September 2003

A common misconception about a U.S. patent applicant’s duty of disclosure is that there is only an obligation to report prior art that a patent examiner could use to support a rejection of the claims based on anticipation (lack of novelty, 35 U.S.C. § 102) or obviousness (lack of inventive step, 35 U.S.C. § 103). The recent Federal Circuit decision, Bristol-Myers Squibb Co. v. Rhone-Poulenc Rorer, Inc., makes clear that such a misconception can be fatal to the patent grant.

37 C.F.R. § 1.56 provides guidelines for the duty of disclosing information material to patentability. Failure to follow these guidelines may lead to charges of inequitable conduct and ultimately, a judgment of unenforceability. Section 1.56, in relevant part, states that

(b) … information is material to patentability when it is not cumulative to information already of record or being made of record in the application, and

(1) It establishes, by itself or in combination with other information, a prima facie case of unpatentability of a claim, …

As this rule relates to the “unpatentability” of a claim, it is not limited to rejections based on anticipation or obviousness. Prior art which calls into question (i) whether a claim has utility (35 U.S.C. § 101), is adequately described, enabled or has the best mode described (35 U.S.C. § 112, first paragraph); or (ii) whether the scope of the claim can be readily ascertained (35 U.S.C. § 112, second paragraph) also can establish a prima facie case of unpatentability for the claim. Therefore, prior art supporting these types of rejections does not have to qualify as prior art under 35 U.S.C. § 102 and § 103, and, as such, the duty of disclosure does not end with the filing of an application.

In Bristol-Myers, the Federal Circuit held that the patentee-inventors engaged in inequitable conduct by failing to disclose an article written by the inventors and published after the filing of a French patent application from which the U.S. application claimed priority. The Federal Circuit found that the article was relevant to enablement and there had been numerous opportunities to disclose this reference in the initial U.S. application, as well as in a subsequent reissue application. The patentee had discounted the relevancy of the article because the article did not qualify as prior art under 35 U.S.C. § 102.

The lesson learned is that the duty of disclosure is not limited to publications predating the filing of an application. Disclosures published or made public after the filing date of the application can still be used against a claim, and special care should be given to post-filing publications by the same inventive entity or assignee that provide further details of an earlier inventive concept. If there is any doubt as to whether a post-filing disclosure should be presented, the safer course is to file the disclosure in an Information Disclosure Statement.