Eye on Pharma: Sandoz Files Antitrust Suit; Yuflyma Interchangeability; Costco’s Ustekinumab Pick

Sandoz's antitrust suit against Amgen, the FDA’s interchangeability designation for Celltrion’s adalimumab biosimilar, and the inclusion of an ustekinumab biosimilar in Costco’s prescription program highlight growing momentum to expand biosimilar access and affordability for patients with chronic inflammatory diseases.

Sandoz Files Antitrust Suit Against Amgen

Sandoz has filed an antitrust lawsuit in the US against Amgen, accusing the company of using unlawful patent practices to maintain its dominant market position for Enbrel (etanercept).¹

Enbrel, a biologic therapy widely used to treat chronic inflammatory diseases, generated $3.3 billion in US revenue in 2024. Sandoz alleges that Amgen improperly acquired and leveraged certain patent rights to block the market entry of biosimilar competitors, including Sandoz’s FDA-approved biosimilar Erelzi (etanercept-szzs), which received approval in 2016 but has yet to launch in the US.

The lawsuit, filed in the US District Court for the Eastern District of Virginia, seeks both an injunction to halt Amgen's anticompetitive use of patents and monetary damages, which could be tripled under antitrust laws. Sandoz claims that millions of Americans with inflammatory diseases—such as rheumatoid arthritis, psoriatic arthritis, and juvenile idiopathic arthritis—are being denied access to more affordable treatment options due to Amgen’s actions. It notes that Erelzi has undergone a robust global development program demonstrating its similarity to Enbrel in terms of safety, efficacy, and quality, and is already approved for multiple indications by the FDA.

Yuflyma Is Deemed Interchangeable

Celltrion announced that its biosimilar Yuflyma (adalimumab-aaty) has been designated by the FDA as an interchangeable biosimilar to Humira (adalimumab).² The new label, which allows pharmacists to substitute Yuflyma for Humira without prescriber intervention, was supported by data from a phase 3 interchangeability study, which were shared at the 2024 European Academy of Dermatology & Venereology Congress.

"With this new designation, Yuflyma is further positioned to help more patients gain access to and afford the therapy they need," Thomas Nusbickel, chief commercial officer at Celltrion USA, said in a statement.

Yuflyma is a high-concentration (100 mg/mL), citrate-free biosimilar approved for multiple inflammatory diseases; it became commercially available in the US on July 2, 2023.³ It comes in multiple dosage forms, including prefilled syringes and autoinjector pens. To support patient affordability, Celltrion offers 2 pricing models: The unbranded version is available at an 85% discount to Humira’s wholesale acquisition cost, while the branded version is offered at a 5% discount, providing cost-saving options for patients and the health care system.

Steqeyma Added to Costco Member Prescription Program

In other Celltrion news, the company announced that its ustekinumab biosimilar, Steqeyma (ustekinumab-stba), has been added to the Costco Member Prescription Program.⁴

Steqeyma, a biosimilar to Stelara (ustekinumab), is used to treat multiple immune-mediated conditions, including plaque psoriasis, psoriatic arthritis, Crohn disease, and ulcerative colitis in both adult and pediatric patients. Available in both subcutaneous and intravenous forms, Steqeyma is set to launch through Costco Specialty Pharmacies on April 1, 2025, targeting self-funded employer plans and uninsured Costco members or those denied coverage by their insurance providers.

Celltrion leaders emphasized that this partnership reinforces their commitment to reducing financial barriers for patients. "By partnering with Costco Health Solutions once again, we are able to help even more Americans lower the price of their prescriptions, given the fact that Stelara ranks as one of the most expensive prescription drugs on the market," Nusbickel commented.

References

1. Sandoz files antitrust litigation against Amgen regarding patient access to etanercept biosimilar in the US. Press release. Sandoz; April 14, 2025. Accessed April 22, 2025. https://www.us.sandoz.com/sandoz-files-antitrust-litigation-against-amgen-regarding-patient-access-etanercept-biosimilar-us/

2. U.S. FDA grants interchangeable designation to Yuflyma^® (adalimumab-aaty), Celltrion's biosimilar to Humira^® (adalimumab). Press release. Celltrion; April 14, 2025. Accessed April 22, 2025. https://www.prnewswire.com/news-releases/us-fda-grants-interchangeable-designation-to-yuflyma-adalimumab-aaty-celltrions-biosimilar-to-humira-adalimumab-302428226.html

3. Jeremias S. Celltrion launches Yuflyma on the US market. July 2, 2023. Accessed April 22, 2024. https://www.centerforbiosimilars.com/view/celltrion-launches-yuflyma-on-the-us-market

4. Celltrion's Steqeyma^® (ustekinumab-stba), now added to the Costco Member Prescription Program. Press release. Celltrion; March 27, 2025. Accessed April 22, 2025. https://www.prnewswire.com/news-releases/celltrions-steqeyma-ustekinumab-stba-now-added-to-the-costco-member-prescription-program-302412910.html