The journey of EXL01 began with the identification of Faecalibacterium prausnitzii as a pivotal player in gut health by our scientific co-founder, Professor Harry Sokol, a leading gastroenterologist at Saint Antoine Hospital in Paris.
By correlating clinical observational data across multiple indications in oncology and inflammatory diseases, Professor Sokol and Dr. Philippe Langella, Research Director at INRAe, uncovered the unique immune-modulatory properties of F. prausnitzii. 
This work, initially driven by correlation-based insights, revealed that patients in these indications often lacked sufficient F. prausnitzii, highlighting its critical role in immune homeostasis.

Supported by Professor Patrick Gervais, an expert in process engineering from AgroSup Dijon, the team overcame the challenge of cultivating the oxygen-sensitive bacterium for therapeutic applications. Together, their efforts culminated in the creation of EXL01, a first-in-class immunomodulator derived from F. prausnitzii.

Crucially, subsequent research into EXL01's mechanism of action revealed that its therapeutic effect is mediated by the activation of NOD2 receptors in macrophages.
This breakthrough not only clarified the drug's ability to drive metabolic reprogramming in immune cells but also explained its versatility across diverse therapeutic contexts.
NOD2's central role in regulating inflammation, infection control, and tissue repair enabled us to understand how EXL01 could address such different diseases as Crohn’s disease, oncology indications (e.g., gastric cancer, NSCLC, HCC), and infectious diseases like C. difficile.

At Exeliom, our mission is to bring this disruptive approach—single-strain live biotherapeutics—to patients, transforming the treatment landscape for immune-mediated diseases. We are guided by our core values: keeping patients at the center of everything we do, overcoming challenges together as a team, and showing respect to all parties involved in our journey.

Since Exeliom’s first fundraising in 2018, EXL01 has reached critical milestones, including the successful completion of a Phase 1 trial in Crohn’s disease patients, the production of over 10 GMP batches at kilogram scale, long-term drug product stability and a clear regulatory pathway. EXL01 is now being evaluated in multiple Phase 2 trials across three therapeutic areas, supported by a solid technical and operational foundation.

Our lean but dedicated team of seven people remains focused on turning cutting-edge scientific discoveries into transformative therapies, with every effort driven by our mission and values.