The Doctrine Of Inherency In The Context Of An Obviousness Analysis

In this board decision, the Patent Trial and Appeal Board (PTAB) reversed the Examiner’s rejections of claims 22, 54-56, and 60-62 in US 16/765,024. The board’s decision focuses on application of the doctrine of inherency in an obviousness analysis.

The invention is directed to the treatment of cancer pain using dicycloplatin (“DCP”) in a patient whose cancer is insensitive to DCP treatment. The invention comprises a product containing DCP and an acid, such as 1,1-cyclobutanedicarboxylic acid, citric acid, chlorogenic acid, ferulic acid, maleic acid, salicylic acid, folic acid and gallic acid.

Sole independent claim 22 on appeal recites as follows:

22. A method of treating cancer pain, the method comprising administering an effective dose of dicycloplatin for treating the cancer pain to a patient in need thereof, wherein the patient has developed drug resistance to platinum anticancer drugs and is a cancer patient whose tumor is insensitive to dicycloplatin treatment.

In the non-final action, the Examiner rejected the claims as obvious over WO 2016/172393 A1 (Liu ‘393), Giuseppe Giaccone, Clinical Perspectives on Platinum Resistance, 59 (Suppl. 4) Drugs 9–17 (2000) (Giaccone), and WO 2016/187191 A1 (Liu ‘191). Liu ‘393 describes using DCP for the prophylaxis or treatment of various diseases, including prostate cancer. Giaccone describes insensitivity of certain tumors to platinum-based chemotherapeutic agents and clinical approaches to overcoming resistance. However, the references do not teach or suggest treating cancer pain with DCP or other platinum compounds. In fact, the Examiner acknowledged that the references do not teach or suggest treating cancer pain, but relied on inherency to find that because the references teach administering DCP to subjects suffering from prostate cancer, this administration would inherently treat cancer pain.

The Appellant countered that the claimed invention is not directed to treating a cancer patient without the cancer patient requiring treatment of cancer pain. Further, the Appellant argued that the invention is unobvious because there is a lack of evidence to support the idea that the quantity of DCP administered to treat cancer would be effective in treating cancer pain.

The Examiner responded similarly as in their non-final rejection by stating that performing the method steps of the references would naturally result in treating the pain caused by cancer.

In the Reply Brief, the Appellant argued that a subject suffering from prostate cancer is not the same as a subject suffering from cancer pain. Further, treating cancer does not necessarily involve treating cancer pain, and treating cancer pain does not necessarily involve treating cancer itself.

The PTAB panel reversed the Examiner’s rejection and agreed with the Appellant that the Examiner had not established that the limitation at issue was inherent to the elements provided in the references.

With reference to In re Oelrich, 666 F.2d 578, 581 (CCPA 1981) and Par Pharm., Inc. v. TWi Pharms., Inc., 773 F.3d 1186, 1194-95, 1195-96 (Fed. Cir. 2014), the decision shows that the mere fact that an outcome may occur is not sufficient to support an inherency rejection. The decision serves as a reminder that while the doctrine of inherency can provide a claim limitation that is not present, reliance on inherency requires that the missing claim limitation be necessarily present or a natural result of the explicit teachings of the prior art.

When responding to rejections of inherency based on obviousness, patent applicants should consider whether an Examiner has justly provided rationale under MPEP 2112(IV) for relying on the doctrine of inherency, and explain why an allegedly inherent claim limitation is not necessarily present or is not a natural result from the teachings of the prior art. 

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.