Invivyd stock: FLINTLOCK trial targets Long COVID

Published on 11/12/2026 at 03:25 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

Invivyd stock is tied to a new Phase 2 study of VYD2311 for Long COVID. Initial results are expected in mid-2027.

Trial scope and next milestone

FLINTLOCK will test VYD2311 in a randomized, double-blind, placebo-controlled Phase 2 study.
The trial targets adults with Long COVID or Post-Vaccination Syndrome, with initial results expected in mid-2027.
Invivyd is expanding its VYD2311 program beyond prevention into a potential therapeutic application.

IVVD, US00534A1025, Illustration mit AI erstellt.

Invivyd and the SPEAR Study Group started the FLINTLOCK Phase 2 trial on October 14, testing the investigational monoclonal antibody VYD2311 in adults with Long COVID or Post-Vaccination Syndrome. The announcement was published by GlobeNewswire on behalf of Invivyd.

Study tests therapeutic potential

FLINTLOCK is designed as a randomized, double-blind, placebo-controlled proof-of-concept study. It will evaluate safety, tolerability, pharmacokinetics and clinical activity over 90 days, with approximately 130 participants aged 18 to 65.

Participants are scheduled to receive an initial intravenous infusion followed by intramuscular injections on Day 30 and Day 60. The study includes adults with at least two persistent symptoms after a COVID-19 infection or COVID-19 vaccination. Functional performance tests and safety assessments will form part of the evaluation.

Mid-2027 is the next milestone

Invivyd expects initial results in mid-2027. The company is positioning FLINTLOCK within its broader REVOLUTION clinical program for VYD2311, alongside the DECLARATION and LIBERTY studies.

The company said VYD2311 has shown in vitro antiviral activity against the SARS-CoV-2 variants tested, from the original Wuhan strain through contemporary Omicron variants. That laboratory finding does not establish clinical efficacy, making the controlled Phase 2 trial the next relevant test for the therapeutic approach.

Invivyd develops antibody medicines

Invivyd is a United States biopharmaceutical company focused on protection from serious viral infectious diseases, initially targeting SARS-CoV-2. Its INVYMAB platform combines viral surveillance, predictive modeling and antibody engineering to develop monoclonal antibodies for evolving viral threats.