A study to test different doses of BI 730357 and find out the effect they have on symptoms in people with active psoriatic arthritis

INTERVENTION: Randomised, double‐blind, placebo‐controlled, parallel group, doseranging, of treatment over 12 weeks with three BI 730357 dose levels compared to placebo. 160 patients globally will be randomised in a 1:1:1:1 ratio in the following groups: Arm 1: 100 mg, n=40 Arm 2: 200 mg, n=40 Arm 3: 400 mg, n=40 The doses listed above will be administered in tablet form. Every patient will be required to take 3 tablets, once per day for 12 weeks. The patient's adherence to taking the trial medication will be checked by clinical trial staff at study visits. The patient will be required to complete a diary to document their compliance. Arm 4: matching placebo, n=40 CONDITION: Inflammatory and Immune System ‐ Rheumatoid arthritis Musculoskeletal ‐ Other muscular and skeletal disorders Psoriatic Arthritis; ; Psoriatic Arthritis PRIMARY OUTCOME: Response to treatment assessed as >/= 20% change in symptoms determined by the American College of Rheumatology rheumatoid arthritis response to treatment criteria (ACR). The ACR criteria is a validated criteria and is a composite endpoint as it requires assessment of a number of different factors, It involves both a physical assessment and also the completion of questionnaires by both the patient and assessor. ACR is assessed as at least 20% improvement in swollen joint count compared to baseline, at least 20% improvement in TJC* compared to baseline and a least 20% improvement in at least 3 out of the following 5 variables:; Patient’s assessment of pain on VAS (patient questionnaire ); Patient’s global assessment of the disease on VAS (patient questionnaire); Investigator’s global assessment of the disease on VAS (questionnaire); Patient’s assessment of disability on HAQ (patient questionnaire); Acute phase reactant (serum CRP) (blood test)[Baseline, Day 1, Week 1, Week 2, Week 4 and Week 8, Week 12 and then one month post‐completion of intervention period] SECONDARY OUTCOME: Change in patient's physical function/disability determined by patient completion of the twenty‐ item Health Assessment Questionnaire Disability Index (HAQ‐DI). [Baseline, Week 1, Week 2, Week 4 and Week 8, Week 12 and then one month post‐completion of intervention period] Response to treatment assessed as >/= 50% change in symptoms determined by the American College of Rheumatology rheumatoid arthritis response to treatment criteria (ACR). The ACR criteria is a validated criteria and is a composite endpoint as it requires assessment of a number of different factors, It involves both a physical assessment and also the completion of questionnaires by both the patient and assessor. ACR is assessed as at least 50% improvement in swollen joint count compared to baseline, at least 50% improvement in TJC* compared to baseline and a least 50% improvement in at least 3 out of the following 5 variables: ; Patient’s assessment of pain on VAS (patient questionnaire ) ; Patient’s global assessment of the disease on VAS (patient questionnaire) ; Investigator’s global assessment of the disease on VAS (questionnaire) ; Patient’s assessment of disability on HAQ (patient questionnaire) ; Acute phase reactant (serum CRP) (blood test)[Baseline, Day 1, Week 1, Week 2, Week 4 and Week 8, Week 12 and then one month post‐completion of intervention period] Response to treatment assessed as >/= 70% change in symptoms determined by the American College of Rheumatology rheumatoid arthritis response to treatment criteria (ACR). The ACR criteria is a validated criteria and is a composite endpoint as it requires assessment of a number of different factors, It involves both a physical assessment and also the completion of questionnaires by both the patient and assessor. ACR is assessed as at least 70% improvement in swollen joint count compared to baseline, at least 50% improvement in TJC* compared to baseline and a least 70% improvement in at least 3 out of the following 5 variables: ; Patient’s assessment of pain on VAS (patient questionnaire ) ; Patient’s global assessment of the disease on VAS (patient questionnaire) ; Investigator’s global assessment of the disease on VAS (questionnaire) ; Patient’s assessment of disability on HAQ (patient questionnaire) ; Acute phase reactant (serum CRP) (blood test)[Baseline, Day 1, Week 1, Week 2, Week 4 and Week 8, Week 12 and then one month post‐completion of intervention period] Response to treatment for patients with a greater than or equal to 3% baseline psoriasis body surface area assessed according to the Psoriasis Area and Severity Index (PASI75). Four areas of the patient's skin will be reviewed and assessed for psoriasis at Week 12.[PASI will be assessed at Day 1, Week 1, Week 4 and Week 8 and Week 12.] Response will be measured by change in Swollen Joint Count at Week 12 as compared to baseline. [Baseline, Week 1, Week 2, Week 4 and Week 8 and Week 12] Response will be measured by change in Tender Joint Count at Week 12 as compared to baseline[Baseline, Day 1, Week 1, Week 2, Week 4 and Week 8 and Week 12] The safety of the treatment will be assessed by the number of adverse events (AE)s, treatment urgent AEs, Serious AEs (SAEs), intensity of the events assessed according to the Rheumatology Common Toxicity Criteria (RCTC) version 2.0), measurement of patient vital signs and safety laboratory values. [Baseline, Day 1, Week 1, Week 2, Week 4, Week 8, Week 12 and one month post completion of treatment ] Tolerability of the treatment will be assessed by the number of patients who discontinue drug due to drug‐related adverse events. [Baseline, Day 1, Week 1, Week 2, Week 4 and Week 8 and Week 12] INCLUSION CRITERIA: ‐ Males or females, aged >/= 18 years and <= 75 years at screening ‐ Have PsA symptoms for at least 6 months prior to screening, as assessed by the investigator ‐ Have PsA on the basis of the CASPAR with peripheral symptoms at screening visit, as assessed by the investigator ‐ Have at least 3 tender joints and at least 3 swollen joints at screening and randomisation visits, as assessed by the investigator ‐ At least one PsO skin or nail lesion or a documented personal history of PsO at screening, as assessed by the investigator ‐ Signed and dated written informed consent in accordance with ICH‐GCP and local legislation prior to admission to the trial.