Your scientists have developed a drug / diagnostic combination for treating a severe disease. The drug works when the diagnosis is positive, but fails when the diagnosis is negative. You have spent millions of dollars to make this discovery, including human trials and the development of a diagnostic kit, but can you protect it?
Unfortunately, if you are the diagnostic kit’s manufacturer, the odds of securing meaningful patent protection are quite low. You could conceivably claim a method of treating diseased patients based on their diagnosis, but this would not stop other diagnostic manufacturers from marketing a similar diagnostic kit because there will almost always be “substantial non-infringing uses” for the diagnosis unrelated to the use of the drug.
Promethius Labs, a diagnostic service provider, tried to overcome this problem in Mayo Collaborative Servs. v. Prometheus Labs., Inc., 566 U.S. 66, 72 (2012) (“Mayo”), by claiming the doctor’s mental analysis of the diagnostic test results, but the Supreme Court rebuffed it. In Mayo, Promethius offered a test for measuring 6-thioguanine, a drug used in chemotherapy, and had been granted a patent that covered:
A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:
(a) administering a drug providing 6-thioguanine to a subject having said immune mediated gastrointestinal disorder; and
(b) determining the level of 6-thioguanine in said subject having said immune mediated gastrointestinal disorder,
wherein the level of 6-thioguanine less than about 230 pmol per 8x108 red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and wherein the level of 6-thioguanine greater than about 400 pmol per 8x108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.
The claim recited two manipulative steps (administering 6-thioguanine to a subject and determining the level of 6-thioguanine in the subject), in combination with a purely mental step (determining whether to increase or decrease the dose of 6-thioguanine). The mental step was the point of novelty because the manipulative steps had been widely practiced in the prior art.
Supreme Court held that this mental step added nothing to the patentability of the claim, and struck down the patent claim, because it was an unpatentable “law of nature,” stating:
Prometheus' patents set forth laws of nature-namely, relationships between concentrations of certain metabolites in the blood and the likelihood that a dosage of a thiopurine drug will prove ineffective or cause harm.
Contrast this result with the Federal Circuit’s decision to uphold a dose reduction patent in Vanda Pharm. Inc. v. West-Ward Pharm. Int’l Ltd., 2018 U.S. App. LEXIS 9360 (Fed. Cir. Apr. 13, 2018) (“Vanda”), a case we previously blogged about. There, the pharmaceutical manufacturer’s patent claimed:
A method for treating a patient with iloperidone, wherein the patient is suffering from schizophrenia, the method comprising the steps of: determining whether the patient is a CYP2D6 poor metabolizer by:
obtaining or having obtained a biological sample from the patient; and
performing or having performed a genotyping assay on the biological sample to determine if the patient has a CYP2D6 poor metabolizer genotype; and if the patient has a CYP2D6 poor metabolizer genotype, then internally administering iloperidone to the patient in an amount of 12 mg/day or less, and if the patient does not have a CYP2D6 poor metabolizer genotype, then internally administering iloperidone to the patient in an amount that is greater than 12 mg/day, up to 24 mg/day,
wherein a risk of QTc prolongation for a patient having a CYP2D6 poor metabolizer genotype is lower following the internal administration of 12 mg/day or less than it would be if the iloperidone were administered in an amount of greater than 12 mg/day, up to 24 mg/day.
The claim was practically identical to Prometheus’ patent claim struck down by the Supreme Court, except it recited one additional manipulative step: administering a reduced dose of the drug in response to the diagnosis. Where Prometheus’ patent had covered the doctor’s mental process of determining whether to reduce the dose, Vanda’s patent put that mental process into action, and claimed the actual administration of a reduced dose.
My Mother always taught me that actions speak louder than words. As these two cases make clear, in the patent world, she was absolutely correct.
