On July 17, 2006 the U.S. Circuit of Appeals for the Federal Circuit in the Regents of the University of California v. University of Iowa Research Foundation et al. has affirmed the Board of Patent Appeals and Interferences (the Board) decision that a claim filed more than one year after an issued patent would bar such a claim from the interference under 35 U.S.C. § 135 (b) (1). The appeal was filed by the Regents of the University of California against the Board’s decision to grant University of Iowa Research Foundation et al. motion for judgment under 35 U.S.C. § 135 (b) (1) barring California’s sole claim interfering with Iowa’s U.S. Patent No. 6,207,646 (the ‘646 patent). 35 U.S.C. § 135 (b) (1). A claim which is the same as, or for the same or substantially the same subject matter as, a claim of an issued patent may not be made in any application unless such a claim is made prior to one year from the date on which the patent was granted. The ‘646 patent. The ‘646 patent assigned to University of Iowa Research Foundation, Coley Pharmaceutical Group and The United States of America as represented by the Department of Health and Human Services is directed to compositions and their use to minimize allergic reactions. Particularly, claim 3 of the ‘646 patent, the count in the interference, claims a method of desensitizing a subject against the occurrence of an allergic reaction by administering allergen together with an effective amount of an immunostimulatory nucleic acid. California’s Request for Interference The ‘646 patent was issued on March 27, 2001. However, at the time of issuance of the ‘646 patent, California’s Application No. 09/265,191 (the ‘191 application) was pending before the USPTO. California later, on October 31, 2001 (seven months after the ‘646 patent issued) added claims 202-204 to the ‘191 application, and subsequently requested an interference with the ‘646 patent. In that request, California proposed that the interference include two counts, one to the composition corresponding to claims 202 and 203, and the other to the method corresponding to claim 204. In response to California’s amendment, the USPTO rejected claims 202-204 but California continued to prosecute the ‘191 application even after rejection of claims 202-204. Interference by USPTO On May 09, 2002 more than one year after the ‘646 patent had issued, California added another method claim, claim 205, to the ‘191 application. Later, during prosecution California canceled claims 202-204 and subsequently the USPTO declared an interference between claim 205 of California’s ‘191 application and the ‘646 patent. Claim 3 of the ‘646 patent became the sole count in the interference. Iowa’s Motion for Judgment under 35 U.S.C. § 135 (b) (1) During preliminary motions phase of the interference, Iowa filed a motion that claim 205 was not patentable to California under 35 U.S.C. § 135 (b) (1), and as a result of that the Board opted to consider first the 35 U.S.C. § 135 (b) (1) threshold issue. In its decision, the Board found that California filed claim 205 more than on year after the ‘646 patent issued and unless California could link that claim to claims filed within a year of the ‘646 issue date, section 135 (b) (1) would bar claim 205 from the interference. Accordingly, the Board examined claim 205 for material difference from California’s earlier claims, particularly with claims 202-204 and found that California’s claim 205 contained material differences from claims 202-204. The Board concluded that claim 205 could not benefit from the earlier filing date of claims 202-204 and thereby barred under 35 U.S.C. § 135 (b) (1). Accordingly, the Board granted Iowa’s motion for judgment under 35 U.S.C. § 135 (b) (1). California Appealed to CAFC California subsequently made an appeal to the CAFC. However, California does not contest the Board’s finding of material differences between claim 205 and claims 202-204 but instead challenged the Board’s conclusion that the correct inquiry under 35 U.S.C. § 135 (b) (1) asks whether claims 202-204 contain material differences from claim 205 and not whether claims 202-204 are to the same invention as claims in the ‘646 patent. In its appeal, California argued that when it filed claims 202-204 within a year of the issuance of the ‘646 patent, it “discharged” its duty under section 135 (b) (1), and that section 135 (b) (1) no longer bars any subsequent claim filed in the ‘191 application. California asserted that the proper 135 (b)(1) test requires the Board to confine its analysis to pre-critical date claims, where the “critical date” is the date one year after the issuance of the patent relevant to the section 135(b)(1) analysis. Test to Determine Material Differences In re Berger, 279 F.3d 975, 980 (Fed. Cir. 2002), the court while applying section 135 (b) (1) ruled in the favor of the Board. In Berger, the appellant had copied a claim from the Muller patent more that one year after the patent has issued, and later amended his application to add the copied claim as new claim 7. The Board affirmed the examiner’s rejection of claim 7 under section 135 (b) and further explained that the rejected claim contained material differences from claims 1-6, which were on file before the critical date. On appeal, the court assessed the correctness of the Board’s test to determine whether the earlier claims 1-6 supported claim 7. In Corbett v. Chisholm, 568 F.2d 759 (CAFC 1977), the court explained that “to establish entitlement to the earlier effective date of existing claims for purposes of the one-year bar of U.S.C § 135 (b), a party must show that the later filed claim does not differ from an earlier claim in any ‘material limitation.’” In Cryns v. Musher, 161 F.2d 217 (CCPA 1947), the court permitted a party confronted with a section 135 (b)(1) bar to show that claims filed after the critical date find support in claims filed before the critical date. If a party can show such support, section 135 (b)(1) will not act as a bar. Relying on Berger, Corbett, and Cryns, the court maintained that California’s position that the relationship between the post- and pre-critical date claims is not relevant to section 135(b)(1) contravenes the weight of precedent. The Court affirmed that the Board has correctly construed section 135 (b)(1).