2020002616 (P.T.A.B. Mar. 24, 2021)

BIOTRONIK AG

Patent Trials and Appeals BoardMar 24, 2021

2020002616 (P.T.A.B. Mar. 24, 2021)

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. 14/395,709 10/20/2014 Heinz Mueller 1119737-0010-010-301 2307 106224 7590 03/24/2021 White & Case LLP 701 13th Street NW Washington, DC 20005 EXAMINER YANG, JIE ART UNIT PAPER NUMBER 1734 NOTIFICATION DATE DELIVERY MODE 03/24/2021 ELECTRONIC 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. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): wcpatents@whitecase.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE _________ BEFORE THE PATENT TRIAL AND APPEAL BOARD __________ Ex parte HEINZ MUELLER, PETER UGGOWITZER, and JOERG LOEFFLER __________ Appeal 2020-002616 Application 14/395,709 Technology Center 1700 ___________ Before ADRIENE LEPIANE HANLON, BRIAN D. RANGE, and MERRELL C. CASHION, JR., Administrative Patent Judges. HANLON, Administrative Patent Judge. DECISION ON APPEAL A. STATEMENT OF THE CASE The Appellant1 filed an appeal under 35 U.S.C. § 134(a) from an Examiner’s decision finally rejecting claims 1–5, 15, 18–20, 22, 24, and 25. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. The Appellant identifies the real party in interest as BIOTRONIK AG. Appeal Brief dated October 17, 2019 (“Appeal Br.”), at 3. Appeal 2020-002616 Application 14/395,709 2 The claims on appeal are directed to a biodegradable implant formed from a magnesium (Mg) alloy comprising less than or equal to 4.0% by weight zinc (Zn), 2.0 to 10.0% by weight aluminum (Al), and impurities in a total amount of no more than 0.0063% by weight. The Appellant discloses that the properties of magnesium alloys are determined by the type and quantity of the alloying elements and impurities as well as production conditions. Spec. 1, ll. 22–23.2 The Appellant discloses that aluminum provides increased tensile strength due to solid solution and precipitation hardening and zinc improves the mechanical properties as a result of solid solution hardening. Spec. 1, ll. 28–29; id. at 2, l. 19; see also id. at 8, ll. 21– 23 (disclosing that the matrix of the inventive magnesium alloy “is solid solution hardening due to Al and Zn and is also particle hardening due to the intermetallic phases formed of Mg and Al” (emphasis added)). The Appellant discloses that a preferred method for producing a magnesium alloy according to the invention comprises the following steps: a) generating high-purity magnesium by vacuum distillation; b) generating a billet of the alloy by synthesis of the magnesium according to step a) with less or equal 4.0% by weight Zn, 2.0 to 10.0% by weight Al, wherein the alloy content of Al is % by weight is greater than or equal to the alloy content of Zn in % by weight, the remainder being magnesium containing impurities, which promote electrochemical potential differences and/or the formation of precipitations and/or intermetallic phases, in a total amount of no more than 0.0063% by weight of Fe, Si, Mn, Co, Ni, Cu, Zr, Y, Sc or rare earths having the ordinal numbers 21, 57 to 71 and 89 to 103, Be, Cd, In, Sn and/or Pb as well as P, wherein the matrix of the alloy is solid solution hardening due to Al and Zn and is also particle hardening due to the intermetallic phases formed of Mg and Al; 2 Substitute Specification dated October 20, 2014. Appeal 2020-002616 Application 14/395,709 3 c) homogenizing the alloy by annealing at a temperature between 150°C and 450°C with a holding period of 4 to 40 hours; and d) forming the homogenized alloy in the temperature range between 200°C and 400°C. Spec. 11, l. 25–12, l. 6 (emphasis added). The Appellant discloses that “[p]referably steps c) and d) can be repeated at least once” and “[a]fter step c) and before step d) an ageing treatment step can be performed.” Spec. 12, ll. 8–9. The ageing treatment step is said to be performed at a temperature between 20°C and 300°C with a holding period of 1h to 168h. Spec. 12, ll. 11–12. The alloy is subsequently formed by extrusion, equal channel angular extrusion, and/or multiple forging. Spec. 14, ll. 5–7. Independent claim 1 is reproduced below from the Claims Appendix to the Appeal Brief. 