W L Gore & Associates Inc v. LifePort Sciences LLC

1. Case Identification

• Case #: IPR2014-01321
• Patent #: 5,716,365
• Filed: August 18, 2014
• Petitioner(s): WL. Gore & Associates, Inc.
• Patent Owner(s): LifePort Sciences LLC
• Challenged Claims: 1-24

2. Patent Overview

• Title: Bifurcated Endoluminal Prosthesis
• Brief Description: The ’365 patent describes a modular endoluminal prosthesis for reinforcing bifurcated blood vessels. The system involves joining a first stent, having a "male engaging portion," to a second, often bifurcated, stent with a "female cooperating portion" by inserting and expanding the male portion within the female portion to prevent longitudinal movement and form a continuous lumen. The invention also discloses the use of shape memory alloys for thermal expansion of the stents.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 3-8, 10, 12-22, and 24 under 35 U.S.C. §102(e) over Ryan

• Prior Art Relied Upon: Ryan (Patent 8,206,427).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Ryan, which was not before the examiner during prosecution, discloses every limitation of the challenged claims. Ryan teaches an endovascular bifurcated stent graft system with a bifurcated base structure (second stent) and modular tubular grafts (first stent) that are anchored within the base structure’s connector legs. Petitioner asserted this corresponds to the claimed male portion (tubular graft) engaging a female portion (connector leg). Ryan explicitly discloses using a shape memory alloy like Nitinol for thermal self-expansion, creating a frictional inter-engagement that prevents longitudinal separation. Ryan also teaches the use of grafts made of sinuous wires and having internal and/or external graft liners, which may be folded over to form a seal, as recited in various dependent claims.

Ground 2: Obviousness of Claims 1-24 under 35 U.S.C. §103 over Martin in view of Ryan

• Prior Art Relied Upon: Martin (Patent 5,575,817) and Ryan (Patent 8,206,427).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Martin discloses the fundamental concept of the ’365 patent: a two-part bifurcated stent graft where a second section is joined to a first section via a friction fit. In Martin, the second section (male portion) expands within the first section (female portion) to prevent longitudinal movement. While Martin teaches a self-expanding mesh made of materials like stainless steel, it does not explicitly disclose a thermally-induced shape memory alloy or certain stent configurations. Ryan supplies these missing elements.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Ryan’s teachings with Martin to improve upon Martin’s design. A POSITA would have found it obvious to substitute Martin's self-expanding mesh with the thermally-activated shape memory alloy (Nitinol) taught by Ryan to achieve more controlled and reliable deployment at body temperature. Furthermore, it would have been a simple design choice to form Martin’s mesh support using the common sinuous wire configurations taught in Ryan to enhance flexibility and radial strength, which were known benefits of such designs.
  • Expectation of Success: A POSITA would have had a high expectation of success in making these combinations. Both references are in the same field of endoluminal grafts, and incorporating a well-known, advantageous material like Nitinol or a standard stent pattern like sinuous wires into an existing graft system were predictable modifications with known outcomes.

Ground 3: Obviousness of Claims 11 and 23 under §103 over Martin in view of Ryan and Pinchuk

• Prior Art Relied Upon: Martin (Patent 5,575,817), Ryan (Patent 8,206,427), and Pinchuk (Patent 5,226,913).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the Martin and Ryan combination to specifically address the limitations in claims 11 and 23 requiring frustoconical (tapered) walls. Petitioner argued that to the extent Martin and Ryan do not explicitly teach these specific shapes for the male and female engaging portions, Pinchuk renders the addition of this feature obvious. Pinchuk discloses that radially expandable stents can be fabricated in non-cylindrical shapes, including as "tapered, truncated cone-shaped stents," to better conform to patient anatomy.
  • Motivation to Combine: A POSITA would combine Pinchuk’s teaching of tapered stent shapes with the Martin/Ryan graft system to improve the device's anatomical fit and sealing capability within a patient's vasculature. Creating a frustoconical flare on the male portion or a taper on the female portion to match the natural taper of blood vessels was a known technique to enhance performance and stability, providing a clear motivation for the combination.
  • Expectation of Success: Applying a known shaping technique to a stent was a routine design modification. A POSITA would have reasonably expected that shaping the components of the Martin/Ryan stent system as taught by Pinchuk would successfully improve anatomical conformity without undue experimentation.

4. Key Claim Construction Positions

• Preamble "means" language: Petitioner argued that the preamble phrase "stent joining means" does not invoke means-plus-function claiming under pre-AIA §112, paragraph 6. Instead, it serves to state the intended use of the invention, with the structure being recited in the subsequent limitations of the claim body.
• Term Definitions: Petitioner proposed constructions for key terms based on the specification:
  • "proximal": "nearest to the heart"
  • "distal": "furthest from the heart"
  • "shape memory alloy": "alloy that recovers original shape on being raised to a higher temperature"

5. Key Technical Contentions (Beyond Claim Construction)

• Invalid Priority Claim: A central contention of the petition was that the ’365 patent is not entitled to its claimed priority date from earlier European applications. Petitioner cited a prior interference proceeding (’192 Interference) involving a related application from the same family as the ’365 patent. The outcome of that interference, affirmed on appeal, determined that the priority claim was improper and established Ryan as the senior party.
• Applicability of Prior Art: Based on the loss of the priority date, Petitioner argued that both the Martin and Ryan patents are valid §102(e) prior art against the ’365 patent. This directly contradicts the position the patent owner took during prosecution, where it overcame a rejection over Martin by asserting the now-invalidated priority claim.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-24 of Patent 5,716,365 as unpatentable.