The Federal Circuit remanded a final written decision of the Patent Trial and Appeal Board ("PTAB" or "Board") because the Board invalidated certain claims in a patent without providing adequate notice or opportunity to the patentee to respond to an assertion about a prior art reference.  Interestingly, in the In re NuVasive, Inc. opinion decided on November 9, 2016, the Federal Circuit reviewed the outcome of two IPR proceedings related to the same patent, U.S. Patent No. 8,187,334, directed to implants for spinal fusion surgery.  In the first proceeding, IPR2013-00507, the original petition had specifically cited to a section of U.S. Patent No. 5,860,973 ("Michelson"), and that section included a description of a prior art structure.  In the other proceeding, IPR2013-00508, there was no such specific citation to the structure, although the Michelson reference was cited.  In both cases, the Board relied on that prior art structure as represented in Figure 18 to invalidate all but one of the challenged claims as obvious.  In reaching its decision for the IPR2013-00508 proceeding, the Federal Circuit concluded that because Figure 18 was not referenced until the petitioner's reply, and because the Board's citation to Figure 18 was material to its invalidation of the claims, NuVasive was entitled to an opportunity to respond to the assertion about this figure.  The same was not true for IPR2013-00507.  The Federal Circuit concluded in that case that because Figure 18 was referenced in the petition, although not with specificity, NuVasive had sufficient notice (although "barely") that it should address the prior art structure found in that figure.  Claims 16 and 17 were the only two claims invalidated in the IPR2013-00508 proceedings that were not also invalidated in the IPR2013-00507 case, so the IPR2013-00508 case was remanded "for further proceedings regarding claims 16 and 17 in accordance with" the opinion.

The technology in the case involved spinal fusion implants designed to be inserted between two vertebrae to replace damaged or diseased discs.  One claimed feature of the patented implants related to its dimensions, specifically a length that is both greater than 40 mm and at least 2.5 times the maximum width. This can be seen in this representative claim (with relevant language highlighted):

1.  A spinal fusion implant of non-bone construction positionable within an interbody space between a first vertebra and a second vertebra, said implant comprising:
    an upper surface including anti-migration elements to contact said first vertebra when said implant is positioned within the interbody space, a lower surface including anti-migration elements to contact said second vertebra when said implant is positioned within the interbody space, a distal wall, a proximal wall, a first sidewall and a second sidewall, said distal wall, proximal wall, first sidewall, and second sidewall comprising a radiolucent material;
    wherein said implant has a longitudinal length greater than 40 mm extending from a proximal end of said proximal wall to a distal end of said distal wall;
    wherein a central region of said implant includes portions of the first and second sidewalls positioned generally centrally between the proximal wall and the distal wall, at least a portion of the central region defining a maximum lateral width of said implant extending from said first sidewall to said second sidewall, wherein said longitudinal length is at least two and half times greater than said maximum lateral width;
    at least a first fusion aperture extending through said upper surface and lower surface and configured to permit bone growth between the first vertebra and the second vertebra when said implant is positioned within the interbody space, said first fusion aperture having: a longitudinal aperture length extending generally parallel to the longitudinal length of said implant, and a lateral aperture width extending between said first sidewall to said second sidewall, wherein the longitudinal aperture length is greater than the lateral aperture width; and at least three radiopaque markers;
    wherein a first of the at least three radiopaque markers is at least partially positioned in said distal wall, a second of said at least three radiopaque markers is at least partially positioned in said proximal wall, and a third of said at least three radiopaque markers is at least partially positioned in said central region.

The prior art Michelson reference described several spinal fusion implants, some of which were long and wide, but one of which was long and narrow.  The following four picture from that patent show two different implants and their respective insertion into the vertebrae:

Both petitions cited to other references as the primary reference for an obviousness assertion, but also cited to Michelson as teaching implants with elongated shapes with "dimensions that are longer than wide."  However, only in the IPR2013-00507 petition did Medtronic (the petitioner) cite to column 10, line 6 through column 11, line 15 for this proposition.  Nevertheless, this section described five different figures (16-20), and Figure 18 itself was never specifically identified.

Medtronic only specifically identified Figure 18 in both proceedings after NuVasive filed its Patent Owner Response, in which it argued that "no single reference taught an implant that was both longer than 40 mm and had a length at least 2.5 times its width."  Medtronic pointed out in its Reply that Figure 18 disclosed exactly such an implant.  NuVasive requested leave to file a motion to strike or in the alternative, the opportunity to file a surreply, but the Board denied all such attempts.  Instead, the Board assured NuVasive it understood its position and would take it into account when making the final determination.  Nevertheless, the PTAB ultimately held all but one challenged claim obvious, relying heavily on Figure 18.  NuVasive appealed, and Medtronic cross-appealed on claim 18 but ultimately withdrew from the case.

The Federal Circuit pointed out that the APA imposes particular requirements on the Patent Office, including timely informing patent owners of the matters of fact and law asserted against the patent and providing all parties the opportunity to respond after notice is provided.  In this case, the Court found the assertions regarding Figure 18 to be material, differentiating this case from Genzyme Therapeutic Prods. Ltd. v. Biomarin Pharm. Inc., in which the Court found that newly cited references were provided to establish the state of the art.  The Federal Circuit concluded that NuVasive was entitled to an opportunity to respond to the facts about Figure 18, even though Michelson was cited in both petitions ("And under the APA's fact-specific standard, common sense, and this court's precedent, that entitlement was not lessened in this case by virtue of the opportunity NuVasive had to respond to other factual assertions about Michelson.").  In other words, even though NuVasive had to respond to other assertions regarding Michelson, the new assertions regarding Figure 18 were sufficiently distinct to assure NuVasive an opportunity to respond to them.

However, for the IPR2013-00507, the Court found that NuVasive had had that opportunity from the outset of the case, because Medtronic had cited to the section of the specification that happened to include a description of Figure 18.  This was sufficient, according to the Court, to put NuVasive on notice that it should address the dimensions of the implant in its Patent Owner Response.  What is unclear, however, is what is the maximum amount of text that needs to be referenced to still create such an obligation for a Patent Owner?  The clear takeaway for petitioners, however, is that to the extent possible with word-count constraints, make as many ancillary citations to as much cited art as possible in the hopes of creating such an obligation.

One final observation that was not adequately explained by the Court is that NuVasive cited to Michelson Figures 16, 19, and 20 in its Patent Owner Response to demonstrate that the art used long-and-wide implants.  The patent owner explained that these configurations were desirable because they maximized the surface area of contact with the vertebrae.  Nevertheless, it is difficult to explain why NuVasive wasn't already on notice that it should explain why Figure 18 had similar dimensions as the claim invention, especially considering this figure was found in the midst of the other cited figures.  In fact, the Board had concluded that this citation to the other figures by NuVasive was sufficient to allow Medtronic to raise Figure 18 in its reply.  ("[A] reply may only respond to arguments raised in the corresponding opposition, patent owner preliminary response, or patent owner response.")  It is unclear, therefore, why NuVasive was not under an obligation at that point to differentiate the dimensions of Figure 18 from the claimed invention.  Going forward, it would probably behoove a Patent Owner to do so.  But, until the law changes, this In re NuVasive case should sufficiently support any requirement that the Patent Owner be provided with the opportunity to respond in such situations.

In re NuVasive, Inc. (Fed. Cir. 2016)
Panel: Circuit Judges Moore, Wallach, and Taranto
Opinion by Circuit Judge Taranto