Study KIN-1901-2001 is a multi-center, adaptive, randomized, double-blind, placebo-controlled study to assess the efficacy and safety of gimsilumab in subjects with lung injury or acute respiratory distress syndrome (ARDS) secondary to COVID-19.

Gimsilumab is a monoclonal antibody against granulocyte macrophage-colony stimulating factor (GM-CSF), which is a myeloid cell growth factor and pro- inflammatory cytokine. Late stages of COVID-19 can be marked by a "cytokine storm" and the overactivation of inflammatory myeloid cells that infiltrate and damage tissue, such as the lungs. Inhibition of GM-CSF may be able to reverse this pathology. The anti-GM-CSF mechanism is distinct from antiviral therapeutic mechanisms and may provide synergistic effects when used in combination.

Study KIN-1901-2001 will consist of a 2-week treatment period (last dose Day 8, if administered) and a 22-week follow-up period, for a total study duration of 24 weeks for each subject. A total of 270 subjects (135 subjects per arm) who have a confirmed diagnosis of COVID-19 with clinical evidence of acute lung injury or ARDS will be entered into the trial.

Subjects will receive a 400 mg dose of gimsilumab on Day 1 and a 200 mg dose of gimsilumab on Day 8, or matching placebo (saline solution) on Day 1 and on Day 8. The Day 8 dose will be omitted if the subject is discharged from the hospital prior to the dose or is no longer in need of supplemental oxygen or ventilatory support for >48 hours.

The primary objective of Study KIN-1901-2001 is to evaluate the impact of IV treatment with gimsilumab on mortality in subjects with lung injury or ARDS secondary to COVID-19.

Inclusion Criteria:

1. Male or non-pregnant female age ≥18 years, inclusive
2. Subject (or legally authorized representative) is able and willing to provide written informed consent, which includes compliance with study requirements and restrictions listed in the consent form
3. Has laboratory-confirmed SARS-CoV-2 infection as determined by PCR or other approved clinical testing prior to randomization
4. Radiographic evidence of bilateral infiltrates
5. Subject requires high-flow oxygen or meets clinical classification for ARDS
6. Elevated serum CRP or ferritin
7. Subjects who have been treated with convalescent plasma (CP) prior to enrollment are eligible if the subject continues to meet all inclusion criteria at screening
8. The use of investigational anti-viral treatment (e.g., remdesivir) is allowed if the subject continues to meet all inclusion criteria at screening

Additional inclusion criteria are detailed in the protocol

Exclusion Criteria:

1. Evidence of life-threatening dysrhythmia or cardiac arrest on presentation
2. Intubated >72 hours
3. Absolute neutrophil count < 1,000 per mm3
4. Platelet count < 50,000 per mm3
5. AST or ALT > 5X upper limit of normal
6. eGFR <30 mL/min/1.73m2 or requiring hemofiltration or dialysis
7. History of known anti-GM-CSF autoantibodies or pulmonary alveolar proteinosis
8. Severe chronic respiratory disease (e.g., COPD, PAH, IPF, ILD) requiring supplemental oxygen therapy or mechanical ventilation pre-hospitalization (e.g., prior to COVID-19 diagnosis)
9. Use of any immunomodulatory biologic, cell therapy, or small molecule JAK inhibitor within past 7 days or 5 half lives or planned use of any of these agents unless approved by medical monitor
10. Chronic (>4 weeks) use of corticosteroids >10mg/day of prednisone or equivalent
11. Known or suspected active and untreated TB, HIV, hepatitis B or C infection

Additional exclusion criteria are detailed in the protocol.

PIs generally may not publish/present on study results before sponsor's first publication. If there is no sponsor publication within 12-18 months after study completion [timeframe may vary among PIs], PIs may publish/present results from only their site, provided the PI submits the publication to sponsor for review. Upon sponsor's request, PIs must delete references to sponsor's confidential information and delay publication to allow sponsor to obtain IP protection.