Preparing for Changes in AIA Post-Grant Amendment Practice

July 17, 2015

Edmund J. Walsh, Turhan F. Sarwar, Charles T. Steenburg

Reproduced with permission from BNA's Patent, Trademark & Copyright Journal, 90 PTCJ 2648, 07/17/15. Copyright [1] 2015 by The Bureau of National Affairs, Inc. (800-372-1033)

Current statistics give patent owners little reason to hope—and challengers little reason to fear—that the Patent Trial & Appeal Board will grant motions to amend claims during inter partes reviews (IPRs), covered business method proceedings (CBMs), and post-grant reviews (PGRs). The Board has rejected over 90% of all motions to amend aside from those that merely cancelled claims outright.1

However, the tide may be turning. There are signs suggesting that patentees will soon have a more realistic chance to amend claims during America Invents Act (AIA) post-grant proceedings. Further, past statistics are presumably slanted by missteps that patentees made when previously filing motions without fully understanding the Board’s requirements.

Stakeholders thus should anticipate at least a modest—and perhaps a substantial—rise in the success rate for motions to amend. Laid out in this article are certain practical guidelines that patentees and potential challengers should consider when preparing for this change and navigating the present uncertainty.    

Current Requirements for Amending Claims During AIA Proceedings

Current U.S. Patent and Trademark Office (PTO) rules significantly restrict a patentee’s ability even to propose amended claims. Absent special permission, patent owners can only file a single motion to amend. They must file the motion no later than the date when they respond to the IPR, CBM, or PGR—normally three months after the Board institutes review, and long before it reaches a final decision concerning the original claims. Further, the Board can reject any amendment that (1) does not respond to a ground of unpatentability involved in the trial or (2) seeks to broaden the scope of the claims and/or introduce new subject matter. The PTO also presumptively limits patentees to one proposed substitute claim for each challenged claim.2

In addition, motions to amend must identify support in the specification—and also the earlier priority document, if applicable—for each proposed amendment or new claim.3

The Board has also broadly interpreted other rules—not tied to the amendment process—to restrict patentees’ ability to amend during AIA proceedings. In June 2013, the Board issued and designated as “Informative” a decision in Idle Free Systems v. Bergstrom holding that patentees seeking to amend claims during IPRs bear the burden to establish a “patentable distinction over the prior art of record and also prior art known to the patent owner,” with a specific representation concerning “the specific technical disclosure of the closest prior art known to the patent owner.”4 The Board later reiterated that patentees bear the burden to establish “patentability of the proposed substitute claims over the prior art in general” rather than only the references underlying the IPR.5 The Board therefore denied the patentee’s motion even while agreeing that the proposed substitute claims (1) did not broaden the original patent claims, (2) had written description support, and (3) adequately distinguished the invention over the particular prior art that the IPR concerned—findings that likely would have led the PTO to accept the amendment and even grant the patent in traditional prosecution or reexamination.6 Citing a rule concerning motion practice generally, the Board reasoned that in an IPR the patentee bore the burden of proof to justify the motion to amend and distinguished the practice from the traditional exercise of “rebutting a rejection in an Office Action.”7

Subsequently, the Board has cited Idle Free when denying various other motions to amend during IPRs as well as CBMs.8 In particular, the Board has reiterated that distinguishing prior art applied by petitioners “against the original patent claims is not the main event” of a motion to amend.9 Instead, motions should indicate whether the feature added in the proposed substitute claim “was previously known anywhere, in whatever setting, and whether or not the feature was known in combination with any of the other elements in the claim.”10

Signs That Changes Are Coming

Nevertheless, there are indications inside and outside the PTO that patentees may soon enjoy somewhat greater flexibility to amend claims during IPRs and other AIA proceedings.          

Recent Federal Circuit Decisions. When the Federal Circuit decided In re Cuozzo Speed Technologies and affirmed the “broadest reasonable interpretation” (BRI) standard for interpreting patent claims during IPRs, commentators touted the decision as vindicating the Board and the status quo.11 Yet Cuozzo and the Federal Circuit’s more recent decision in Microsoft v. Proxyconn may ultimately undermine Idle Free.

