J&J Sues Samsung Bioepis Over Alleged Breach in Stelara Biosimilar Agreement

Johnson & Johnson (J&J) has filed a lawsuit against Samsung Bioepis, accusing the South Korean company of violating a settlement agreement regarding the launch of a biosimilar version of J&J's blockbuster drug Stelara. The legal action comes amidst a flurry of biosimilar entries into the U.S. market, signaling a significant shift in the immunology treatment landscape.

Legal Battle Unfolds

J&J's lawsuit, filed in the U.S. District Court of New Jersey, alleges that Samsung Bioepis entered into an unauthorized agreement with an unnamed third-party healthcare company. This agreement purportedly allows the third party to market its own private label biosimilar of Stelara, a move J&J claims is in "clear breach" of the settlement reached between Samsung Bioepis and J&J's subsidiary Janssen in November 2023.

The original settlement permitted Samsung Bioepis to launch its Stelara biosimilar, Pyzchiva, in the U.S. by February 22, 2025. However, J&J contends that the alleged sublicensing deal with the third party threatens to cause "irreparable harm" to J&J and could compromise fair competition in the market.

While the identity of the third-party provider remains undisclosed in the complaint, J&J describes it as a subsidiary of a "vertically integrated health conglomerate" that includes one of the largest insurers and providers in the U.S., as well as a major pharmacy chain and a pharmacy benefit manager.

Biosimilar Market Dynamics

The legal dispute unfolds against the backdrop of increasing competition in the Stelara biosimilar market. Several companies have recently launched or are preparing to launch their versions of the drug:

• Amgen's Wezlana, which launched in January 2025, holds the FDA's interchangeability designation.
• Biocon Biologics' Yesintek and Samsung Bioepis' Pyzchiva both launched on February 25, 2025.
• Other entrants include Accord BioPharma's Imuldosa, Teva and Alvotech's Selarsdi, and Celltrion's Steqeyma.

This influx of biosimilars is expected to significantly impact Stelara's market dominance, which has been a key revenue driver for J&J. The company reported a 14.7% year-over-year drop in global Stelara sales to approximately $2.3 billion in Q4 2024, with full-year 2024 sales declining 4.6% to $10.4 billion.

Industry Implications

The lawsuit and the broader context of biosimilar competition highlight the complex dynamics of the pharmaceutical industry as blockbuster drugs face patent expiration. J&J's legal action against Samsung Bioepis underscores the high stakes involved in biosimilar launches and the intricate agreements that govern market entry.

As the case unfolds, industry observers will be watching closely to see how it might impact future biosimilar development and licensing agreements. The outcome could have far-reaching implications for pharmaceutical companies, healthcare providers, and patients alike, potentially shaping the future landscape of biosimilar competition in the United States.