Holding: Whether applicant admitted prior art is used as the basis for an IPR petition is determined by the grounds raised in the IPR petition and not by the characterization of the prior art made by the PTAB in its Final Written Decision.
Cardiovascular Systems (“CSI”) challenged Shockwave’s U.S. Patent No. 8,956,371 in an IPR. The ‘371 Patent is directed to the treatment of atherosclerosis through intravascular lithotripsy (“IVL”). Lithotripsy is a well-known technique typically used for breaking up kidney stones by sending shockwaves directly to the kidney stones. IVL applies this technique to break up plaque that hardens on the walls of blood vessels through the use of a balloon catheter with a balloon that is inflated at the position of the plaque buildup. Electrodes and a pulse generator are positioned within the fluid filled balloon to produce shockwaves that are delivered to the hardened plaque.
In its IPR petition, CSI alleged that all 17 claims of the ‘371 Patent were obvious in view of European Patent Application Publication No. EP 0571306 to Levy, which discloses the use of laser-generated pulses to disintegrate plaque in blood vessels. Although the EP’306 Application does not describe the use of balloons, CSI argued that it would have been obvious to modify the EP’306 Application to include an angioplasty balloon catheter as disclosed in the ‘371 Patent as applicant admitted prior art (“AAPA”). The PTAB found claims 1-4 and 6-17 of the ‘371 Patent to be unpatentable as obvious and found claim 5 of the ‘371 Patent to not be unpatentable.
Shockwave argued that both CSI’s petition and the PTAB’s decision improperly relied on AAPA to provide the basis for the petition. Section 311(b) allows a petitioner in an IPR to request to cancel claims of a patent as unpatentable only on a ground that could be raised under Section 102 or Section 103 and only on the basis of prior art consisting of patents or printed publications. In Qualcomm Incorporated v. Apple Inc., 134 F.4th 1355 (Fed. Cir. 2025), the Federal Circuit affirmed that the AAPA cannot be used as the basis of a ground in an IPR petition, but AAPA may be used as evidence of background knowledge of a person of ordinary skill in the art.
In this case, the Federal Circuit found that CSI did not use the AAPA as a basis for its challenge, but instead only to show that an over-the-wire angioplasty balloon catheter would have been known to a person of ordinary skill in the art. It is permissible for a challenger in an IPR to use general knowledge to supply a missing claim limitation. Shockwave also pointed out that the PTAB included the AAPA in a column titled “Reference(s)/Basis” in a table listing the challenged claims and the references offered by CSI. Shockwave argued that this shows that the PTAB improperly considered the AAPA as a basis for CSI’s challenge rather than simply background knowledge. In Qualcomm, the Federal Circuit found the petitioner’s inclusion of AAPA in a chart designating its grounds for challenging the patent as sufficient evidence to show that improper consideration of AAPA as a basis for the challenge. However, this case differs in that it was the PTAB that included the AAPA in a chart describing the basis for challenge and not a chart offered by the petitioner. The metes and bounds of the IPR are defined by the IPR petition, not by disthe PTAB’s discretion. Since CSI never described the AAPA as a basis for its challenge of the ‘371 Patent, and only relied on the AAPA as evidence of background knowledge, the use of the AAPA was appropriate.
With regard to claim 5, the Federal Circuit found that the PTAB erred in finding that claim 5 was not unpatentable as obvious in view of Levy implemented in an over-the-wire balloon as supported by the AAPA, and further in view of Japanese Patent Application No. JP 62-275446 to Uchiyama. Claim 5 relates to the placement of electrodes adjacent to and outside the guide wire lumen. Initially, Shockwave argued that CSI lacked standing to challenge this appeal in Court. Article III standing is not required to request an IPR, but must be established if review of an IPR decision is sought in federal court. CSI had developed an IVL device that was in its final stages of development and close to a clinical trial. Shockwave’s President publicly stated that it would aggressively assert its IVL claims, including claim 5 of the ‘371 Patent. These statements, along with the fact that CSI’s product was nearly complete were sufficient to confer standing to CSI’s appeal of the PTAB’s decision on claim 5.
As for the finding on patentability, the Federal Circuit found that the PTAB erroneously considered the teachings of the JP ‘446 Application on their own rather than in view of Levy and the background information provided by the AAPA. The JP ‘446 Application taught a lithotripter for breaking up kidney stones with a pair of electrodes on a tube located in a fluid-inflatable balloon, but failed to teach that electrodes could be adjacent to and radially spaced from the lumen of the catheter. However, the PTAB’s failure to view the JP ‘446 Application in view of the other prior art improperly discounted CSI’s argument that the position of the electrodes would have been routine design choice.
Federal Circuit Precedential 
Leave a comment