We’ve written previously about ex parte decisions of the Patent Trial and Appeal Board (PTAB) affirming patent eligibility rejections that seem to be inconsistent with the USPTO’s Subject Matter Eligibility Guidance. Apparently, applicants should be wary about appealing any rejection of a diagnostic method claim, because the PTAB may enter sua sponte patent eligibility rejections even if the examiner did not make a § 101 rejection.

Ex Parte Patterson

The PTAB decision in Ex Parte Patterson, Appeal 2016-001355 (Nov. 30, 2017), is an example of such a case. The claims at issue were directed to in vitro methods of screening for cervical cancer. Claim 1 is representative:

1. A method of predicting whether a subject has a cervical intraepithelial neoplasia (ON) lesion that is a CIN2+ lesion, the method comprising: obtaining data from a labeled liquid sample of cervical cells in suspension from the subject, wherein the data are obtained by analyzing the liquid sample with a flow cytometric device and comprise per cell morphometric data and data selected from the group consisting of: per cell biomarker data, per cell DNA content data, and combinations thereof; and predicting from the per cell morphometric data and from the data selected from the group consisting of: per cell biomarker data, per cell DNA content data, and combinations thereof; whether the subject has a CIN2+ lesion.

The Prior Art Rejection On Appeal

The Examiner had rejected the claims as being obvious over a combination of prior art references. The PTAB reversed that rejection, finding that “the Examiner has not established that the prior art methods would have provided the claimed means to distinguish cancerous cervical cells from normal cells,” and agreeing with the application that “the Examiner has not established a prima facie case that a skilled artisan would have a reasonable expectation of success in predicting or determining the presence of a particular type of CIN lesion or a cancerous cervical cell using morphometric data obtained through flow cytometry.”

The New Patent Eligibility Rejection

The PTAB cited the Supreme Court’s Myriad decision for the proposition that its “finding of non-obviousness, … does not necessarily lead to the conclusion that subject matter is patentable eligible.” The PTAB applied the two-step analytical framework set forth in Supreme Court’s Mayo decision, and entered a new rejection under § 101.

The PTAB’s analysis under Mayo/Alice step 2 explains its non-obvious but still non-eligible determination:

Like the claims in Mayo, the manipulative steps of claim 1 on appeal “consist of well-understood, routine, conventional activity,” as shown by Ling and Basiji. ….

Neither does considering the above steps as an ordered combination add anything new to the law of nature that is not already present when the steps are considered separately. In this respect, we note that our conclusion that the Examiner has not shown claim 1 to be obvious over Ling and Basiji does not change our conclusion that claim 1 is directed to an abstract idea without sufficiently more to transform the claim into a patent-eligible application. …. Here, Basiji shows that obtaining cell morphometric data via flow cytometry … is something routinely engaged in by the scientific community. (FF12-FF18.) The fact that such data can also be used to predict the presence of a CIN2+ lesion, despite lack of a reasonable expectation of success … does not transform the claim into a patent-eligible application of the natural correlation between cell morphometric data generally (as the claim requires) and cell biomarker or cell DNA content data and presence of a particular type of cervical lesion.

The PTAB noted that the claims did “not recite a new method of performing flow cytometry,” and the applicant did not assert that the flow cytometer used is “structurally distinguishable from [the prior art] imaging flow cytometer.”

Thus, the PTAB invoked 37 C.F.R. § 41.50(b) and entered a new ground of rejection.

A Victim Of Evolving Standards?

When the Appeal Brief was filed in this case, the Federal Circuit had not yet issued its decision in Arisoa, and many believed that a diagnostic method involving specifically recited, concrete method steps that was patentable over the prior art passed muster under § 101. This decision underscores the way patent eligibility standards have evolved over the past few years, and highlights the more difficult scrutiny that novel, non-obvious, and even “[g]roundbreaking, innovative, or … brilliant” diagnostic methods face today.