In Cuozzo, the Federal Circuit affirmed the Board’s use of BRI, citing the PTO’s long history of giving claims their broadest reasonable construction in other post-grant proceedings such as reissues, reexaminations, and interferences and rejecting Cuozzo’s attempt to distinguish IPRs from these traditional mechanisms based on the restrictions placed on amendments. Previous decisions had emphasized the “ability to amend” as a key factor distinguishing PTO proceedings from litigation and justifying the BRI standard.12 The Federal Circuit rejected this distinction, acknowledging the restrictions in the AIA and related regulations, but emphasizing nonetheless that IPRs were “not materially different” from traditional proceedings with respect to a patentee’s ability to amend.13 Notably, Cuozzo did not address Idle Free or other evidence concerning how the Board is implementing its regulations in practice. Cuozzo thus opened the door for challenging the reality of how the Board treats motions to amend during IPRs as inconsistent with the premise (i.e., the lack of any “material difference” relative to traditional post-grant proceedings like reexamination) on which the Federal Circuit relied when blessing BRI.14

The subsequent Microsoft v. Proxyconn appeal analyzed certain aspects of the Board’s actual approach to amendments, but not the full scope of Idle Free. The appeal arose from an IPR in which the Board cancelled all but one of Proxyconn’s claims while denying a motion to amend.15 The Board denied Proxyconn’s attempt to replace claims 1 and 3 because Proxyconn had failed to distinguish these claims over a prior art reference that Microsoft’s IPR petition had cited against a series of “closely related claims,” albeit not claims 1 and 3 themselves.16 Microsoft emphasized this prior art reference when opposing Proxyconn’s motion to amend, and Proxyconn’s reply brief lacked any substantive response.17

The Federal Circuit took an interest in Proxyconn’s unsuccessful motion during oral argument even though the prior art in question was undisputedly part of the IPR record.18 Later, the Federal Circuit issued an unusual order requesting that the parties and PTO submit letters addressing three amendment-related issues.19

First, the court solicited input concerning the “proper interpretation” of 37 C.F.R. § 42.121(a)(2) and asked whether this regulation constitutes an exhaustive list of reasons for which the Board can reject proposed amendments. The request referred specifically to Idle Free, implying that the Board’s decision exceeds the scope of the rule.

Second, the Federal Circuit asked what the proper standard of review should be for reviewing the Board’s denial of motions to amend.20

Third, the Federal Circuit questioned how the Board’s interpretation of § 42.121 squares “with the rule of broadest reasonable interpretation, one of the rationales for which is the right to amend.”21

The PTO’s response defended Idle Free and stressed the “adjudicatory” nature of IPRs, reasoning that a “‘motion to amend’ a patent during an IPR proceeding should not—and cannot—be treated in the same way as an amendment submitted during an examination proceeding.” The PTO’s letter also noted that it had already announced “improvements” to amendment practice and was considering “additional changes.”22

While the Federal Circuit ultimately affirmed the Board’s decision to deny Proxyconn’s motion to amend, it took care not to endorse Idle Free as a whole. The court merely affirmed the Board’s interpretation of regulations so as to require that patentees “show patentable distinction [of the substitute claims] over the prior art of record.”23 The decision expressly declined to hold that all of Idle Free’s requirements were “permissible interpretation[s] of the PTO’s regulations.”24 Indeed, the Federal Circuit stressed that it was not endorsing the requirement that a patentee “show patentable distinction over all ‘prior art known to the patent owner.’”25

This hesitance concerning Idle Free was particularly notable given that the Proxyconn decision made no attempt to square the BRI standard with the Board’s actual approach to amendment practice even though this was one of the three questions that the Federal Circuit highlighted in the post-argument request for letter briefs. By contrast, Proxyconn addressed the first two questions. It held that § 42.121(a)(2) was not exhaustive and confirmed that the Board could require a showing of patentable distinction “over the prior art of record.” The Federal Circuit also adopted a deferential standard of review.26

