Invivyd (IVVD) shares extended gains in premarket activity Tuesday after the company disclosed "positive" data from an ongoing phase 1/2 trial of a monoclonal antibody candidate designed to be a "superior alternative" to COVID-19 vaccination for the broad population.

Phase 1/2 clinical data for VYD2311 to date were "positive" for both safety and pharmacokinetics and supported by antiviral activity, the company said Monday. Pooled, blinded adverse events to date were "mild or moderate." As of Day 65, serum concentrations remained high with a half-life not yet reached, indicating the potential long clinical dosing interval.

Invivyd said the trial has fully enrolled, and all planned doses have been administered, with only long-term follow-up remaining.

The company added that VYD2311 is designed to be "frontline" protection in a convenient form while providing a "potent, long-acting option for the treatment of COVID-19."

Invivyd shares traded 26% higher in premarket activity after almost tripling in Monday's regular trading session.