Viagra, aspirin and a fungicide. Not three things you’d expect in the same sentence. But in my field, they have something important in common: second use. Second use means patenting a new use of a known chemical compound, composition or product. You don’t get a patent on the product itself, which already exists, but on its new use.
Aspirin and Viagra
Second use is common in medicine, where it’s called second medical use. Aspirin is a good example. Bayer launched aspirin as a painkiller in 1899. Over the years, aspirin turned out to have many other benefits. It can, for example, reduce the risk of cardiovascular disease. So it became possible to patent aspirin specifically for treating cardiovascular disease. New uses are still being found for aspirin, and patent applications are still being filed for them.
Viagra is another example. It was originally developed to treat heart conditions, but trials revealed a ‘side effect’ in men. A new patent application followed for that use. From then on, until the patent expired, others couldn’t sell sildenafil for impotence. Second use covers more than a new condition. It can also cover a specific patient group, a different way of administering the drug or a different dosage.
Plant growth product and fungicide
Second use isn’t limited to pharmaceuticals. It also applies when someone discovers a new effect of a known chemical compound. Take a well-known plant growth product. It was later found to inhibit fungi too.
The question was whether someone else could patent the product’s use against fungi. The product already existed, so it wasn’t new, and novelty is a requirement for a patent. And doesn’t a plant grow better anyway if fungi don’t stand a chance? But the antifungal effect had never been described, and it could lead to entirely new uses. So the new use could be patented. The EPO’s Enlarged Board of Appeal confirmed this in its 1989 decision G 6/88.
Advantage of second use in the pharmaceutical industry
Second use is attractive to inventors, especially in pharmaceuticals. Instead of developing an entirely new drug, a company can patent the use of an existing drug for a particular condition. That cuts development costs and gets treatments to patients faster.
Package inserts and advertising
Patenting a new use of a product doesn’t give a company rights to the product itself. Only the holder of a second use patent may mention that use on the package insert.
This also applies to non-medical products. While the antifungal use patent is in force, the maker of the plant growth product may not advertise on its packaging or website that the product also works against fungi. And the same applies the other way around. Package inserts, product descriptions and advertising may only mention a protected use if you hold the patent for it. If you advertise someone else’s patented use anyway, you may be liable for indirect infringement.
The devil is in the wording
In patents, wording is everything. Keep it too general, for example, and infringement becomes harder to prove. Getting the wording right matters just as much for second use. There are specific rules for wording use claims. And call the new use a discovery rather than an invention, and you’ll fall at the first hurdle. The patent must clearly state that it’s a new effect, and that this can lead to entirely new uses.
The rules also differ between medical and non-medical uses. If the application is drafted incorrectly, it may not be granted and the protection may be lost.
Finally, countries have different rules for wording claims. I’ll spare you the details, but remember that the devil is in the wording, and it largely decides whether an application succeeds. So always get a patent attorney to help with your application.
Want to know more about second use, a patent application or other intellectual property issues? Get in touch. We'd be glad to help.
