Our Science

Precision Endocrine Peptides (PEPs)™ – Transforming Native Hormones into Innovative Medicines

At MBX Biosciences, we are pioneering PEPs to overcome the limitations of native peptide therapeutics. Our intent is to transform the treatment landscape for endocrine disease with efficacious, safe and convenient treatments.

Disclaimer: PEPs are investigational; none are approved drugs.

Endocrine organs secrete peptide hormones (a chain of amino acids) that bind to cell surface receptors and trigger intracellular effects. Peptide hormones can disrupt appropriate biological function. In these instances, therapeutic peptides acting as hormones have been used to replace or block endogenous biology with the goal of restoring homeostasis and appropriate endocrine function.


Pioneering Precision Endocrine Peptides (PEPs)

Therapeutic proteins have traditionally been developed to mimic naturally occurring hormones, but when developed as medicines they often have some potentially significant drawbacks. Native peptide therapeutics often have short half-lives. They are rapidly degraded by enzymes and swiftly cleared (within minutes to hours) by the liver and kidney. This often necessitates frequent injections, which can result in high variability in peptide plasma concentrations that can promote undesired biological effects of the drug. To overcome these challenges, MBX Biosciences is pioneering PEPs. PEPs are engineered to have optimized pharmaceutical properties that we believe will allow us to transform native peptides into innovative, ground-breaking therapeutics.


  • Enhanced physical properties including stability and solubility.
  • Increased potency.
  • Multiple mechanisms of action in a single peptide.


  • Precisely timed chemical conversion of prodrug to active drug that we believe will reduce peak-to-trough and may improve clinical outcomes.


  • Increased duration of action (potentially resulting in a more convenient dosing regimen).
  • Compatible with non-injectable formulations.


Our World-Class Peptide Delivery Platform

Potential Benefits of PEP™ Platform Technology

  • Extended half-life
  • Deliver consistent drug concentrations (reduce peak-to-trough)
  • Consistent exposure to target tissue potentially leading to better outcomes
  • Infrequent dosing

We have created a world-class technology platform to design PEPs. PEPs are innovative peptide hormone analogs and are designed to overcome key limitations of native peptide therapeutics.

The biological activity of a peptide hormone is intimately related to its chemical structure. Understanding the chemistry is key to knowing how and where to modify the peptide to enhance its pharmacologic effects.

By developing groundbreaking new approaches, our co-founder Richard DiMarchi PhD and his research team are recognized as global leaders in the field of peptide drug design. Leveraging this expertise, we are advancing a pipeline of PEPs that have been selectively modified using state-of-the-art and proprietary chemical modifications to enhance stability and improve pharmacokinetics compared to the native peptide hormone. Further, we aim to extend the duration of action of the PEP thereby potentially enabling less frequent administration.

Through the use of our platform technology, we are actively pursuing discovery opportunities in a variety of endocrine and metabolic disorders. Visit our pipeline page for more information about some of our current PEP product candidates.

Our Pipeline