1. A biodegradable implant formed from a magnesium alloy having improved mechanical and electrochemical properties, comprising: less or equal 4.0% by weight Zn, 2.0 to 10.0% by weight Al, the alloy content of Al in % by weight being greater than or equal to the alloy content of Zn in % by weight defining an alloy matrix having solid solutions of Al and/or Zn and intermetallic phases of magnesium and Al in the alloy matrix, the matrix lacking Mn as an alloying element to suppress formation of the ternary intermetallic phase FeMnSi and thereby improve corrosion resistance, the remainder being high-purity vacuum distilled magnesium, and the magnesium alloy containing impurities, which promote electrochemical potential differences and/or the formation of precipitations and/or intermetallic phases, in a total amount of no more than 0.0063% by weight, the impurities comprising one or more of Fe, Si, Mn, Co, Ni, Cu, Zr, Y, Sc, rare earth lanthanoids and actinoids, Be, Cd, In, Sn, and/or Pb as well as P, Appeal 2020-002616 Application 14/395,709 4 wherein the matrix of the alloy is solid solution hardening due to Al and/or Zn and is also particle hardening due to the intermetallic phases formed of Mg and Al, and wherein the biodegradable implant has a tensile strength of ˃ 275 MPa[,] a yield point of ˃ 200 MPa, a yield ratio of < 0.8, and a difference between tensile strength and yield point of ˃ 50 MPa. Appeal Br. 19. Claims 1–5, 15, 18–20, 22, 24, and 25 are rejected under 35 U.S.C. § 103(a) as unpatentable over Wang et al.3 in view of Xie4 and Numano et al.5 B. DISCUSSION The Examiner finds Wang discloses a high-purity Mg-Al-Zn alloy for use as an absorbable stent. Non-Final Act. 4.6 The Examiner finds Wang discloses that the alloy comprises 2.6–3.0 wt% Al and 0.6–1.0 wt% Zn, which fall within the ranges recited in claim 1. Id. The Examiner finds Wang discloses that the purity of the Mg-Al-Zn alloy is greater than 99.99% and the impurity content of Mn, Fe, Si, Cu, and Ni in the alloy is less than 0.005 wt%. Id. The Examiner also finds Wang discloses that the alloy has a tensile strength greater than 300 MPa and a 3 CN 101658691 A, published March 3, 2010. In the record, the reference is referred to as “CN’891,” “CN’691,” and “Wang.” In this Decision on Appeal, we refer to the reference as “Wang” and rely on the English translation entered in the record on September 14, 2017. The pages of the translation are not numbered. Therefore, we refer to the page numbers automatically generated in the Official file of the instant Application. 4 CN 101948957 A, published January 19, 2011. In the record, the reference is referred to as “CN’957” and “Xie.” In this Decision on Appeal, we refer to the reference as “Xie” and rely on the English translation entered in the record on December 11, 2018. 5 US 2012/0128997 A1, published May 24, 2012. In the record, the reference is referred to as “PG’997” and “Numano.” In this Decision on Appeal, we refer to the reference as “Numano.” 6 Non-Final Office Action dated December 11, 2018. Appeal 2020-002616 Application 14/395,709 5 yield strength greater than 210 MPa, which fall within the ranges recited in claim 1. Id. The Examiner finds the difference between Wang and the claimed invention is (1) Wang does not disclose the vacuum distillation technique recited in claim 1 and (2) Wang does not expressly disclose that the matrix of the alloy is solid solution hardening and particle hardening as recited in claim 1. Id. at 4, 5. The Examiner relies on Xie to show that vacuum distillation was a known technique for preparing a high-purity Mg alloy. Id. at 4. The Examiner relies on Numano to show that forming a Mg-Al intermetallic compound in precipitation form was known to improve the strength of a Mg alloy. Id. at 5. The Appellant argues that “Wang describes a Mg alloy in which the full alloy has a total impurity level of 0.01%” and describes that “a subset of the impurities including Mn, Fe, Si, Cu, and Ni are limited to a lower amount of 0.005%.” Appeal Br. 8 (emphasis added). The Appellant argues that “[t]he total impurity level of 0.01% described in Wang is substantially higher than the claimed impurities ‘in a total amount of no more than 0.0063% by weight.’” Id. Contrary to the Appellant’s argument, Wang discloses that the Mg-Al-Zn alloy has a purity “greater than 99.99%” or “more than 99.99%,” and thus has an impurity level less than 0.01%. Wang 6, 7 (emphasis added). Although the Appellant characterizes the total impurity amount of Mn, Fe, Si, Cu, and Ni (totaling 0.005%) as a “subset” of the impurities in Wang’s alloy, the Appellant does not identify any additional impurities disclosed in Wang or their amount(s). See Wang 7 (identifying the impurities as Mn, Si, Cu, Ni, and Fe). Thus, on this record, a preponderance of the evidence supports a finding that the total amount of impurities in Wang’s alloy is 0.005%, an amount