MRx-4DP0004

**MRx-4DP0004** is an orally administered, single-strain live biotherapeutic product developed by **4D pharma** as an immunomodulatory microbiome-derived therapeutic. Public sources describe it as a bacterial live biotherapeutic identified using 4D pharma's MicroRx platform and designed to reduce inflammatory responses systemically, including airway inflammation in asthma. In preclinical severe asthma models, MRx-4DP0004 reduced both neutrophilic and eosinophilic airway infiltration and inflammation. Clinically, it has been studied in a randomized, double-blind, placebo-controlled Phase I/II trial in patients with partly controlled asthma and in a pilot randomized placebo-controlled study in hospitalized patients with COVID-19, with the proposed therapeutic rationale of dampening hyperinflammation without impairing viral clearance. No molecular target or strain identity was disclosed in the provided sources, so its mechanism is best characterized as host immune modulation mediated by a live bacterial therapeutic rather than by a defined single receptor target.