Invivyd’s experimental antibody VYD2311 showed superior safety and tolerability compared with an mRNA-based COVID-19 vaccine in the phase 3 LIBERTY trial, the company said.

Adverse events occurred in 56.5 per cent of VYD2311 recipients versus 91.4 per cent of vaccine recipients over six days. The gap remained statistically significant through 56 days of follow-up.

The study enrolled 210 healthy adults aged 18 to 49. Participants received either a single 250 mg intramuscular dose of VYD2311, an mRNA vaccine, or both together.

VYD2311 did not interfere with vaccine-induced antibodies when given together. It added to the overall neutralising antibody levels instead.

Invivyd plans to use the data to support a US biologics license application under the FDA’s accelerated approval pathway. The antibody is designed as a pre-exposure prophylaxis for COVID-19.

The company reported no hypersensitivity or anaphylaxis in the study. VYD2311 is the second Invivyd drug targeting pre-exposure COVID protection.

Topline results from the companion DECLARATION study are expected later this month.