Ex Parte TanDownload PDFPatent Trial and Appeal BoardSep 2, 201410889432 (P.T.A.B. Sep. 2, 2014) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE __________ BEFORE THE PATENT TRIAL AND APPEAL BOARD __________ Ex parte SHARON MI LYN TAN1 __________ Appeal 2012-004446 Application 10/889,432 Technology Center 3700 __________ Before ERIC B. GRIMES, MELANIE L. McCOLLUM, and JEFFREY N. FREDMAN, Administrative Patent Judges. McCOLLUM, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134 involving claims to a composite vascular graft. The Examiner has rejected the claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm. STATEMENT OF THE CASE Claims 1–4, 6, 10–18, and 25–27 are on appeal (App. Br. 5).2 The claims have not been argued separately and therefore stand or fall together. 37 C.F.R. § 41.37(c)(1)(vii). Claim 1 is representative and reads as follows: 1 Appellant identifies the real party in interest as Boston Scientific Scimed, Inc., formerly known as Scimed Life Systems, Inc., which is a subsidiary of Boston Scientific Corporation (App. Br. 3). Appeal 2012-004446 Application 10/889,432 2 1. A composite vascular graft comprising: a porous, flexible tubular extruded, expanded polytetrafluoroethylene graft member comprising nodes and fibrils; a biodegradable, bioactive agent coating layer disposed over said graft member; said coating layer including at least one bioactive agent; and a biodegradable sheath disposed over said coating layer, said sheath having a rigidity greater than said flexible tubular graft member; and being biodegradable to expose said coating layer so as to re-establish the flexibility of said tubular graft member. Claims 1–4, 6, 10–18, and 25–27 stand rejected under 35 U.S.C. § 103(a) as obvious over Sirhan et al. (WO 02/056790 A2, July 25, 2002) in view of Hill et al. (US 2003/0060871 A1, Mar. 27, 2003) (Ans. 4). The Examiner relies on Sirhan for teaching a composite vascular graft (see Figs. 2C-2N) comprising: a flexible tubular graft member 16 . . . made from expanded polytetrafluoroethylene . . . ; a coating layer 40/46 (as shown in Figs 2F-2G, 2I, and 2K for example) comprising a biodegradable material . . . and bioactive agent 28 disposed over said graft member 16; . . . and a sheath 43/49/52 (see Figs 2F-2G, 2I, and 2K) made from a biodegradable material . . . disposed over said coating layer 40/46 (as shown in Figs 2F-2G, 2I, and 2K for example). (Ans. 4 (emphasis omitted).) The Examiner finds that “Sirhan specifically teaches the sheath to be made from polylactides, polyanhydrides, polyvinylpyrolidone [sic], polyglycols, polycaprolactone, gelatin derivatives, and combinations thereof” (id. at 4-5). However, the Examiner finds that 2 Claims 5 and 7–9 are also pending but have been withdrawn from consideration (App. Br. 5). Appeal 2012-004446 Application 10/889,432 3 “Sirhan fails to explicitly teach the PTFE graft 16 to be extruded, porous, and to comprise nodes and fibrils” (id. at 5 (emphasis omitted)). The Examiner relies on Hill for teaching “that is known to make vascular grafts from extruded porous tubes of PTFE, specifically from porous expanded ePTFE having nodes and fibrils” (id.). The Examiner concludes: [I]t would have been obvious to one having ordinary skill in the art at the time of the invention to modify the graft 16 of Sirhan by constructing it from the ePTFE having nodes and fibrils, as taught by Hill, in order to employ a well-known type of PTFE that is commonly used to construct vascular grafts, and in order to employ a material that has a tailorable pore size to achieve desired properties of the graft. (Id.) ISSUE Does the evidence support the Examiner’s position that Sirhan and Hill suggest a biodegradable sheath having a rigidity greater than the flexible tubular graft member? FINDINGS OF FACT 1. The Specification states: [The] prior art describes an antimicrobial vascular graft made with a porous antimicrobial fabric formed by fibers which are laid transverse to each other, and which define pores between the fibers. The fibers may be of ePTFE. Ceramic particles are bound to the fabric material, the particles including antimicrobial metal cations thereon, which may be silver ions. The ceramic particles are exteriorly exposed and may be bound to the graft by a polymeric coating material, which may be a biodegradable polymer. A disadvantage of this device is that the biodegradable coating layer does not provide sufficient rigidity during implantation for an outer graft layer. Appeal 2012-004446 Application 10/889,432 4 (Spec. ¶ 17.) 2. The Specification discloses that “the biodegradable sheath is comprised of a material selected from, but not limited to, the following: polylactides, polyanhydrides, polyvinyl alcohol, polyvinylpyrolidone [sic], polyglycols, gelatin derivatives and combinations thereof” (id. at ¶ 60). 3. Sirhan “provides luminal prostheses, such as vascular stents and grafts for reducing or inhibiting restenosis” (Sirhan 1: 5–6). 4. Sirhan discloses that “the device includes a structure and at least one source of at least one therapeutic capable agent associated with the structure” (id. at 5: 32–33). 