This study with ALTB-268 will determine the safety, tolerability, pharmacokinetics and pharmacodynamics of single and multiple ascending doses of ALTB-268 in healthy volunteers.

This is a Phase I, first-in-human, randomized, double-blind, single and multiple ascending dose study to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of subcutaneously administered ALTB-268 in healthy volunteers. Up to 40 and 24 healthy volunteers will be recruited in single and multiple ascending doses, respectively.

The primary objective is to assess the safety and tolerability of subcutaneously (sc) administered ALTB-268 in healthy volunteers. The secondary objective is to assess the plasma pharmacokinetics of sc administered ALTB-268 in healthy volunteers. The exploratory objectives are to assess the pharmacodynamics and evaluate immunogenicity of sc administered ALTB-268 in healthy volunteers.

Inclusion Criteria:

1. Written Informed Consent and willingness to comply with the study restrictions.
2. Sex: male or female volunteers.
3. Age: 18 to 55 years, inclusive, at screening.
4. Body mass index (BMI): 18.0 to 32.0 kg/m2, inclusive, at screening.
5. Weight: 50 kg to 110 kg, inclusive, at screening.
6. Healthy volunteers: Healthy status as defined by the absence of evidence of any clinically significant, in the opinion of the Investigator, active or chronic disease following a detailed medical and surgical history, a complete physical examination including vital signs, 12-lead ECG, hematology, blood chemistry, serology, and urinalysis

Exclusion Criteria:

1. Males with female partners who are pregnant, lactating, or planning to become pregnant during this study or within 90 days after dosing of study drug.
2. Use of any investigational drug or device within 30 days or five half-lives whichever is longer, of the first dose of study drug.
3. Any disease which, in the opinion of the Investigator, poses an unacceptable risk to the volunteers.
4. Clinically significant history of any drug sensitivity, drug allergy, or food allergy, as determined by the Investigator (such as anaphylaxis, hepatotoxicity, or treatment with steroids or epinephrine). Confirmatory circumstances would include treatment with epinephrine or in emergency department.