Vilobelimab Reduces Mortality Risk in Patients With Severe COVID-19 Pneumonia

All-cause mortality risk was significantly decreased in patients with COVID-19 pneumonia who received vilobelimab, an anti-C5a monoclonal antibody.

The addition of vilobelimab to standard care for mechanically-ventilated patients with COVID-19 pneumonia significantly reduces the risk of all-cause mortality, according to study results presented at IDWeek 2022, held from October 19 to 23, in Washington, DC.

Vilobelimab is a monoclonal antibody which works to reduce the level of complement split factor C5a by preserving the membrane attack complex. Higher levels of C5a increase the inflammatory response, which may result in multiorgan failure following COVID-19 activation of the complement system.

Researchers conducted a randomized, controlled, phase 3 trial to analyze the efficacy of vilobelimab in preventing 28- and 60-day all-cause mortality in 559 mechanically-ventilated patients with COVID-19 pneumonia. The researchers randomly assigned patients (N=368) to receive either vilobelimab plus standard care (n=177) or placebo plus standard care (n=191).

Standard care included corticosteroids and anticoagulants, which were administered to 97% and 98% of patients in both groups, respectively. Additionally, patients in the vilobelimab group received up to 6 infusions of 800 mg of vilobelimab.

The researchers performed a site-stratified Cox proportional hazards regression analysis. At 28 days, the rate of all-cause mortality was 31.7% among patients in the vilobelimab group compared with 41.6% among those in the placebo group (hazard ratio [HR], 0.73; 95% CI, 0.50-1.06; P =.094). Without site stratification, receipt of vilobelimab was associated with significantly reduced 28-day (HR, 0.67; 95% CI, 0.48-0.96; P =.027) and 60-day (HR, 0.67; 95% CI, 0.48-0.92; P =.016) mortality compared with placebo plus standard care.

Vilo targets inflammation which may represent an approach to treat sepsis and ARDS caused by other respiratory viruses.

Receipt of vilobelimab also was associated significantly increased 28-day survival rates among patients with severe disease at baseline.

When comparing the safety of vilobelimab plus standard care with placebo plus standard care, the researchers observed a similar rate of treatment-emergent adverse events among patients in the vilobelimab vs placebo groups (90.9% vs 91.0%). However, there was an increased rate of severe adverse events among patients in the placebo group vs those in the vilobelimab group (63.5% vs 58.9%).

Infection incidence per 100 patient-days was equal among patients in both groups, and no meningococcal infections were reported.

According to the researchers, “Vilo [vilobelimab] targets inflammation which may represent an approach to treat sepsis and ARDS [acute respiratory distress syndrome] caused by other respiratory viruses.”

Disclosure: Some authors declared affiliations with industry. Please see the reference for a full list of disclosures.


Mourvillier B, Vlaar A, Witzenrath M, et al. Randomized, controlled, phase 3 study of anti-C5a vilobelimab’s effect on mortality in critically ill COVID-19 patients: a therapy for viral pneumonia. Presented at: IDWeek 2022; October 19-23; Washington, DC. Poster LB1529.