Background
Medtronic, Inc. is the market leader in sacral neuromodulation — a therapy that uses implanted devices to deliver electrical stimulation to the sacral nerves to treat bladder and bowel conditions. Axonics, Inc. is a smaller competitor that entered the neuromodulation market with its own implantable sacral nerve stimulation system. Medtronic sued Axonics for infringement of patents covering lead designs and placement methods used in its InterStim system.
Axonics challenged the validity of Medtronic’s patents by filing inter partes review (IPR) petitions before the PTAB, arguing that the asserted claims were obvious in light of combinations of prior art references — specifically, references called “Young” and “Gerber.” The Young reference disclosed a lead designed for use in the trigeminal nerve region of the face, while Gerber disclosed techniques relevant to sacral neuromodulation. Axonics argued that a skilled artisan would have been motivated to combine Young and Gerber to arrive at the claimed invention. The PTAB rejected Axonics’ obviousness argument, finding no motivation to combine because Young was specifically designed for the trigeminal nerve area and would not be feasible for sacral use. The PTAB did not assess whether a skilled artisan would be motivated to combine the references to achieve the claimed invention more broadly. Axonics appealed.
The Court’s Holding
The Federal Circuit vacated and remanded, finding the PTAB committed a fundamental legal error in framing the motivation-to-combine inquiry. The Board had asked the wrong question: it evaluated whether someone would be motivated to use Young’s lead specifically in the trigeminal nerve context for which Young was designed, and concluded that application would not be feasible in the sacral region. But the correct inquiry — as established by the Supreme Court in KSR and by Federal Circuit precedent — is whether a skilled artisan would be motivated to combine the teachings of the references to arrive at the claimed invention, regardless of the specific application context of any individual reference.
By tethering its analysis to Young’s intended trigeminal nerve application, the Board artificially constrained the motivation inquiry in a way that ignored how skilled artisans actually approach combination of prior art: by looking at the teachings across references for what they collectively suggest, not by asking whether the specific use-case of one reference maps onto another. Because the Board’s error was not harmless — it may have infected the entire analysis — the Federal Circuit vacated both final written decisions and remanded for the Board to apply the correct legal standard.
Key Takeaways
- The motivation-to-combine inquiry in obviousness analysis must focus on whether a skilled artisan would be motivated to combine the prior art teachings to achieve the claimed invention — not on whether the primary reference’s specific intended application would transfer to the proposed combination.
- The PTAB errs when it limits its obviousness analysis by anchoring the motivation inquiry to one reference’s particular use context rather than the full scope of what the combined references teach.
- IPR petitioners challenging medical device patents should clearly articulate in their petitions that motivation to combine is assessed from the perspective of the claimed invention as a whole, not any single reference’s target application.
- The decision reinforces the KSR principle that prior art references should be read for all they teach, not just their primary intended purpose.
Why It Matters
The medical device sector relies heavily on IPR proceedings to challenge competitors’ patents, and the motivation-to-combine requirement is frequently the pivotal battleground. This decision corrects a recurring PTAB error: evaluating motivation through the narrow lens of what a primary reference was designed to do, rather than what a skilled artisan could learn from combining all the relevant prior art. For IPR petitioners, the ruling underscores the importance of presenting clear, claim-focused arguments about motivation — and for patent owners, it confirms that the PTAB must engage with those arguments through the correct legal lens.
The Axonics-Medtronic rivalry also illustrates the broader dynamic in medtech: market leaders with large, mature patent portfolios frequently use litigation to slow the entry of innovative competitors. Correct application of obviousness law is essential to ensuring that the IPR system functions as Congress intended — as a rigorous but fair mechanism for weeding out patents that would not have been granted had the prior art been fully considered.