Recombinant Human Angiotensin-converting Enzyme 2 (rhACE2) as a Treatment for Patients With COVID-19

This is an open label, randomized, controlled, pilot clinical study in patients with COVID-19, to obtain preliminary biologic, physiologic, and clinical data in patients with COVID-19 treated with rhACE2 or control patients, to help determine whether a subsequent Phase 2B trial is warranted.

This is a small pilot study investigating whether there is any efficacy signal that warrants a larger Phase 2B trial, or any harm that suggests that such a trial should not be done. It is not expected to produce statistically significant results in the major endpoints. The investigators will examine all of the biologic, physiological, and clinical data to determine whether a Phase 2B trial is warranted.

Primary efficacy analysis will be carried only on patients receiving at least 4 doses of active drug. Safety analysis will be carried out on all patients receiving at least one dose of active drug.

It is planned to enroll more than or equal to 24 subjects with COVID-19. It is expected to have at least 12 evaluable patients in each group.

Experimental group: 0.4 mg/kg rhACE2 IV BID and standard of care Control group: standard of care

Intervention duration: up to 7 days of therapy

No planned interim analysis.

Eligibility Criteria:
Inclusion Criteria:

1. Laboratory diagnosis:

   * Respiratory specimen is positive for SARS-CoV-2 nucleic acid by RT-PCR; OR,
   * The viral gene sequencing of the respiratory specimen is highly homologous to known novel coronavirus.
2. Fever:

   Axillary temperature \>37.3℃
3. Respiratory variables (meets one of the following criteria):

   * Respiratory rate: RR ≥25 breaths/min
   * Oxygen saturation ≤93% at rest on room air
   * PaO2/FiO2 ≤300 mmHg（1 mmHg=0.133 KPa）
   * Pulmonary imaging showed that the lesions progressed more than 50% within 24-48 hours, and the patients were managed as severe
4. HBsAg negative, or HBV DNA ≤10\^4 copy/ml if HBsAg positive; anti-HCV negative; HIV negative two weeks prior to signed Informed Consent Form (ICF)
5. Appropriate ethics approval and
6. ICF

Exclusion Criteria:

* Age \<18 years; Age \>80 years
* Pregnant or breast feeding woman or with positive pregnancy test result
* P/F \<100 mmHg
* Moribund condition (death likely in days) or not expected to survive for \>7 days
* Refusal by attending MD
* Not hemodynamically stable in the preceding 4 hours (MAP ≤65 mmHg, or SAP \<90 mmHg, DAP \<60 mmHg, vasoactive agents are required)
* Patient on invasive mechanical ventilation or ECMO
* Patient in other therapeutic clinical trial within 30 days before ICF
* Receive any other ACE inhibitors (ACEI), angiotensin-receptor blockers (ARB) treatment within 7 days before ICF
* Chronic immunosuppression: current autoimmune diseases or patients who received immunotherapy within 30 days before ICF
* Hematologic malignancy (lymphoma, leukemia, multiple myeloma)
* Other patient characteristics (not thought to be related to underlying COVID-19) that portend a very poor prognosis (e.g, severe liver failure, and ect)
* Known allergy to study drug or its ingredients related to renin-angiotensin system (RAS), or frequent and/or severe allergic reactions with multiple medications
* Other uncontrolled diseases, as judged by investigators
* Body weight ≥85 kg