1. Home
  2. |Insights
  3. |Federal Circuit Stops the Launch of the First U.S. Biosimilar Pending Appeal

Federal Circuit Stops the Launch of the First U.S. Biosimilar Pending Appeal

Client Alert | 3 min read | 05.08.15

Just when the first biosimilar was poised to hit the lucrative U.S. market, the Federal Circuit put the brakes on ZARXIO®, Sandoz's biosimilar based on Amgen Inc.'s blockbuster Neupogen®. On Tuesday, the Federal Circuit temporarily blocked Sandoz, Inc. from selling ZARXIO®, saying the product can't be sold until the court resolves a dispute over information-sharing requirements of the Affordable Care Act's biosimilars pathway.

In a terse, per curiam order, the Circuit court offered no explanation for its granting an injunction on the first U.S. biosimilar while the appeal of the district court's decision is pending. That decision rejected Amgen's arguments, which were, essentially, that Sandoz is hiding the ball by not handing over the information that it's required to disclose under the Biologics Price Competition and Innovation Act (BPCIA), which, in turn, prevents Amgen from digging through that information to see whether it has a patent-infringement case against the biosimilar maker.

On January 14, 2015, ZARXIO® made history as the first U.S. biosimilar approved by the U.S. Food and Drug Administration (FDA). See our previous Client Alert: Three Take-Aways from Novartis' Historic First U.S. Biosimilar Approval (Mar. 11, 2015). In early March, the district court in Amgen v. Sandoz, Case No. 3:14-cv-04741-RS heard arguments on the parties' disputes of the disclosure requirements imposed by the new biosimilar pathway. The district court sided with Sandoz on its interpretation of the portion of BPCIA governing the disclosure requirements imposed on biosimilar manufacturers prior to sale of a biosimilar product. See our previous Client Alert: District Court's Decision Paves the Way for the First U.S. Biosimilar (Mar. 23, 2015). The district court also rejected Amgen's interpretation of the statute that would have required Sandoz to wait 180 days from approval of the biosimilar product before going to market.  Instead, the district court found Sandoz was within its rights to resist sharing certain information with Amgen as part of the BPCIA's so-called patent dance.

One of the main areas of contention in this dispute was whether either of the drug makers faced irreparable harm. Amgen argued that it would suffer "irreversible price erosion" if ZARXIO® sales commenced. On the other hand, Sandoz claimed that its "head start" on other prospective makers of Neupogen® biosimilars, which is the key incentive in the biosimilar pathway, would be unfairly shortened or eliminated by an injunction.

While the Federal Circuit was apparently more sympathetic to Amgen's concerns, the order did indicate that Amgen may be required to post a bond that will compensate Sandoz on a daily basis if it turns out that ZARXIO® sales shouldn't have been delayed. The Circuit court order indicates that the parties are directed to file pleadings "concerning what amount of a bond, if any, should be posted for each day that the injunction is in place." (emphasis added).

The size of the daily bond will be the next biosimilar battleground. Neupogen® sales in the U.S. for the fourth quarter of 2013 alone were over $229 million. Needless to say, Sandoz will likely demand that Amgen post a very sizable bond for each day that it is enjoined. The Circuit court will determine the amount of the bond in a subsequent order.

Oral arguments on the injunction are set for June 3.

Contacts

Insights

Client Alert | 5 min read | 12.12.25

Eleventh Circuit Hears Argument on False Claims Act Qui Tam Constitutionality

On the morning of December 12, 2025, the Eleventh Circuit heard argument in United States ex rel. Zafirov v. Florida Medical Associates, LLC, et al., No. 24-13581 (11th Cir. 2025). This case concerns the constitutionality of the False Claims Act (FCA) qui tam provisions and a groundbreaking September 2024 opinion in which the United States District Court for the Middle District of Florida held that the FCA’s qui tam provisions were unconstitutional under Article II. See United States ex rel. Zafirov v. Fla. Med. Assocs., LLC, 751 F. Supp. 3d 1293 (M.D. Fla. 2024). That decision, penned by District Judge Kathryn Kimball Mizelle, was the first success story for a legal theory that has been gaining steam ever since Justices Thomas, Barrett, and Kavanaugh indicated they would be willing to consider arguments about the constitutionality of the qui tam provisions in U.S. ex rel. Polansky v. Exec. Health Res., 599 U.S. 419 (2023). In her opinion, Judge Mizelle held (1) qui tam relators are officers of the U.S. who must be appointed under the Appointments Clause; and (2) historical practice treating qui tam and similar relators as less than “officers” for constitutional purposes was not enough to save the qui tam provisions from the fundamental Article II infirmity the court identified. That ruling was appealed and, after full briefing, including by the government and a bevy of amici, the litigants stepped up to the plate this morning for oral argument....

View All Insights