Reexamined Claims Must Be "Amended or New" to Trigger Absolute Intervening Rights

Authored by D. Brian Kacedon, Douglas W. Meier, and John C. Paul

The doctrine of intervening rights provides a defense against patents that are modified through reissue procedures or reexamination before the United States Patent and Trademark Office ("USPTO"). For patent owners and potential licensees, whether intervening rights applies to a reissued or reexamined patent can substantially affect the value of a patent, particularly as to products that were made or used before the issuance of the reissued or reexamined patent. In Marine Polymer Technologies, Inc. v. HemCon, Inc.,¹ the Federal Circuit recently considered whether intervening rights may apply where claims were neither amended nor added during reexamination. The court ruled that the claims must be "amended or new" to trigger the doctrine of intervening rights for reexamined patents.

The Marine Polymer Decision

Marine Polymer sued HemCon on a patent relating to "biocompatibility." The patent specification discloses a test for determining biocompatibility that results in a score of zero to four, where zero represents no reactivity, and one, two, three, and four represent slight, mild, moderate, and severe reactivity, respectively. Three of the original dependent claims required a test score of zero. The district court construed "biocompatible" to include "no detectable biological reactivity" and granted Marine Polymer's motion for summary judgment of infringement based on that construction.

Meanwhile, in a separate reexamination proceeding before the USPTO, the examiner construed "biocompatible" more broadly than the district court to include "little or no detectable reactivity." Based on the broader construction, the examiner rejected the claim as invalid. In response, Marine Polymer urged the examiner to adopt the district court's narrower construction of "biocompatible" and cancelled the dependent claims that specifically required a test score of one or two (i.e., the claims that would allow for something other than "no detectable biological reactivity"). In light of the cancellation, the examiner agreed with the district court's narrower construction of "biocompatible" and issued a final reexamination certificate, which cancelled five of the claims and confirmed the patentability of the remaining claims.

On appeal, HemCon argued that the finding of infringement should be reversed because Marine Polymer changed the scope of the patent's claims during reexamination, triggering absolute intervening rights. The doctrine of absolute intervening rights protects an accused infringer's right to continue using, selling, or offering to sell products covered by reexamined claims when the product was made or used before the date of reexamination and the scope of the claims is substantively changed. Intervening rights do not apply, however, where the accused product infringes a valid claim of the reexamined patent that was also in the original patent.

According to the original three-judge appeal panel, absolute intervening rights are available only if the original claims have been "substantively changed," and in determining whether substantive changes have been made, the question is whether the scope of the claims has changed, not merely whether different words are used.

HemCon argued that intervening rights applies because Marine Polymer urged the examiner during reexamination to adopt the district court's narrower construction ("no detectable biological reactivity"). According to HemCon, the original claims had no such limitation, and thus, the examiner's adoption of the district court's construction substantively changed the scope of the claims. In other words, properly construed, the claims allowed some reactivity before reexamination and no reactivity after reexamination. In response, Marine Polymer argued that intervening rights cannot apply because the actual language of the asserted claims was not changed during reexamination.

Agreeing with HemCon, the three-judge panel ruled that intervening rights apply, and Marine Polymer petitioned for a rehearing en banc. An evenly divided (5-5) en banc court upheld the district court's narrower construction of "biocompatible" and affirmed the district court's infringement finding.

On the issue of intervening rights, a 6-4 majority of the court held that absolute intervening rights do not apply. The court relied on the plain language of the statutes, 35 U.S.C. §§ 307(b) and 316(b), providing intervening rights in the reexamination context. According to the statute, intervening rights applies to any "amended or new" claim determined to be patented and incorporated into a patent during reexamination. Then, and only then, does the inquiry shift to whether or not the claims have been substantively changed. Thus, the first question is whether the asserted claim is "amended or new." If the answer is no, then the inquiry ends there. If the answer is yes, then the next question is whether the claims have been substantively changed.

In Marine Polymer, because the reexamined claims were neither amended nor new, the majority found that absolute intervening rights do not apply. The court explained that regardless of whether the cancellation of claims during reexamination may have affected the scope of the remaining claims, the cancellation of the claims did not "amend" the claims for intervening rights purposes or make them "new," which is what the statutory language requires.

Strategy and Conclusion

"Amended or new" claims during reexamination can trigger intervening rights. Patent owners should keep in mind that any claim amended or added during reexamination may be subject to intervening rights. To avoid this, patent owners should attempt to keep at least some of the original claims unamended during reexamination.

The statute requiring "amended or new" claims applies only to reexaminations. The Federal Circuit relied on statutory language that applies intervening rights only to claims that are "amended or new" during reexamination. The relied upon statute does not apply to reissued claims.

Endnotes

¹The Marine Polymer en banc decision: http://www.cafc.uscourts.gov/images/stories/opinions-orders/10-1548.pdf.

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