Boston Scientific Corp v. Nevro Corp

1. Case Identification

• Case #: IPR2022-00510
• Patent #: 8,892,209
• Filed: February 10, 2022
• Petitioner(s): Boston Scientific Corporation, Boston Scientific Neuromodulation Corporation
• Patent Owner(s): Nevro Corporation
• Challenged Claims: 1, 5-13, 16-21, 23-24, and 27-30

2. Patent Overview

• Title: Selective High Frequency Spinal Cord Modulation for Inhibiting Pain with Reduced Side Effects, and Associated Systems and Methods
• Brief Description: The ’209 patent discloses spinal cord stimulation (SCS) systems and methods for inhibiting pain without causing paresthesia (a tingling sensation). The invention purports to achieve this using therapy signals with specific pulse width ranges delivered as sequential bi-phasic pulses.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claims 1, 5-13, 16-21, 23-24, and 27-30 over Eddicks

• Prior Art Relied Upon: Eddicks (a 2007 journal article titled Thoracic Spinal Cord Stimulation Improves Functional Status and Relieves Symptoms in Patients with Refractory Angina Pectoris).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Eddicks taught all elements of the challenged claims. Eddicks described a study using Medtronic SCS systems to provide "subthreshold" stimulation for treating angina, which explicitly did not produce paresthesia. To achieve this, Eddicks taught lowering the stimulation amplitude to 85% of the level that causes paresthesia, ensuring patients "reported no perception of paraesthesia at any time." The standard parameters used in Eddicks included a pulse width of 210-300 µs, which falls within the broadest range of challenged claim 1 (10-333 µs). Eddicks also used standard implantable leads (Medtronic Pisces Quad) placed in the epidural space.
  • Motivation to Combine (for §103 grounds): While Petitioner asserted anticipation for claims 1 and 8, the broader obviousness argument contended that any claim elements not explicitly disclosed by Eddicks were obvious modifications. For example, using sequential bi-phasic pulses was a standard, well-known feature of commercial SCS systems (like those used in Eddicks) to ensure charge-balancing and prevent cell trauma. A POSITA would have found it obvious to use this standard waveform. Similarly, selecting a pulse width within the narrower dependent claim ranges was merely optimizing a known, adjustable parameter to suit an individual patient, a routine practice in the art.
  • Expectation of Success: A POSITA would have had a high expectation of success in applying Eddicks’ subthreshold, paresthesia-free technique using standard SCS system features, as Eddicks itself demonstrated the successful application of this method for pain relief using commercially available hardware.

Ground 2: Obviousness of Claims 1, 5-13, 16-21, 23-24, and 27-30 over Eddicks in view of Woods

• Prior Art Relied Upon: Eddicks (a 2007 journal article) and Woods (Patent 7,177,690).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground combined the paresthesia-free programming method from Eddicks with the detailed SCS system architecture disclosed in Woods. Woods described a complete, implantable SCS system with a processor-based implantable pulse generator (IPG), memory for storing instructions, and various implantable leads (both percutaneous and paddle). Woods explicitly taught using symmetrical, bi-phasic, square-wave pulses to create a "balanced charge condition" and disclosed a programmable pulse width range of 10 to 1000 µs, which fully encompasses all pulse width ranges in the challenged claims.
  • Motivation to Combine: A POSITA would combine Eddicks’ method with a system like Woods to implement paresthesia-free therapy in a well-understood, fully-featured SCS system. Eddicks provided the "how" (subthreshold amplitude) and "why" (enhanced patient comfort, avoiding unwanted paresthesia), while Woods provided a detailed, exemplary "what" (a robust, programmable SCS system). The combination amounted to applying a known therapeutic technique (from Eddicks) to a known, suitable device (from Woods) to achieve the predictable result of pain relief without paresthesia.
  • Expectation of Success: Success was predictable because the combination involved only programming changes (lowering amplitude) on a standard SCS system architecture like that in Woods. No hardware modifications were required, and the underlying components and principles of operation were identical.

Ground 3: Obviousness of Claims 1, 5-13, 16-21, 23-24, and 27-30 over Yearwood

• Prior Art Relied Upon: Yearwood (a 2006 conference presentation titled A Prospective Comparison of Spinal Cord Stimulation (SCS) Using Dorsal Column Stimulation (DCS)...).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Yearwood, standing alone, rendered the claims obvious. Yearwood described using a Boston Scientific Precision SCS system to treat low back pain with "subthreshold" stimulation that did not cause paresthesia and provided significant pain relief. The study explicitly used pulse widths "between a range of 10 and 1000 µsec," and the commercial system used was capable of generating the claimed bi-phasic pulses. Yearwood also disclosed using 8-electrode percutaneous leads implanted in the epidural space, meeting further claim limitations.
  • Motivation to Combine (for §103 grounds): Yearwood itself provided the motivation: to achieve "[e]ffective pain relief and comfortable stimulation." A POSITA reading Yearwood would understand that using subthreshold parameters on a standard SCS system was a known and effective way to treat pain without the side effect of paresthesia. The claimed parameters and hardware were all disclosed or readily available in the system Yearwood used.
  • Expectation of Success: Yearwood's own results demonstrated a high expectation of success, as it reported up to 80% pain relief using the subthreshold, non-paresthesia-producing method on a commercially available SCS system.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Eddicks, Woods, and Feler892 (Patent 6,236,892) to address claims requiring paddle leads and specific vertebral target locations (T9-T12), arguing Feler892 taught targeting these specific levels for back and leg pain. Further grounds combined Yearwood with Eddicks and/or Woods.

4. Key Claim Construction Positions

• Petitioner argued that the terms "a plurality of sequential bi-phasic pulses" and related "bi-phasic" phrases should be construed to require that each pulse has a positive and negative phase that are charge-balanced. This construction was based on the prosecution history, where the patent owner amended the claims to recite "sequential biphasic pulses" to overcome a rejection over a prior art reference (DeRidder1) that disclosed charge-balancing at the end of a burst of pulses, but not for each individual pulse. Petitioner contended this construction was critical to patentability and that the prior art teaches such per-pulse charge balancing.

5. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under §314(a) and the Fintiv factors, stating that the co-pending district court litigation was in its infancy, with no trial date set and minimal discovery exchanged. It was argued that a trial would occur long after a Final Written Decision, and the merits of the petition were strong.
• Petitioner also argued against denial under §325(d), asserting that the primary prior art references (Eddicks and Yearwood) were not before the examiner during prosecution. Petitioner contended these references presented a materially different and stronger case for unpatentability than the art considered by the USPTO, particularly by demonstrating that paresthesia-free SCS therapy was successfully practiced before the patent's priority date.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1, 5-13, 16-21, 23-24, and 27-30 of the ’209 patent as unpatentable.