This is a randomized, double-blind, placebo-controlled, single ascending dose phase I clinical study to evaluate the safety, tolerability, PK, PD and immunogenicity of SSS68 in healthy adult participants following a single subcutaneous administration.
Able to understand and comply with protocol requirements, voluntarily participate in the trial and sign a written informed consent form (ICF).
Male or female participants aged 18-45 years (inclusive) when signing the ICF.
Male participants with body weight ≥ 50 kg, and female participants with body weight ≥ 45 kg.
Participants whose vital signs, physical examination results, laboratory test results, 12-lead electrocardiogram (ECG) and other test results are normal, or abnormal without clinical significance as determined by the investigator.
History of severe allergy, or with a history of allergy to the investigational drug, any of its components, or related excipients.
With any clinically significant diseases (including but not limited to gastrointestinal, hepatic, renal, neurological, hematological, endocrine, tumor, pulmonary, immunological, psychiatric, or cardiovascular diseases) prior to the screening visit.
Had any confirmed or suspected immunosuppressive or immune-deficient condition, including but not limited to history of opportunistic infections, asplenia, or primary immunodeficiency.
History of recurrent or chronic infections, or any infection requiring hospitalization or intravenous antiviral/antibiotic treatment within 6 months before dosing.