Appeal No. 2012-009281

Serial No. 12/845,521

Art Unit 1674

Examiner: Kimberly Chong

PTAB Panel: Demetra J. Mills, Eric Grimes, and Jeffrey N. Fredman

Opinion by Grimes, E.

For some unpredictable fields, like cancer therapeutics, one of skill in the art is able to, and even expects or anticipates the need to, fine-tune and perform additional experiments based on prior teachings.  In Ex parte Gleave, the PTAB reversed the Examiner’s conclusions that claims to methods of treating cancer were not described in the specification in a such a way to enable one of skill in the art to make and/or use the invention.

The Invention and Claims

The invention relates to treatment methods to reduce the level of clusterin expression in cancer cells using RNA interference (RNAi) technology.

Claims 31 and 32 are representative and read:

31. A method of treating a cancer that expresses clusterin, comprising administering to an individual in need of treatment an RNA molecule having a sequence effective to mediate degradation or block translation of mRNA that is the transcriptional product of a target gene, wherein the target gene encodes clusterin, and the RNA molecule comprises a sequence of bases as defined by Seq. ID No. 6, wherein the individual has a cancer that expresses clusterin.

32. The method of claim 31, wherein the cancer is selected from the group consisting of sarcomas, renal cell carcinoma, breast cancer, bladder cancer, lung cancer, colon cancer, ovarian cancer, anaplastic large cell lymphoma and melanoma.

Examiner Rejection

The Examiner rejected the claims on the grounds that the specification did not enable the claims under 35 U.S.C. § 112, first paragraph.  Namely the Examiner found lack of enablement “based on the unpredictability in treating any type of cancer using the claimed method given the state of the prior art wherein it is shown that clusterin expression is not predictably overexpressed or expressed in subjects having certain cancers.” (Ans. at 8).

The Examiner cited two references which teach variable clusterin expression levels in different types of cancer. (Id. at 9).  Based upon the prior arts’ failure to provide similar results for the role and level of clusterin expression and treatment effects across the breadth of the cancer types claimed, the Examiner found that “the [in vitro] working embodiment d[id] not provide adequate guidance to enable the claimed invention.” (Id.).  In particular the Examiner noted that while the specification discloses a decrease in clusterin expression after treatment with clusterin-RNAi in certain types of cancer, the specification does not “include specific embodiments wherein the skilled artisan could predictably use the claimed method for treatment of cancer.” (Id. at 7).  The Examiner concluded that, without further guidance, substantial trial-and-error experimentation would be necessary to practice the instantly claimed invention. (Id. at 11).

PTAB Opinion

The PTAB agreed with the Applicants that the Examiner had not provided evidence to support aprima facie case of lack of enablement.  (Opinion at 3).  The PTAB reiterated the common understanding in the field that in many situations in vitro experiments may adequately enable one skilled in the art to produce effective therapeutics.  (Id. at 4).  Further, the PTAB noted that “a disclosure does not have to describe a claimed method in all its particulars in order to be enabling” and that some additional research and development, particularly in the field of pharmaceuticals, is expected.  (Id. at 7-8).

In addition, the PTAB held that the two references did not provide sufficient evidence in support of the Examiner’s conclusion of nonenablement.  (Id. at 5).  While one reference indicated research using RNAi directed to clusterin was ongoing, it showed promise for clusterin RNAi as a cancer therapy — although not necessarily for all cancer types.  On the other hand, the second reference did not cast doubt on the effectiveness of the claimed invention.  (Id. at 7).  The PTAB noted in support of its enablement determination that the Applicant’s specific list of cancers of claim 32 were not those cancer types which the references of record in the case reported a decrease in clusterin expression. (Id. at 6).

Practice Tips

  1. For overcoming similar enablement arguments Applicants may find it helpful to support their responses by citing, as the PTAB did in its opinion, to:
  • Amgen, Inc. v. Hoechst Marion Roussel, Inc. 314 F.3d 1313, 1334 (Fed. Cir. 2003)

“The specification need not explicitly teach those in the art to make and use the invention; the requirement is satisfied if, given what they already know, the specification teaches those in the art enough that they can make and use the invention without ‘undue experimentation.’”

  • In re Brana, 51 F.3d 1560, 1568 (Fed. Cir. 1995)

“[P]harmaceutical inventions, necessarily include[] the expectation of further research and development.”

  1. Although an Applicant does not need to establish that all embodiments are operative, the Applicant should point out the exact locations in the specification of working examples that do support enablement (similar to Opinion at 5).
  2. Addressing which specific elements were left out of a claim (e.g., those cancers not listed in claim 32) and reasons for their absence may help prove up factors in support of enablement, such as the state of the prior art, the amount of direction provided by inventor, and/or the quantity of experimentation needed to make or use the invention.

Ellen Smith