Dong-A ST received FDA approval for Imuldosa, a Stelara biosimilar, amidst a crowded market of approved but unlaunched biosimilars. Stelara's sales are expected to decline post-2023 patent expiry, with biosimilars like Amgen's Wezlana and Samsung Bioepis's Pyzchiva set to launch in 2025. Stelara, an IL-12/IL-23 inhibitor, treats psoriatic arthritis, Crohn’s disease, plaque psoriasis, and ulcerative colitis.