Difficulty in patient recruitment and will start again if study population increases to allow study feasibility

TB006, a monoclonal antibody, is an anti-inflammatory and anti-fibrotic agent that reduces the severity of underlying diseases in COVID-19 patients. The primary objective of TB006 treatment is to decrease the potential acute severe deterioration in outpatient COVID-19 patients with underlying diseases, such as diabetes, hypertension, and cancer. TB006 has been developed to treat the ambulatory patients with diagnosed mild to moderate COVID-19 who are considered at low risk for severe disease or hospitalization.

TB006, a monoclonal antibody, is an anti-inflammatory and anti-fibrotic agent that reduces the severity of underlying diseases in COVID-19 patients. The primary objective of TB006 treatment is to decrease the potential acute severe deterioration in outpatient COVID-19 patients with underlying diseases, such as diabetes, hypertension, and cancer. TB006 has been developed to treat the ambulatory patients with diagnosed mild to moderate COVID-19 who are considered at low risk for severe disease or hospitalization.

In the single ascending dose study, the dosages of 5 mg/kg ~ 50 mg/kg will be investigated in patients with mild to moderate COVID-19, and will be administered to patients over 60 minutes after dilution in 0.9% Sodium Chloride Injection, USP (normal saline) to a final volume of 250 mL. The primary objective of the SAD study is to evaluate the safety and tolerability of single ascending doses of TB006 vs placebo administered via i.v. infusion in outpatient patients with mild-to-moderate COVID-19 and to determine the dose recommended for Phase Ib study.

Inclusion Criteria:

1. Willing and able to provide written informed consent prior to performing study procedures (or legally authorized representative able to provide consent on the patient's behalf).

2. Age ≥ 18 years

3. A positive Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection confirmed by polymerase chain reaction (PCR) test or an equivalent test ≤ 3 days before randomization

4. Patients with mild to moderate COVID-19 experiencing any of the following symptoms:

   • Mild (without shortness of breath or dyspnea): Fever, cough, sore throat, malaise, headache, muscle pain, gastrointestinal symptoms
   • Moderate: Any symptom of mild illness, shortness of breath with excursion, clinically suggestive of moderate illness with COVID-19, such as respiratory rate ≥ 20 breaths per minute, saturation of oxygen (SpO2) > 93% on room air at sea level, heart rate ≥ 90 beats per minute

5. At low risk for progressing to severe COVID-19 and/or hospitalization.

6. Adequate organ function at screening as evidenced by:

   • Hemoglobin > 10.9 g/dL
   • Absolute neutrophil count (ANC) > 1.0 × 10^9/L
   • Platelets > 125 × 10^9/L
   • Alanine Aminotransferase (ALT) or aspartate aminotransferase (AST) < 1.25 × upper limit of normal (ULN)
   • Creatinine clearance > 90 mL/min using the Cockcroft-Gault formula for patients ≥ 18 years of age [Cockcroft 1976]

7. Normal electrocardiogram with QTcF of ≤ 450 ms

Exclusion Criteria:

1. Participation in any other clinical trial of an experimental treatment for COVID-19

2. Clinical signs indicative of Severe or Critical Illness Severity

   • SEVERE:

   • Any symptom of severe, systematic illness, including moderate illness, shortness of breath, or respiratory distress

   • Clinically suggestive of severe illness with COVID-19, such as respiratory rate ≥ 30 breaths per minute, heart rate ≥ 125 per minute, saturation of oxygen (SpO2) ≤ 93% on room air at sea level, or PaO2/FiO2 < 300

   • CRITICAL ILLNESS (one of the following):

   • Respiratory failure defined based on resource utilization requiring at least one of the following:

     1. Endotracheal intubation and mechanical ventilation, oxygen delivered by high483 flow nasal cannula (heated, humidified, oxygen delivered via reinforced nasal cannula at flow rates > 20 L/min with fraction of delivered oxygen ≥ 0.5)
     2. Noninvasive positive pressure ventilation, ECMO, or clinical diagnosis of respiratory failure (i.e., clinical need for one of the preceding therapies, but preceding therapies not able to be administered in setting of resource limitation)

   • Shock (defined by systolic blood pressure < 90 mm Hg, or diastolic blood pressure < 60 mm Hg or requiring vasopressors)

   • Multi-organ dysfunction/failure

3. Have a history of a positive SARS-CoV-2 serology test

4. Evidence of shock (defined by systolic blood pressure < 90 mm Hg, or diastolic blood pressure < 60 mm Hg or requiring vasopressors)

5. Patients who are hospitalized due to COVID-19

6. Patients who required oxygen therapy due to COVID-19

7. Patients who required mechanical ventilation or anticipated impending need for mechanical ventilation

8. Receiving V-V ECMO ≥ 5 days, or any duration of V-A ECMO

9. Have a history of convalescent COVID-19 plasma treatment

10. Women who are pregnant or breastfeeding

11. Male or female of childbearing potential who has plans to become pregnant during the study period and for six months after the clinical study or who is not willing to take appropriate contraceptive measures (e.g., concomitant use of a spermicidal agent, barrier contraceptive, or/and intrauterine contraceptive)

12. Viral disease (HIV, HBV, HCV, etc.) other than COVID-19 that are not adequately controlled or require administration of other antiviral agents or medications that could potentially interact with TB006

13. Patients with a history or current evidence of any concomitant condition, therapy, or laboratory abnormality that, in the opinion of the investigator, might confound the results of the trial, interfere with the patient's participation and compliance