Background
Vanda Pharmaceuticals developed iloperidone, an antipsychotic drug marketed as Fanapt, for treating schizophrenia. The drug carries a known risk of causing QTc prolongation — a disruption in the heart’s electrical rhythm that can trigger life-threatening arrhythmias. Vanda’s research revealed that patients with a particular variant of the CYP2D6 gene metabolize iloperidone more slowly, leading to higher blood concentrations of the drug and a greater risk of QTc prolongation. To address this, Vanda’s patent claimed a method of treating a schizophrenia patient that incorporated genetic testing: if the patient is a poor CYP2D6 metabolizer, the clinician administers a lower dose; if the patient is a normal metabolizer, a higher dose may be given safely.
West-Ward sought FDA approval for a generic iloperidone product. Vanda sued for patent infringement under the Hatch-Waxman Act. West-Ward challenged the validity of Vanda’s patent under § 101, arguing that the claims were directed to a natural law — the relationship between CYP2D6 genotype and drug metabolism — and therefore ineligible under the Supreme Court’s 2012 ruling in Mayo Collaborative Services v. Prometheus Laboratories.
The Court’s Holding
The Federal Circuit affirmed the district court and held the claims patent eligible. Writing for a unanimous panel, Judge Lourie distinguished the claims from those invalidated in Mayo. In Mayo, the claims were directed to the relationship itself between thiopurine drug levels and patient outcomes — they essentially claimed that doctors should be aware of the natural correlation. Vanda’s claims, by contrast, go further: they specify a concrete method of treatment — a specific dosing regimen tied to genetic testing — that applies the natural relationship to achieve a defined therapeutic result. The inventors didn’t merely claim the natural phenomenon; they claimed a treatment method that uses it.
The court held that method-of-treatment claims satisfying the traditional requirements of patentability are patent eligible even when they incorporate a natural correlation, as long as the claims are directed to an application of that correlation rather than to the correlation itself. Crucially, the court also held that method-of-treatment claims can clear § 101 at Alice/Mayo step one — they need not necessarily show “inventive concept” at step two if the claim itself is properly directed to a treatment application. This was a meaningful clarification because it meant personalized medicine patents could survive eligibility challenges without needing to show that every step was nonroutine or unconventional.
Key Takeaways
- Method-of-treatment claims that apply a natural correlation to specify a specific dosing regimen are patent eligible under §101, even when the underlying correlation is a natural phenomenon.
- Mayo is limited to claims that are directed to the natural law itself (e.g., “be aware of this correlation”); claims that go further by specifying a concrete treatment based on that law survive step one of the Alice/Mayo analysis.
- Personalized medicine patents that link genetic testing to specific dosing or treatment decisions occupy more favorable §101 ground than pure diagnostic patents that merely describe a natural relationship without a treatment step.
- The USPTO issued a memorandum citing Vanda to guide examiners in evaluating method-of-treatment claims, directing examiners to find such claims eligible when they recite specific treatment steps rather than mere awareness of a natural phenomenon.
Why It Matters
After the Supreme Court’s Mayo decision in 2012, the pharmaceutical and biotechnology industries faced deep uncertainty about whether personalized medicine patents — patents that tailor treatment to a patient’s individual characteristics — would survive patent eligibility challenges. If merely connecting a genetic trait to a dosing decision is enough to render a claim ineligible, a wide swath of modern precision medicine would be unpatentable, removing much of the commercial incentive for the expensive research required to develop such therapies.
Vanda drew a workable line. The key is whether the claim is directed to a treatment application or merely to the underlying natural relationship. Claims that incorporate testing and specify what to do with the results in a concrete medical context pass muster; claims that essentially say “you should know about this correlation” do not. That distinction has become a touchstone for drafting and litigating personalized medicine patents, and the USPTO’s guidance memo ensured the decision’s principles were applied uniformly across patent prosecution.