The impact on human health of the global pandemic of the SARS-CoV-2 virus and the resulting disease termed COVID-19 cannot be overstated. Not since the influenza pandemic of 1918 have so many regions of the world been so acutely impacted by a single pathogen. Society in 2020 has the advantage of a more sophisticated biotechnology industry. Testing is considered crucial in controlling (or at least mitigating) the pandemic, and tests from several companies have become widely available.  However, many of the tests have proven inaccurate, and it is becoming clear that more needs to be invested in validation before tests can be rolled out to the public. It is also becoming clear that this pandemic will persist for months or possibly years — it may even recur periodically like many other communicable diseases. This has created incentives for the development of validated tests for use not only in the immediate future, but possibly for years to come.

The cost of developing and validating diagnostic tests can be efficiently recouped if the test is patented, giving the developer an exclusive market for a finite period. However, one hoping to patent a COVID-19 test must plan to avoid certain foreseeable difficulties inherent in American law in doing so.

Obviousness in the Post-Genomics Age

Under Section 103 of the Patent Act, a patent cannot be obtained if “the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains.” Novelty by itself is not sufficient for patenting. Even an invention that has never existed before can be denied a patent if a judge or a patent examiner deems it to be “obvious.” The American obviousness standard is a vague and subjective standard compared to foreign analogs. This virtually always presents an obstacle to patenting in the United States, and it is a particular concern when it comes to diagnosing COVID-19.

The genome of SARS-CoV-2 has been elucidated and is publicly known, and a great deal has been learned and published about the structural proteins in the virus. Any test that functions just by detecting a sequence in the genome is likely to be considered obvious. The rationale is that a person of ordinary skill would look to sequences in the virus’ genome, determine which are unique to the virus (or at least absent from the human host), and try such sequences as a diagnostic target. The same holds true for structural proteins: If they are known to be part of the virus, it would be obvious to test for them to detect infection in the host. Stated another way, if the analyte is known but has never been used as a diagnostic indicator, it is presumed to be obvious to do so.

However, if it can be shown that testing for a certain target has unexpected advantages compared to other targets, then the test is not obvious. Examples of such advantages can include higher accuracy, higher specificity, less stringent purification steps, etc. In order to obtain a patent, one should be prepared to present evidence of such unexpected advantages, ideally in the patent application itself.

There can be non-obvious aspects of a diagnostic test apart from the analyte. For example, if the invention is a new assay to detect the analyte, or a new instrument to measure the analyte, it does not matter as much that the analyte itself might already be known. However, if the invention is a traditional type of test used on a known analyte (even if for the first time), be prepared to rebut an obviousness challenge.

The Mayo Ban on Patenting Diagnostic Tests

The United States also stands with a small number of countries that consider diagnostic tests as forbidden subject matter for patenting, regardless of how novel or non-obvious. The doctrine (“the Mayo ban”) has been reviewed in numerous earlier blog posts. The Supreme Court has taken the position that any actions that directly result in making a medical diagnosis cannot be patented as a method, because they are nothing more than “laws of nature.” In this case the “law of nature” is that the presence of an analyte is indicative to the presence of the disease. This includes physical steps such as obtaining samples and performing chemical and biochemical tests on the samples.

However, the courts have also opined that including a medical intervention in the method renders it more than just a law of nature. As a result, patents are allowed for combined methods of testing and treatment (or other forms of medical intervention). These usually take the form of a method that involves the act of testing followed by the act of treating if the test has a certain result.

In the context of COVID-19 this poses a specific difficulty: There is only one drug that is thought to be effective to treat the disease, and its effectiveness is still being validated to a great extent. This creates a problem if one tries to draft a patent claim that includes the act of treating COVID-19. A patent can only cover what a person of ordinary skill could successfully make and use based on the state of the art combined with the information in the patent application. It is not clear at present that the disease can be treated given the state of the art.

One possible solution to that dilemma is to claim an intervention that is not limited to treatment or does not include treatment. It could be mere supportive measures. It could be a contagion control measure, such as quarantine. Such measures go beyond simply diagnosing the patient.

Enablement: Are You Sure It Works?

As mentioned above, a requirement for patenting is that evidence must be provided that a person of ordinary skill could make and use the invention (i.e., it is “enabled”). The law allows such evidence to be provided as “paper chemistry” (modelling), in vitro data, animal data, and human trial data. However, the USPTO has a marked preference for animal and human data; they will sometimes accept in vitro results but will infrequently accept paper chemistry models when it comes to methods of medical diagnosis. This poses another problem. Presently there is no universally accepted animal model for COVID-19. A recent review concluded that several animals are permissive of the virus, but none appear to show the same severity of symptoms as humans; this calls into question the applicability of the models to human vaccines and treatments. Of course, human subjects provide the strongest data, but human testing is expensive and time consuming; human data are rarely available at the time a patent application is filed.

It is possible that the USPTO will view in vitro data permissively in light of these acknowledged issues at the present time. However, an accused infringer in court will not, and will take advantage of current limitations in validating COVID-19 tests in animals and humans to argue that patents are invalid because they are not enabled.

Summing Up: Prepare Your Patents Carefully

Under the best of conditions patent procurement can be a long and expensive process. Given the immediate demand for accurate and inexpensive COVID-19 tests and the complicating factors discussed above, patenting COVID-19 tests could be especially challenging unless preparations are made to avoid such challenges. Consideration should be given during the drafting process for ways to avoid rejections for obviousness, banned subject matter, and enablement. A modest amount of effort in the beginning of the process could shorten the patenting process by years and reduce patenting costs by thousands of dollars.