Anti-C5a antibody (vilobelimab) therapy for critically ill, invasively mechanically ventilated patients with COVID-19 (PANAMO): a multicentre, double-blind, randomised, placebo-controlled, phase 3 trial

BACKGROUND

Vilobelimab, an anti-C5a monoclonal antibody, was shown to be safe in a phase 2 trial of invasively mechanically ventilated patients with COVID-19. Here, we aimed to determine whether vilobelimab in addition to standard of care improves survival outcomes in this patient population.

METHODS

This randomised, double-blind, placebo-controlled, multicentre phase 3 trial was performed at 46 hospitals in the Netherlands, Germany, France, Belgium, Russia, Brazil, Peru, Mexico, and South Africa. Participants aged 18 years or older who were receiving invasive mechanical ventilation, but not more than 48 h after intubation at time of first infusion, had a PaO2/FiO2 ratio of 60-200 mm Hg, and a confirmed SARS-CoV-2 infection with any variant in the past 14 days were eligible for this study. Eligible patients were randomly assigned (1:1) to receive standard of care and vilobelimab at a dose of 800 mg intravenously for a maximum of six doses (days 1, 2, 4, 8, 15, and 22) or standard of care and a matching placebo using permuted block randomisation. Treatment was not continued after hospital discharge. Participants, caregivers, and assessors were masked to group assignment. The primary outcome was defined as all-cause mortality at 28 days in the full analysis set (defined as all randomly assigned participants regardless of whether a patient started treatment, excluding patients randomly assigned in error) and measured using Kaplan-Meier analysis. Safety analyses included all patients who had received at least one infusion of either vilobelimab or placebo. This study is registered with ClinicalTrials.gov, NCT04333420.

FINDINGS

From Oct 1, 2020, to Oct 4, 2021, we included 368 patients in the ITT analysis (full analysis set; 177 in the vilobelimab group and 191 in the placebo group). One patient in the vilobelimab group was excluded from the primary analysis due to random assignment in error without treatment. At least one dose of study treatment was given to 364 (99%) patients (safety analysis set). 54 patients (31%) of 177 in the vilobelimab group and 77 patients (40%) of 191 in the placebo group died in the first 28 days. The all-cause mortality rate at 28 days was 32% (95% CI 25-39) in the vilobelimab group and 42% (35-49) in the placebo group (hazard ratio 0·73, 95% CI 0·50-1·06; p=0·094). In the predefined analysis without site-stratification, vilobelimab significantly reduced all-cause mortality at 28 days (HR 0·67, 95% CI 0·48-0·96; p=0·027). The most common TEAEs were acute kidney injury (35 [20%] of 175 in the vilobelimab group vs 40 [21%] of 189 in the placebo), pneumonia (38 [22%] vs 26 [14%]), and septic shock (24 [14%] vs 31 [16%]). Serious treatment-emergent adverse events were reported in 103 (59%) of 175 patients in the vilobelimab group versus 120 (63%) of 189 in the placebo group.

INTERPRETATION

In addition to standard of care, vilobelimab improves survival of invasive mechanically ventilated patients with COVID-19 and leads to a significant decrease in mortality. Vilobelimab could be considered as an additional therapy for patients in this setting and further research is needed on the role of vilobelimab and C5a in other acute respiratory distress syndrome-causing viral infections.

FUNDING

InflaRx and the German Federal Government.

Seasonal Influence on the Risk of Relapse at a Rise of Antineutrophil Cytoplasmic Antibodies in Vasculitis Patients with Renal Involvement

Objective.

The objective of this study was to identify risk factors for a relapse at the time of an increase in antineutrophil cytoplasmic antibodies (ANCA) in patients with renal ANCA-associated vasculitis (AAV).

Methods.

All patients between January 2000 and November 2011 with renal AAV having an ANCA rise during remission were included. Differences in time to relapse since the ANCA rise were assessed using a Cox regression model. The level of 25-hydroxy Vitamin D (25(OH)D) was assessed at the ANCA rise and at a subsequent relapse or time-matched during remission.

Results.

Sixty patients had an ANCA rise, of whom 36 patients relapsed. Three risk factors were associated with a relapse at the time of the ANCA increase: previous disease activity not treated with cyclophosphamide or rituximab (HR 3.48, 95% CI 1.60–7.59), an ANCA rise during the fall season (HR 4.37, 95% CI 1.60–11.90), and an extended ANCA rise (HR 3.57, 95% CI 1.50–8.48). Levels of 25(OH)D significantly decreased during followup in relapsing patients, but not in patients who remained in remission (difference −6.3 ± 14.4, p = 0.017 vs 2.7 ± 16.3, p = 0.430).

Conclusion.

ANCA rises occurring during the fall season are more frequently followed by a relapse than ANCA rises occurring during other seasons. Although it is tempting to speculate that decreasing Vitamin D levels following the ANCA rise can be held responsible for the subsequent relapse, this remains to be determined.

Endothelial progenitor cells are differentially impaired in ANCA-associated vasculitis compared to healthy controls

Background

Endothelial progenitor cells (EPC) are of major importance in vascular repair under healthy circumstances. Vascular injury in need of repair occurs frequently in ANCA-associated vasculitis (AAV). A specialized T cell subset enhancing EPC function and differentiation has recently been described. These angiogenic T cells (T_ang) may have an important impact on the vascular repair process. Therefore, the aim of our study was to investigate EPC and T_ang in AAV.

Methods

Fifty-three patients suffering from AAV and 29 healthy controls (HC) were enrolled in our study. Forty-four patients were in remission, nine patients were in active state of disease. Patients were either untreated or were under monotherapy with low-dose steroids (max. 5 mg/day) at the time of sampling. Circulating EPC and T_ang were determined by flow cytometry (FACS). The functional capacity of EPC was assessed by established cell culture methods.

Results

Circulating EPC were significantly decreased in AAV as compared to HC. The capacity of EPC to differentiate and proliferate was differentially impaired in patients as compared to HC. The outgrowth of endothelial colony-forming cells (ECFC) was severely decreased in patients whereas colony-forming units-endothelial cell (CFU-EC) outgrowth was unaffected. ECFC and CFU-EC differentiation was strictly T cell-dependent. Patients with a relapsing disease course had an impaired ECFC outgrowth and expansion of T_ang as compared to patients with a stable, nonrelapsing disease.

Conclusions

The differentiation process of EPC is impaired in AAV. This may favor insufficient vascular repair promoting a relapsing disease course. Finally, these factors may explain a higher cardiovascular morbidity as has been previously documented in AAV.