August 30, 2023

In re Cellect: Federal Circuit Opens New Path for Double Patenting Challenges

On August 28, 2023, the U.S. Court of Appeals for the Federal Circuit issued a precedential decision in In re Cellect (No. 22-1293) that answered a longstanding question regarding the relationship between Obvious-Type Double Patenting (“ODP”) and Patent Term Adjustment (“PTA”).1 Specifically, the Court held that when members of a patent family differ in their expiration dates solely on the basis of PTA, the earlier-expiring family members can be used as the basis for an ODP validity attack on later-expiring family members. This result with respect to ODP in the context of patents with PTA is notably distinct from the Court’s holding with respect to ODP in the context of Patent Term Extension (“PTE”).2 In its 2018 decision in Novartis AG v. Ezra Ventures LLC  (“Ezra”)3 the Court prohibited this same type of intra-family ODP attack when the difference in expiration dates was due to PTE, rather than PTA. The Court’s holding in Cellect is potentially wide-ranging and is likely to be particularly impactful in the life science and pharmaceutical industries, where patent holders frequently rely on grants of PTA to maintain market exclusivity.

Case Summary:

Cellect arose from the appeal of four related ex parte reexamination proceedings involving a family of patents that cover devices containing electronic image sensors.4 Many of these family members received PTA due to prosecution delays and, as a result, the family had a wide range of different expiration dates.5 During the ex parte reexamination, the examiner issued ODP rejections that invalidated the claims of four different patents in the family.6 These rejections—summarized in the figure below—relied on earlier expiring members of the same patent family as references.7 Ordinarily, a patent holder can cure an ODP rejection by filing a terminal disclaimer that causes the challenged patent to expire on the same date as the earlier-expiring reference patent. However, in Cellect, terminal disclaimers could not be filed because the reference patents had all since expired. This meant that the examiner’s ODP rejections had the effect of invalidating the challenged claims. The Patent Trial and Appeal Board (“PTAB”) affirmed the examiner’s rejections and the patent holder appealed.

Recellect chart

On appeal, the patent holder did not dispute the obviousness component of the examiner’s  ODP rejections, but instead argued that the rejections were procedurally improper under Ezra and other related cases.8 The Federal Circuit rejected this argument and, following an extensive analysis of the relevant statutes and caselaw, held that PTA and PTE should be treated differently in the context of ODP because the “PTA and PTE are dealt with in different statutes and deal with differing circumstances.”9 Specifically, the Court pointed to the fact that “[t]he expiration date used for an ODP analysis where a patent has received a PTE is the expiration date before the PTE has been added” whereas “the expiration date used for an ODP analysis where a patent has received PTA is the expiration date after the PTA has been added.”10

Moreover, the Court identified different purposes for PTE and PTA, with PTE being “designed to effectively extend the overall patent term for a single invention due to regulatory delays in a product approval.”11 In contrast, the Court explained that “PTA is designed to extend the term of a particular patent due to delay in the processing of that Patent.”12 The Court also stressed the importance of the obviousness component of the ODP analysis, but noted that this was not a matter of dispute on the current facts.13

The question of whether ODP could be used to mount intra-family attacks on patents enjoying Patent Term Adjustment has been percolating since at least the Federal Circuit’s 2018 Ezra decision.  In Ezra, the Federal Circuit held that the statute establishing Patent Term Extension overrode the judicially-created doctrine of ODP and that, as a result, patents that received PTE were immune to ODP attacks based on earlier-expiring family members.14 This holding prompted several district courts, most notably in New Jersey, to conclude that PTA should be treated the same as PTE for purposes of ODP and extend Ezra’s prohibition on intra-family ODP attacks to PTA as well.15 The Federal Circuit appears to have now rejected that reasoning by holding in Cellect that PTA and PTE should be treated differently with respect to ODP. 

Looking Forward:

The availability of ODP as a means to attack patents with PTA is of special interest in the pharmaceutical and life sciences industries, where even a single day of patent life can be worth substantial sums. Thus, while In re Cellect addressed patents directed to “Hand-Held Computers Incorporating Reduced Area Imaging Devices,” many amici curiae at the panel stage were trade groups representing both innovators (i.e., patent owners) as well as frequent challengers of drug patents.16 The industry will be following developments in this space closely and further amicus briefing appears likely if Cellect is litigated further, e.g., through a petition for rehearing by the panel or rehearing en banc at the Federal Circuit, or a petition for certiorari at the U.S. Supreme Court. A rehearing petition would be due September 27, unless the deadline is extended. Amicus briefs supporting rehearing will be due 14 days after the rehearing petition.

Given the Court’s decision in Cellect, patent owners, patent licensees, patent licensors, intellectual property attorneys (e.g., patent prosecutors and patent litigators), and others should be especially attentive to issued patent claims within the same family. Issued patent claims in a family should be analyzed for any possible ODP issues, even if an ODP rejection was not raised by an examiner during prosecution. During patent prosecution, patent claims should be drafted so they are patentably distinct from patent claims in issued patents and pending applications within the same family. Companies and patent prosecutors should also consider auditing their existing patent portfolios to identify key claims that might be subject to a Cellect-type attack and determine whether terminal disclaimers are necessary to eliminate unacceptable risks. Where the filing of a terminal disclaimer could preserve additional exclusivity, counsel should collaborate with business leaders to weigh the benefits and drawbacks. Similarly, parties involved in litigation should be attuned to which (if any) patents in the case benefit from PTA and, if so, whether these patents might be vulnerable to an intra-family ODP in light of Cellect. Finally, attorneys in both the prosecution and litigation spheres should make note of the Federal Circuit’s emphasis on obviousness when assessing ODP and make sure that their strategy (whether offensive or defensive) meaningfully accounts for this element.


[1] Patent Term Adjustment (“PTA”) refers to time added to a patent’s term under 35 U.S.C. § 154(b) to account for delays caused by the examiner and/or USPTO during patent prosecution.
[2] Patent Term Extension (“PTE”) is specific to patents covering pharmaceutical products and refers to the process under 35 U.S.C. § 156 by which patent owners can recover a portion of a patent’s term that elapsed during the FDA regulatory review process for the covered product.  PTE is assessed separately from PTA and can be awarded concurrently.
[3] Novartis AG v. Ezra Ventures LLC, 909 F.3d 1367 (Fed. Cir. 2018).
[4] In re Cellect, LLC, No. 2022-1293, at *2–*3 (Fed. Cir. Aug. 28, 2023).
[5] Id. at *3–*4 .
[6] Id. at *4–*5.
[7] Id. 
[8] See id. at *5–*6, *13–*14, *18.
[9] See id. at *15–*16.
[10] Id. (emphasis added).
[11] Id. at 18 (emphasis added).
[12] Id. (emphasis added).  
[13] See id. at *14.
[14] See Ezra, 909 F.3d at 1373–74.
[15] See, e.g., Mitsubishi Tanabe Pharma Corp. v. Sandoz, Inc., 533 F.Supp.3d 170 (D.N.J. 2021); Amgen, Inc. v. Sandoz, Inc., CA No. 18-11206 (MAS) (DEA), 2021 WL 5366800 (D.N.J. Sept. 20, 2021); Abiomed, Inc. v. Maquet Cardiovascular LLC, CV No. 16-10914-FDS, 2023 WL 4038564 (D. Mass. June 15, 2023).
[16] See, e.g., In re Cellect, LLC, No. 2022-1293, at *13–*14 (Fed. Cir. Aug. 28, 2023).