Phase 1, randomized, double-blind, placebo-controlled first-in-human study to investigate the safety, tolerability, PK and PD properties of single ascending intravenous (IV) and subcutaneous (SC) doses of KPL-404 in healthy subjects

This study includes 2 single ascending dose (SAD) parts; (Part A) IV SAD (up to 5 planned dose level cohorts) and Part B SC SAD (up to 3 planned dose level cohorts).

Safety assessments will include adverse events (AEs), concomitant medications, clinical laboratory, vital signs, 12-lead electrocardiogram, and physical examination. Serial blood samples for PK, PD, and anti-drug antibodies will be performed during each part of the study during the Treatment and Safety Evaluation Period.

Key Inclusion Criteria:

• Healthy subjects
• Body mass index (BMI) in the range of 18.0 - 32.0 kg/m2

Key Exclusion Criteria:

• Poor peripheral venous access
• Clinically-significant illness within 4 weeks of dose administration
• Active or acute infection requiring systemic antibiotic treatment within 2 weeks prior to Screening