A trial to explore the efficacy and safety of IDOR-1117-2520 in adults with moderate to severe chronic plaque psoriasis, with or without psoriatic arthritis.

Prior treatment

• Any other significant clinically unstable medical condition, or acute illness within 1 month prior to Screening, that, in the investigator’s opinion, could interfere with the participant’s ability to comply with trial assessments or abide by trial restrictions.
• Active skin infections (e.g., sores, blisters) or concurrent skin disease (e.g., acne) of significant severity which could potentially interfere with the trial evaluation (e.g., evaluation of skin pathology) or any other skin comorbidities that could interfere with trial assessments.

Lab values

• Current drug-induced psoriasis (including a new onset or an exacerbation of psoriasis from beta blockers, calcium channel blockers, or lithium).

Other

• Generalized erythrodermic, generalized pustular (von Zumbusch), guttate, scalp only, and palmo-plantar psoriasis only.

• Stable moderate to severe chronic plaque psoriasis (with or without psoriatic arthritis) for at least 6 months (clinical diagnosis) before screening.
• Psoriasis Area and Severity Index (PASI) score ≥ 12, static physician’s global assessment (sPGA) score ≥ 3, and affected body surface area ≥ 10 % at both Screening and randomization.
• Participant must be a candidate for systemic therapy, including phototherapy, for psoriasis treatment, as judged by the investigator.
• For participants of childbearing potential: - have a negative pregnancy test at Screening and at randomization - agree to use a highly effective method of contraception from Screening up to 30 days after permanent trial intervention discontinuation, be sexually inactive, or have a vasectomized partner - agree to undertake monthly urine pregnancy tests during the trial and up to at least 30 days after discontinuation of trial intervention.