Cancer Cachexia Syndrome

This study is a first-in-human, randomized, double-blind, placebo-controlled, dose-escalation trial in healthy adult participants to evaluate the safety, tolerability, PK, PD, and immunogenicity of GB18. A total of 36 healthy participants will be enrolled, including 5 dose cohorts (A1-A5) of 50 mg, 100 mg, 200 mg, 400 mg and 600 mg, with 4 participants in Cohort A1, and 8 participants per following cohorts (A2-A5). Participants in each cohort will be randomized to receive GB18 or placebo. The arms of this study include: To evaluate the safety and tolerability of GB18 following a single subcutaneous (SC) administered dose in healthy adult participants. To characterize the serum pharmacokinetics (PK) of GB18 following a single SC administered dose in healthy adult participants. To characterize the pharmacodynamics (PD) of a single SC administration of GB18 on circulating GDF15 concentrations in healthy adult participants. To evaluate the immunogenicity profile of GB18 in healthy adult participants. To evaluate the effect of GB18 on body weight in healthy adult participants. To preliminary evaluation of the relationship between GB18 serum concentration and QTc interval after a single SC administration in healthy adult participants.