Ex Parte Breitenbach et al

Board of Patent Appeals and Interferences

May 30, 2012

10508483 (B.P.A.I. May. 30, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 10/508,483 02/23/2005 Joerg Breitenbach M/42252-US 2525 26474 7590 05/31/2012 NOVAK DRUCE DELUCA + QUIGG LLP 300 NEW JERSEY AVENUE NW FIFTH FLOOR WASHINGTON, DC 20001 EXAMINER GAKH, YELENA G ART UNIT PAPER NUMBER 1777 MAIL DATE DELIVERY MODE 05/31/2012 PAPER Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________ Ex parte JOERG BREITENBACH and BERND LIEPOLD ____________ Appeal 2010-012449 Application 10/508,483 Technology Center 1700 ____________ Before CHARLES F. WARREN, ROMULO H. DELMENDO and GRACE KARAFFA OBERMANN, Administrative Patent Judges. OBERMANN, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134 involving claims 7-9 directed to a method for using a test solvent to evaluate the compatibility of a biologically active substance with a copolymer. We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE. Appeal 2010-012449 Application 10/508,483 2 THE INVENTION It cannot be predicted with certainty whether a biologically active ingredient will form a solid solution with a copolymer used as a binder and coating for slow-release pharmaceutical preparations. Spec. 1, ll. 13, 30-33; see App. Br. 7.1 When drug products based on new active ingredients are being developed, often only relatively small amounts of the active ingredient are available. Spec. 1, ll. 33-36. Thus, the ability to evaluate the compatibility of a biologically active substance with a copolymer by means of a simple test is extremely desirable. Id. at 1, ll. 36-38. Claim 7 is illustrative of the subject matter on appeal: 7. A method for evaluating the compatibility of a biologically active substance with an N-vinylpyrrolidone copolymer which includes units of N-vinylpyrrolidone in a proportion by weight of XVP and units of at least one ethylenically unsaturated monomer of the formula II CH2=CR-Z′ (II) in which R is hydrogen or methyl, Z′ is C1-C20-alkylcarbonyloxy, carboxyl, C1-C20-alkyloxycarbonyl, C2-C4-hydroxyalkyloxycarbonyl, di(C1-C4-alkyl)amino-C2-C4-alkyloxycarbonyl or tri(C1-C4- alkyl)ammonium-C2-C4-alkyloxycarbonyl, in a proportion by weight of XM, in which a) a test solvent which comprises 1,3-bis-(pyrrolidon-1-yl)butane in a proportion by weight of XVP and a compound of the formula I in a proportion by weight of XM 1 Our analysis makes reference to the Appeal Brief filed February 5, 2010 (“App. Br.”), the Examiner’s Answer mailed March 30, 2010 (“Ans.”), the Reply Brief (“Reply Br.”) filed May 25, 2010, the Supplemental Examiner’s Answer (“Supp. Ans.”) mailed July 7, 2010, and the Reply Brief Supplement (“Supp. Reply Br.”) filed August 10, 2010. Appeal 2010-012449 Application 10/508,483 3 (I) in which Q is CH2-Z, CH2-CH2-Z or CHZ-C1-C4-alkyl, n is 0, 1, 2, or 3, the Z radicals are identical and correspond to the Z′ radical, is prepared, b) the biologically active substance is brought into contact with the test solvent, and c) the phase behavior of the mixture and/or solubility of the biologically active substance in the test solvent is determined. Claim 7 thus relates to a test solvent for evaluating the compatibility of a biologically active substance with a copolymer formed of units of two different monomers, namely, N-vinylpyrrolidone and at least one ethylenically unsaturated monomer of the specified formula II that includes, for example, vinyl acetate (when Z in formula II is carboxyl). Claim 7; Ans. 3. Claim 7 covers a method in which the test solvent comprises “dimers of both monomers forming the copolymer in the same [weight] ratio.” Ans. 3. THE PRIOR ART The Examiner relies upon the following references in the rejection (Ans. 2): Breitenbach US 6,599,931 B1 Jul. 29, 2003 Buehler US 5,426,163 Jun. 20, 1995 The Appellants rely on the following reference as evidence of nonobviousness (see App. Br. 12; Supp. Reply Br. 4-5): Appeal 2010-012449 Application 10/508,483 4 Kolter US 6,066,334 May 23, 20002 THE REJECTION Claims 7-9 are pending in the application. Claims 7-9 stand rejected as under 35 U.S.C. § 103(a) as obvious over Breitenbach in view of Buehler. ANALYSIS The Appellants’ arguments are directed solely to the patentability of claim 7. App. Br. 2. We select claim 7 as the representative claim. Claims 8-9 stand or fall with claim 7. 37 C.F.R. § 41.37(c)(1)(vii). We find that Breitenbach would have disclosed to an ordinary artisan a test solvent for evaluating the compatibility of a biologically active substance with a homopolymer of N-vinylpyrrolidone. Breitenbach, e.g., Abstract, col. 1, ll. 6-60; see Ans. 3. Specifically, Breitenbach discloses that a solid dispersion of the N-vinylpyrrolidone dimer 1,3-bis(1- pyrrolidonyl)butane and a biologically active substance successfully mimics the compatibility of that biologically active substance with an N- vinylpyrrolidone homopolymer. Breitenbach, e.g., col. 1, ll. 50-60. The Examiner determines that the subject matter of claim 7 would have been obvious over Breitenbach in view of Buehler. We find that Buehler would have disclosed to an ordinary artisan a copolymer of N-vinylpyrrolidone and vinyl acetate that is useful in the controlled release of biologically active substances. Buehler, e.g., Abstract, col. 1, ll. 9-14. 