Guselkumab, sold under the brand name Tremfya, is a monoclonal antibody against interleukin-23 used for the treatment of plaque psoriasis, psoriatic arthritis, and ulcerative colitis. [5][7][8][9], Learn about side effects, dosage, cost, and more of Tremfya (guselkumab), a prescription injection that treats psoriatic arthritis and plaque psoriasis., Find patient medical information for Tremfya (guselkumab) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings, TREMFYA is an interleukin-23 antagonist indicated for the treatment of adult patients with: • moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy (1.1) • active psoriatic arthritis (1.2) • moderately to severely active ulcerative colitis (1.3) • moderately to severely active Crohn’s disease (1.4), Tremfya (also known by its generic name guselkumab) is a biologic medication that was approved by the FDA in July 2017 for the treatment of moderate-to-severe plaque psoriasis in adults. In July 2020, the FDA also approved Tremfya to treat adults with active psoriatic arthritis. Tremfya is given by injection under the skin at week 0 (the first week of treatment) and week 4, and then every 8 , Learn about TREMFYA® (guselkumab), including dosing, injection, and side effects information. See full Prescribing & Safety Information..