Inclusion Criteria:  Patients who have completed treatment in the parent Hidradenitis suppurativa (HS) spesolimab trial (1368-0052) without premature discontinuation Signed and dated written informed consent in accordance with ICH Harmonized Guideline for Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial Woman of childbearing potential (WOCBP) 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 is provided in the patient information and consent form.  Exclusion Criteria:  Women who are pregnant, nursing, or who plan to become pregnant while in the trial Patients who experienced study treatment-limiting adverse events during the 1368-0052 parent trial Severe, progressive, or uncontrolled condition such as renal, hepatic, haematological, endocrine, pulmonary, cardiac, neurologic, cerebral, or psychiatric disease, or signs and symptoms thereof Any new documented active or suspected malignancy except appropriately treated basal cell carcinoma, squamous cell carcinoma of the skin or in situ carcinoma of uterine cervix Use of any restricted medication or any drug considered by the investigator likely to interfere with the safe conduct of the study since the last visit of the 1368-0052 parent trial History of allergy/hypersensitivity to the systemically administered trial medication agent or its excipients Major surgery (major according to the investigator's assessment) planned during this extension trial (e.g. hip replacement, aneurysm removal, stomach ligation), as assessed by the investigator Any condition which in the opinion of the investigator affects the safety of the patient, the patient's ability to participate in this trial or could compromise the quality of data Further exclusion criteria apply