Next week, a House Judiciary subcommittee will revisit familiar accusations about pharmaceutical patents and drug prices. Testimony will likely invoke two concepts: that drug companies create patent "thickets" to thwart generic competition, and "evergreen" patents to extend exclusivity and keep prices high.
Decades of evidence tells a different story: generic competition routinely arrives years before all patents associated with a medicine expire, and over 90% of prescriptions in the U.S. are filled with generics. Generic competition is robust, and the system is working as intended.
If lawmakers are going to consider rewriting patent rules for medicines, they must do so based on evidence, not metaphors.
Researchers and advocacy groups advance the claim that every patent associated with a drug prevents generics from entering the market. They allege that companies file scores of patents on trivial modifications to create impenetrable thickets around new drugs. They count all patents connected with a medicine, identify which patents expire latest, and imply that generics are blocked until then.
These arguments mischaracterize how the patent system works.
What most people view as a drug is actually a bundle of inventions. Transforming a promising molecule into a drug that can be administered to patients and secure regulatory approval requires that scientists solve a range of problems. Each solution may represent a patentable invention.
This process of scientific problem-solving explains why multiple patents are filed on a medicine at different points in time. Later patents protect inventions created later in drug development, including post-marketing approval. They cover new formulations, easier delivery systems, and new uses that benefit more patients. They protect improvements to a medicine or, in the case of combinations, new products -- not the original medicine itself. Once patents on the original medicine expire, competitors are free to sell generic versions of that original product, even if patents on later improvements are still in force.
Critics often treat later-filed patents as extensions of earlier ones. But patents have fixed terms, expiring 20 years from their filing date. Later-filed patents do not prolong earlier patents. What critics call "evergreening" is often the process of improving a medicine over time to improve benefits for patients.
Researchers have confirmed that the "patent thickets" narrative contradicts market realities, and that "evergreening" predictions do not align with the actual timing of generic entry.
The average time from a brand drug's launch to its first generic patent challenge has fallen from nearly 19 years in the mid-1990s to about 6 years today. Over 80% of new drugs now face patent challenges.
One study analyzed 130 bestselling drugs and found that the number of patents on a drug has no significant correlation with effective patent life. The conclusion: patent thickets, if they even exist, "appear to be rather easy to circumvent."
Generics, accustomed to navigating patents, arrive on a predictable schedule. Studies have found that generics enter the market roughly 13 to 14 years, on average, after the launch of a brand name drug. That timing has remained stable for decades. When generics enter, they rapidly capture market share.
In an audit of more than 200 entries in the UCSF Evergreen Drug Patent Database, which is frequently cited and relied upon to support evergreening claims, researchers Kristina Acri and Erika Lietzan found that generic competition arrived, on average, seven years before the database's prediction.
The UCSF database's claims about aspirin -- generic for over 100 years -- show the problems with the evergreening story. The database claims that aspirin's patent protection had been extended until 2032. However, the later patents were on a new liquid-filled aspirin capsule designed to dissolve in the small intestine -- not ordinary aspirin. Aspirin's exclusivity was not extended.
Even the argument that biopharma companies receive excessive numbers of patents doesn't hold up to scrutiny. The U.S. Patent and Trademark Office, in a study designed to examine alleged pharmaceutical patent thickets, found that large patent families are significantly less common in biopharma (only 1.3% of large patent families) than in technologies like computer networks and semiconductors (55.5%). Biopharma companies receive far fewer patents per R&D dollar than leading innovators in other sectors.
Congress should ask witnesses a simple question: Are you showing us patent counts and concepts, or are you bringing evidence of delayed generic competition?
If the answer relies on metaphors and assumptions rather than market evidence, be skeptical. Restricting patents on drug improvements may not lower prices, but it would reduce incentives to develop more patient-friendly medicines and new treatments.
Congress deserves evidence, not slogans. Patients do too.
Mark Schultz is the Faculty Chair of the IP Policy Institute, The University of Akron.
Jennifer Brant is Senior Advisor at Sidley and Practitioner in Residence at the IP Policy Institute.
