The FDA approved Inflectra–Celltrion’s biosimilar version of Janssen’s Remicade® (infliximab) product–in April 2016, but according to Pfizer’s press release it’s commercial launch still “depend[s] on a number of factors” including “intellectual property considerations.” The pending biosimilar patent litigation got one step closer to resolution last week when Judge Wolf of the U.S. District Court for the District of Massachusetts granted Celltrion’s “Gilead Motion” for summary judgment of invalidity of U.S. Patent 6,284,471. The court entered final judgment on that patent to expedite Janssen’s ability to pursue an appeal and finally resolve at least that issue.

The Gilead Motion

As summarized in the court’s September 28, 2016 Memorandum and Order, Celltrion filed a motion for summary judgment of invalidity of the ‘471 patent based on obviousness-type double patenting in view of U.S. Patent 6,790,444.  Since the ‘471 patent was granted before the ‘444 patent, the theory of obviousness-type double patenting was based on the Federal Circuit decision in Gilead. In that case, the court held that a patent that issues after but expires before another patent can qualify as a double patenting reference for that other patent.

The ‘471 patent is a pre-GATT patent filed February 4, 1994, and granted September 4, 2001. Its earliest priority claim is to U.S. Application 07/670,827, filed Mar. 18, 1991. Its 17-year term would expire September 4, 2018.  The court characterized the ‘471 patent as covering a genus of compounds that includes infliximab.

The ‘444 patent is a post-GATT patent that claims priority through several continuation-in-part applications to the application that granted as the ‘471 patent. Its earliest priority claim also is to U.S. Application 07/670,827, filed Mar. 18, 1991. Since the ‘444 patent is a post-GATT patent, its 20-year term expired in 2011. The court characterized the ‘444 patent as covering “the infliximab antibody specifically.”

Importantly, Janssen conceded that the claims of the ‘444 patent “are not patentably distinct” from the claims of the ‘471 patent.  Thus, the only question before the court was whether the ‘444 patent could be cited as a double patenting reference.

Pre-GATT/Post-GATT

As the court noted, the issue presented by Celltrion’s Gilead Motion was factually distinct from the facts before the Federal Circuit in Gilead, because both patents at issue in Gilead were post-GATT patents. The court nevertheless determined that “the Federal Circuit would apply the Gilead ruling to the circumstances of this case.”

The court first noted that the URAA, which changed the basic patent term paradigm from 17 years from grant to 20 years from filing, did not address the scenario at issue:

The URAA is silent on this issue. It does not state that pre-URAA patents will always have 17 years’ protection. Nor does it reference the doctrine of obviousness-type double patenting.

The court then emphasized the policy concerns behind the doctrine, and found that they would be violated if the ‘471 patent was permitted to extend beyond the term of the ‘444 patent:

If plaintiffs’ position were correct, the public would be prevented from practicing the expired ‘444 patent and an obvious, patentably indistinct variation of it. This would violate the “bedrock principle . . . that when a patent expires, the public is free to use not only the same invention claimed in the expired patent but also obvious or patentably indistinct modifications of that invention,” … which is at the heart of the obviousness-type double patenting doctrine and which the Federal Circuit has found to be unaltered by the URAA.

Thus, the court determined that the ‘444 patent is citable as an obviousness-type double patenting reference against the ‘471 patent. In view of Celltrion’s concession that the claims were not patentably distinct, the court held that the challenged claims of the ‘471 patent are invalid for obviousness-type double patenting.

Duly Warned

In a section of his opinion that may make stakeholders cringe, Judge Wolf expressed no sympathy for Celltrion:

The obviousness-type double patenting doctrine was well-established when plaintiff applied for and when it accepted the ‘444 patent, which it knew would expire in 2011. Plaintiffs decided to take at least the risk that the ‘471 would be deemed invalid when the ‘444 expired.

Did Celltrion know in 2004 that in 2014 the Federal Circuit would hold that a later-granted patent could be cited against an earlier-granted patent?