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INSIGHT: Mallinckrodt Impacts Patent Protection for Medical Treatment Methods

Nov. 1, 2019, 8:00 AM

In a break with its own recent precedent, the Federal Circuit Court of Appeal found in Mallinckrodt that a specific medical treatment method was not subject matter eligible for patent protection. Patent attorneys have since been pouring over the decision to determine how it impacts patent protection for medical treatment methods.

This article discusses the decision, its significance in the context of prior precedent, and provides practical advice to patent attorneys on how to cope with the decision while advising their clients on obtaining patent protection medical treatment inventions

Patent Dispute Between Mallinckrodt and Praxair

Mallinckrodt concerned appeal of a district court ruling in a patent infringement dispute between Mallinckrodt Pharmaceuticals and competitor Praxair. The patent in issue in the case concerned a method for treating infants suffering hypogenic respiratory failure (HRF), a condition in which infants and babies have low levels of oxygen in their tissue, using inhaled nitric oxide (iNO) gas.

Mallinckrodt’s patented method of treatment was based on the discovery that babies suffering from HRF, with a heart condition, known as left ventricular dysfunction (LVD), were at an increased risk of pulmonary edema (swelling of lung tissue due to excessive liquid) when treated with iNO gas.

The key claim at issue in Mallinckrodt included the steps of 1) identifying patients who suffer from HRF and are candidates for iNO treatment; 2) screening the candidates for LVD; 3) treating the patients who do not have LVD with iNO; 4) excluding patients with LVD from the iNO treatment.

Court Finds Claim Ineligible for Patent Protection

Under longstanding interpretation, Section 101 of the patent act excludes laws of nature, natural phenomena, and abstract ideas from eligibility for patent protection.

Under Supreme Court precedent in Mayo, courts determine subject matter eligibility under Section 101 in a two-step test. First, the claim is examined as to whether it is directed to a patent-ineligible concept, such as a natural phenomenon, abstract idea or a law of nature.

If so, then the claim is further examined for a determination as to whether it includes functions, features or aspects, which would sufficiently transform the claim to render it patent eligible.

The Mallincrodkt majority (it was a split 2-1 decision) found that the claim in issue in that case was ineligible for patent protection because it was directed to a natural phenomenon in that the claim merely withheld treatment from a screened group, without administering any treatment on them.

The majority found that withholding treatment merely allows natural law to take its course in the untreated subgroup. The dissenting opinion disagreed, pointing out that the claim, as a whole, was subject matter eligible as a man-made medical treatment procedure, which did not exist in nature.

Mallinckrodt Directs Mayo Analysis to ‘the Focus of the Invention’

As pointed out, the Supreme Court’s Mayo test requires courts to analyze subject matter eligibility under section 101 by examining the entire claim, not merely its individual elements. In Mallinckrodt, however, the court conducted its examination of the claim not on the entire claim, but on what it understood at ‘the focus of the invention,” which the majority found to be “screening for a particular adverse condition that, once identified, requires iNO treatment be withheld.”

This “focus of the invention” approach is inconsistent with binding precedent, which requires analysis of the claim in its entirety.

Mallinckrodt Breaks Section 101 Precedent

Mallinckrodt is notable because it breaks with recent Federal Circuit trend in Section 101 eligibility determinations under which medical treatment methods have been found eligible for patent protection.

For example, in Vanda, the Federal Circuit affirmed subject matter eligibility for a method for treatment of schizophrenia. The claims at issue in that case were directed to the impact of iloperidone, a drug used for treating schizophrenia, on increasing the risk of serious cardiac problems in certain patients. The patented invention in Vanda instructed treating such high-risk patients with a lower dose of the drug.

Likewise, in Nat. Alternatives, the court of appeal found the invention directed to using dietary supplements to increase an athlete’s anaerobic working capacity to pass the Section 101 eligibility test. According to the claims, administering certain quantities of beta-alanine results in production of greater levels of creatine, which, in turn, increases the working capacity for athletes engaged in intensive exercise.

Similarly, as to the invention in issue in Endo Pharmaceuticals, the Federal Circuit found that a method for treating pain in patients suffering from a kidney disorder with a dosage regimen of the drug oxymorphone, to be subject matter eligible for patent protection.

These precedents support the conclusion that methods of treatment directed to identifying a natural phenomenon, screening patients for a particular condition and leveraging that condition to affect the treatment decisions made with respect to screened patients constitute eligible subject matter for patent protection.

In fact, the Federal Circuit has specifically found that “singling out a particular subset of patients for treatment . . . may reflect a new and useful invention that is patent eligible despite the existence of prior art or a prior art patent disclosing the treatment method to patients generally.”

Post-Mallinckrodt Claim Drafting Tips

The Mallinckrodt majority repeatedly referred to “the focus of the invention” in conducting its Section 101 analysis. Patent attorneys would thus be well advised to also tailor their description of their inventions in the patent specification to emphasize the focus of the invention, rather than leaving it to the challengers and courts to determine.

Also, to the extent practicable, the claims should strive to include a dosage regulation step, under which the subgroup identified as a result of screening for a certain condition do receive some level of treatment.

This column does not necessarily reflect the opinion of The Bureau of National Affairs, Inc. or its owners.

Author Information

Dr. Dariush Adli is the founder and president of ADLI Law Group in Los Angeles. With more than two decades of experience, Adli has successfully counseled and represented U.S., Asian, and European businesses, from Fortune 500 corporations to startup companies, in intellectual property and business matters.