A Study to Test How Well Different Doses of BI 765250 Are Tolerated by People With a Skin Disease Called Plaque Psoriasis

Inclusion Criteria: * Female participants of non-childbearing potential and male participants * Age 18 to 75 years (both inclusive) at the time of informed consent * Diagnosis of chronic plaque psoriasis for at least 6 months prior to randomisation, as confirmed by their medical record or history * Moderate to severe plaque psoriasis, as defined by: * Body surface area (BSA) ≥5% and \<30% * Static Physician's Global Assessment (sPGA) ≥3 * Target lesions suitable for skin biopsy * Body mass index (BMI) \<35 kg/m2 * Male participants able to father a child must be ready and able to use highly effective methods of birth control per ICH M3 (R2) that result in a low failure rate of less than 1% per year when used consistently and correctly. A list of contraception methods meeting these criteria and instructions on the duration of their use is provided in the participant information * Signed and dated written informed consent in accordance with ICH-GCP and local legislation prior to admission to the trial Exclusion Criteria: * Non-plaque forms of psoriasis, current drug-induced psoriasis, or active ongoing inflammatory diseases other than psoriasis that might confound trial evaluations * Major surgery (major according to the investigator's assessment, e.g. hip replacement) performed within 16 weeks prior to randomisation or planned during the trial (i.e. until the End of Study Visit) * Women of childbearing potential (WOCBP), breastfeeding women, and men unwilling or unable to use highly effective methods of birth control * Any documented active or suspected malignancy or history of malignancy within 5 years prior to screening * Live or attenuated vaccination ≤6 weeks prior to randomisation, or any plan to receive a live vaccination during the conduct of this trial until the End of Treatment Visit * Participants who must or wish to continue the intake of restricted medications or any drug considered likely to interfere with the safe conduct of the trial * Hepatic/renal impairment: * Hepatic impairment defined as \>3-fold Upper Limit of Normal (ULN) elevation in AST or ALT or alkaline phosphatase, or \>2-fold ULN elevation in total bilirubin. Trial participants with Gilbert´s syndrome can be included unless total bilirubin elevation was \>5-fold ULN at screening visit and unless proportions of bilirubin fractions are inconsistent with diagnosis of Gilbert´s syndrome. * Renal impairment defined as estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m2 * Currently enrolled in an investigational drug or device study, or use of any investigational drug or device within 4 weeks prior to randomisation or 5 half-lives of the drug (whichever is longer) Further exclusion criteria apply