Santarus v. Par Pharms – Family & Priority Lessons (Part I)

by Ryan Alley on May 7, 2013

in +, -, CAFC District Court appeals

Happy Patent FamilyCase Nos. 2010-1360 (Rader, Newman, Moore)

Happy patent families are all alike; every unhappy patent family is unhappy in its own way. (I’m sure this is how Tolstoy really meant it.) Properly managing a portfolio of related applications is difficult. The incremental nature of invention, vagrant inventors, and constraints in IP harvesting often make for tough decisions in dividing up subject matter between related applications, determining proper priority chains, and providing correct inventorship for each application in a family. Complex and occasionally inconsistent Federal Circuit caselaw does not make these jobs easier. This series looks at two cases dealing with problems in patent families: this post will look at last fall’s Santarus v. Par Pharma for issues in priority claiming; the next post will deal with the more recent In re Hubbell for double patenting troubles.

Santarus owned a family of patents covering the drug Zegrid, including US Pats. 6,489,346; 7,399,772; 6,780,882; 6,699,885; and 6,645,988, each of which sprang from an ancestor patent 5,840,737 as continuations or continuations-in-part. Par Pharma filed an ANDA, creating a Paragraph IV challenge to the validity and enforceability of the patents. The challenge was successful; the district court found several claims of the ‘346, ‘885, and ‘998 patent obvious over the ancestor ‘737 patent itself, to which the invalidated patents claimed priority. Santarus appealed these findings. . .

Could the ‘737 patent be prior art against the only partially-supported child patents? Unfortunately, the majority on appeal found that Santarus had waived any argument that the ‘737 provided priority for the invalidated claims (except for claim 1 of the ‘772 patent, discussed in the second section below). Thus, we get no discussion from the majority as to whether a parent application claimed to under § 120 by a continuation-in-part can be prior art against the claiming application. In re Chu is probably the best stand-in for the position that, yes, claims in a C-I-P can be invalidated by the priority application, if the priority application does not completely support the claims.

Judge Newman, apparently finding the issue not waived, does provide contrary commentary about C-I-P priority in a dissent. It was the dissent’s view that a claim of priority to any ancestor patent eliminates the ancestor patent from the prior art, regardless of whether the ancestor patent supports the claim. That is, as long as a child application has overlapping inventorship with, is filed during the pendency of, and includes a reference to a parent, the subject matter of the parent is off limits as prior art. As Judge Newman put it:

The panel majority forgets that “matter disclosed in the parent application is entitled to the benefit of the filing date of the parent application.” Waldemar Link, GmbH & Co. v. Osteonics Corp., 32 F.3d 556, 558 (Fed. Cir. 1994); see Litton Sys., Inc. v. Whirlpool Corp., 728 F.2d 1423, 1438 (Fed. Cir. 1984) (“The earlier filing date of the parent application pertains to material in the C-I-P application also disclosed in the prior application. 35 U.S.C. §120.”). Instead, the panel majority relies upon the common subject matter from the ’737 patent disclosure to invalidate the ’885 claims supported by that subject matter. This is incorrect, for the common subject matter in the ’885 patent is entitled to the ’737 filing date. That entitlement is not lost by issuance of the ’737 patent. The common subject matter, properly carried forward in copending continuing patents, cannot be prior art against itself, as the majority holds.

The majority, treating the ‘737 patent as proper prior art against claims in the continuation-in-part applications, further agreed that the disclosure in the ‘737 application rendered these claims obvious (The substantive obviousness discussion might be discussed in a future post). Invalidity affirmed as to the claims for which the ‘737 patent was prior art.

Killer AncestorsLessons: Continuation-in-part practice might look like a good idea for improvement or related disclosures, but it offers mostly illusory benefits. As seen in Santarus, a C-I-P priority claim will not eliminate parent applications as prior art if they do not fully support the C-I-P claims (and if they did, you could simply claim straight continuation priority). And C-I-P practice has real drawbacks, like needless loss of patent term and false assurances of validity. So the take-away is that priority is best, and most safely, claimed only between true continuation and divisional applications having the same disclosure or at least fully supporting the claims of the child application.

Nonetheless, I think a C-I-P has some usefulness when it’s not clear whether a parent application provides full § 112 support for a child claim. This can happen in a slowly-evolving project that has incremental improvements, as well an in large system inventions having several separately-patentable parts, where different subject matter can get spread across multiple applications. The uncertainties of BRI, litigation claim construction, and written description jurisprudence can make determining claim support at filing rather fuzzy, and the determination can easily vary from claim-to-claim. A C-I-P priority claim at least preserves the option of relying on priority for a subset of supported claims, which may become much more apparent during prosecution. If following this approach of making a C-I-P claim in light of uncertain support, make sure the Examiner is aware of potentially differing claim priorities and properly policing it – both in according the earlier filing date for supported claims and applying parent applications and intervening prior art to unsupported claims – to avoid the PowerOasis problem of specious validity. Also confirm that you’re ok losing patent term on any unsupported claims that are nonetheless found patentable over the parent and intervening art (and, if not, consider dividing supported and unsupported claims into the existing and a new application and appropriately deleting priority claims to maximize term).

