PRX004 is a humanized IgG1 monoclonal antibody that binds to epitope exposed on abnormal TTR protein and is intended to promote active clearance of ATTR amyloid thought a phagocytic uptake.9 Although promising, the phase 1, open-label study (NCT03336580) investigating the effects of this agent in patients with ATTRv amyloidosis was prematurely terminated in 2020 because of the impact of COVID-19 pandemic. Here, TTR is linked to familial amyloid neuropathy.