Investigating Otilimab in Patients With Severe Pulmonary COVID-19 Related Disease

• Otilimab (Biological): Otilimab will be administered once via IV route.
• Placebo 1 (Biological): Placebo 1 will consist of sterile 0.9 percent (%) sodium chloride solution administered once via IV route.
• Placebo 2 (Biological): Placebo 2 will consist of sterile 5% dextrose or 5% glucose solution administered once via IV route.
• Standard of care (Drug): All participants will receive standard of care as per institutional protocol.

Primary outcomes

• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 28 [At Day 28]: Participants were considered alive and free of respiratory failure if they were in category 1, 2, 3, or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (greater than or equal to \[>=\]15 liters per minute \[L/min\]), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 28 [At Day 28]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.

Secondary outcomes

• Part 1: Number of Participants Who Died Due to All Causes at Day 60 [At Day 60]: Number of participants who died due to all causes at Day 60 are reported.
• Part 2: Number of Participants Who Died Due to All Causes at Day 28 [At Day 28]: Number of participants who died due to all causes at Day 28 is reported
• Part 2: Number of Participants Who Died Due to All Causes at Day 60 [At Day 60]: Number of participants who died due to all causes at Day 60 is reported
• Part 1: Time to Death Due to All Causes up to Day 60 [Up to Day 60]: Time to death due to all causes was defined as the time (days) from dosing to death, due to any cause, up to (and including) Day 60. Median and inter-quartile range (first quartile and third quartile) of time to death are presented.
• Part 2: Time to Death Due to All Causes up to Day 60 [Up to Day 60]: Time to death due to all causes was defined as the time (days) from dosing to death, due to any cause, up to (and including) Day 60. Median and inter-quartile range (first quartile and third quartile) of time to death are presented.
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 7 [At Day 7]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 14 [At Day 14]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 42 [At Day 42]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 60 [At Day 60]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 7 [At Day 7]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 14 [At Day 14]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 42 [At Day 42]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 60 [At Day 60]: Participants were alive and free of respiratory failure if they were in category 1, 2, 3 or 4 from the GlaxoSmithKline (GSK) modified version ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Higher scale indicates higher intensity of respiratory failure. Percentage values are rounded off.
• Part 1: Time to Recovery From Respiratory Failure up to Day 28 [Up to Day 28]: Time to recovery from respiratory failure was defined as the time (days) from dosing to last recovery from respiratory failure up to (and including) Day 28. Participants were in respiratory failure if they were in category 5 or above from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Median and inter-quartile range (first quartile and third quartile) of time to recovery from respiratory failure are presented.
• Part 2: Time to Recovery From Respiratory Failure up to Day 28 [Up to Day 28]: Time to recovery from respiratory failure was defined as the time (days) from dosing to last recovery from respiratory failure up to (and including) Day 28. Participants were in respiratory failure if they were in category 5 or above from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Median and inter-quartile range (first quartile and third quartile) of time to recovery from respiratory failure are presented.
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 7 [At Day 7]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 14 [At Day 14]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 28 [At Day 28]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 42 [At Day 42]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 60 [At Day 60]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 7 [At Day 7]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 14 [At Day 14]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 28 [At Day 28]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 42 [At Day 42]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 2: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 60 [At Day 60]: Participants were independent of supplementary oxygen if they were in category 1, 2 or 3 from the GlaxoSmithKline (GSK) modified ordinal scale adapted from World Health Organization (WHO) scale 2020. The 8-point scale was as follows: 1) Non-hospitalized, no limitation of activity; 2) Non-hospitalized,limitation of activity; 3) Hospitalized, no oxygen therapy; 4) Hospitalized, low-flow oxygen by mask or nasal prongs; 5) Hospitalized, highflow oxygen (>=15L/min), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP), non-invasive ventilation; 6) Hospitalized, intubation and mechanical ventilation; 7) Hospitalized, mechanical ventilation plus additional organ support; 8) Death. Percentage values are rounded off.
