Phase I Study to Evaluate Safety, Tolerability, and Drug Effects of SSS55 Injection in Healthy Adults Aged 18 to 45

What this Trial Is About

Researchers are evaluating the safety, tolerability, pharmacokinetics PK, pharmacodynamics PD, immunogenicity, and preliminary efficacy of a single intravenous dose of the SSS55 injection in healthy adults aged 18 to 45 years. This randomized, double-blind, placebo-controlled Phase I clinical trial is conducted to understand how the drug behaves in the body and its initial effects, focusing on safety in healthy volunteers. The study includes four dose groups with increasing amounts of SSS55. Initially, two subjects receive the SSS55 injection alone in the first dose group. Subsequent groups include sentinel subjects randomly assigned to SSS55 or placebo in a 11 ratio, with safety assessments performed 8 days after administration before dosing the remaining participants. The trial uses a quadruple-blind design to compare SSS55 against placebo across low to higher dose groups. Participants will undergo screening including vital signs, physical exams, blood and urine tests, ECG, chest imaging, and pregnancy tests for women of childbearing age. They will receive meningococcal and pneumococcal vaccines at least 14 days before randomization. Researchers will monitor safety and tolerability over 22 days following infusion, along with PK, PD, and antibody development. The goal is to gather comprehensive safety and biological data during the follow-up period after the single-dose injection.

Safety, Tolerability, PK and PD of SSS55 in Healthy Subjects