A divided Federal Circuit panel upheld Vanda’s patent covering its iloperidone schizophrenia treatment (Fanapt^®), holding the method of treatment claims were directed to patent-eligible subject matter.  Vanda Pharms. Inc., et al. v. West-Ward Pharms. Int’l Ltd., et al., Nos. 2016-2707, 2016-2708 (Fed. Cir. Apr. 13, 2018).  In meticulously evading the Supreme Court’s Mayo decision, Vanda suggests patentees can save otherwise patent-ineligible treatment optimization claims directed to natural laws by incorporating specific dosing regimens.

Vanda’s method claims describe, to paraphrase, a method of treating a schizophrenia patient with iloperidone comprising (1) determining whether the patient is a CYP2D6 poor metabolizer by testing the patient’s genotype, and (2) administering ≤12 mg/day iloperidone if the patient has a CYP2D6 poor metabolizer genotype, and administering >12 – 24 mg/day if the patient is not a poor metabolizer.  The claims explain that this dosing regimen reduces the risk of QTc prolongation, a lengthened QT interval that can cause serious cardiac problems.  As one might surmise from the claim, CYP2D6 is a gene encoding an enzyme that metabolizes iloperidone, and low metabolizers are at risk of QTc prolongation with higher doses.

For comparison, Mayo, which was directed to unpatentable subject matter, involved claims to a method of optimizing treatment via (1) administering a drug providing 6-thioguanine to a subject with immune-mediated gastrointestinal disorder, and (2) determining the level of 6-thioguanine in the subject.  The claims further explained that a level of 6-thioguanine <230 pmol in the blood indicates a need to increase the amount of drug subsequently administered to the subject, and a level of 6-thioguanine >400 pmol indicates a need to decrease amount of drug subsequently administered.   By staying within these parameters, the administered dose is less likely to be ineffective or produce toxic side effects.

The ANDA-filer argued that, like the claims in Mayo, the challenged claims were directed to the natural relationship between levels of a drug in the blood and the safety and efficacy of that drug, and added nothing inventive to these natural laws.  The Court disagreed, finding the claims not “directed to patent-ineligible subject matter” under step one of Alice.

The opinion goes to great lengths to differentiate Vanda’s claims from those at issue in Mayo.  “First, the claims in Mayo were not directed to a novel method of treating a disease.  Instead, the claims were directed to a diagnostic method…. Although the representative claim in Mayo recited administering a thiopurine drug to a patient, the claim as a whole was not directed to the application of a drug to treat a particular disease.”  In contrast, Vanda’s claims “are directed to a method of using iloperidone to treat schizophrenia.  The inventors recognized the relationships between iloperidone, CYP2D6 metabolism, and QTc prolongation, but that is not what they claimed.  They claimed an application of that relationship.”  In particular, the claims require a treating doctor to administer a specific amount of iloperidone based on the result of the genotyping assay.  In contrast, “[t]he claim in Mayo did not go beyond recognizing (i.e., ‘indicates’) a need to increase or decrease a dose,” without prescribing a specific dosage regimen.

The Court’s hairsplitting to distinguish this case from Mayo is a departure from prior encounters with § 101 in pharma cases, which we’ve previously commented on here and here.  Indeed, Chief Judge Prost’s dissent examined the Mayo and Vanda claims side-by-side and concluded the majority’s “efforts to distinguish Mayo cannot withstand scrutiny.”  The differences in Vanda’s claims, if any, reflect “drafting efforts designed to monopolize the law of nature itself,” and the “patent simply discloses the natural law that a known side effect of the existing treatment could be reduced by administering a lower dose to CYP2D6 poor-metabolizers.”  Thus, barring further clarification, it appears that Vanda will make it possible for patent prosecutors to avoid patent eligibility roadblocks through a simple tweak in claim language.  Whether the rest of the Federal Circuit agrees with that outcome remains to be seen.