Company decision: re-evaluation of risk vs benefit (based on animal data)

This study will assess how safe ABBV-990 is and how ABBV-990 moves through the body of adult healthy participants. Adverse Events will be assessed.

ABBV-990 is an investigational drug being developed for the treatment of SARS-CoV-2 infections. Participants are randomly assigned to one of the 5 treatment groups. Each group receives different treatment. There is 1 in 4 chance that participants are assigned to placebo. Approximately 40 adult healthy volunteers will be enrolled in a single site in the United States.

Participants will receive oral tablet of ABBV-990 or matching placebo on Day 1 and followed for approximately 30 days.

Participants will be confined for 5 days. Adverse Events and blood tests will be performed.

Inclusion Criteria:

• Body Mass Index (BMI) is >= 18.0 to <= 32.0 kg/m2.
• Laboratory values meet the protocol-specified criteria.
• A condition of general good health, based upon the results of a medical history, physical examination, vital signs, laboratory profile and a 12-lead electrocardiogram (ECG).
• In the opinion of the investigator, participant is a suitable candidate for enrollment in the study.

Exclusion Criteria:

• Have any clinically significant ECG abnormalities.
• History of any clinically significant sensitivity or allergy to any medication or food.
• Known active SARS-CoV-2 infection at screening and upon initial confinement.
• History of any clinically significant illness/infection/major febrile illness, hospitalization, or any surgical procedure within 30 days prior to the first dose of study drug.
• Currently enrolled in another interventional clinical study.