Endo Pharmaceuticals Inc. v. Teva Pharmaceuticals USA, Inc., 2017-1240, 2017-1455, 2017-1887 (Fed. Cir. March 28, 2019)

In Endo Pharmaceuticals Inc. v. Teva the Federal Circuit has further clarified the patent eligibility of treatment methods which include natural elements. The Opinion, which includes comparisons with other cases such as Vanda, CellzDirect and Ariosa Diagnostics, leaves one crafting such claims on ground that is fairly firm.

The dispute in this case involved Endo’s patent U.S. 8,808,737 (‘737 Patent) which relates to methods for the treatment of pain in renal patients. It has long been recognized that controlled -release dosage forms of pain relief are important to maintain proper levels in the body. However, this is even more challenging with patients having kidney problems. The ‘737 Patent leverages work performed relating oxymorphone content in the bloodstream, measured as AUC, to creatinine clearance. Creatinine in the blood is removed by the kidneys, so that higher levels of creatinine correlate to poorer kidney function. A range of kidney performance (healthy, mild renal impairment, moderate renal impairment, and severe renal impairment) can be defined relating to a corresponding range (high to low) of creatinine clearance. The patent data demonstrates that as kidney function deteriorates, especially with moderate or severe renal impairment, oxymorphone AUC’s increase rapidly. The patent claims, therefore, set out a method for taking renal impairment into account when administering oxymorphone.

When Endo sued Actavis for infringement of claims 1-6 of the ‘737 Patent, Activis moved for dismissal based on the theory that the claims were ineligible subject matter under §101. A magistrate, analyzing the case under the Alice/Mayo test, found the claims ineligible, reasoning that the steps were similar to those of Mayo. With respect to the administering step, the magistrate indicated

The administering step simply limits the relevant audience to patients and prescribing physicians, who treat chronic or acute pain with oymorphone, and instructs the administration of the correct dosage of oxymorphone depending on the severity of the renal impairment, a step very similar to Mayo, which limited the relevant audience to “doctors who treat patients with certain diseases with thiopurine drugs.

The District Court agreed with the Magistrate, particularly with the comparison of the claims to that of Mayo. Endo appealed.

In rejecting the District Court’s analysis, the Federal Circuit approvingly cited the holding and claims in Vanda as an example of treatment claims meeting the requirements of §101. Table 1 summarizes claim 1 of both the ‘737 Patent and Vanda.

Table 1.

The Federal Circuit Opinion, together with the claims of the ‘737 Patent and Vanda provide key lessons for avoiding §101 problems in crafting method of treatment claims.

1. The claim as a whole is evaluated

The Federal Circuit repeated that the claims must be read as a whole.[10] This reinforces the Bahr memo issued to Examiners previously, as mentioned above.

2. Treatment methods are eligible, detection methods or observation are not.

The Federal Circuit differentiated treatment claims that are eligible from detection methods, that are not, as in the Ariosa & Athena Diagnostics decisions.[11] The claims found ineligible in Ariosa were directed to a method for detecting paternally inherited cell-free fetal DNA.[12] In Athena, the Federal Circuit observed that the claims related to a natural law and conventional means for detecting it.[13] A key point when considering these treatment claims is to understand that the natural ability of an element in a claim to be incorporated in the method does not mean that the claim is directed to that natural ability.[14] In CellzDirect the claims were directed to a method for freezing hepatocytes.[15]

Treatment method should contain specific steps

To be patent eligible, the treatment method claim should contain specific steps. In contrast to the Mayo claims where a thiopurine drug was simply administered to a patient, the Federal Circuit noted that the Endo claims are directed to an application of a drug treatment for a particular disease, where a specific dose was administered based on the results of kidney function testing.[16] Likewise in Vanda, doctors administered iloperidone for schizophrenia, with dosages based on whether the patient had a CYP2D6 poor metabolizer genotype. The claims were not directed to a method for corelating the “natural phenomenon” of poor kidney function (in Endo) or to measuring genotype (in Vanda), but to their use in a treatment step. In other words, the claims do not just recite a natural relationship, but instead use the natural law or phenomenon in the treatment.[17]