• Part 1: Time to Last Dependence on Supplementary Oxygen [Up to Day 28]: Time to last dependence on supplementary oxygen was defined as the time (days) from dosing to last dependence on supplementary oxygen up to (and including) Day 28. Median and inter-quartile range (first quartile and third quartile) of time to last dependence on supplementary oxygen are presented.
• Part 2: Time to Last Dependence on Supplementary Oxygen [Up to Day 28]: Time to last dependence on supplementary oxygen was defined as the time (days) from dosing to last dependence on supplementary oxygen up to (and including) Day 28. Median and inter-quartile range (first quartile and third quartile) of time to last dependence on supplementary oxygen are presented.
• Part 1: Percentage of Participants Admitted to Intensive Care Unit (ICU) up to Day 28 [Up to Day 28]: Participants who were admitted to the ICU up to (and including) Day 28 were evaluated. Percentage values are rounded off.
• Part 1: Time to Final ICU Discharge [Up to Day 28]: Time to final ICU discharge was defined as the time from dosing to when the participant is discharged from the ICU for the last time up to (and including) Day 28. Median and inter-quartile range (first quartile and third quartile) of time to final ICU discharge is presented.
• Part 2: Time to Final ICU Discharge [Up to Day 28]: Time to final ICU discharge was defined as the time from dosing to when the participant was discharged from the ICU for the last time up to (and including) Day 28. Median and inter-quartile range (first quartile and third quartile) of time to final ICU discharge is presented.
• Part 1: Time to First Discharge From Investigator Site up to Day 60 [Up to Day 60]: Time to first discharge from investigator site was defined as the time (days) from dosing to when the participant was first discharged from investigator site (IS) up to (and including) Day 60. Median and inter-quartile range (first quartile and third quartile) of time to first discharge from investigator site is presented.
• Part 1: Time to First Discharge to Non-hospitalized Residence up to Day 60 [Up to Day 60]: Time to first discharge to non-hospitalized residence was defined as the time (days) from dosing to when the participant was discharged to a non-hospitalized residence for the first time up to (and including) Day 60. Median and inter-quartile range (first quartile and third quartile) of time to first discharge to non-hospitalized residence is presented.
• Part 2: Time to First Discharge From Investigator Site up to Day 60 [Up to Day 60]: Time to first discharge from investigator site was defined as the time (days) from dosing to when the participant was first discharged from investigator site up to (and including) Day 60. Median and inter-quartile range (first quartile and third quartile) of time to first discharge from investigator site is presented.
• Part 2: Time to First Discharge to Non-hospitalized Residence [Up to Day 60]: Time to first discharge to non-hospitalized residence was defined as the time (days) from dosing to when the participant was discharged to a non-hospitalized residence for the first time up to (and including) Day 60. Median and inter-quartile range (first quartile and third quartile) of time to first discharge to non-hospitalized residence is presented.
• Part 1: Number of Participants With Serious Adverse Events (SAEs) and Common (>=5%) Non-serious Adverse Events (Non-SAEs) [Up to Day 60]: An adverse event (AE) is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study intervention, whether or not considered related to the study intervention. An SAE is defined as any untoward medical occurrence that, at any dose may result in death or is life-threatening or requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity or is a congenital anomaly/birth defect or any other situation according to medical or scientific judgment or is associated with liver injury and impaired liver function. Number of participants with any SAE and common (>=5%) non-SAEs are presented.
• Part 2: Number of Participants With SAEs and Common (>=5%) Non-SAEs [Up to Day 60]: An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study intervention, whether or not considered related to the study intervention. An SAE is defined as any untoward medical occurrence that, at any dose may result in death or is life-threatening or requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity or is a congenital anomaly/birth defect or any other situation according to medical or scientific judgment or is associated with liver injury and impaired liver function. Number of participants with any SAE and common (>=5%) non-SAEs are presented.

