Patents filed since 1995 last for 20 years from the date of patent application filing. This is true for “utility” patents, but the terms for certain other, less common types of patents, are different.
The short answer to how long drug patents last is “twenty years.” It’s usually more complex than that, however.
Utility patents will last the full 20 years from the date of filing unless the patent is somehow found to be invalid or the inventor does not pay maintenance fees 3.5, 7.5, and 11.5 years after the original patent is granted.
Sometimes patent duration can be extended, and pharmaceutical companies, which make about 80% of their overall revenue because of their patents, often try to extend patent terms for as long as they can. Once drug patents fully expire, the way is paved for generic competitors to undercut prices significantly. Therefore, pharmaceutical manufacturers use many legal techniques for prolonging drug patents. Some of them are straightforward, while others are more complex and legally risky.
The Most Straightforward Way to Extend Drug Patents: The Hatch-Waxman Act
Drug manufacturers patent new compounds early in the drug research process to protect their intellectual property. However, since gaining FDA approval for a new drug can take far longer, their practical protection from competition on the market can end up only being a few years. The Hatch-Waxman Act was passed in 1984 to allow patent extensions of five years to make up for how long the FDA approval process is. This is great if a drug goes from conception to market in five or six years. But in reality, FDA approval can take much longer, and Hatch-Waxman grants five years regardless of how long FDA approval takes.
New Formulations, Administration Techniques, or Uses
Another relatively straightforward way drug companies can extend a patent is by reformulating a drug – often to simplify dosing or how it’s administered. Extended-release versions of drugs are common ways companies reformulate products, for example. New methods of administering drugs may mean taking a drug that was previously only available by injection (like migraine medication Imitrex used to be) and creating a nasal spray version. Dissolvable tablets that don’t have to be taken with water can help pharmaceutical companies extend patent protection too.
When a new use is discovered for a drug, it can earn an additional three years of protection under FDA rules. Suppose a drug designed to treat clinical depression was found to treat another disorder, like ADHD. In such cases, the drug can gain three additional years of patent protection under new use rules.
Reformulating a drug so it can be administered in a different form can confer longer patent protection.
Orphan Drug Exclusivity Periods
The Orphan Drug Act promotes the development of drugs to treat rare diseases (those that affect 200,000 or fewer people in the US). Under this law, drugs developed for rare diseases gain seven years of additional exclusivity on drug sales, and the FDA is blocked from approving any competing generics during this time. The purpose of orphan drug legislation is to help drug developers recoup the considerable costs of developing and marketing drugs which are never expected to have wide markets. Of course, this method of drug patent extension can’t be used by just anyone. It’s straightforward, but few drug manufacturers are able to take advantage of the protections orphan drug legislation offers.
Creative Legal Maneuvering Not Unheard Of
Sometimes, drug manufacturers go to extraordinary lengths to attempt to hold onto patent protection and keep generic competitors out of the market. One example is the maneuvering done by Allergan in a bid to protect its patent for dry eye medication Restasis. Allergan transferred patent rights for Restasis to a Native American tribal entity, the New York State Saint Regis Mohawk Tribe, thus granting the patent sovereign immunity from being overturned. This tactic was struck down at the District Court level in 2017, with Federal Judge William Bryson decrying what he considered legal chicanery by Allergan.
There’s no question that drug development is remarkably expensive, and that the patent system is designed to help drug manufacturers recoup drug development costs. To that end, there are several methods drug makers can use to extend patents, with some being relatively straightforward and others being more complex. The bottom line is, determining when generics will reach the market is far more complex than calculating out 20 years from the date a pharmaceutical company patents a new compound, because many other factors can result in patent extensions.