Changes by the PTO. Proxyconn may have bypassed the potential tension between BRI and the Board’s amendment practice given indications that this practice will soon change. Similarly, the Federal Circuit summarily affirmed the Board’s decision in Helferich Patent Licensing v. CBS Interactive under Rule 36 (i.e., without any opinion)27 despite repeatedly questioning the PTO’s attorney about amendment-related issues during oral argument.28 Former Chief Judge Paul Michel suggested that the panel in Helferich had “ducked” the amendment issue given “that the rules on motion to amend may change soon.”29

Indeed, PTO Director Michelle Lee had highlighted amendment practice at the top of a list of “quick fixes” announced on March 27, 2015.30 Acknowledging that 15 pages “is not sufficient to explain adequately why the amended claims are patentable,” the PTO authorized motions of up to 25 pages along with corresponding allowances for oppositions and replies. The new rules—finalized on May 19th—also authorize claim appendices, which do not count against the page limits.31

Lee also reported that the PTO is considering additional changes to amendment practice as part of a “second rule package.” The notice suggested that patentees may soon be able to file motions without “mak[ing] a prior art representation as to the patentability of the narrowed amended claims beyond the art of record before the Office.”32 The proposed rule package is projected by the “end of July 2015."33

Changes by Congress. Congress may mandate changes to amendment practice even if the PTO maintains—and the Federal Circuit accepts—the status quo. As of this writing, it is unclear whether legislation will be enacted and if so how it would impact patentees’ ability to amend during AIA proceedings. Senate Judiciary Committee Chairman Grassley called the amendment issue a “difficult nut to crack.”34 Further, many reform proposals call for requiring the Board to abandon the BRI standard and instead interpret claims as they would be construed in litigation. This may undermine proposals to mandate more flexible amendment practice. The PTO in particular maintains that Congress should completely repeal the right to amend if it mandates the claim interpretation change.35

Change by the Board. The Board itself may have already started to treat proposed amendments more favorably as reports swirl of rule changes and patent reform legislation. It recently granted a patentee’s motion to amend four claims to narrow a range to circumvent prior art, notwithstanding the challenger’s argument that the patentee had failed “to address all relevant prior art known to” the patentee.36 While citing Idle Free, the panel stressed that the patentee need only explain why the claims were “patentable over the prior art of record”—not prove patentability over all references known to one of ordinary skill.37 This approach appears at odds with previous holdings that patentees must indicate whether the additional feature recited in the proposed substitute claim “was previously known anywhere.”38

Do Amendments Matter?

Challengers who use AIA procedures submit themselves to the AIA’s estoppel provisions, limiting invalidity defenses that can be raised against a patent claim for which the Board issues a final written decision in an IPR, CBM, or PGR. This is a particular concern for IPRs and PGRs, as the statutory estoppel includes all grounds “that the petitioner reasonably could have raised during” the PTO proceeding.39 Because challengers are entitled to raise arguments against proposed amendments, challengers might be estopped from later raising invalidity arguments against amended claims.

It is an open question how courts will apply estoppel to amended claims40 and also whether the current statutory provisions will remain in place—especially if Congress amends the AIA to force the Board’s hand toward more liberal amendment practice. The bottom line, however, is that parties considering IPRs should evaluate the risk of patentees emerging with amended claims that the filers will be estopped from challenging in court based on virtually any patent, printed publication, or § 112 defense.41 PGR filers could face an even more extreme estoppel that extends to “physical” prior art and any other invalidity defense available under § 282.42

Navigating the Uncertainty

The current uncertainty surrounding amendment practice and the possibility of estoppel creates both risks and opportunities for prospective challengers as well as patentees.

Accused infringers should assess potential amendment-related risks when deciding whether to utilize AIA post-grant options. The possibility of amendments should also help shape tactics (e.g., which claims to challenge, what invalidity grounds to raise, etc.) if one decides to proceed.

At present, aggressive IPR or CBM requests have become a near-automatic response for many accused infringers. Cancellation rates are high, and many district courts grant stays almost as a matter of course. Further, it is normally possible for defendants to develop solid “backstop” invalidity positions based on § 101, § 112, and/or “physical” prior art (as opposed to patents and printed publications) to hold in reserve in case the patentee prevails in an IPR and the challenger is therefore estopped from raising invalidity defenses based on paper references that the challenger raised or reasonably could have raised with the Board.