Sex: All, ages: 18 Years to any

Inclusion criteria for Part 1:

* Participants aged >=18 years and <=79 years at the time of obtaining informed consent.
* Participants must:

  1. have positive severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) result (any validated test, for example. reverse transcription polymerase chain reaction \[RT-PCR\] \[performed on an appropriate specimen; for example: respiratory tract sample\])
  2. and be hospitalized due to diagnosis of pneumonia (chest X-ray or computerized tomography \[CT\] scan consistent with COVID-19)
  3. and be developing new onset of oxygenation impairment requiring any of the following:

     1. high-flow oxygen (>=15L/min)
     2. non-invasive ventilation (for example. CPAP, BIPAP)
     3. mechanical ventilation <=48 hours prior to dose
  4. and have increased biological markers of systemic inflammation (either C-reactive protein \[CRP\] >upper limit of normal \[ULN\] or serum ferritin >ULN).
* No gender restriction.
* Female participants must meet and agree to abide by the contraceptive criteria detailed in the protocol. Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
* A female participant is eligible to participate if she is not pregnant or breastfeeding or if she is using highly effective contraceptive methods. Women of non-childbearing potential can also participate. A negative highly sensitive pregnancy test at hospital admission or before the first dose of study intervention.
* Capable of giving written informed consent.

Inclusion Criteria for Part 2:

* Participants aged 70 years or above at the time of obtaining informed consent.
* Participants must:

  1. have positive SARS-CoV-2 result (any validated test, for example. RT-PCR \[performed on an appropriate specimen; for example. respiratory tract sample\])
  2. and be hospitalized due to diagnosis of pneumonia (chest X-ray or CT scan consistent with COVID-19).
  3. and be developing new onset of oxygenation impairment requiring any of the following:

     1. high-flow oxygen (>=15L/min)
     2. non-invasive ventilation (for example. CPAP, BiPAP)
     3. mechanical ventilation <=48 hours prior to dose
  4. and have increased biological markers of systemic inflammation (either CRP >ULN or serum ferritin >ULN.
* No gender restriction.
* Capable of giving written informed consent.

Exclusion Criteria for Part 1:

* Progression to death is imminent and inevitable within the next 48 hours, irrespective of the provision of treatments, in the opinion of the investigator.
* Multiple organ failure according to the investigator's judgement or a Sequential Organ Failure assessment (SOFA score) >10 if in the ICU.
* Extracorporeal membrane oxygenation (ECMO) hemofiltration/dialysis or high-dose (>0.15 micrograms \[mcg\]/kilograms \[kg\]/min) noradrenaline (or equivalent) or more than one vasopressor.
* Current serious or uncontrolled medical condition (for example: significant pulmonary disease \[such as severe chronic obstructive pulmonary disease (COPD) or pulmonary fibrosis\], heart failure \[New York Heart Association {NYHA} class III or higher\], renal dysfunction, acute myocardial infarction or acute cerebrovascular accident within the last 3 months) or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the participant's safe participation in and completion of the study.
* Untreated systemic bacterial, fungal, viral, or other infection (other than SARS-CoV-2).
* Known active tuberculosis (TB), history of untreated or incompletely treated active or latent TB, suspected or known extrapulmonary TB.
* Known Human Immunodeficiency Virus (HIV) regardless of immunological status.
* Known hepatitis B surface antigen (HBsAg) and/or anti-hepatitis C virus (HCV) positive.
* Currently receiving radiotherapy, chemotherapy or immunotherapy for malignancy.
* Received monoclonal antibody therapy (for examplee. tocilizumab, sarilumab) within the past 3 months prior to randomization, including intravenous immunoglobulin, or planned to be received, during the study.
* Received immunosuppressant therapy including but not limited to cyclosporin, azathioprine, tacrolimus, mycophenolate, Janus Kinase (JAK) inhibitors (for examplee. baricitinib, tofacitinib, upadacitinib) within the last 3 months prior to randomization or planned to be received during the study.
* History of allergic reaction, including anaphylaxis to any previous treatment with an anti-GM-CSF therapy.
* Received COVID-19 convalescent plasma within 48 hours of randomization.
* Currently receiving chronic oral corticosteroids for a non-COVID-19 related condition in a dose higher than prednisone 10 milligrams (mg) or equivalent per day.
* Treatment with an investigational drug within 30 days of randomization.
* Participating in other drug clinical trials, including for COVID-19.
* Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >5 times ULN.
* Platelets <50,000/cubic millimeters (mm\^3)
* Hemoglobin <=9 grams per deciliter (g/dL)
* Absolute neutrophil count (ANC) <1.5 times 10\^9/L (neutropenia >= Grade 2)
* Estimated glomerular filtration rate (GFR) <=30 milliliters (mL)/min/1.73 meter square (/m\^2).
* Pregnant or breastfeeding females.

