In Shenzhen Silver Star Intelligent Tech. v. iRobot Corp., IPR2018-00761, Paper 15 (PTAB Sept. 5, 2018), the PTAB denied institution of Shenzhen Silver Star’s IPR petition in view of an earlier challenge to the same patent by a different petitioner. The PTAB relied on the General Plastic factors—a non-exhaustive list of seven factors—to exercise its discretion under 35 U.S.C. § 314(a) to deny the follow-on petition. General Plastic Industrial Co., Ltd. v. Canon Kabushiki Kaisha, IPR2016-01357, Paper 19, § II.B.4.i (PTAB Sept. 6, 2017) (precedential).

Litigation began in April 2017 when patent owner iRobot Corp. filed complaints in the ITC and district court, alleging infringement of U.S. Patent No. 7,155,308 (“the ’308 patent”), against Shenzhen Silver Star and others, including Shenzhen Zhiyi Technology Co., Ltd. Shenzhen Zhiyi brought the first challenge to the ’308 patent in an IPR petition filed September 8, 2017. After the patent owner filed a Preliminary Response to that petition in December 2017, the PTAB denied institution on March 12, 2018. Shenzhen Silver Star filed the second IPR petition challenging the ’308 patent, the petition at issue here, on March 8, 2018.

The PTAB held that, on balance, the General Plastic factors supported a decision denying the second petition—four factors weighed against institution, two factors were neutral, and one factor weighed in favor of institution. Shenzhen Silver Star, Paper 15 at 14. The factors weighing most strongly against institution were the third factor (“whether at the time of filing of the second petition the petitioner already received the patent owner’s preliminary response to the first petition or received the Board’s decision on whether to institute review in the first petition”) and the fourth factor (“the length of time that elapsed between the time the petitioner learned of the prior art asserted in the second petition and the filing of the second petition”). Only the first factor (“whether the same petitioner previously filed a petition directed to the same claims of the same patent”) favored institution.

In a concurring opinion, Administrative Patent Judge William V. Saindon reasoned that similarly situated defendants should ordinarily file their petitions around the same time:

Given petitions filed by two or more similarly situated defendants, there is a rebuttable presumption that a later-filed petition will be denied under General Plastic if that later-filed petition is filed after an earlier-filed petition has received a preliminary response or a decision on institution.

The concept behind this is that, all things being equal, if two or more co-defendants are sued around the same time, they should, within reason, file their petitions around the same time; it is generally unfair for one defendant to wait for a “test case” to go through the inter partes review process by another defendant before filing their own petition.

Id. at 16–17.

To specifically address timing issues in cases with similarly situated defendants, Judge Saindon proposed an additional factor for consideration in the § 314(a) analysis:

8. the extent to which the petitioner and any prior petitioner(s) were similarly situated defendants or otherwise realized a similar-in-time hazard regarding the challenged patent.

Id. at 18.

Judge Saindon cautioned that there might be legitimate reasons not to deny petitions filed after a preliminary response or institution decision. Id. In such cases, “petitioners are encouraged to explain timing differences relative to the filing of previous petitions by similarly situated defendants.” Id. at 18–19.

This case is a reminder that the one-year time bar of 35 U.S.C. § 315(b) serves as a “hard ceiling,” which the PTAB understands it is “free to lower as fairness dictates.” Id. at 18 n.2. In addition to satisfying the one-year time bar, petitioners should consider filing IPR petitions “around the same time” as other similarly situated defendants.