2 Appellants cited and supplied a copy of Kolter in the Amendment filed July 28, 2009 (Amendment) in response to the Office Action mailed April 28, 2009. Amendment 2 and n.2. Appeal 2010-012449 Application 10/508,483 5 We determine that Buehler’s disclosure would have motivated an ordinary artisan to seek a biocompatibility test solvent for a copolymer of N- vinylpyrrolidone and vinyl acetate. We further determine that an ordinary artisan seeking to develop a test solvent for Buehler’s copolymer would have looked to Breitenbach’s disclosed test, which demonstrates modeling the behavior of N-vinylpyrrolidone homopolymer with a test solvent comprised of the dimer 1,3-bis(1-pyrrolidonyl) butane. We thus agree with the Examiner to the extent that Breitenbach would have suggested to an ordinary artisan “that [a] dimer can mimic the behavior of a [homo]polymer in [a] biological compatibility test.” Supp. Ans. 3. The Examiner determines that it would have been “obvious to try” expanding Breitenbach’s method to the problem of developing a test solvent for Buehler’s copolymer by employing a mixture of dimers formed of the same monomer units, in the same weight ratio, as the monomer units that form the copolymer. Ans. 3-4 (citing KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007)). The Appellants argue that the Examiner misapplies the Supreme Court’s decision in KSR. App. Br. 5-6. Furthermore, the Appellants contend that “[t]he properties of a copolymer which is formed by two different monomer units . . . differ from those of a physical mixture of two homopolymers each of which consists of units of one of the monomers.” Id. at 5-6 and n. 26 (citing Kolter col. 2, ll. 57-60). On that basis, the Appellants contend that it is not apparent from the cited references why an ordinary artisan “would reasonably contemplate a physical mixture of (homo)oligomers as a suitable model for a co(oligomer), let alone a copolymer, and how such a person could reasonably expect that such an approach would be successful.” App. Br. 7-8. Appeal 2010-012449 Application 10/508,483 6 The Examiner admits that a physical mixture of oligomers “is not absolutely equivalent to a copolymer of the same monomers,” but finds that most chemical properties of oligomers remain the same in the copolymer. Ans. 4. That finding, however, is not supported by a citation to the record. The Examiner further finds that the Appellants’ reliance on Kolter is misplaced because Kolter speaks to the miscibility of polymers, Ans. 5, and “[n]o mixing of polymers [is] either disclosed in the specification or recited in the claims.” Supp. Ans. 3. In the Examiner’s view, therefore, Kolter does not undercut the determination “that a success of modeling miscibility of a polymer with a biological compound by using its dimer can be extended to . . . mixing two dimers to model a copolymer.” Supp. Ans. 3. The Examiner further finds, and the Appellants further dispute, that Kolter discloses that for “binding purposes either a mixture of polyvinyl acetate and N-vinylpyrrolidone or vinyl acetate/vinylpyrrolidone copolymers can be used.” Supp. Ans. 3; see Supp. Reply Br. 4. The Appellants contend that the “binding purposes” of Kolter cited by the Examiner are unrelated to the biocompatibility test of the instant application. Supp. Reply Br. 4. As the Appellants point out, both the Examiner and the Appellants advance other technical arguments that are uncorroborated by evidence and, therefore, are entitled to little or no weight. Supp. Reply Br. 6. We have reviewed the Examiner’s ground of rejection and responses to the Appellants’ arguments, and determine that the Examiner has failed to set forth adequate articulated reasoning with a rational underpinning to support the conclusion of obviousness. See In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006) (cited approvingly in KSR Int’l Co., 550 U.S. at 418 (2007)). The Examiner finds that the combined disclosures of Breitenbach Appeal 2010-012449 Application 10/508,483 7 and Buehler would have presented “a finite number of identified, predictable solutions” for developing a test solvent for Buehler’s copolymer. KSR Int'l Co., 550 U.S. at 421; see Ans. 4. However, except for the disclosure contained in the Appellants’ application, not a single possible solution for evaluating the compatibility of a copolymer with a biologically active substance is identified per se in the record on appeal. It is unclear to us, and the Examiner has not adequately explained, why one would have been led by the teachings and inferences of the combined disclosures of Breitenbach and Buehler to the particular test solvent that is specified in claim 7. See KSR Int’l Co., 55 U.S. at 418 (“it can be important to identify a reason that would have prompted a person of ordinary skill in the relevant field to combine elements in the way the claimed new invention does”); In re Rouffet, 149 F.3d 1350, 1358 (Fed. Cir. 1998) (“hindsight” is inferred when the specific understanding or principal within the knowledge of one of ordinary skill in the art leading to the modification of the prior art in order to arrive at appellant's claimed invention has not been explained). Furthermore, the Appellants have come forward with evidence suggesting that an ordinary artisan would not have expected a mixture of N- vinylpyrrolidone and vinyl acetate dimers to comprise a successful test solvent for Buehler’s copolymer. App. Br. 5-6 (citing Kolter col. 2, ll. 57- 60); Supp. Reply Br. 4-6. In the absence of a reasonable scientific explanation or evidence establishing a reason why an ordinary artisan would have reasonably expected such success, the preponderance of the evidence on this point weighs in favor of the Appellants’ position. On the record before us, therefore, we cannot sustain the Examiner’s rejection of claim 7. Appeal 2010-012449 Application 10/508,483 8 CONCLUSION The rejection of claims 7-9 under § 103(a) is reversed. REVERSED ssl