Domain Therapeutics announces the European Patent Office decision to grant a patent for its proprietary immuno-oncology EP4 receptor antagonist program including DT-9081

  • Broad patent provides strong protection until October 2040 in more than 15 European territories.
  • DT-9081 is currently in a Phase I ascending dose study in patients with advanced, recurrent or metastatic solid tumors and is Domain’s first fully-owned immuno-oncology asset to enter the clinic.

Strasbourg, France – Montreal, Canada, July 18, 2023 – Domain Therapeutics (“Domain” or “the Company”), a clinical-stage biopharmaceutical company developing innovative drug candidates in immuno-oncology targeting G Protein-Coupled Receptors (GPCRs), today announces the decision by the European Patent Office to grant a composition of matter European patent providing strong intellectual property protection until October 2040, for its proprietary EP4 receptor antagonist series including the candidate DT-9081. DT-9081 is currently evaluated in monotherapy in a first-in-human Phase I ascending dose study.

Dr. Stephan Schann, VP Research at Domain Therapeutics, commented: “After the successful launch of the clinical Phase I study, in late 2022, with our best-in-class EP4 receptor antagonist candidate, DT-9081, the decision to grant this European patent for the EP4 receptor antagonist program across key European territories represents an important step for our proprietary program. Reversing immunosuppression remains an unmet need in many patient populations where new therapeutic options are required. As we work to use our science to unlock new possibilities in cancer, we look forward to continuing our precision research based on a thoughtful biomarker strategy to quantify EP4 receptor target engagement and optimize the selection of subpopulation of patients aiming at having optimal clinical outcomes.”

DT-9081 is an orally administered small molecule drug candidate which blocks the EP4 receptor on immune cells and is able to reverse the prostaglandin E2-mediated immunosuppression (PGE2) triggered by certain tumors to bypass the immune system. The findings from preclinical studies with DT-9081, demonstrated significant anti-tumor effects in synergy with immune checkpoint inhibitors, such as anti-PD1 drugs, in multiple models.

The Phase I study, named EPRAD, is a multi-center, open-label study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of DT-9081 in adult patients with advanced, recurrent or metastatic solid tumors. Domain has developed a precise biomarker strategy guiding the clinical positioning and monitoring the antagonist activity of the candidate during the patient’s treatment. This precision research enables a differentiated positioning of DT-9081.


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For more information, please contact:
Consilium Strategic Communications
Amber Fennell, Namrata Taak, Andrew Stern, Renna Foufouni
Tel: +44 (0)20 3709 5813

NewCap (for French media)
Annie-Florence Loyer
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About Domain Therapeutics
Domain Therapeutics, a clinical-stage biopharmaceutical company operating in France and Canada, focuses on developing innovative immunotherapies targeting G Protein-Coupled Receptors (GPCRs), one of the most important drug target classes, to unlock new possibilities in cancer. As a leader in GPCRs in immuno-oncology, Domain sees cancer differently, using a precise biomarker strategy to address the specific needs of patients based on unique signatures of individual cancers. Two decades of solid experience in GPCR drug discovery, validated by multiple pharma partnerships, associated to a target identification and drug discovery platform enable the Company to enhance the understanding of cancer and deliver innovative immunotherapies to patients.

Domain’s proprietary programs include DT-7012, a Treg-depleting CCR8 antibody, DT-9045, a PAR2 negative allosteric modulator, DT-9081, an EP4 receptor antagonist and M1069, an A2aR/A2b receptor antagonist identified in partnership with Merck KGaA, and alongside a rich, optimized pipeline of best-in-class and first-in-class GPCR targets selected through Domain’s proprietary cross-validation drug discovery and development platform.

The Company raised €39m ($42m) in 2022 to progress preclinical and clinical development of its high-value drug candidates to address GPCR-mediated immunosuppression. Domain is supported by leading international venture capital firms from Europe, Asia and North America.

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