Exclusion Criteria for Part 2:

* Progression to death is imminent and inevitable within the next 48 hours, irrespective of the provision of treatments, in the opinion of the investigator.
* Multiple organ failure according to the investigator's judgement or a SOFA score >10 if intubated in the ICU.
* ECMO hemofiltration/dialysis, or more than one inotrope/vasopressor of any class.
* Current serious or uncontrolled medical condition (for example. significant pulmonary disease \[such as severe COPD or pulmonary fibrosis\], heart failure \[NYHA class III or higher\], severe renal dysfunction, acute myocardial infarction or acute cerebrovascular accident within the last 3 months), severe dementia, severe disability, or abnormality of clinical laboratory tests that, in the investigator's judgment, precludes the participant's safe participation in and completion of the study.
* Untreated systemic bacterial, fungal, viral, or other infection (other than SARSCoV-2).
* Known active TB, history of untreated or incompletely treated active or latent TB, suspected or known extrapulmonary TB.
* Known HIV regardless of immunological status.
* Known HBsAg and/or anti-HCV positive (participants demonstrating a sustained virologic response (SVR) are not excluded from participation).
* Currently receiving radiotherapy, chemotherapy (hormone based therapies are permitted) or immunotherapy for malignancy.
* Received monoclonal antibody therapy (for example. tocilizumab, sarilumab) within the past 3 months prior to randomization, including intravenous immunoglobulin, or planned to be received during the study.
* Received immunosuppressant therapy including but not limited to cyclosporin, azathioprine, tacrolimus, mycophenolate, JAK inhibitors (for example. baricitinib, tofacitinib, upadacitinib), nintedanib, disease modifying antirheumatic drugs (DMARDs) (for example. methotrexate) within the last 3 months prior to randomization or planned to be received during the study.
* History of allergic reaction, including anaphylaxis to any previous treatment with an anti-GM-CSF therapy.
* Received COVID-19 convalescent plasma within 48 hours of randomization.
* Currently receiving chronic oral corticosteroids for a non-COVID-19 related condition at a dose higher than prednisone 10 mg or equivalent per day.
* Treatment with an investigational drug or substance within 30 days of randomization unless approved by the Medical Monitor.
* Participating in other drug clinical trials, including for COVID-19.
* AST or ALT >5 times ULN.
* Platelets <50,000/mm\^3.
* Hemoglobin <=9 g/dL
* ANC <1.0 x 10\^9/L (neutropenia >= Grade 3).
* Estimated GFR <=30 mL/min/1.73 m\^2.

