Be careful what you claim for - U.S. drug case sets precedent for patents
The United States Court of Appeals for the Federal Circuit has set a precedent for U.S. patents with its decision in Nuvo Pharmaceuticals v Dr. Reddy's Laboratories Inc., which offers guidance on the written description of patents.
Typically, non-steroidal anti-inflammatory drugs (NSAIDs), like aspirin, control pain but cause gastrointestinal problems as a side effect. To combat this, the 2 patented inventions also had an enteric envelope around the NSAID tablet core that prevented its premature release. This envelope had acid inhibitors, like proton pump inhibitors (PPIs), on its outside that increased the gastrointestinal tract pH to at least 3.5.
Despite both patent specifications having no experimental data to substantiate the level of increase of the pH, the lower district court held that the disputed claims were valid and that the written description requirement was met. The lower court found that it was not obvious to use a PPI to prevent NSAID-related gastric injury due to prior art discouraging the use of such uncoated PPIs. This judgment was overturned by the Court of Appeals.
Principles of Enablement and Written Description
In the U.S., the enablement requirement is distinct from the written description requirement. Similar to many other jurisdictions like Australia, enablement requires that the patent specification teach those skilled in the art how to make and use the claimed invention (i.e. replicate the invention).
The written description’s purpose is broader and requires that the specification notify the public about the scope of the claimed invention and show that the inventor possessed all the aspects of the claimed invention.
While the Court of Appeals confirmed that U.S. case law did not require experimental data to show or explain effectiveness, there must at least be some description establishing that the inventor was in possession of the claimed invention.
Further, there was no evidence that pointed towards the written description being inherent in the patent’s enablement or that a person of ordinary skill in the art would expect the efficacy of the invention. This meant that the inventor was not in possession of the claimed invention of an amount of uncoated PPI that was effective to raise gastric pH to at least 3.5, hence rendering the claims invalid.
Consequences of the Decision
If an inventor is claiming that a pharmaceutical compound can achieve a certain result, that result must be supported by adequate disclosure in the specification. Thus, to avoid having only a “mere wish or hope” that the invention works, a functional feature in a claim must at least be supported by some experimental data in the specification.
How Can We Help?
If you plan on protecting your invention in the U.S. with a patent, or already have a patent there that you wish to enforce, this case may impact you. Contact us now if you have queries regarding how you may safeguard or defend your patent.
This article intends to outline some of the patent issues that you may need to address with your legal counsel when protecting your patent. It does not go into great depth with the subject matter, but offers useful insights into the basics. It is not legal advice and it is not exhaustive of all laws and issues that may apply to your particular business. Qualified legal counsel should review the details of your patent protection in the relevant jurisdiction.