This is a double-blind, randomized, placebo-controlled, multiple ascending dose escalation study of TT-00920 in healthy subjects.

This is a double-blind, randomized, placebo-controlled, multiple ascending dose escalation study of TT-00920 in healthy subjects. Each dosing cohort will be comprised of 10 randomized subjects dosed three times daily for 13 days and one time for 1 day. The study will consist of a Screening Period, an In-house Period and a Follow-up.

Inclusion Criteria:

• Written informed consent must be obtained
• Age ≥ 18.0 years and ≤ 55.0 years, male or female
• BMI between 18.0 and 30.0 kg/m2, inclusive, and weighs at least 50.0 kg
• No clinically significant findings in medical examination

Exclusion Criteria:

• Known hypersensitivity or allergy to lactose
• Vaccination with any live vaccine, or vaccination employing an mRNA platform within 28 days and/or vaccination with any inactivated vaccine within 7 days of study drug administration
• Impaired cardiac function including clinically significant arrhythmias or clinically significant abnormality
• HbA1c > 5.7 % at Screening
• Subject with a history of severe visual diseases; or visual changes
• Subject is unable to complete this study for other reasons or the Investigator believes that he or she should be excluded