Icosavax Touts Encouraging Early-Cut Data From Phase 1 Trial Of RSV Vaccine

Icosavax Inc ICVX announced topline interim results from its Phase 1 trial of IVX-A12 against the respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) in older adults. 

• IVX-A12 was generally well-tolerated across all dosage groups.
• Solicited local and systemic adverse events (AEs) were generally mild or moderate, without dose-limiting reactogenicity.
• IVX-A12 induced robust immune responses against RSV and hMPV in older adults across dosage levels and with and without adjuvant.
• When administered in combination, there was no evidence of immune interference between RSV and hMPV VLPs.
• Across dosage groups, IVX-A12 induced geometric mean titers (GMTs) in RSV-A neutralizing antibody titers (nAbs) of up to 16,100 IU/mL compared to 2,600 IU/mL for placebo.
• GMTs in RSV-B nAbs were up to approximately 8,300 IU/mL compared to 2,500 IU/mL for the placebo.
• Across dosage groups, IVX-A12 induced GMTs in hMPV-A nAbs of up to roughly 3,300 assay units/mL compared to 900 assay units/mL for placebo. 
• IVX-A12 induced GMTs in hMPV-B nAbs of up to 23,900 assay units/mL compared to 11,500 assay units/mL for placebo. 
• Icosavax plans to initiate a Phase 2 trial for IVX-A12 in RSV and hMPV in mid-2023 and evaluate two formulations.
• Pending the planned Phase 2 trial results, Icosavax intends to conduct an IVX-A12 hMPV human challenge clinical trial. 
• This hMPV human challenge model is currently in development and builds on an established precedent in the RSV field.
• In December, Icosavax reported durability data at six months; 12-month immunogenicity data is expected in mid-2023.
• Icosavax has priced a $67.8 million registered direct offering with select healthcare investors. The Seattle-based company now expects its cash balance to be sufficient to fund operations into 2H 2025.  

Price Action: ICVX shares are up 11.2% at $8.75 during the premarket session on the last check Tuesday.