Medical Use Exception v. Divided Infringement (Part 3 of 3): Seeing Medical Treatment Claims in a New (Lime)Light

by VolpeKoenig on February 5, 2013

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Recent developments in the case law have expanded induced infringement to include performance of the method claims steps by multiple actors. See Value Added to Medical Method and Diagnostic Patents through Induced Divided Infringement. The change comes from the Federal Circuit in Akamai Tech. v. Limelight Networks and may impact how claim drafters formulate method claims. It will be interesting to see how medical treatment claims are drafted in light of divided infringement.  Could a case like Mayo v. Prometheus have had a different result if the method claims had been directed toward divided infringement? See Supreme Court Invalidates Medical Treatment Claims as Unpatentable Subject Matter.

In Prometheus, the Supreme Court invalidated the two step method claims as unpatentable subject matter. The steps at issue were (a) administering the drug, and (b) determining the level of drug in the patient’s system.  As part of the determining step, two wherein clauses set forth a previously undiscovered correlation criteria between the amount of drug in the patient’s system, and whether more or less drug should be administered. The Court held that the correlation described in the wherein clauses was a law of nature and therefore the claim would be unpatentable, “unless [it had] additional features that provide practical assurance that the processes are genu­ine applications of those laws rather than drafting efforts designed to monopolize the correlations.” The application of a law of nature is patentable. But the court also held that the steps (a) and (b) were well known and routine, and as such, steps (a) and (b) would not rescue the claim.

Adding an additional step to the method claim could have limited the claim to an inventive application of the law of nature identified by the Court, which would have rendered it patentable subject matter. For example, if a step (c) were added involving “administering an adjusted dose to a patient based on the results,” the claim would have been limited to an application of the law of nature, and would have introduced multiple actors in performance of all of the steps of the method.  However, the method claims inPrometheus may have been a by-product of the times; drafted so that single actor would perform all the steps and infringe the patent. A substantial value in a medical method patent is derived from instances of induced infringement and contributory infringement because doctors who directly infringed by performing the method are exempt from liability under the medical procedure exception. See All is Not Lost to the Medical Procedure Exception. To recover under induced infringement at the time the Prometheus patents were drafted, a single actor would have to be induced to perform all of the steps of the method claim.

Under the change made by Limelight, a patentee may avoid a finding of invalidity if its patent claims including a “law of nature” are drafted to include an extra novel step that applies the law of nature and is to be performed by a second actor. Further, the patentee may succeed in enforcing the claim under induced infringement.

Post By: Douglas J. Bucklin, Ph.D. of Volpe and Koenig, P.C.

Note:  Special thanks to Amber Stiles, Law Clerk at Volpe and Koenig, for her contributions to this post.

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