Domain Therapeutics to progress into clinical trials with

Domain Therapeutics to progress into clinical trials with its EP4R antagonist DT-9081 in solid tumors

• Clinical trial applications accepted in France and Belgium for initiation of Phase I clinical trial

of DT-9081

• Domain’s first fully owned immuno-oncology program to enter the clinic by end of 2022
• Extensive biomarker strategy developed to optimize future clinical trials

Strasbourg, France – Montreal, Canada, October 19th, 2022 – Domain Therapeutics (“Domain” or “the Company”), a drug discovery and development company focused on G Protein-Coupled Receptors (GPCRs) in immuno-oncology (IO), today announces that its proprietary IO candidate, DT-9081, has cleared its clinical trial applications (CTA) by the ANSM (Agence Nationale de Sécurité du Médicament et des produits de santé) in France and the AFMPS (Agence Fédérale des Médicaments et des Produits de Santé) in Belgium, enabling Domain to start its Phase I clinical trial. The first-in-human clinical trial is on track to initiate by the end of the year.

DT-9081 is an oral small molecule drug candidate, which is able to reverse the prostaglandin E2 (PGE2)-mediated immunosuppression triggered by some tumors to bypass the immune system, by blocking the EP4 receptor present on immune cells. Given the high concentrations of PGE2 exhibited by a range of different solid tumors, Domain Therapeutics has developed an extensive biomarker strategy, enabling optimal selection of tumor types and patient subpopulations and monitoring the target engagement in future clinical trials. Furthermore, this approach will help in finalizing the design of future clinical trials, in combination with standard of care including immune checkpoint inhibitors (such as anti-PD1).

Dr. Pascal Neuville, CEO of Domain Therapeutics, commented: “Today’s news marks a pivotal moment for Domain as we progress our first fully-owned immuno-oncology drug candidate towards the clinic. Our proprietary assets in immuno-oncology are…