PRESS RELEASE

Dublin, Ireland – 3rd March 2022 – Priothera, a late-clinical stage biotechnology company pioneering the development of its S1P receptor modulator drug, mocravimod, today announced that the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have both granted orphan drug designation (ODD) to mocravimod for the treatment of Acute Myeloid Leukemia (AML) in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). EMA’s ODD follows a recommendation from the Committee for Orphan Medicinal Products (COMP).

Florent Gros, Co-Founder and CEO of Priothera, commented: “The orphan drug designations we received for mocravimod from both the FDA and EMA are important milestones towards addressing the urgent, unmet needs of AML patients. Allogenic stem cell transplantation is the only potentially curative approach for AML patients but has unacceptably high mortality rates with current treatments. We are looking forward to initiating the global Phase 2b clinical trial with mocravimod in multiple centers in the US, Europe and Asia in the coming months.”

Mocravimod, a sphingosine 1 phosphate (S1P) receptor modulator which has been previously tested in multiple autoimmune indications, is being developed to enhance the curative potential of HSCT. Moreover, it has shown a clinically relevant benefit in an early clinical study in patients with hematologic malignancies undergoing HSCT.

A multicenter Phase 2b study evaluating the efficacy and safety of mocravimod as an adjunctive and maintenance therapy to HSCT in adult AML patients is planned for the second half of 2022. The study will include approximately 250 patients in several countries in Europe, the US and Asia, upon approvals from respective health authorities.

Orphan drug designation is reserved for medicines treating rare, life-threatening or chronically debilitating diseases.