Given the current restrictions on amendments and the Board’s aggressiveness in enforcing them, previous IPR and CBM requesters may be excused for downplaying potential amendment practice. This was a particularly logical approach following Idle Free in June 2013. Notably, IPR requests rose sharply during 2013—from 93 in the first quarter and 137 in the second quarter to 204 in the third quarter and 267 in the fourth quarter.43

As discussed above, however, the tables may be tilting toward more liberal amendment practice. Accused infringers should weigh the possibility of the Board allowing amended claims that could be essentially immune from printed publication attack or even § 112 challenges (i.e., if courts aggressively interpret the AIA estoppel provisions) and which may also be a poor fit for whatever physical prior art the defendant identified as a backstop.

Granted, it will often make sense to pursue IPR, CBM, or PGR even if the anticipated liberalization materializes. Particular specifications may not support narrowing amendments at all—let alone claims that cover accused products. Even if troublesome new claims did emerge, the patentee could only enforce them prospectively and even then may be limited by intervening rights.44 The point simply is to make an informed decision.

Patent owners responding to AIA proceedings likewise should take potential amendment practice seriously, notwithstanding the discouraging statistics. Here again, the key is to make an informed decision. Even assuming that more liberal amendment policies do materialize, many patentees may still rationally reject this option given the negative impact on damage claims. In the inter partes reexamination era, sophisticated patentees rarely amended existing claims, but instead added new claims. This tactic is not possible in AIA proceedings given that the Board normally requires patentees to cancel an existing claim for each new claim they want to add.45 Instead, however, patentees may propose “conditional” amendments—to be entered only if the Board concludes that the original challenged claims are not patentable.

Strategic Considerations for Petitioners. There are a handful of specific amendment-related guidelines that potential IPR, CBM, and PGR petitioners should consider when deciding whether to file and, if so, how best to proceed.

For one, potential challengers should scrutinize the written description to assess whether it would support any new claims that pose a viable infringement threat while working around the prior art under consideration. This is a task unfamiliar to many patent litigators given that patentees cannot amend their claims in court. Yet this limitation in litigation also explains why there will be situations in which accused infringers are better off raising particular prior art references in court than in an AIA proceeding. If a defendant secures a judgment of invalidity, the claim is dead. If the defendant instead files an IPR petition advancing the same arguments, the patentee could potentially amend the claim to work around the art and return to court with a patent that would be particularly difficult to challenge given the possibility of estoppel (as discussed above) and the practical difficulty of overcoming the Board’s imprimatur.

Challengers likewise should consider potential amendment practice when searching for prior art and selecting among the available options. There are obvious benefits to litigating validity issues at the Board rather than in court. If accused infringers can locate prior art to support a persuasive technical story that the underlying concepts in the patent are not inventive, it often will be preferable to file an IPR. Such references often exist, but are not necessarily the first materials that come to light. For example, it may be easy to find prior art publications from the named inventors that anticipate the claims, but omit certain other aspects of the specification that could translate into amended claims still posing an infringement risk. In such a situation, challengers should dig deeper for references that teach the specification as a whole.

Further, challengers should be wary of invalidity theories that turn on claim constructions straining the limits of “the broadest reasonable interpretation” standard. This is sound advice in any event, but will be particularly important if the Board begins granting motions to amend more frequently. Even if the Board credits a proposed construction that is on the edge of what is reasonable in light of the specification, patentees may be able to alter language and circumvent the prior art.

In addition, challengers should think twice before challenging claims that do not pose a genuine infringement risk. IPR and CBM petitions today sometimes contest all claims as a matter of course to maximize the pressure on the patentee while avoiding any chance of the patent coming back to haunt the challenger later (e.g., if the patentee is allowed to amend infringement contentions). However, increasing the number of challenged claims also increases the patentee’s flexibility when proposing amendments given the Board’s presumption that patentees can only propose one amended or substitute claim for each challenged claim.

