Pipeline compound, small molecule

    ATX-304

    ATX-304, previously designated O-304, is an orally available small-molecule pan-AMPK activator developed by Amplifier Therapeutics, a Cambrian Bio company. It is a small molecule rather than a peptide, and is included in this library because AMP-activated protein kinase sits on the same cellular energy-sensing axis studied alongside metabolic peptides. It is investigational and has no marketing authorisation.

    Developer
    Amplifier Therapeutics, a Cambrian Bio company
    Also known as
    O-304, ATX304

    Mechanism

    AMP-activated protein kinase (AMPK) is a heterotrimeric serine/threonine kinase that functions as a cellular energy sensor. It is activated when the AMP or ADP to ATP ratio rises, and its downstream signalling shifts cells away from anabolic, ATP-consuming pathways and toward catabolic, ATP-generating ones. Reported consequences studied in the literature include increased skeletal-muscle glucose uptake and effects on mitochondrial function.

    AMPK exists as multiple isoform combinations built from alpha, beta and gamma subunits. A pan-AMPK, or full-spectrum, activator is one described as engaging the isoform complexes broadly rather than selectively targeting a single combination. ATX-304 is described by its developer in those terms. The developer also calls it peripherally restricted; that is a company description rather than a published finding.

    Later work shows O-304 is also a mitochondrial uncoupler. The originating group reported this in 2023, and an unaffiliated laboratory confirmed it in 2025. Uncoupling is itself an indirect route to AMPK activation, so how much of the effect comes from each action is debated; the developer now describes ATX-304 as a dual AMPK and mitochondrial activator.

    The combination research context is mechanistic rather than clinical: incretin receptor agonists such as semaglutide act at a cell-surface G-protein-coupled receptor, while an AMPK activator acts on an intracellular kinase. Preclinical combination work presented by the developer sits in that framing. No combination outcome in humans is claimed here.

    Clinical programme status

    • Investigational. ATX-304 is not approved in the United Kingdom, European Union or United States, and is not supplied by Peptx.
    • As O-304, the compound was evaluated in a clinical study in adults with type 2 diabetes, published in JCI Insight in 2018 by Steneberg and colleagues.
    • Amplifier Therapeutics describes ATX-304 in its public materials as an oral small molecule in clinical development for obesity and cardiometabolic disease. Combination data with semaglutide have been presented by the developer at scientific meetings as preclinical work.
    • A Phase 1b study in 23 adults with obesity and prediabetes was reported by the developer as a 2026 conference abstract, with changes measured against baseline rather than placebo. No ATX-304 or O-304 record could be found on ClinicalTrials.gov in October 2026.

    Published statements, quoted

    Reproduced verbatim from the sources named. Peptx makes no claim of its own on these points.

    “ATX-304 is a full-spectrum AMPK activator that increases both energy supply and metabolic demand. The drug is a peripherally restricted, oral small molecule entering Phase 2 clinical trials in obesity and other cardiometabolic diseases.”
    Amplifier Therapeutics / Cambrian Bio, company pipeline description.
    “Pan-AMPK activator O304 improves glucose homeostasis and microvascular perfusion in mice and type 2 diabetes patients.”
    Steneberg P, Lindahl E, Dahl U, et al. JCI Insight. 2018;3(12):e99114. doi:10.1172/jci.insight.99114 (article title).

    Not yet stocked

    Register interest

    ATX-304 is not currently supplied by Peptx. Leave an email address and we will notify you once verified reference material is available. No purchase, no obligation, and the address is used for this notice only.

    5.018 verified customer reviewsRead all reviews

    Frequently asked questions

    Is ATX-304 a peptide?
    No. ATX-304 is an orally available small molecule, not a peptide. It is listed here because AMPK sits on the cellular energy-sensing axis studied alongside metabolic peptides, following the same precedent as 5-Amino-1MQ in this library.
    What does pan-AMPK activation mean?
    AMP-activated protein kinase is assembled from alpha, beta and gamma subunits in multiple isoform combinations. A pan, or full-spectrum, activator is described as engaging those complexes broadly rather than selectively targeting one isoform combination.
    What was O-304?
    O-304 is the earlier development code for the same compound. It was evaluated in a clinical study in adults with type 2 diabetes published in JCI Insight in 2018.
    Does Peptx supply ATX-304?
    No. ATX-304 is not stocked. You can register an email address on this page to be notified if verified reference material becomes available.

    Citations

    1. Steneberg P, et al. Pan-AMPK activator O304 improves glucose homeostasis and microvascular perfusion in mice and type 2 diabetes patients. JCI Insight. 2018;3(12):e99114. doi:10.1172/jci.insight.99114.
    2. Norlin S, et al. O304 ameliorates hyperglycemia in mice by dually promoting muscle glucose effectiveness and preserving β-cell function. Communications Biology. 2023;6:877.
    3. Li WF, et al. O304 is a mitochondrial uncoupler which extends C. elegans lifespan and induces vasorelaxation of rat mesenteric arteries. Chemico-Biological Interactions. 2025;421:111788.
    4. Thieroff-Ekerdt RI, et al. 1782-P: Phase 1b Study of AMPK/Mitochondrial Activator ATX-304 in Prediabetic Obese Participants. Diabetes. 2026 (conference abstract).
    5. Amplifier Therapeutics (Cambrian Bio): ATX-304 programme.

    Related reading