In Immunex v. Sandoz, the Federal Circuit explained that where a patent license transfers the right to control prosecution, the ”all substantial rights” test can be informative in determining the “effective” patent owner for the purpose of evaluating common ownership in the obviousness-type double patenting context.  Accordingly, a license that is deemed to convey all substantial rights in a set of patents to a licensee could potentially expose the licensed patents and patents owned by the licensee to obviousness-type double patenting invalidity attacks.  Therefore, going forward, it may be increasingly important to assess the scope of the license grant, the scope of the licensed patents, and the scope of the licensee’s overall patent portfolio to assess and/or mitigate risk. 

Obviousness-Type Double Patenting

In Immunex, the Court outlined the well-established doctrine known as obviousness-type double patenting:

Obviousness-type double patenting is a judicially-created doctrine aimed at preventing claims in separate patents that claim obvious variants of the same subject matter where “granting both exclusive rights would effectively extend the life of patent protection.”  In re Hubbell, 709 F.3d 1140, 1145 (2013) (quotations omitted); Eli Lilly and Co. v. Barr Labs., Inc., 251 F.3d 955, 967 (Fed. Cir. 2001) (“The judicially-created doctrine of obviousness-type double patenting . . . prohibit[s] a party from obtaining an extension of the right to exclude through claims in a later patent that are not patentably distinct from claims in a commonly owned earlier patent.”).  The doctrine applies to all commonly-owned patents, even in cases where the obvious variants are invented by different inventors.  In re Longi, 759 F.2d 887, 895 (Fed. Cir. 1985). 

The Immunex Court, citing Hubbell, went on to explain that “there are two justifications for this doctrine: (1) to prevent timewise extension of the right to exclude; and (2) to prevent multiple infringement suits by different assignees.” 


The Federal Circuit Immunex case involved an appeal from a US District Court for the District of New Jersey holding that found Sandoz, Inc., Sandoz International GmbH, and Sandoz GmbH (“Sandoz”) failed to prove the asserted claims of the two patents-in-suit (Us 8,063,182 and 8,163,522) were invalid.  Hoffmann-La Roche Inc. (“Roche”) owns the patents-in-suit, which are exclusively licensed to Immunex Corp., and exclusively sublicensee Amgen Manufacturing, Ltd (collectively referred to as “Immunex”). 

On appeal Sandoz argued that the asserted claims of the patents-in-suit were invalid for (1) obviousness-type double patenting; (2) failure to meet the written description requirement; and (3) obviousness.  In Immunex, the Federal Circuit affirmed the district court’s judgment that Sandoz had not shown the asserted claims of the patents-in-suit were invalid on any of the alleged grounds.  Nonetheless, the Federal Circuit’s holding regarding Sandoz’s novel invalidity argument for obviousness-type double patenting is particularly instructive. 

In Immunex, “[b]orrowing from . . . 35 U.S.C. § 281 case law, Sandoz argue[d] that an agreement that conveys ‘all substantial rights’ in a patent is tantamount to an assignment of ownership,” and “this ‘all substantial rights’ test—to date used only to determine who may sue for infringement as a ‘patentee’ pursuant to 35 U.S.C. § 281—should apply in the obviousness-type double patenting context as well.”  In particular, Sandoz argued that the Accord & Satisfaction agreement gave Immunex “all substantial rights” in the patents-in-suit because it granted Immunex a “’paid-up, irrevocable, exclusive license’ and ‘first right to rectify any alleged infringement,’” along with the “ability to drive the prosecution of the patents.”  Accordingly, Sandoz argued that the patents-in-suit were invalid for obviousness-type double patenting over other Immunex owned patents.

In addressing Sandoz’s novel argument, the Federal Circuit held:

[A]lthough we agree with Sandoz that the ‘all substantial rights’ test can be informative in determining common ownership in the obviousness-type double patenting context, we conclude that the agreement at issue here did not transfer all substantial rights from the assignee, Roche, to the exclusive licensee, Immunex. Accordingly, we need not address the other layers of the district court’s detailed analysis on obviousness-type double patenting. . .

We are mindful, however, of the existing complexities in applying the equitable doctrine of obviousness-type double patenting and see no reason to import into this judicially-created doctrine the entirety of our body of law analyzing who is a statutory “patentee” pursuant to 35 U.S.C. § 281.  We conclude only that where one of the rights transferred is the right to prosecute the patent at issue, identification of the effective ‘patentee’ is informative in evaluating whether the patents are “commonly owned” for purposes of obviousness-type double patenting.  Where, as here, a party ultimately controls prosecution of both sets of patents, the “all substantial rights” test aids in preventing the unjustifiable issuance of claims that are patentably in-distinct from claims already owned by that party.  Under these circumstances, looking to the “all substantial rights” test achieves the proper balance between deterring gamesmanship in prosecution, on the one hand, and avoiding any chilling effect on routine collaborations and licensing be-tween parties working in the same field of research, on the other.  [emphasis in original]

The Federal Circuit outlined that in determining whether all substantial rights in a patent have been transferred to a licensee, it “examine[s] the ‘totality’ of the agreement,” and often considers “factors such as the scope of the licensee’s right to sublicense, the nature of license provisions regarding reversion of rights, the duration of the license grant, and the nature of any limits on the licensee’s right to assign its interests in the patent.”

Additionally, the Court noted that it has “often focused on two salient rights: enforcement and alienation.”  In Immunex, the Federal Circuit found that the enforcement and alienation rights under the Accord & Satisfaction agreement made it clear that Roche did not transfer all substantial rights in the patents-in-suit to Immunex because, although Immunex obtained the first right to sue for infringement, Roche retained a secondary right to sue.  The Federal Circuit went on to note that Roche had retained the right to veto any assignment of Immunex’s interest in the patents in suit and that this also weighed in favor of concluding that all substantial rights had not been transferred to Immunex.  Accordingly, the Federal Circuit found “the Immunex Patents and the patents-in-suit are not ‘commonly owned,’ and obviousness-type double patenting did not apply.

Of note, Judge Reyna dissented in the Immunex case, writing that he would interpret the “Accord & Satisfaction as an effective assignment of the patents-in-suit to Immunex” and hold that Immunex “is a common owner for obviousness-type double patenting purposes.” 


Going forward, it will be interesting to see how this area of law evolves.  However, when evaluating or contemplating a patent license, the potential grant of “all substantial rights” should clearly be considered in the context of obviousness-type double patenting.  For example, when contemplating a new patent license, it may be prudent to carefully evaluate the precise scope of grant that is required and the risk of an obviousness-type double patenting invalidity challenge to the combined portfolio of licensed and owned patents.  Stay tuned.



Immunex Corp. v. Sandoz Inc., 964 F.3d 1049 (Fed. Cir. 2020)