A Study of the Safety of INCB054707 in Participants With Hidradenitis Suppurativa

Inclusion Criteria:

- Diagnosis of HS (confirmed by a dermatologist) with a disease duration of at least 6
months before screening.

- Stable course of HS for at least 90 days before screening, as determined by the
investigator.

- HS lesions present in at least 2 distinct anatomic areas, 1 of which must be Hurley
Stage II or III at screening and baseline.

- Total AN count of at least 3 at screening and baseline.

- Male participants must agree to use contraception per protocol-defined criteria.

Exclusion Criteria:

- Women of childbearing potential or who are currently pregnant or lactating.

- Presence of > 20 draining fistulas at screening and baseline.

- Participants with concurrent conditions or history of other diseases as follows:

- Any clinically significant medical condition other than HS, as determined by the
investigator, that is not adequately controlled with appropriate treatment.

- Any other active skin disease or condition (eg, bacterial, fungal, or viral
infection) that may interfere with the course, severity, or assessments of HS.

- Active systemic viral infection or any active viral infection that, based on the
investigator's clinical assessment, make the participant an unsuitable candidate
for the study.

- Current herpes zoster infection, a history of recurrent herpes zoster, a history
of disseminated herpes simplex, or a history of herpes zoster.

- History of malignancy, including lymphoma and leukemia within 5 years before
baseline, other than a successfully treated nonmetastatic cutaneous squamous cell
carcinoma, basal cell carcinoma, or localized carcinoma in situ of the cervix.

- Albinism.

- Prolonged QT interval corrected for heart rate using Fridericia's formula (QTcF),
defined as ≥ 450 msec.

- Positive test result for tuberculosis (TB) from the QuantiFERON-TB Gold test, or
equivalent, at screening (or, if 2 indeterminate tests or not available, then as
evaluated by a purified protein derivative test with a result of < 5 mm of induration
within 3 months of screening) or a history of active TB.

- Positive serology test results for HIV, HBsAg, hepatitis B virus (HBV) core antibody,
or HCV (HCV antibody with positive HCV-RNA) at screening.

- Decreased blood cell counts at screening as per protocol-defined parameters.

- Severely impaired liver function (Child-Pugh Class C) or alanine aminotransferase
(ALT) or aspartate aminotransferase (AST) levels ≥ 1.5 × upper limit of normal (ULN).

- Impaired renal function with serum creatinine > 1.5 mg/dL.

- Use of prohibited medications per protocol-defined criteria.

- Known or suspected allergy to INCB054707 or any component of the study drug.

- Known history of clinically significant drug or alcohol abuse in the last year prior
to baseline.

- Any condition that would, in the investigator's judgment, interfere with full
participation in the study, including administration of study drug and attending
required study visits; pose a significant risk to the participant; or interfere with
interpretation of study data.