Effectiveness of Namilumab and Infliximab in Treating COVID-19 Pneumonia

A study of patients hospitalized with COVID-19 pneumonia found namilumab, but not infliximab, significantly reduced inflammation and CRP concentration.

Severe or fatal COVID-19 disease is often associated with dysregulated inflammation. One study, published this week in The Lancet, assessed the efficacy of 2 anti-inflammatories among patients hospitalized with COVID-19.

The drugs studied were namilumab, a granulocyte-macrophage colony stimulating factor inhibitor, and infliximab, a tumor necrosis factor inhibitor.

The investigators launched CATALYST, a randomized, multicenter, multi-arm, multistage, parallel-group, open-label, adaptive, phase 2, proof-of-concept trial. In the study, they recruited hospitalized COVID-19 patients 16 years of age and older. The patients were admitted to 1 of 9 UK hospitals with COVID-19 pneumonia and C-reactive protein (CRP) concentrations of 40 mg/L or greater.

The participants were randomly assigned either usual care, usual care and a single intravenous dose of infliximab (5 mg/kg), or usual care and a single intravenous dose of namilumab (150 mg).

From June 15, 2020-February 18, 2021, the investigators enrolled 146 participants, 54 of whom received usual care, 57 received namilumab, and 35 received infliximab.

The study’s primary endpoint was improvement in inflammation, measured by CRP concentration over time and analyzed with Bayesian multilevel models.

After adjusting for other factors that affect patient outcome, namilumab reduced CRP concentration by 97%, and infliximab reduced CRP concentration by 15%.

In the namilumab group, there were 134 reported adverse events reported in 55% (n=30) of patients. Comparatively, the usual care group recorded 134 adverse events occurring in 54% (n=29) of patients.

Among the infliximab recipients, there were 102 adverse events in 69% (n=20) of patients. The corresponding usual care group experienced 112 adverse events in 50% (n=17) of patients.

Mortalities occurred in 11% (n=6) of namilumab patients and 19% (n=10) in the usual care group. 14% (n=4) of the infliximab group died, and 15% (n=5) died in the usual care group.

The completed CATALYST study showed that only namilumab reduced inflammation as measured by CRP concentration. The significant 97% CRP concentration reduction should prompt further investigations into namilumab for COVID-19 treatment.