Invivyd, Inc. announced positive initial data from its ongoing Phase 1 healthy volunteer clinical trial of its lead investigational monoclonal antibody (mAb) candidate, VYD222. VYD222 is a broadly neutralizing, half-life extended mAb candidate in development for the prevention of symptomatic COVID-19 in vulnerable populations, such as immunocompromised people. Initial Phase 1 data show that a single administration of VYD222 was generally well-tolerated at all three dose levels tested with no serious adverse events (SAEs) reported to date.

At the lowest VYD222 dose tested (1500 mg), geometric mean serum neutralizing titers were 3245.1 (95% CI: 1882.5, 5594.0) against Omicron XBB.1.5 at Day 7, with a geometric mean 38.87-fold rise (95% CI: 10.3, 146.8) from baseline to Day 7 (n=8). Omicron XBB.1.5 and other related XBB sublineages are currently the dominant SARS-CoV-2 variants circulating globally. VYD222 was designed for broad activity and has previously demonstrated in vitro neutralizing activity against prior circulating SARS-CoV-2 variants and current variants of concern, including Omicron sublineages up to and through XBB.1.5. Higher VYD222 dose levels tested in the Phase 1 clinical trial are designed to provide greater protection from any potential loss of neutralization activity as SARS-CoV-2 evolves over time.

Analysis of the serum neutralizing activity from samples collected at different timepoints across all dose cohorts is ongoing, as is detailed pharmacokinetic analysis and modeling. Invivyd intends to use these analyses, combined with published clinical outcome data from prior clinical trials of vaccines and mAbs for the prevention of symptomatic COVID-19, including data from its Phase 2/3 clinical trial of adintrevimab for the prevention of COVID-19 (EVADE), to inform VYD222 dose selection for its pivotal clinical trial. Invivyd plans to utilize initial data from the Phase 1 VYD222 clinical trial to help support the anticipated rapid transition to a VYD222 pivotal clinical trial.

Additionally, the company plans to present additional results from the Phase 1 clinical trial at an upcoming medical meeting.