Mavrilimumab in Severe COVID-19 Pneumonia and Hyper-inflammation (COMBAT-19)

To evaluate the efficacy and safety of mavrilimumab versus placebo in addition to best standard of care (SoC) in the treatment of COVID-19 pneumonia. As of May 13, 2020, COVID-19 has been confirmed in more than 4.2 million people worldwide. Mortality rate has been reported to be approximately 3.7%, which is nearly 4 times higher than that of influenza: there is an urgent need for effective treatment. Accumulating evidence suggests that patients with severe acute COVID-19 pneumonia have a cytokine storm syndrome, or unbalanced hyper-inflammatory response resulting in markedly elevated cytokine and chemokine production. GM-CSF is a cytokine with dual roles as a critical pulmonary hormone and proinflammatory properties that can exaggerate tissue inflammation. Recent preliminary uncontrolled clinical observations on 13 non-mechanically-ventilated patients in the promoter institution suggest that GM-CSF pathway blockade with mavrilimumab is an effective and well-tolerated treatment for COVID-19 pneumonia. We will perform a prospective, phase II, multi-center, randomized, double-blind, placebo-controlled trial to evaluate the efficacy and safety of mavrilimumab in hospitalized patients with acute respiratory failure requiring oxygen supplementation in COVID- 19 pneumonia and a hyper-inflammatory status. The study will randomize non-mechanically-ventilated adult patients to mavrilimumab or placebo, in addition to standard of care per local practice, which may include but not limited to anti-viral treatment, hydroxychloroquine, low-dose corticosteroids (≤ 10 mg of prednisone or equivalent) and/or supportive care. The total trial duration will be 12 weeks after single mavrilimumab or placebo infusion. Safety will be closely monitored by a dedicated external data safety monitoring board (DSMB) at regular intervals during the study.