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

This is a double-blind, randomized, placebo-controlled, ascending single dose and multiple dose escalation study of TT-00920 in healthy subjects. Each dosing cohort will comprise of 10 randomized subjects. Subjects received a single dose of TT-00920/ placebo during a single dose period, followed by a 3-10 day washout period, and then entered a 7-day multiple dose period, in which subjects received TT-00920/ placebo three times daily (TID) for days 1-6 and a single dose on day 7. 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 male weighs at least 50.0 kg and female weighs at least 45.0 kg

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
• Subject with a history of severe visual diseases; or visual changes
• Subject is unable to complete this study for other reasons