Coming at the issue from the other angle, recognize that in some situations you don’t even need priority, continuation or C-I-P, between related applications (“related” meaning overlapping inventorship and co-owned or jointly-researched ownership). Due to publication delay, pre-AIA, applicants could get up to 30-months between filing dates of related applications with no priority claim before the original US filing became prior art to the later filing. Post-AIA, this window shrank to 18 months. (These windows can be extended through non-publication requests for US-only, non-prioritized filings.) If you are the only innovator in the narrow field of the family and not otherwise disclosing/commercializing before publication, such that it is only parent applications and not intervening disclosures that are prior art concerns, priority claims within these windows mostly just kill patent term because the parent will be ineligible or removable as prior art through other means. Moreover, if you find out during prosecution that the priority claim was wrongly omitted, you can add it late for a hefty fee as long as you have co-pendency and inventorship overlap. I’ve seen this route actually be less expensive than preparing a 131 declaration for antedating an anticipating earlier application/disclosure in complex families pre-AIA. In sum, even if you are in one of the above-mentioned scenarios where a continuation or C-I-P claim is useful, think very hard before making any such claim before the parent has published.

Comment: Judge Newman, to me, seems to be quite out on a limb arguing that the non-supporting parent application, to which priority is otherwise properly claimed, cannot be prior art for all that it teaches. She took a similar position in Tronzo v. Biomet, stating in dissent that the unsupporting parent application eliminated other intervening prior art having the same disclosure as the parent application to which priority was claimed. These seem at odds with Chu, for which Judge Newman was a panelist. The cases cited by the dissent (Waldemar Link and Litton Sys.) are also not on-point for the dissent’s position, and older cases like Stryker or Stempel discussed on other comment threads are rather limited to the swearing back milieu where they discuss eliminating less than fully-supporting references from the prior art. What’s more, in her concluding paragraphs Judge Newman seems to suggest that the USPTO always ensures that written description for priority exists, which is contrary to the reasoning in PowerOasis. I don’t think Judge Newman’s take on this issue is necessarily bad policy-wise, considering patent term is now from claimed priority filing date and double patenting will snuff out attempts at de facto term extension, but I don’t think it lines up with precedent.

* * *

Since we’re on the issue of priority, it’s worthwhile to take a look at a related in Santarus: written description support for a negative claim limitation. The youngest patent in the family, ‘772, included a claim 1 with a negative limitation of “wherein the composition contains no sucralfate.” The ‘737 parent application mentioned sucralfate as a known ingredient for treatment of gastric disorders, but in the context of causing problems (well, death) in the background. The district court thought that this was insufficient to provide written description to the negative limitation. The Federal Circuit disagreed and found that this mention, even though not in connection with any example embodiment, was sufficient to provide written description for the negative limitation and thus priority to the ‘737 parent application. As the majority put it:

Santarus argues that it is not necessary to include in the specification evidence of “contraindication” of sucralfate. . .

We agree. The claim limitation specifying that sucralfate is not administered in conjunction with the Phillips formulation restricted the claims to this preferred use of the Phillips formulations. This exclusion narrowed the claims, as the patentee is entitled to do. The Manual of Patent Examining Procedure explains that claims may state the exclusion of alternatives. See MPEP § 2173.05(i) (“If alternative elements are positively recited in the specification, they may be explicitly excluded in the claims.”).

. . . Negative claim limitations are adequately supported when the specification describes a reason to exclude the relevant limitation. Such written description support need not rise to the level of disclaimer. In fact, it is possible for the patentee to support both the inclusion and exclusion of the same material. The claim limitation that the Phillips formulations contain no sucralfate is adequately supported by statements in the specification expressly listing the disadvantages of using sucralfate.

Judge Newman in concurrence did not like the majority’s phrasing. Particularly, she pointed out that there is no requirement the specification disclose any reason to exclude the subject matter of the negative limitation. All that is required is that the specification identify the subject matter:

The applicant’s obligation is to describe and claim the invention in accordance with 35 U.S.C. §112. Thereafter, patent examination may lead to amendments to the claims. The MPEP §2173.05(i) advises that: “If alternative elements are positively recited in the specification, they may be explicitly excluded in the claims.” The MPEP does not require that the reason for such exclusion must be stated in the specification. The panel majority creates a new and far-reaching ground of invalidity, a ground that received no deliberation and advice from the concerned communities.

Because the ‘737 disclosure supported the claim of the child ‘772 patent, including the negative limitation, the ‘737 patent was not prior art against the ‘772 patent, and the claim was not invalid for lacking written description. The invalidation of this claim was reversed and remanded.

Lessons: A negative claim limitation can likely be supported by disclosure of the subject matter of the same in the specification merely as an alternative or by disclosure of the subject matter, even in the background, as something to be avoided. I do not read the Santarus majority as undercutting the rule of MPEP § 2173 dealing with disclosure of alternatives; rather, I think the majority expands the bases for written description support to include a disclosures unrelated to any example embodiment that nonetheless denigrate the subject matter sought to be the object of a negative limitation. Thus, all the more reason to disclose as many alternative species as possible in the specification, and explicitly state that any combination of disclosed elements are useable in example embodiments. The expansion by the majority also works well with problem-and-solution statements in the specification, as this might provide support for a negative limitation disclaiming identified particulars of the problem.

A short caution, however, on negative limitations in general. Distinguishing prior art with a negative limitation alone can be less than productive; it can feel like (and sometimes is) a cheap dodge to which an Examiner will respond to by throwing in a combinable reference also lacking the feature and/or an obvious reason for the omission. Negative limitations also receive somewhat higher scrutiny abroad. The EPO and JPO have several complex guidelines for treating “disclaimer,” and I’ve found none of them as kind as the US rule.

Comment: Again, I think the majority is correct here, and I have some trouble understanding Judge Newman’s response and alarm. I don’t see Santarus as dealing with the situation of disclosure of alternatives in the detailed description, or the majority as attacking the same, so I’m not sure why Judge Newman felt like this basis for negative claiming required defending in a separate opinion.

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