A US District Court decision of 4 August 2017 reduced the chances of patenting diagnostic methods. This decision illustrates well the challenges of applying for a patent on medical devices for diagnostic methods in the USA and EU.

The chances of obtaining patent on diagnostic methods lost ground yet again when a US District Court rendered its decision on 4 August 2017 in the lawsuit between the pharmaceutical company Athena Diagnostics inc. (Athena) and the laboratory testing company Mayo Medical Laboratories (Mayo).

Under the patent legislation of most countries, it is not possible to obtain a patent on certain inventions, such as inventions merely constituting an abstract concept, a mathematical method or a discovery. In Denmark, a “discovery” is defined as the recognition of something that already occurs in nature, even if it has not yet been described by anybody. The USA is among the few countries in the world in which diagnostic methods are not per se exempted from forming the basis of a patent application.

The case in brief

The lawsuit was filed by Athena against Mayo for infringing Athena's patent on a method for diagnosing patients with the autoimmune disorder Myasthenia Gravis. Along the way, however, focus changed, questioning whether Athena's patent was valid at all. As it was, Mayo countered the infringement claim arguing that the patent was directed to the recognition of a natural phenomenon, that is something that already occurs in nature (a discovery), and that no new useful technique had been documented. In brief, the patented method was used for attaching a radioactive label to a receptor – characteristic of 20% of Myasthenia Gravis patients – and adding body fluid. If antibodies attacked the receptor, this was an indication of the patient suffering from the disorder.

The US District Court concluded that the method could not be patented as the invention described a discovery and as the process of detecting antibodies, according to its description, was not new (which was also infered from the patent application itself).

The lawsuit is the latest in a series of US court decisions since 2012 in which patents on diagnostic methods have been found invalid with reference to the basis for the patent applications being a natural phenomenon (a discovery) void of any novel useful concept.

Patents in EPO and Denmark

The patent systems of the EPO and Denmark distinguish themselves from the US system in that therapeutic treatment or diagnostic methods do not constitute inventions that may be patented. However, the definition of a "diagnostic method" is quite narrow, often making it possible – to put it simply – to obtain a patent by choosing and using the proper wording in a patent application. The European Patent Convention lays down that a diagnostic method includes all four steps stated below:

  1. An examination phase, involving the collection of data.
  2. A comparison of these data with standard values.
  3. The finding of any significant deviation, i.e. a symptom, during the comparison.
  4. The attribution of the deviation to a particular clinical picture.

If the diagnostic method does not include all the steps, the invention will not be excluded from the Convention's exceptions to patentability in respect of diagnostic methods.

Comments by Bech-Bruun

In the USA, the grant of a patent depends first of all on whether the invention is a new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, which is not just a law of nature, physical phenomena, or an abstract idea. In some circumstances, we have seen applications where one or all the patent claims were rejected because their subject matter was directed to medicinal correlations (discovery of a physical phenomena) without establishing any new useful method, process or the like.

The requirements for obtaining a patent with the EPO and in Denmark are in many ways similar to those applying in the USA. In these latitudes, however, European laws also lay down that patents cannot be obtained on methods for treatment or diagnosis of the human body. Consequently, other things being equal, it seems less probable obtaining a patent with the EPO and in Denmark if the invention pertains to medicinal correlations since such correlation supposedly always constitutes (part of) a diagnosis or a treatment.

Paradoxically, however, we have seen several instances of applications for patents on diagnostic methods and treatments being rejected in the USA while granted by the EPO. Accordingly, and unsurprisingly perhaps, it may prove an advantage for the applicant to phrase the patent applications to match and satisfy the various authorities' patentability requirements even though the applications concern the same subject matter. In the USA, it may be necessary for the applicant to include as many details as possible in the application to ensure that the subject matter of the claimed invention distinguishes itself from discoveries and existing inventions. The EPO does not exercise the same restrictive approach of distinguishing an invention from discoveries. Instead, however, the applicant will have to make sure that the invention is not categorised as a diagnostic method, the description of which includes all of the four steps from examination, collection and testing of data to the attribution of the deviation to a particular clinical picture.