Invivyd Initiates DECLARATION Trial Evaluating VYD2311, Investigational Vaccine-Alternative Monoclonal Antibody Candidate For Prevention Of COVID

• DECLARATION is a Phase 3, randomized, placebo-controlled clinical trial to evaluate the safety and efficacy of VYD2311 in the prevention of COVID versus placebo, at three months, from a single intramuscular (IM) dose, with protection beyond three months anticipated  
• A second arm will evaluate monthly IM doses versus placebo to demonstrate the safety and efficacy of more frequent dosing to support individual choice should at-risk persons seek periodic extra protection from COVID
• Primary endpoint is the reduction of PCR-confirmed symptomatic COVID incidence versus placebo; total expected enrollment of 1770 people across all three arms
• DECLARATION is part of the Company's REVOLUTION clinical program aimed at establishing monoclonal antibody prophylaxis for prevention of COVID; top-line data are expected mid-2026

NEW HAVEN, Conn., Dec. 23, 2025 (GLOBE NEWSWIRE) -- Invivyd, Inc. (NASDAQ:IVVD) today announced initiation of the DECLARATION trial evaluating VYD2311, an investigational vaccine-alternative monoclonal antibody candidate for the prevention of COVID. DECLARATION is the company's Biologics License Application (BLA)-enabling, Phase 3 randomized, triple-blind, placebo-controlled clinical trial to evaluate VYD2311 efficacy and safety in prevention of symptomatic COVID in a broad population of participants including adults and adolescents.

The DECLARATION study will evaluate prevention of symptomatic COVID at three months, with either a single dose or monthly doses of VYD2311, each administered via intramuscular (IM) injection, compared to placebo. A single IM dose of VYD2311 is expected to confer strong protection from COVID across the three-month measured dosing interval and beyond, with further clinical demonstration of long-term protection possible post-approval. By including a monthly dosing arm, the DECLARATION trial could also provide safety and efficacy data that support a VYD2311 indication and administration paradigm that enables individual choice and flexibility for extra periodic protection from COVID if desired, as opposed to a single centrally defined or mandated protection regimen. If approved, access to baseline and periodic extra protection via VYD2311 could, for example, support long interval protection such as annual or semi-annual dosing, as well as provide a mechanism for increased protection through additional doses for at-risk populations seeking extra protection or for individuals facing periods of enhanced risk of COVID. In the Phase 1/2 study, IM administered VYD2311, at 4 times the planned dose in DECLARATION, was well tolerated, with all adverse events (AEs) considered mild to moderate in severity with no serious or severe AEs reported. All AEs, including headache and injection site pain, were deemed unrelated to study drug.

Invivyd has produced commercial launch quantities of VYD2311 and, over the past four months, has secured significant capital to support the DECLARATION pivotal study and commercial preparedness for the potential launch of VYD2311, if approved.