BPAI reminder that silence in one reference as to what another teaches is not "teaching away"

Takeaway: In Ex parte Greve, the Applicant presented technical reasons why a POSITA would not combine the references. The Applicant concluded the argument by explaining that because the reference didn't mention a claimed feature, a POSITA would understand that the feature should be avoided. "Therefore, Gross et al. clearly teaches away from the presently claimed invention." The Board affirmed the obviousness rejection, stating that "silence in one reference as to what another teaches is not 'teaching away'. "

Details:
Ex parte Greve
Appeal 2010002433; Appl. No. 10/984,628; Tech. Center 1600
Decided April 4, 2011

The claims on appeal were directed to a drug for treating rhinitis or inflammation of the nasal cavity. A representative claim on appeal read:

18. A pharmaceutical composition for the curative topical treatment of rhinitis, comprising in combination and in each case based on the pharmaceutical composition
     (a) 0.001 to 1% by weight of at least one sympathomimetic selected from the group consisting of oxymetazoline hydrochloride and xylometazoline hydrochloride;
     (b) 0.01 to 5 % by weight of hyaluronic acid in the form of its physiologically acceptable salts; and
     (c) 0.01 to 15 % by weight of at least one of pantothenol or its esters and/or pantothenic acid or its physiologically acceptable salts,
     wherein the pharmaceutical composition is formulated as a solution, a dispersion, a paste, a spray, an ointment, a cream or a gel.

The Examiner rejected as obvious over a combination of three references.The Examiner found that Greve taught a composition including (c) and a sympathomimetic in the claimed range, though not one of the two specific compounds named in (a). Moreover,  Castellano taught a composition including (b) and one of the specific compounds named in (a). Furthermore, Gross taught (c) and (b). Finally, each of the compositions found in the references was described as a treatment for rhinitis or a rhinological condition. 

The Examiner found that the references themselves provided the motivation to combine:

The skilled artisan would have been motivated to do so with an expectation of success because Gross et al. teach a synergistic effect with the combination of pantothenic acid [c] and hyaluronate [b] for the treatment of rhinitis; Greve et al. teach a synergistic effect with the combination of a sympathomimetic [a] and pantothenic acid [c] for the treatment of rhinitis; and Castellano et al. teach a combination of a sympathomimetic [a] and hyaluronic acid [b] for the treatment of rhinitis.

During prosecution, the Applicant argued that:

[T]he prior art documents do not teach the use of the compositions described therein each for the same purpose. Rather, each reference has its own technical solution for its own specific object, each being readily distinguishable and different, respectively, from the others. Thus, it is not believed to be obvious in any way that the ordinarily skilled person would take a combination of these documents into consideration in coming up with the present claims.

The Applicant buttressed this argument by submitting an expert declaration which explained why a POSITA would not modify Gross to add sympathomimetic [a] (the compound missing from Gross).

The specific use of a sympathomimetic would be even disadvantageous with respect to the treatment of ophthalmological malfunctions especially since this reference [Gross] focuses on the treatment of the so-called "dry eye" which is linked to disturbances to wetting of the cornea and conjunctiva of the eye. Furthemore, this document also deals with the treatment of dry mucous membrane of the nose. Thus, the use of a sympathomimetic would strongly counteract these treatments since sympathomimetics as such even enhance the drying out of tissues treated therewith. Thus, it is absolutely clear to the skilled practitioner to explicitly avoid the addition of a vasoconstrictor with respect to the teaching of this reference. Consequently, the skilled practitioner would never consider this reference with
respect to the claimed invention.

The Applicant reiterated this same argument on appeal, concluding with:

To bring this clearly to the point, if the addition of a vasoconstrictor [such as a sympathomimetic] would be evident with respect to why is the complete document silent to do so? The answer for this is quite simple. The use of a vasoconstricting agent is to be completely avoided in Gross al. since it would even intensify the drying out. Therefore, Gross et al. clearly teach away from the present claimed invention as is and would be consequently not considered relevant or obvious by the ordinarily skilled person in the way alleged by the Examiner in this Action.
(Emphasis added.)

The Board found the "teaching away" argument was misplaced:

The fact that one reference is silent as to what another reference teaches is not a “teaching away” within the meaning of 35 U.S.C. § 103(a). See In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir. 2004) (“The prior art's mere disclosure of more than one alternative does not constitute a teaching away from any … alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed.…”).

The expert declaration also asserted that the claimed ternary composition provided unexpected results:

[T]he surprisingly found  synergism is mainly based on the fact that the combination of the hyaluronic acid, on the one hand, and the pantothenol and/or pantothenic acid component, on the other hand, leads to a significant diminishing of the side-effects induced by the vasoconstrictor [such as a sympathomimetic].  

However, the Board found the evidence to be unpersuasive:

Dr. Greve provides no evidence that the result is “unexpected.” See In re Klosak, 455 F.2d
1077, 1080 (CCPA 1972) (“[I]t is not enough to show that results are obtained which differ from those obtained in the prior art: that difference must be shown to be an unexpected difference”). Dr. Greve does not provide, either in the Declaration or in the Specification, a comparison of the results of the ternary composition with the closest prior art with a showing of an actual difference other than an asserted “synergistic effect” (see Greve Dec. 4 ¶ 7; Spec. 13-14). See In re Baxter Travenol Labs., 952 F.2d 388, 392 (Fed. Cir. 1991) (“[W]hen unexpected results are used as evidence of nonobviousness, the results must be shown to be unexpected compared with the closest prior art.”).

My two cents: I don't do chemical cases, but the Board's comment about teaching away caught my eye.

The Board appeared to ignore reasons why a POSITA would not combine the references – reasons presented in the form of expert evidence -- simply because the Applicant mischaracterized this as "teaching away." The Board should have instead weighed the expert evidence (pointing away from a combination) against the teachings of the references themselves (pointing toward a combination) to decide on obviousness/non-obviousness.

This case highlights the danger of improperly characterizing arguments. The Board should have looked beyond the label the Applicant put on the argument – but you should make their job easy, not hard.