Problems ' And Solutions ' For Securing Patent Protection Over Diagnostic Technologies

• Published date: 09 August 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Fox Rothschild LLP
• Author: Peter J. Butch III

Drafting claims for methods of diagnosing and treating patients can be challenging since they involve the measurement of patent-ineligible subject matter and because these methods are often performed by multiple parties.

But "Test and Treat" claims are particularly desirable when connected to regulatory approval of a drug for use in patients with a positive test result. These claims must be carefully written to capture patent-eligible aspects of the diagnostic method in a manner that ensures that at least one party is held accountable in the event of infringement.

Background

In the United States, multiple parties are typically involved in a patient's diagnosis and subsequent treatment. A hospital or clinic usually does the initial examination and makes the decision to run a test. They may take samples and perform the tests themselves with in-house diagnostic equipment or contract with a third-party diagnostic laboratory facility. When the results are ready, a physician generally interprets them and determines which intervention to apply.

Two problems

When drafting method claims that cover a diagnostic testing method, two problems arise. First, the subject matter will include patent-ineligible elements because the method measures a natural phenomenon. That is especially true if the method merely recites performing the test and making a diagnosis. Second, the divided responsibilities of the laboratory and the hospital might mean that neither party performs all the elements of the method claim, allowing the parties to evade infringement liability.

As articles of manufacture, diagnostic testing products are patent-eligible subject matter. However, under the Mayo standard, the testing methods performed at the diagnostic facility encroach on patent-ineligible subject matter because the diagnostic process unavoidably involves measurement of a naturally occurring phenomenon.¹ Subject matter eligibility comes from novel applications of the naturally occurring phenomenon beyond making a diagnosis merely based on the test numbers. This is often just a matter of semantics because subject matter eligibility hinges not on what you claim, but how you claim it.

For example, an improved method of testing cholesterol levels and diagnosing hyperlipidemia would not be patent eligible without a nexus to a significant improvement attributable to the testing device, nor would treating with a statin based on the diagnosis. The steps for detecting cholesterol levels, even if...