that falls within the range recited in claim 1 (i.e., “no more than 0.0063% by weight”). Appeal 2020-002616 Application 14/395,709 6 The Appellant also argues that “Wang’s manufacturing method does not produce a suitable magnesium alloy for use in a biodegradable medical implant.” Appeal Br. 9. To support its argument, the Appellant relies on a Declaration of Heinz Mueller dated September 11, 2018 (“Mueller Decl.”).7 Id. The Declaration is said to “include[] objective experimental evidence of a magnesium alloy treated according to the manufacturing method described in Wang, and conclude[] that the produced magnesium alloy became overly brittle and inappropriate for the production of a biodegradable implant formed from a magnesium alloy.” Id. at 10. Turning to the Declaration, Mr. Mueller states: According to my experience it is not possible to perform the manufacturing process as disclosed in CN’691 [Wang] to form a biodegradable implant of a magnesium alloy. The cold extrusion according to step 4 of CN ‘691 would lead to a very brittle extrusion product, which would break into pieces right after leaving the extrusion die or to failure of the extrusion equipment. Exhibit 1 shows the results of an extrusion of magnesium alloy containing 3 wt% aluminum, 0.8 wt% zinc and less than 0.0063 wt% impurities. The extrusion took place at 150 °C and at a [sic] extrusion ratio at approx. 9 with an extrusion speed of 10 mm/min respectively 3 mm/min. If the material breaks in pieces even at 150 °C, the problem would be worse at room temperature. According to my experience it seems impossible to perform the extrusion at room temperature and at the speed as disclosed in CN’691 without completely crushing the extrusion product or the extrusion apparatus even at a lower extrusion ratio. Mueller Decl. ¶ 7 (emphasis added). It is unclear from the Mueller Declaration whether the cold extrusion step, which is said to correspond to Wang’s step 4, was performed in isolation or in combination with the two previous extrusion steps disclosed in Wang (i.e., steps 7 Mr. Mueller is one of the named inventors in the instant Application. Mueller Decl. ¶ 1. Appeal 2020-002616 Application 14/395,709 7 two and three). See Wang 7 (describing a hot extrusion in steps two and three). The Mueller Declaration also does not identify the impurities and the total amount of those impurities in the Mg-Al-Zn alloy discussed in paragraph 7. Finally, the Mueller Declaration states that “[t]he extrusion took place at 150 °C and at a [sic] extrusion ratio at approx. 9.” Mueller Decl. ¶ 7. Those conditions, however, are outside the cold extrusion conditions disclosed in step 4 of Wang’s process. See Wang 7 (disclosing that the extrusion temperature is “room temperature” and the extrusion ratio is “4 ~ 6”). Mr. Mueller states that “it seems impossible to perform the extrusion at room temperature and at the speed as disclosed in CN’691 [Wang] without completely crushing the extrusion product or the extrusion apparatus even at a lower extrusion ratio,” but Mr. Mueller does not provide any data to support his statement. Mueller Decl. ¶ 7 (emphasis added); see also In re Brandstadter, 484 F.2d 1395, 1406 (CCPA 1973) (“[T]he affidavits fail in their purpose since they recite conclusions and few facts to buttress said conclusions.”). Based on the foregoing, a preponderance of the evidence supports a finding that Wang’s manufacturing method produces a magnesium alloy that is suitable for use as a biodegradable medical implant, as expressly disclosed in Wang. See, e.g., Wang 3 (disclosing that “[t]he present invention relates to a method of manufacturing an endovascular treatment within the field of use of metal stents, and more particularly to a high-purity magnesium alloy absorbable stent plastic manufacturing method”). Turning to the differences between the claimed alloy and Wang’s alloy identified above, the Appellant argues that the Examiner “has offered no reason why a POSITA [person of ordinary skill in the art] would find it obvious to apply Xie’s vacuum distillation technique for automobile and airplane structural Appeal 2020-002616 Application 14/395,709 8 components . . . to Wang’s method over other possible sources for Mg.” Appeal Br. 12. The Examiner finds that vacuum distillation was a well-known technique for preparing a high purity Mg alloy at the time of the Appellant’s invention. Non- Final Act. 4. The Examiner concludes that it would have been obvious to one of ordinary skill in the art to use vacuum distillation to manufacture