To take an extreme scenario, suppose that an accused infringer wants to challenge a patent with one independent claim and nine dependent claims, but only the independent claim poses a genuine infringement risk. If the defendant files an IPR petition targeting only the independent claim, the patentee will normally only be able to propose a single conditional amendment. By contrast, targeting all 10 claims would potentially allow the patentee to propose 10 different claims with different scopes, thus experimenting with a range of options to work around the prior art.46

Challengers should also anticipate potentially threatening amendments and be ready to oppose them even before the patent owner seeks to amend. Once the patentee files the actual motion, challengers typically have no more than three months to respond. Here again, locating the right prior art and persuasively connecting it to an underlying narrative (i.e., regarding the patentee’s lack of a genuine inventive contribution) is important for ensuring that challengers will have the necessary ammunition when the time comes.  

There are also several practical steps that challengers facing a motion to amend should discuss with the appropriate engineers and/or supply personnel.

For one, proposed amendments could open the door for viable design-around strategies beyond those (if any) possible based on the original claims. Further, the challenger may be able to sell off its inventory of the original version without liability even if the Board allows the amendment and the revised claim continues to cover the original design. In particular, the doctrine of “absolute” intervening rights would preclude the patent owner from collecting damages based on units that existed in the United States (whether made here or imported) before the PTO issues an IPR or PGR certificate—even if the challenger sold those units after the certificate issued.47 Further, the PTO cannot issue the certificate and incorporate the new or amended claims into the patent until “the time for appeal has expired or any appeal has terminated.”48

Indeed, challengers may elect to stockpile inventory and appeal as a matter of course (assuming a good faith basis) any Board decision that grants a motion to amend. Intervening rights would be available for products manufactured or imported prior to the Federal Circuit’s decision, even in situations where the challenger has not made any design-around efforts.

That said, not every case will justify extensive analysis and/or contingency planning concerning potential amendments. Challengers may rationally decide to limit this work or even skip it entirely if the patent is set to expire soon or if potential exposure otherwise arises mostly from past acts of alleged infringement (e.g., if accused products have been discontinued). Notably, however, that will rarely—if ever—be applicable for PGRs, which can only be requested within nine months after the patent issues.49

Strategic Considerations for Patentees. There are also a handful of specific guidelines that patentees should consider when facing AIA proceedings.

For one, patentees should look beyond current statistics and consider whether it makes sense to propose amendments. Recent events suggest that the Board may be growing more receptive and in any event could have its hand forced by the PTO (via new rules), Congress (via amendments to the AIA), or perhaps even the Federal Circuit (via a decision that follows through on the threat in Proxyconn). Further, many motions to amend in the past have failed because of procedural defects that experienced counsel today should be able to avoid.

While there are alternatives (e.g., reissue) for narrowing claims, a successful amendment in an AIA proceeding will typically take effect faster.50 The challenger may also be limited by statutory estoppel provisions, as discussed above.

However, there is no guarantee that courts will resolve this estoppel question in favor of patentees. Worse yet, accused infringers may undercut the presumption of validity by citing the abbreviated nature of AIA proceedings and the Board’s emphasis that they are adversarial actions rather than examinations.51

For these reasons, patent owners considering amendments should strive to defend the substitute claims against all known prior art that raises a genuine concern. This will remain true even if Idle Free is overturned and patentees technically may focus only on the particular references at issue in the IPR, CBM, or PGR. Further, withholding prior art that is material under Therasense could render the entire patent unenforceable for inequitable conduct.52

Patent owners should also keep in mind the constraints (e.g., absolute intervening rights, as discussed above) that claim amendments create when seeking damages even after the AIA proceeding is complete. While “conditional” motions to amend allow patentees to hedge their bets and narrow a claim only if the Board deems the original version unpatentable, there may be situations—particularly under a liberalized amendment regime—where bringing such a motion tips the scales in favor of the Board cancelling the original claim.


It will likely become incrementally easier for patentees to amend claims during IPRs and other AIA post-grant proceedings. There are a series of practical steps that patentees and potential challengers should take to prepare for this shift and make fully informed decisions.


