A Trial to Understand How Safe and Well Tolerated ZP9830 is and How it Works in People With Plaque Psoriasis Over an 8-week Treatment Period

Inclusion Criteria: * Participants with a confirmed diagnosis of psoriasis (stable plaque psoriasis ≥ 2 months). * Participants who have ≥ 2 vulgar psoriatic plaques. * BMI within the range 18.0-35.0 kg/m2 (inclusive). * Further inclusion criteria apply. Exclusion Criteria: * Erythrodermic, predominantly guttate, exclusively palmar/plantar, or generalized pustular psoriasis. * Current drug-induced or aggravated psoriasis (e.g., a new onset of psoriasis or an exacerbation of psoriasis from beta-blockers, calcium-channel blockers, or lithium carbonate). * Any clinically significant abnormalities, as judged by the investigator, in laboratory test results (including hematology, biochemistry, and urinalysis). * Any clinically significant abnormal findings during the standardized neurological examination conducted at screening. * Use of any concurrent systemic medications that could affect psoriasis or psoriasis evaluation, including corticosteroids, retinoids, cyclosporine, methotrexate, PDE4s (phosphodiesterase 4), or biologic agents within 30 days prior to IMP administration or planned to use during the course of the trial. * Use of concurrent topical medications containing corticosteroids, retinoids, calcitriol or other topical medication relevant to psoriasis treatment (must be discontinued at least 2 weeks prior to baseline). * Use of any biologic or advance systemic therapies for any autoimmune disease within the last 12 months. * Use of UVA, PUVA, or UVB therapy and tanning beds within 4 weeks of baseline or during trial participation. * Further exclusion criteria apply.