Participant flow

Outcome results

• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 28 (Primary), Number, Percentage of participants: Part 1: Placebo 1 67; Part 1: Otilimab 90 mg 71 (p 0.0456)
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 28 (Primary), Number, Percentage of participants: Part 2: Placebo 2 51; Part 2: Otilimab 90 mg 52 (p 0.8574)
• Part 1: Number of Participants Who Died Due to All Causes at Day 60 (Secondary), Count of participants, Participants: Part 1: Placebo 1 93; Part 1: Otilimab 90 mg 84 (p 0.2057)
• Part 2: Number of Participants Who Died Due to All Causes at Day 28 (Secondary), Count of participants, Participants: Part 2: Placebo 2 70; Part 2: Otilimab 90 mg 63 (p 0.3061)
• Part 2: Number of Participants Who Died Due to All Causes at Day 60 (Secondary), Count of participants, Participants: Part 2: Placebo 2 76; Part 2: Otilimab 90 mg 74 (p 0.6665)
• Part 1: Time to Death Due to All Causes up to Day 60 (Secondary), Median, Days: Part 1: Placebo 1 NA (NA to NA); Part 1: Otilimab 90 mg NA (NA to NA) (p 0.1942)
• Part 2: Time to Death Due to All Causes up to Day 60 (Secondary), Median, Days: Part 2: Placebo 2 NA (16 to NA); Part 2: Otilimab 90 mg NA (16 to NA) (p 0.5324)
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 7 (Secondary), Number, Percentage of participants: Part 1: Placebo 1 42; Part 1: Otilimab 90 mg 44 (p 0.2871)
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 14 (Secondary), Number, Percentage of participants: Part 1: Placebo 1 61; Part 1: Otilimab 90 mg 63 (p 0.1754)
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 42 (Secondary), Number, Percentage of participants: Part 1: Placebo 1 70; Part 1: Otilimab 90 mg 74 (p 0.0616)
• Part 1: Percentage of Participants Alive and Free of Respiratory Failure at Day 60 (Secondary), Number, Percentage of participants: Part 1: Placebo 1 74; Part 1: Otilimab 90 mg 75 (p 0.1830)
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 7 (Secondary), Number, Percentage of participants: Part 2: Placebo 2 28; Part 2: Otilimab 90 mg 37 (p 0.0831)
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 14 (Secondary), Number, Percentage of participants: Part 2: Placebo 2 43; Part 2: Otilimab 90 mg 49 (p 0.2557)
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 42 (Secondary), Number, Percentage of participants: Part 2: Placebo 2 54; Part 2: Otilimab 90 mg 54 (p 0.8560)
• Part 2: Percentage of Participants Alive and Free of Respiratory Failure at Day 60 (Secondary), Number, Percentage of participants: Part 2: Placebo 2 55; Part 2: Otilimab 90 mg 56 (p 0.7533)
• Part 1: Time to Recovery From Respiratory Failure up to Day 28 (Secondary), Median, Days: Part 1: Placebo 1 10 (5 to NA); Part 1: Otilimab 90 mg 9 (5 to NA) (p 0.0959)
• Part 2: Time to Recovery From Respiratory Failure up to Day 28 (Secondary), Median, Days: Part 2: Placebo 2 24 (7 to NA); Part 2: Otilimab 90 mg 22 (5 to NA) (p 0.4421)
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 7 (Secondary), Number, Percentage of participants: Part 1: Placebo 1 11; Part 1: Otilimab 90 mg 12 (p 0.2814)
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 14 (Secondary), Number, Percentage of participants: Part 1: Placebo 1 37; Part 1: Otilimab 90 mg 37 (p 0.3901)
• Part 1: Percentage of Participants Alive and Independent of Supplementary Oxygen at Day 28 (Secondary), Number, Percentage of participants: Part 1: Placebo 1 57; Part 1: Otilimab 90 mg 57 (p 0.4763)
• 18 more outcome measures not shown.

Adverse events

Time frame: All-cause mortality, SAEs, and non-SAEs were collected up to Day 60 in Part 1 and 2 of the study

Serious adverse events by term

124 more terms not shown.

Other adverse events by term

20 more sites not listed.

• Patel J, Bass D, Beishuizen A, Bocca Ruiz X, Boughanmi H, Cahn A, Colombo H, Criner GJ, Davy K, de-Miguel-Diez J, Doreski PA, Fernandes S, Francois B, Gupta A, Hanrott K, Hatlen T, Inman D, Isaacs JD, Jarvis E, Kostina N, Kropotina T, Lacherade JC, Lakshminarayanan D, Martinez-Ayala P, McEvoy C, Meziani F, Monchi M, Mukherjee S, Munoz-Bermudez R, Neisen J, O'Shea C, Plantefeve G, Schifano L, Schwab LE, Shahid Z, Shirano M, Smith JE, Sprinz E, Summers C, Terzi N, Tidswell MA, Trefilova Y, Williamson R, Wyncoll D, Layton M. A randomised trial of anti-GM-CSF otilimab in severe COVID-19 pneumonia (OSCAR). Eur Respir J. 2023 Feb 2;61(2):2101870. doi: 10.1183/13993003.01870-2021. Print 2023 Feb. PMID 36229048

• Study Protocol (PDF, 2021-01-25)
• Statistical Analysis Plan (PDF, 2021-06-03)

• GSK Clinical Trials, Study director, GlaxoSmithKline