Tentative Approval and Litigation: How Generic Drug Companies Wait for Market Entry

When a generic drug company gets tentative approval from the FDA, it’s not a green light to sell its product. It’s a pause button. The science checks out. The manufacturing is solid. The paperwork is clean. But there’s a patent standing in the way. And that patent might not expire for another year-or five. This is the reality for most generic drug makers in the U.S. They don’t wait for the patent to run out and then start applying. They apply while the patent is still active. And then they wait. And they watch. And they prepare.

What Tentative Approval Really Means

Tentative approval isn’t a loophole. It’s a built-in feature of the U.S. generic drug system, created by the Hatch-Waxman Act in 1984. The law was designed to balance two things: protecting brand-name drug companies’ patents and letting generics enter the market as soon as legally possible. Tentative approval is how the FDA handles the middle ground.

If your ANDA (Abbreviated New Drug Application) passes every technical review-bioequivalence, stability, labeling, manufacturing-but there’s still an unexpired patent on the brand drug, the FDA doesn’t say no. They say: “We’re ready. Just wait.” That’s tentative approval. It’s a formal notice that your drug is approved in every way except one: timing.

This isn’t just paperwork. It’s a strategic advantage. Companies that get tentative approval lock in their spot in line. When the patent finally expires, they don’t have to reapply. They don’t have to wait months for another review. They just send a quick notice to the FDA and, if everything’s in order, get final approval within 30 days. Some companies have gone from tentative to market in under 24 hours.

The Litigation Gamble: Paragraph IV Certifications

Here’s where things get tense. Most generic companies don’t just wait passively. They challenge the patents. That’s called a Paragraph IV certification. It’s a legal shot across the bow. You’re telling the brand-name company: “Your patent is invalid, or we don’t infringe it.”

When you file a Paragraph IV, you trigger a 45-day window for the brand company to sue you for patent infringement. If they do, the FDA is legally required to pause final approval for up to 30 months. That’s called a 30-month stay. It’s a legal timeout. But here’s the twist: if you’re the first company to file a Paragraph IV, you get 180 days of exclusive market access once you finally launch. That’s worth hundreds of millions of dollars.

So companies play a high-stakes game. File early. Get tentative approval. Wait for the patent to expire-or wait for the lawsuit to end. Some settle. Some fight. Some win. Some lose. But if you don’t get tentative approval first, you’re not even in the game.

The Hidden Work: Managing the Wait

A lot of people think once you get tentative approval, you can relax. You can’t. The waiting period is the most dangerous part of the whole process.

The FDA requires you to submit any changes to your application-like a new supplier, a tweaked formula, or even a different label design-as an amendment. But there are strict rules. Minor changes? You need to file at least three months before the patent expires. Major changes? Ten months. Miss that deadline, and your final approval gets delayed. Not by days. By months.

One company, Aurobindo Pharma, lost $150 million in revenue because they changed their manufacturing site and didn’t document it properly. Their tentative approval was still valid. Their drug was ready. But the FDA flagged the change. Final approval stalled for four months. The patent expired. The market opened. And they weren’t ready.

Another company, Mylan, got tentative approval for a generic EpiPen. But they didn’t realize the brand company had gotten a six-month pediatric exclusivity extension. That pushed the earliest legal launch date out by half a year. They were sitting on tentative approval for 18 months. But they couldn’t launch until that extra exclusivity period ended. They missed their window.

These aren’t rare mistakes. Evaluate Pharma found that 15% of tentatively approved drugs face delays because of sloppy amendment filings. The FDA doesn’t remind you. They don’t call. They just hold your application until you submit the right paperwork.

Who Uses This System-and Why

This isn’t just for big companies. But it’s mostly used by them. The top 10 generic drug makers each have 15 to 25 products in tentative approval status at any given time. Smaller companies might have two or three. Why? Because the cost of filing an ANDA, hiring legal counsel, and managing the regulatory process runs into millions of dollars. Only companies with deep pockets and strong regulatory teams can play.

But the payoff is huge. About 85% of all generic drugs entering the U.S. market today use this tentative approval pathway. And if you’re the first to file a Paragraph IV, you can capture 65% to 80% of the market during your 180-day exclusivity window. That’s how Lupin Limited captured 42% of the Cialis market in the first month after patent expiry in 2018.

Even global health programs rely on it. Companies developing generic HIV drugs under PEPFAR (the U.S. President’s Emergency Plan for AIDS Relief) use tentative approval to secure funding and manufacturing partnerships while waiting for U.S. patents to expire. It’s not just about profit. It’s about access.

What’s Changing in 2025

The FDA is making moves to speed things up. Starting in 2023, they cut the review time for final approval requests from 60-90 days down to 30 days for minor amendments. That’s a big deal. It means if you file on time, you’re likely to launch within weeks of patent expiry.

But complexity is rising. More drugs are complex generics-injectables, inhalers, patches-where proving bioequivalence is harder. And patents are getting more layered. Brand companies now file multiple patents covering everything from the pill’s shape to the way it dissolves. Each one can delay entry.

Some lawmakers are pushing to extend patent terms even further. The “Protecting Drug Patents Act,” introduced in March 2023, could add months-or even years-to the wait. If it passes, it could shrink the window for generic companies to launch.

Still, experts agree: tentative approval isn’t going away. Barclays analysts say there’s a 95% chance it’ll still be around in 2030. The Hatch-Waxman Act is too deeply woven into the fabric of the U.S. drug market. The system works. It’s just not easy.

How to Get Started

If you’re a generic drug maker looking to use this system, here’s the real roadmap:

1. Start with a complete ANDA. No shortcuts. Every section must be flawless.
2. Decide: Do you challenge the patent with a Paragraph IV certification? If yes, you’re in for a legal battle-but you might win 180 days of exclusivity.
3. Submit your application. Expect the first FDA review to take about 10 months.
4. If you get tentative approval, don’t stop. Set up a patent tracker. Monitor every patent and exclusivity period. Use legal and regulatory teams together.
5. Three months before the earliest legal launch date, submit your final approval request. No later.
6. Keep your manufacturing site in full cGMP compliance. 27% of delays in 2022 came from manufacturing issues.

It’s not a sprint. It’s a marathon with hurdles you can’t see until you’re already running. One misstep, and you lose your place in line. But get it right, and you’re not just launching a drug-you’re capturing a market.