Precedential PTAB Decision Holds Inter Partes Review Challengers Can Join Own Petitions

March 14, 2019

A panel of the US Patent Trial and Appeal Board has identified “limited circumstances” in which a patent challenger can join its own inter partes review petition to add new issues. Parties seeking to join their own petitions should consider whether they can show undue prejudice, and the one-year time bar remains relevant.

The US Patent Trial and Appeal Board (PTAB) of the US Patent and Trademark Office issued its first precedential opinion in Proppant Express Investments LLC v. Oren Technologies, LLC on March 13, holding that so-called “issue joinder” is allowed under the America Invents Act.[1] As such, the panel cited “limited circumstances” under which parties can join their own petitions for inter partes review.

Procedural History

Petitioners Proppant Express Investments, LLC and Proppant Express Solutions, LLC filed two serial petitions requesting inter partes review of the same patent owned by Oren Technologies, LLC. The PTAB declined to institute on one ground in the first petition, finding that the petitioners had failed to account for all limitations of a challenged claim.[2] In the second, later-filed petition, the petitioners attempted to correct that error and also simultaneously filed a motion for joinder with the first petition.[3] The PTAB denied both the second petition and the motion for joinder, interpreting 35 USC § 315(c) as providing authority to join only “other parties to existing proceedings without introducing new issues of patentability.”[4] The PTAB also denied the second petition under 35 USC § 315(b) because the petitioners had been served with a complaint alleging patent infringement more than one year before the date the second petition was filed.[5]

After the petitioners requested rehearing of the PTAB’s denial of the second petition, the PTAB’s Precedential Opinion Panel sua sponte ordered a review to address the following issues:

  1. Under 35 USC § 315(c), may a petitioner be joined to a proceeding in which it is already a party?
  2. Does 35 USC § 315(c) permit joinder of new issues into an existing proceeding?
  3. Does the existence of a time bar under 35 USC § 315(b), or any other relevant facts, have any impact on the first two questions?[6]

PTAB Holds Petitioners Can Join Their Own Petitions in ‘Limited Circumstances’

After a lengthy discussion on statutory interpretation, the Precedential Opinion Panel—which in this case included Director Andrei Iancu, Commissioner for Patents Drew Hirshfeld, and Acting Chief Administrative Patent Judge Scott R. Boalick—answered “yes” to all questions.

First, the panel concluded that “35 U.S.C § 315(c) provides discretion to allow a petitioner to be joined to a proceeding in which it is already a party.”[7] The panel noted that the statutory language does not exclude a person who is already a petitioner in a proceeding, nor does the legislative history clearly indicate that Congress intended to allow only a different petitioner to join a proceeding.[8]

Second, as to issue joinder, the panel concluded “35 U.S.C § 315(c) . . . provides discretion to allow joinder of new issues into an existing proceeding,” again noting the statutory language contains no express prohibition against raising new issues and finding its interpretation to be consistent with the legislative history.[9]

Third, the panel concluded that “the existence of a time bar under 35 U.S.C. § 315(b) is one of several factors that may be considered when exercising our discretion under § 315(c).”[10] The panel noted, as to this point, “The statutory language is dispositive, as 35 U.S.C. § 315(b) provides an exception to its own time limitation for a request for joinder under 35 U.S.C. § 315(c).”[11] However, the panel warned that this exception must not “swallow the rule,” as the one-year time bar is important.[12]

Finally, the panel advised the PTAB to only exercise its discretion in “limited circumstances—namely, where fairness requires it and to avoid undue prejudice to a party.”[13] The panel identified one such circumstance: where “actions [are] taken by a patent owner in a co-pending litigation such as the late addition of newly asserted claims.”[14] Attempts to game the system may be considered, as may be the state and schedule of an existing inter partes review.[15] However, the panel explicitly noted that mistakes or omissions will not implicate fairness and prejudice concerns.[16]

PTAB Declines to Exercise Its Discretion in This Case

After laying out the legal analysis, the panel declined to grant the petitioners’ motion for joinder for the second petition because it was based on the petitioners’ failure to make out a proper case in the first petition.[17] “Because Petitioner[s’] own conduct created the need for it to request joinder, this case does not involve one of the limited circumstances in which the Board will exercise its discretion to allow same party and/or issue joinder.”[18] The panel then declined to institute the second petition as untimely.[19]

Parties seeking to join their own petitions should consider whether they can show undue prejudice. It remains best practice to file all petitions before the one-year time bar when possible and preferably simultaneously to avoid 35 USC § 325(d) and 35 USC § 314(a) issues.


If you have any questions or would like more information on the issues discussed in this LawFlash, please contact the authors, Julie Goldemberg (Philadelphia) and Dion Bregman (Silicon Valley), or any of the following lawyers from Morgan Lewis’s post-grant proceedings team:

Joshua M. Dalton

Century City
Andrew V. Devkar

Jason C. White

C. Erik Hawes
Rick L. Rambo

Louis W. Beardell, Jr.

San Francisco
Brent A. Hawkins

Silicon Valley
Andrew J. Gray IV
Michael J. Lyons

Washington, DC
Jeffrey G. Killian, Ph.D.
Robert Smyth, Ph.D.


[1] No. IPR2018-00914, Paper No. 38, slip op. (PTAB Mar. 13, 2019).

[2] Id. at 2.

[3] Id.

[4] Id. (emphasis added).

[5] Id. at 2-3.

[6] Id. at 3.

[7] Id. at 4.

[8] Id. at 6-8.

[9] Id. at 4, 11-13.

[10] Id. at 16.

[11] Id. at 17.

[12] Id. at 18.

[13] Id. at 19 (emphasis added).

[14] Id.

[15] Id.

[16] Id. at 5, 19.

[17] Id. at 19.

[18] Id. at 20.

[19] Id. at 20-21.