Wang’s high purity Mg alloy. Id. at 5; see also In re Fout, 675 F.2d 297, 301 (CCPA 1982) (an “[e]xpress suggestion to substitute one equivalent for another need not be present to render such substitution obvious”). Moreover, we conclude that the claim limitation “high-purity vacuum distilled magnesium” is a process limitation. Appeal Br. 19. That is, the high- purity magnesium recited in claim 1 is prepared using a vacuum distillation technique. Therefore, claim 1 is a product-by-process claim. “If the product in a product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process.” In re Thorpe, 777 F.2d 695, 697 (Fed. Cir. 1985). On this record, we find that the Mg-Al-Zn alloy disclosed in Wang satisfies the ranges recited in claim 1, including the claimed tensile strength and yield point.8 Therefore, a preponderance of the evidence supports a finding that the claimed alloy is the same or substantially the same as Wang’s alloy. See In re Marosi, 710 F.2d 799, 803 (Fed. Cir. 1983) (“Where a product-by-process claim is rejected over a prior art product that appears to be identical, although produced by a different process, the burden is upon the applicants to come forward with 8 Notably, the Appellant does not argue that Wang’s alloy does not have a tensile strength, a yield point, a yield ratio, and a difference between tensile strength and yield point within the ranges recited in claim 1. Appeal 2020-002616 Application 14/395,709 9 evidence establishing an unobvious difference between the claimed product and the prior art product.”). As for Numano, the Appellant argues that Numano is not related to medical implants and would not “logically commend” itself to one of ordinary skill in the art considering how to manufacture a medical device. Appeal Br. 14. The Appellant’s argument is not persuasive of reversible error. Claim 1 recites that “the matrix of the alloy is solid solution hardening due to Al and/or Zn and is also particle hardening due to the intermetallic phases formed of Mg and Al.” Appeal Br. 19 (emphasis added). The Appellant discloses that aluminum provides increased tensile strength due to solid solution and precipitation hardening and zinc improves the mechanical properties as a result of solid solution hardening. Spec. 1, ll. 28–29; id. at 2, l. 19; see also id. at 8, ll. 21–23 (disclosing that the matrix of the alloy is solid solution hardening due to Al and Zn and is particle hardening due to the intermetallic phases formed of Mg and Al). The teachings of Numano appear to be consistent with the Appellant’s disclosure. See Numano ¶ 61 (disclosing that a solid solution type element, e.g., Al, forms a solid solution with a phase of the magnesium alloy); id. (disclosing that Al forms an intermetallic compound with Mg). Claim 1 does not recite that the alloy matrix is solid solution hardened and/or particle hardened. Thus, it is reasonable to find that Wang’s Mg-Al-Zn alloy matrix, which comprises amounts of Al, Zn, and impurities within the claimed ranges, is “solid solution hardening” and “particle hardening.” To the extent that “solid solution hardening” and “particle hardening” imply one or more Appeal 2020-002616 Application 14/395,709 10 process steps,9 as discussed above, process limitations in a product claim do not patentably distinguish the claimed product from a prior art product made by a different process. Thorpe, 777 F.2d at 697. For those reasons, the “solid solution hardening” and “particle hardening” alloy matrix recited in claim 1 does not patentably distinguish the claimed alloy from Wang’s Mg-Al-Zn alloy which satisfies the claimed ranges, including the claimed tensile strength and yield point. In sum, the obviousness rejection of claim 1 is sustained. The Appellant does not present arguments in support of the separate patentability of any of claims 2–5, 15, 18–20, 22, 24, and 25. See Appeal Br. 17 (arguing that the “dependent claims are also patentable for at least the reasons discussed above in reference to independent claim 1”). Therefore, the obviousness rejection of those claims also is sustained. C. CONCLUSION The Examiner’s decision is affirmed. In summary: Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1–5, 15, 18– 20, 22, 24, 25 103(a) Wang, Xie, Numano 1–5, 15, 18– 20, 22, 24, 25 No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED 9 See Appeal Br. 16 (arguing that the Examiner has provided no evidence that one of ordinary skill in the art would think the disparate “manufacturing methods” of Wang and Numano could be “successfully combined”).