In Ex parte Eastman, 2019 PAT. APP. LEXIS 9982 (PTAB 2019) the PTAB gives us an easy-to-follow road map for securing method of treatment patents when our clients make new biomarker discoveries. First and foremost, we must avoid claiming the situation where the doctor chooses not to treat the patient based on the biomarkers, because that method is not eligible for a patent. Once this threshold issue is resolved, and the claim is properly structured, the method should be patentable provided the prior art does not adequately teach a causal link between the biomarkers and the disease being treated.
In Ex parte Eastman the claim covered:
A method for treating a subject having juvenile idiopathic arthritis (JIA) the method comprising:
providing a test sample comprising a sample of bodily fluid taken from the mammal;
determining a sample concentration for a combination of three or more biomarkers selected from the group comprising C-reactive protein (CRP); epidermal growth factor (EGF); interleukin 6 (IL-6); leptin (LEP); matrix metalloproteinase-1 (MMP1); matrix metalloproteinase-3 (MMP3); resistin (RETN); serum amyloid (SAA); tumor necrosis factor receptor, type 1 (TNF-R1); vascular cell adhesion molecule-1 (VCAM1); vascular endothelial growth factor A (VEGF-A); and YKL-40;
determining whether the sample concentration is statistically significantly greater than a combination of concentrations of corresponding control biomarkers that are indicative of JIA; and
administering a JIA therapeutic regimen if the sample concentration is statistically significantly greater than the combination of concentrations of corresponding control biomarkers.
As can be seen, the claim was directed toward a very common drug diagnostic combination that required the user to: (1) perform a diagnostic test, and (2) treat if the diagnostic test gives one result, but don’t treat if the diagnostic test gives another.
Unfortunately, the claim was too broad. The PTAB ruled that the claim was not eligible for a patent because it covered the non-treatment option, stating:
under certain scenarios the claimed method merely results in detection of the biomarker and no action is to be taken based on the information ascertained in the detection of the natural correlation. In other words, if a certain condition precedent is not met, the additional step of administering atreatment is not performed. … This is similar to claims in Ex parte Schulhauser, Appeal No. 2013-007847 (PTAB Apr. 28, 2016) (precedential), where the Board concluded that in a method claim where the additional steps need only be performed if certain conditions precedent were met, the claim covered the method where the additional steps need not be performed. … [L]ike the claims found patent ineligible in Mayo, Appellant's claim involves acquiring information to observe the natural law, but do not require any particular use of the acquired information to, e.g., alter a patient's condition.
Thus, the claim would have been eligible for a patent if it was structured as follows: (1) providing a patient with a disease who meets certain diagnostic criteria, (2) testing the patient for the diagnostic criteria, and (3) treating the patient for the disease using an established prior art method.
The second issue that this claim presented was obviousness. Ex parte Eastman illustrates how, even though the diagnostic criteria are themselves patent ineligible, they can form the basis for the patent. I.e., they can act as the point of novelty and non-obviousness. The key, as the PTAB explained in Ex Parte Eastman, is whether the diagnostic criteria have previously been adequately linked to the disease being treated. In this case, the markers had been linked ito rheumatoid arthritis (“RA”) in the prior art but not juvenile idiopathic arthritis. As explained by the PTAB,
the [prior art] DAIMRK biomarkers are specific to RA and there is no teaching of how one of ordinary skill in the art would know which of those markers would reasonably correlate to JIA. While it may be the case that one of ordinary skill in the art could have used the ‘Model Development Process’ described in Cavet to assess what biomarkers are relevant to JIA, that the described process would be promising to try does not establish obviousness.
While the diagonstic method might not be elibible for a patent, this case proves that claims to a drug / diagnostic combination certainly are.