The purpose of this study is to evaluate safety, tolerability, immunogenicity, pharmacokinetics, pharmacodynamics, and efficacy of KP104 in healthy volunteers. The study will be conducted in 2 parts: Part 1, the single ascending dose (SAD) is the first in human (FIH) study of KP104 and Part 2, multiple ascending dose (MAD).

Inclusion Criteria:

• Weight of > 40 kilograms (kg) and < 120 kg at Screening.
• In good general health, determined by no clinically significant findings in the opinion of the Investigator from medical history, physical examination, 12-lead ECG, clinical laboratory findings, and vital signs at Screening and Check-in.
• Hemoglobin, hematocrit, white blood cell count, absolute neutrophil count, and platelet count results within the normal range at the Screening Visit; participants with Gilbert's disease with associated abnormalities of liver function tests are eligible for enrollment. Tests may be repeated at the discretion of the Investigator to confirm abnormalities.
• Creatinine clearance based on the Cockcroft-Gault equation of >= 80 milliliters per minute (ml/min).
• Females of childbearing potential and males must practice effective contraception from Screening until 28 days after the end of study (EOS) visit.
• Females of childbearing potential must have a negative pregnancy test at Screening and within 24 hours prior to dosing of study drug; for post-menopausal subjects, a blood sample will also be tested for follicle stimulating hormone to confirm post-menopausal status.

Exclusion Criteria:

• Any clinically significant underlying illness in the opinion of the Investigator.
• Any history or sign of significant chronic active or recurrent infection, or screening laboratory evidence consistent with a significant chronic active or recurrent infection requiring treatment with antibacterials, antivirals, or antifungals.
• Treatment of any infection with IV (within 30 days of Screening) or oral (within 14 days of Screening) antibacterials, antivirals, or antifungals.
• History of clinically significant hematologic or bone marrow disease or blood dyscrasias.
• History of meningococcal infection.
• History of tuberculosis.
• History of asplenia (functional or anatomical).
• Prior exposure to KP104.
• Known allergy to penicillin antibiotics or history of allergy or contraindication to required prophylactic antibiotic therapy to be used during the study.
• Known or suspected complement deficiency during screening.
• Positive serology for Hepatitis B virus (HBV), hepatitis C virus (HCV) or human immunodeficiency virus (HIV) at Screening.
• History of drug or alcohol abuse within 1 year of Screening in the opinion of the investigator, or a positive test for drugs of abuse or alcohol at Screening or Check-in.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.