1 To date, the Board has only granted five motions to amend involving substitute claims. See Reg Synthetic Fuels LLC v. Neste Oil Oyj, IPR2014-00192, Paper 48 (June 5, 2015); Chicago Mercantile Exchange, Inc. v. 5th Market, Inc., CBM2013-00027, Paper 38 (Mar. 23, 2015); Riverbed Tech., Inc. v. Silver Peak Sys., Inc., IPR2013-00403, Paper 33 (Dec. 30, 2014); Riverbed Tech., Inc. v. Silver Peak Sys., Inc., IPR2013-00402, Paper 35 (Dec. 30, 2014); Int’l Flavors & Fragrances Inc. v. United States, IPR2013-00124, Paper 12 (May 20, 2014).

2 37 C.F.R. § 42.121(a) (concerning IPRs); 37 C.F.R. § 42.221(a) (concerning PGRs and CBMs).

3 37 C.F.R. § 42.121(b) (IPRs); 37 C.F.R. § 42.221(b) (PGRs and CBMs).

4 Idle Free Systems v. Bergstrom, IPR2012-0027, Paper 26 at 7 (June 11, 2013).

5 Idle Free Systems v. Bergstrom, IPR2012-0027, Paper 66 at 33 (Jan. 7, 2014).

6 See id.

7 Idle Free, Paper 66 at 33 (citing 37 C.F.R. § 42.20(c)).

E.g., Volusion, Inc. v. Versata Software, Inc., CBM2013-00017, Paper 19 (Dec. 20, 2013) (extending Idle Free guidance to CBMs).

9 Corning Optical Commc’ns RF LLC v. PPC Broadband, Inc., IPR2014-00441, Paper 19 at 4 (Oct. 30, 2014).

10 Id. (emphasis added).

11 E.g., Federal Circuit Blesses PTAB Rules on Claim Construction, Trial Grant, Amendment Limits, 89 PTCJ 877, 2/6/15.

12 In re Yamamoto, 740 F.2d 1569, 1571-72 (Fed. Cir. 1984) (affirming BRI in reexamination).

13 In re Cuozzo Speed Techs., LLC, 778 F.3d 1271, 1280-81 (Fed. Cir. 2015).

14 Cuozzo itself did not squarely present this issue and easily disposed of the motion to amend because it would have broadened the challenged claims.

15 Microsoft Corp. v. Proxyconn, Inc., No. 2014-1542, at 2-3 (Fed. Cir. June 16, 2015).

16 Id. at 25-28.

17 Id.

18 Oral Argument at 9:18-13:02, 19:09-25:55, Microsoft Corp. v. Proxyconn, Inc., No. 2014-1542 (Fed. Cir. Apr. 7, 2015) available at

19 Order Requesting Letter from Parties (Doc. 49), Microsoft Corp. v. Proxyconn, Inc., No. 2014-1542 (Fed. Cir. Apr. 13, 2015).

20 Id. at 3.

21 Id.

22 Letter from Intervenor Michelle K. Lee, Director, PTO (Doc. 50) at 7, Microsoft Corp. v. Proxyconn, Inc., No. 2014-1542 (Fed. Cir. Apr. 27, 2015).

23 Microsoft Corp., at 25.

24 Id. at 25 n.4.

25 Id.

26 Id. at 25-25.

27 Helferich Patent Licensing, LLC v. CBS Interactive, Inc., No. 2014-1556 (Fed. Cir. Apr. 8, 2015).

28 Oral Argument at 26:52-35:15, Helferich Patent Licensing, LLC v. CBS Interactive, Inc., No. 2014-1556 (Fed. Cir. Apr. 6, 2015) available at

29 Federal Circuit Affirms Three Cases Without Opinion Two Days After Oral Arguments, 89 PTCJ 1607, 1607-08, 4/10/15.

30 PTAB’s Quick-Fixes for AIA Rules Are to Be Implemented Immediately (Mar. 27, 2015),

31 Amendments to the Rules of Practice for Trials Before the Patent Trial and Appeal Board, 80 Fed. Reg. 28,561 (May 19, 2015).

