Evaluation of Mass Balance and Absolute Bioavailability of GLPG3667

Inclusion Criteria: * Male between 30 and 64 years of age (extremes included), on the date of signing the informed consent form (ICF). * A body mass index (BMI) between 18.0 and 32.0 kg/m2, inclusive. * Has a regular daily defecation pattern (i.e. 1 to 3 times per day). * Judged to be in good health by the investigator based upon the results of a medical history, physical examination, vital signs, 12-lead electrocardiogram (ECG), and fasting clinical laboratory safety tests. Neutrophil, lymphocyte, and platelet counts must be above the lower limit of normal range. Total bilirubin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) must be within normal range. Other clinical laboratory safety test results must be within the normal ranges or test results that are outside the normal ranges need to be considered not clinically significant in the opinion of the investigator. This list only contains the key inclusion criteria. Exclusion Criteria: * Known hypersensitivity to GLPG3667 ingredients or history of a significant allergic reaction to GLPG3667 ingredients as determined by the investigator * Treatment with any medication (including over-the-counter (OTC) and/or prescription medication, COVID-19 vaccines, dietary supplements, nutraceuticals, vitamins and/or herbal supplements), except occasional paracetamol (maximum dose of 2 g/day and maximum of 10 g/2 weeks) in the last 2 weeks or 5 half-lives of the drug, whichever is longer, prior to the first dosing. * Subject has participated in a \[14C\]-radiolabeled study within the past 12 months. * Radiation exposure, including that from the present study, excluding background radiation but including diagnostic X-rays and other medical exposures, exceeding 5 millisievert (mSv) in the last 12 months or 10 mSv in the last 5 years. Occupationally exposed worker, as defined in the Ionising Radiation Regulations 2017 (UK, 2017), cannot participate in the study. This list only contains the key exclusion criteria.