A Study of LY4100511 (DC-853) in Adult Participants With Moderate-to-Severe Plaque Psoriasis

Prior treatment

• Have had a clinically significant flare of psoriasis during the 12 weeks before the baseline, as assessed by the investigator.
• Have a diagnosis of psoriatic arthritis requiring, or are currently receiving, systemic immunosuppressant medical treatment (including corticosteroids, immunosuppressants, and biologics).
• Have a current or recent acute, active infection. Participant must have no symptoms or signs of confirmed or suspected infection and must have completed any appropriate anti-infective treatment for at least 30 days before screening and up to randomization/baseline.

Other illness

• Have a history of erythrodermic psoriasis, generalized or localized pustular psoriasis, predominantly guttate psoriasis, or medication-induced or medication-exacerbated psoriasis.
• Have any known or suspected diagnosis of inflammatory conditions other than psoriasis and psoriatic arthritis, including but not limited to rheumatoid arthritis, sarcoidosis, IBD (Crohn's disease or ulcerative colitis), or systemic lupus erythematosus.

• Clinical diagnosis of plaque psoriasis for 6 months before the baseline day 1 randomization
• Must have a body mass index (BMI) of 18 to 40 kilogram/square meter (kg/m2) (inclusive).
• Must be willing to discontinue topical and/or systemic therapies for psoriasis before the first dose of study intervention.
• Must agree to avoid prolonged exposure to the sun and to refrain from the use of tanning booths, sun lamps, and other sources of ultraviolet light during the study