and District of Delaware are also popular, but Texas now leads by a wide margin. This isn’t about where the companies are based-it’s about choosing the court that gives you the best shot at winning.

Critics call this forum shopping. Supporters say it’s just smart legal strategy. Either way, it’s reshaping how these cases play out.

Pay-for-Delay: Settlements That Aren’t What They Seem

Sometimes, instead of fighting in court, brand and generic companies settle. On paper, it looks like a win-win: the brand avoids a risky trial, and the generic gets paid to stay off the market.

But here’s the catch: those payments often come with a condition-don’t launch until the patent expires, even if you’ve already won your case. That’s called a “pay-for-delay” settlement. The FTC has spent years trying to stop it, calling it anti-competitive.

Yet the IQVIA Institute found something surprising: on average, these settlements actually brought generics to market more than five years before patent expiration. That’s because without the settlement, many generic companies wouldn’t file ANDAs at all. The risk of losing a multi-million-dollar lawsuit is too high.

John T. O’Donnell, an industry analyst, put it bluntly: “If you limit a generic drug manufacturer’s ability to settle cases, that manufacturer does not settle fewer cases-it submits fewer Paragraph IV ANDAs.”

So the real issue isn’t just the settlements. It’s the entire system that forces generics to choose between a risky legal battle or a quiet exit.

Patent Thickets: When One Drug Has 150 Patents

Some drugs are protected by dozens-even hundreds-of patents. Eliquis (apixaban) has 67. Semaglutide products (Ozempic, Wegovy, Rybelsus) have 152. Oncology drugs average 237.

This isn’t innovation. It’s a legal wall. Each patent extends the clock. Each one can be used to trigger another 30-month stay. Even if one patent is invalidated, another one is ready to take its place.

Dr. Rachel Sachs, a law professor at Washington University, calls this a “patent thicket.” And it’s getting worse. The average number of patents per drug has risen from 37 for small molecule drugs to 78 for biologics and biosimilars.

The result? The average time from brand drug approval to first generic entry has doubled-from 14 months in 2005 to 28 months in 2024. For cancer drugs, it’s now an average of 5.7 years after patent expiration before generics appear.

Who’s Paying the Price?

All of this has a cost-and it’s not just paid by drug companies.

The FTC estimates that improper Orange Book listings delay generic competition for about 1,000 drugs every year. That costs the U.S. healthcare system $13.9 billion annually. Patients pay more. Insurers pay more. Medicare and Medicaid pay more.

Meanwhile, specialized law firms are thriving. Fish & Richardson, Quinn Emanuel, and Jones Day reported 35-40% revenue growth in patent litigation in 2024. The legal industry is profiting from the delay.

The FDA is finally responding. In early 2026, new regulations will require brand companies to certify under penalty of perjury that every patent they list in the Orange Book meets legal standards. That’s a step forward. But it’s reactive. The damage has already been done.

What’s Changing? And What’s Not

Generic manufacturers are fighting back with new tools. Inter partes review (IPR) at the Patent Trial and Appeal Board (PTAB) has grown by 47% since 2023. IPR lets challengers attack patents without going to court. But in April 2025, the Supreme Court’s decision in Smith & Nephew v. Arthrex made it harder for generic companies to file these challenges by tightening standing rules.

The FTC has been aggressive too. In 2024, they challenged over 300 improper Orange Book listings. In May 2025, they sent warning letters to 200 more patents across 17 brand-name drugs, including major companies like Teva and Amgen.

But the system still favors the status quo. The 30-month stay remains. The Orange Book is still full of questionable patents. The courts still hear hundreds of cases every year.

The real change won’t come from lawsuits or letters. It’ll come when Congress decides that delaying affordable medicine for profit is no longer acceptable.

What This Means for Patients

If you’re waiting for a generic version of your prescription, you’re not just waiting for production to ramp up. You’re waiting for a legal system to catch up.

That delay isn’t accidental. It’s designed. And it’s expensive.

The next time you hear about a drug company “launching a new generic,” ask: Why did it take so long? And who benefited from the wait?

The answer isn’t just legal. It’s personal.