5. Sirhan also discloses that “the source may further comprise[] a rate-controlling element 43” (id. at 30: 3–4). 6. In addition, Sirhan discloses that the “rate-controlling element may be formed of a non-degradable, partially degradable, substantially degradable material, or a combination thereof” (id. at 13: 11–12). 7. Sirhan also discloses: Suitable biodegradable rate-controlling element materials include, but are not limited to, poly(lactic acid), poly(glycolic acid) and copolymers, poly dioxanone, poly (ethyl glutamate), poly (hydroxybutyrate), polyhydroxyvalerate and copolymers, polycaprolactone, polyanhydride, poly(ortho esters); poly (iminocarbonates), polycyanoacrylates, polyphosphazenes, copolymers and other aliphatic polyesters, or suitable copolymers thereof including copolymers of poly-L-lactic acid and poly-e-caprolactone; mixtures, copolymers, and combinations thereof. (Id. at 13: 18–24.) Appeal 2012-004446 Application 10/889,432 5 8. In addition, Sirhan discloses: “The rate-controlling element will typically have a total thickness in a range from about 10 nm to about 100 μm. The thickness may also range from about 50 nm to about 100 μm, from about 100 nm to about 50 μm, or from about 100 nm to 10 μm.” (Id. at 15: 11–14). 9. Sirhan also discloses that the “expandable structure usually will have a thickness in a range from about 0.025 mm to 2.0 mm, preferably from about 0.05 mm to about 0.5 mm” (id. at 36: 30–31). PRINCIPLES OF LAW [I]t is elementary that the mere recitation of a newly discovered function or property, inherently possessed by things in the prior art, does not cause a claim drawn to those things to distinguish over the prior art. Additionally, where the Patent Office has reason to believe that a functional limitation asserted to be critical for establishing novelty in the claimed subject matter may, in fact, be an inherent characteristic of the prior art, it possesses the authority to require the applicant to prove that the subject matter shown to be in the prior art does not possess the characteristic relied on. In re Best, 562 F.2d 1252, 1254–55 (CCPA 1977). “An assertion of what seems to follow from common experience is just attorney argument and not the kind of factual evidence that is required to rebut a prima facie case of obviousness.” In re Geisler, 116 F.3d 1465, 1470 (Fed. Cir. 1997). ANALYSIS Appellant does not dispute that Hill discloses the claimed expanded polytetrafluoroethylene (ePTFE) graft member or that it would have been obvious to include Hill’s ePTFE graft member in Sirhan’s device. Instead, Appellant argues that “the combination fails to disclose or suggest a more Appeal 2012-004446 Application 10/889,432 6 rigid biodegradable sheath be employed with an ePTFE graft” (App. Br. 11). We are not persuaded. The Examiner relies on Sirhan’s rate controlling element for being a sheath (Ans. 4; see also Finding of Fact (FF) 5). Sirhan discloses that the “rate-controlling element may be formed of a non-degradable, partially degradable, substantially degradable material, or a combination thereof” (FF 6). In addition, Sirhan discloses that suitable biodegradable materials include materials that may be used to form the claimed sheath (compare FF 2 & 7). We conclude that the Examiner has set forth a prima facie case that Sirhan suggests a biodegradable sheath that has a rigidity that is greater than Hill’s ePTFE graft (Ans. 5). Appellant argues: [T]he thickness of [Sirhan’s] scaffold . . . is 0.25 mm [sic, 0.025 mm (FF 9)] to 2.0 mm while the thickness of the rate- controlling element . . . is 1.0 nm [sic, 10 nm (FF 8)] to 100 μm . . . which is significantly less than the thickness of the scaffold. One of ordinary skill in the art would not be lead to believe that such a thin coating is going to provide rigidity to the underlying scaffold. (App. Br. 13.) However, absent sufficient evidence to support the assertion that a thin coating would not provide rigidity, we agree with the Examiner that this argument is not persuasive (Ans. 10). We note Appellant’s reliance on a teaching in the Specification of a “biodegradable coating layer [that] does not provide sufficient rigidity during implantation for an outer graft layer” (App. Br. 13 fn. 8; FF 1). However, in the absence of any indication of what is in this coating layer, how thick it is, and even whether or not it has a rigidity greater than the Appeal 2012-004446 Application 10/889,432 7 graft, we agree with the Examiner that this teaching is insufficient to demonstrate that Sirhan fails to suggest a biodegradable sheath having a rigidity greater than Hill’s ePTFE graft member (Ans. 10). CONCLUSION The evidence supports the Examiner’s position that Sirhan and Hill suggest a biodegradable sheath having a rigidity greater than the flexible tubular graft member. We therefore affirm the obviousness rejection. TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). AFFIRMED cdc Copy with citationCopy as parenthetical citation