A phase 3 clinical trial assessed sipavibart, an investigational monoclonal antibody, in preventing symptomatic COVID-19 in immunocompromised individuals. The trial demonstrated that sipavibart reduced cases of symptomatic COVID-19 by 34.9% in non-Phe456Leu-containing variants but was ineffective against resistant SARS-CoV-2 variants dominated by Phe456Leu-containing variants. Adverse events with sipavibart were comparable to those in the comparator group, and no serious cardiovascular or thrombotic events were linked to sipavibart. Developing monoclonal antibodies for COVID-19 prevention remains challenging due to the rapid evolution of SARS-CoV-2 variants, with alternative preventive measures such as immunobridging strategies being suggested to address the evolving landscape of COVID-19 prophylaxis for immunocompromised patients.

Source: The Lancet