32 PTAB’s Quick-Fixes for AIA Rules Are to Be Implemented Immediately (Mar. 27, 2015).

33 Boardside Chat: Discovery in AIA Trials, United States Patent and Trademark Office (June 2, 2015),

34 E.g., June 4, 2015 Prepared Statement by Sen. Chuck Grassley, (noting markup of PATENT Act and stressing that language concerning claim amendments was “a placeholder,” subject to further negotiations).

35 During Hearing, Lee Identifies Provisions of H.R. 9 Administration Does, Doesn’t Support, 89 PTCJ 1698, 1700, 4/17/15.

36 Reg Synthetic Fuels LLC v Nestle Oil Oyj, IPR2014-00192, Paper 48, at 19 (June 5, 2015).

37 Id.

38 E.g., note 9 supra; Toyota Motor Corp. v. Am. Vehicular Scis. LLC, IPR2013-00419, Paper 32 at 4 (Mar. 7, 2014).

39 35 U.S.C. §§ 315(e)(2) & 325(e)(2). By contrast, CBM estoppel extends only to issues that the petitioner actually raised. Leahy-Smith America Invents Act , Pub. L. No. 112-29, § 18(a)(1)(D), 125 Stat. 329, 330 (2011).

40 E.g., Scott A. McKeown, PTAB Accepts First Contested Claim Amendment, Now What?, Patents Post-Grant, (Jan. 7, 2015) (noting that “this issue will be litigated somewhere down the road,” and questioning whether it would be equitable to apply estoppel to amended claims given procedural restrictions).

41 While IPR petitions cannot directly raise § 112 defects, challengers can assert them in opposition to a motion to amend. E.g., Larose Indus. v. Capriola Corp., IPR2013-00120, Paper 24 at 3 (Oct. 17, 2013). Section 112 defects in amended claims arguably are grounds that the petitioner “reasonably could have raised” during the IPR review.

42 35 U.S.C. § 321(b) (defining permissible scope of PGR).

44 35 U.S.C. § 318(c) (IPRs) and 35 U.S.C. § 328)(c) (PGRs) incorporate 35 U.S.C. § 252, which governs the effect of reissued claims. Most reform proposals would leave this law unchanged.

45 This is another aspect of current amendment practice that appears unlikely to change.

46 Granted, all of those proposed amendments would need to be “responsive” to a ground of unpatentability under the current rules.

47 E.g., BIC Leisure Prods. v. Windsurfing Int’l, 1 F.3d 1214 (Fed. Cir. 1993) (affirming that absolute intervening rights applied under 35 U.S.C. § 252 to bar damages as to products in inventory or on order as of issue date of reissued patent). Section 252 also limits damages based on claims amended or added during AIA proceedings. See 35 U.S.C. §§ 318(c) & 328(c).

48 35 U.S.C. §§ 318(b) & 328(b). This is later than the applicable date for statutory estoppel, which takes effect upon the Board’s final written decision.

49 35 U.S.C. § 321(c). Further, PGRs are only available for post-AIA patents, examined under the first-to-file procedures.

50 Reissue pendency times are falling, but remained 3.5 years in 2014. Saving Patents from Inter Partes Review with Reissue, 90 PTCJ 2213, 5/22/15. In AIA proceedings, amendments will typically take effect (even assuming appeal) approximately two years after the motion to amend. See (10.0 month median time for resolving PTO appeals, FY04-13).

51 Cf. Microsoft Corp. v. i4i, 131 S. Ct. 2238, 2251 (2011) (“When warranted, the jury may be instructed to consider that it has heard evidence that the PTO had no opportunity to evaluate before granting the patent.”).

52 Although Rule 56 does not apply to AIA proceedings, 77 Fed. Reg. 48,612, 48,638 (Aug. 14, 2012), the PTO maintains that patentees must “make of record any additional prior art material to patentability known by the patent owner.” PTAB’s Quick-Fixes for AIA Rules Are to Be Implemented Immediately (Mar. 27, 2015), Further, Therasense defines materiality without reference to Rule 56. 649 F.3d 1276, 1294 (Fed. Cir. 2011).