Feb 24 (Reuters) - Johnson & Johnson JNJ.N said on Monday it had filed a lawsuit against Samsung Bioepis for breaching its contract agreement with the drugmaker over the launch of a biosimilar to Stelara, J&J's autoimmune drug.

J&J said it is seeking a preliminary injunction for Samsung Bioepis' close copy of Stelara over an unauthorized sublicense deal with a private label provider, which the drugmaker declined to identify.

The company, along with partner Sandoz SDZ.S, said earlier on Monday that its biosimilar Pyzchiva is now available in the United States.

J&J over the past two years has signed settlement agreements with several companies to delay the U.S. launches of Stelara, its top-selling drug since 2019.

Close copies of Stelara launched in Europe, Canada and a few other markets last year and at least six close copies of Stelara are expected to launch in the U.S. this year.

Teva Pharmaceuticals TEVA.TA and Alvotech ALVO.O last Friday launched Selarsdi, a biosimilar to Stelara. The U.S. Food and Drug Administration has allowed the use of Selarsdi as an "interchangeable" substitute only after April 30, when the exclusive rights for Amgen's AMGN.O Wezlana expire.

Pyzchiva is approved to treat moderate to severe plaque psoriasis, active psoriatic arthritis, moderately to severely active Crohn's disease and moderately to severely active ulcerative colitis.

(Reporting by Sneha S K in Bengaluru; Editing by Alan Barona)

((Sneha.SK@thomsonreuters.com))