Inclusion Criteria:

1. ≥18 years old, male or female.

2. Subjects hospitalized with moderate to severe COVID-19 with a category 4 or 5 on an
8-category ordinal scale.

3. Has laboratory-confirmed COVID-19 infection within 5 days prior to randomization.

4. Initial COVID-19 symptom onset within 5 days prior to randomization and ≥1
sign/symptom attributable to COVID-19 within 24 hours before randomization.

5. The underlying medical condition was well controlled prior to SARS CoV 2 infection
and does not affect daily life.

6. Subject who did not receive COVID 19 (primary series or booster) vaccine within the
6 months prior to screening.

7. The subject is willing to provide written informed consent to participate in the
study after reading the informed consent form and the information provided and has
had the opportunity to discuss the study with the Investigator or designee.

8. The subject is able to communicate satisfactorily with the Investigator and to
participate in, and comply with, the requirements of the study.

9. The subject is able to understand the nature of the study and any potential hazards
associated with participating in it.

10. Negative pregnancy test for female subjects of childbearing potential and female
subjects less than 2 years of postmenopause. Women of childbearing potential (WOCBP)
and Women of non-childbearing potential are eligible to participate. Both women of
childbearing potential and women of non-childbearing potential must use an approved
method of birth control and agrees to continue to use this method for the duration
of the study and for 30 days after taking the last dose of FB2001.

Exclusion Criteria:

1. Pregnant or breastfeeding, or intending to become pregnant during the study or
within 30 days after the final dose or who are not willing to use a highly effective
method of contraception.

2. HIV-infected subjects with viral load greater than 400 copies/mL or CD4 count less
than 200 cell/µL from known medical history within past 6 months of the Screening
Visit.

3. Subject with moderate to severe hepatic impairment or acute liver failure.

4. Known severe kidney disease.

5. Participated in other intervention studies within 6 months.

6. Has any condition for which, in the opinion of the Investigator, participation would
not be in the best interest of the participant or that could prevent, limit, or
confound the protocol-specified assessments including but not limited to
participants who are not expected to survive longer than 48 hours after
randomization, or participants who are expected to require mechanical ventilation
within 48 hours after randomization, or participants with a recent history of
mechanical ventilation.

7. Subjects receiving any medications or substances that are strong inhibitors or
inducers of CYP3A within 14 days of randomization.

8. Received, ongoing or planed treatment with other anti-SARS CoV 2 therapeutics
(including but not limited to known anti-SARS CoV 2 antibodies, small molecule
antivirals, etc., other than remdesivir).

9. Other conditions that may increase the risk of study participation or, in the
Investigator's judgment, make the participant inappropriate for the study.

10. Have known hypersensitivity to FB2001 or its excipients.

11. Any planned vaccine within 28 days following the last administration of FB2001 for
Injection.