SARS-CoV-2-specific monoclonal antibody AER002 in Long COVID: an exploratory randomized phase 2a mechanistic trial

Persistence of SARS-CoV-2 has been proposed as a biological driver of Long COVID, a disabling chronic illness with no proven treatments. We conducted an exploratory, placebo-controlled, double-blind, 2:1 randomized mechanistic trial (NCT05877508) of the SARS-CoV-2-specific monoclonal antibody AER002 in 36 participants who met the World Health Organization case definition of Long COVID. After baseline characterization, participants received a single infusion and were followed for 360 days. The primary endpoint was the PROMIS-29 Physical Health Summary Score (PHSS) at 90 days; secondary and exploratory endpoints included patient-reported and objective measures of physical and neurocognitive function as well as blood-, imaging-, and tissue-based biomarkers. While AER002 was safe and well tolerated, no significant differences in physical health, quality of life, objective measures of physical function or cognition, or blood-based biomarkers were demonstrated between the treatment and control arms. In a post-hoc analysis, participants with a lower baseline SARS-CoV-2 antibody level and higher drug exposure were more likely to perceive treatment benefit based on the Patient Global Impression of Change scale (p < 0.05 for anti-S, S1, and RBD). Although AER002 was not efficacious in this proof-of-concept study, our findings could inform future trials using monoclonal antibodies to target viral persistence in Long COVID.