Study of Single Doses of SBT777101 in Subjects With Hidradenitis Suppurativa

Inclusion Criteria: * Body mass index (BMI) ≤50 kg/m2, inclusive * Diagnosis of clinically active moderate-to-severe HS (Hurley Stage 2 or 3) * Total abscess or inflammatory nodule (AN) count of ≥5, affecting at least 2 distinct anatomic regions, with at least 1 accessible AN of adequate size for biopsy (diameter \> 1 cm) * Total draining tunnel (dT) count of ≤20 * Documented history of inadequate response or intolerance to at least a 3-month course of 1 conventional systemic therapy (e.g., antibiotic) and 1 biologic drug (e.g., adalimumab or secukinumab) * Doses of medications for HS must be stable for at least 5 weeks prior to study drug administration * Must agree to use highly effective method of contraception for at least 1 year post SBT777101 administration Exclusion Criteria: * Major surgery within 12 weeks prior to screening or planned within 12 months after dosing * History of or current inflammatory or other autoimmune disease * Complex presentations of HS * Skin disease other than HS that may confound clinical assessments or increase subject risk in the study * Uncontrolled concomitant cardiovascular, nervous system, pulmonary, renal, hepatic, endocrine, or gastrointestinal disease * Active current infection or history of recurrent infections * Active or untreated latent tuberculosis * Primary or secondary immunodeficiency