A Study to Evaluate the Safety, Tolerability and Pharmacokinetics of INCB054707

Inclusion Criteria: * Male healthy Japanese adult participants aged 20 to 55 years with a minimum weight of 48 kg. * Body mass index between 18.0 and 30.5 kg/m2. * No clinically significant findings in screening evaluations. * Ability to swallow and retain oral medication. * Willingness to avoid fathering children Exclusion Criteria: * History of clinically significant cardiovascular, respiratory, renal, gastrointestinal, endocrine, hematopoietic, psychiatric, and/or neurological disease. * History of rheumatologic/autoimmune disorders, except for minor eczema and rosacea. * Resting pulse \< 40 bpm or \> 100 bpm, confirmed by repeat testing at screening. * History or presence of an abnormal ECG before initial dose administration that, in the investigator's opinion, is clinically significant. * Presence of a malabsorption syndrome possibly affecting drug absorption (eg, Crohn's disease or chronic pancreatitis). * Hemoglobin, WBC, platelet, or ANC that is out of the laboratory's range unless considered clinically insignificant by the investigator at screening or check-in. * History of malignancy within 5 years of screening, with the exception of cured basal cell or squamous cell carcinoma of the skin. * Current or recent (within 6 months of screening) clinically significant gastrointestinal disease or surgery (including cholecystectomy, excluding appendectomy) that could affect the absorption of study drug. * Any major surgery within 6 months of screening. * Donation of blood to a blood bank or in a clinical study (except a screening visit) within 4 weeks of screening (within 2 weeks for plasma donation). * Blood transfusion within 4 weeks of check-in. * Chronic or current active infectious disease requiring systemic antibiotic, antifungal, or antiviral treatment * Positive test for HIV and known active HBV or HCV infection or risk of reactivation of HBV or HCV. * History of alcoholism within 3 months of screening. * Positive breath or urine test for ethanol or positive urine screen for drugs of abuse that are not otherwise explained by permitted concomitant medications or diet. * Current treatment or treatment within 30 days or 5 half-lives (whichever is longer) before the first dose of study drug with another investigational medication or current enrollment in another investigational drug study. * Current treatment or treatment within 30 days or 5 half-lives (whichever is longer) before the first dose of study drug with an inducer or inhibitor of CYP3A4, P-gp, or BCRP * Current use of prohibited medication * Consumption of Seville oranges, grapefruit or grapefruit juice, pomelos, exotic citrus fruits, grapefruit hybrids, or fruit juices within 72 hours before the first dose of study drug. * History of any significant drug allergy (such as anaphylaxis or hepatotoxicity) deemed clinically relevant by the investigator. * Known hypersensitivity or severe reaction to INCB054707 or any excipients of INCB054707 * Inability to undergo venipuncture or tolerate venous access. * Inability or unlikeliness of the participant to comply with the dose schedule and study evaluations, in the opinion of the investigator. * History of tobacco- or nicotine-containing product use within 1 month of screening. * Use of prescription drugs within 14 days of study drug administration or nonprescription medications/products within 7 days of study drug administration. * Any condition that would, in the investigator's judgment, interfere with full participation in the study. * Positive syphilis test.