Dublin, Ireland – 27 November 2023 – Priothera Ltd., a Phase 3 clinical stage biotechnology company pioneering the development of its S1P receptor modulator compound mocravimod, today announced that the US Food and Drug Administration (FDA) has granted Orphan Drug designation (ODD) to mocravimod for the “treatment to improve outcome following hematopoietic stem cell transplantation in hematologic malignancies”. This ODD aims to potentially increase leukemia-free survival by triggering a ‘graft-versus-leukemia’ (GvL) response.

Florent Gros, Co-Founder and CEO of Priothera, commented: “We are very pleased that the US FDA granted mocravimod this Orphan Drug designation. This designation emphasizes the importance of developing novel therapeutic options to improve the outcome and success of maintenance therapy following allo-HSCT in blood cancer patients. This is an important milestone as this ODD complements the first ODD granted for prevention of ‘graft-versus-host disease’.  

“The two ODDs highlight mocravimod’s dual mode of action which for the first time is being leveraged to improve the allo-HSCT treatment outcomes in hematological malignancies to potentially increase the leukemia free survival – ‘graft-versus-leukemia’ response – while reducing tissue damage resulting from the ‘graft-versus-host disease’.”

The first ODD granted for mocravimod by the US FDA was for the “prevention of graft-versus-host disease (GvHD)” – see press release here.

Mocravimod, a sphingosine-1-phosphate (S1P) receptor modulator, is being investigated in a pivotal global Phase 3 study – MO-TRANS (NCT05429632) – evaluating the efficacy and safety of mocravimod as an adjunctive and maintenance therapy to allo-HSCT.  The study which is enrolling approximately 250 adult Acute Myeloid Leukemia (AML) patients, is ongoing in the US, Europe, Southeast Asia and Latin America.

Mocravimod, which has been previously tested in multiple autoimmune indications, is being developed to enhance the curative potential of allo-HSCT. Moreover, it has shown a clinically meaningful outcome in a Phase 1b/2a study[1] in patients with hematologic malignancies undergoing allo-HSCT.

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

[1]*Ref: Dertschnig et al, 2023

Dublin, Ireland – February 27^th, 2023 – Priothera, a late-clinical stage biotechnology company pioneering the development of its S1P receptor modulator compound mocravimod, today announced that it received clearance from the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan for the pivotal global MO-TRANS Phase 3 study evaluating mocravimod in Acute Myeloid Leukemia (AML) patients undergoing allogeneic hematopoietic cell transplant (HCT).

Elisabeth Kueenburg, M.D., Chief Medical Officer at Priothera, said: “We are grateful for the clearance from the PMDA to start our MO-TRANS Phase 3 study in Japan as we believe mocravimod has the potential to address a significant unmet need for Japanese patients with AML undergoing allogeneic HCT. We look forward to enrolling the first patients in several sites across Japan in the coming months.”

Priothera is conducting the pivotal MO-TRANS study – now classified as a global Phase 3 trial following acceptance by regulatory authorities – in 15 countries, including the US, Japan, Israel, France, and in additional European, Asian and Latin American countries, to assess the efficacy and safety of mocravimod as an adjunctive and maintenance therapy in AML patients undergoing allogeneic HCT. The double-blind, placebo-controlled study assesses relapse-free and overall survival of two dose levels of mocravimod in comparison to placebo. Topline data from this study are expected in 2025.

Dr. Takanori Teshima, M.D., is the Principal Investigator in Japan for the MO-TRANS global Phase 3 trial. Dr. Teshima is Professor of Medicine in the Division of Hematology and Deputy-director of Hokkaido University Hospital. He serves as a president of the Japanese Society of Hematopoietic Cell Transplantation (JSHCT), an executive director of Japanese Society of Hematology (JSH) and Japan Society of Transfusion Medicine and Cell Therapy (JSTMCT).

Dr. Teshima, M.D., commented: “AML is the most common acute leukemia in Japan accounting for approximately 70% of all myeloid leukemias. Despite advances in the use of HCT in Japan, patients are still at risk of relapse with resulting poor prognosis. Any new treatment that can enhance the curative potential of this approach would offer a significant benefit to patients. I am therefore delighted that Japan will be part of the MO-TRANS global Phase 3 study investigating mocravimod as an innovative potential new adjunctive and maintenance therapy for patients with AML undergoing allogeneic Hematopoietic Cell Transplant.”

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 allogeneic HCT. Mocravimod has shown a clinically relevant benefit in an early clinical study in patients with hematologic malignancies undergoing allogeneic HCT.

Florent Gros, Co-Founder and CEO of Priothera, added: “Japan represents an important potential market for us and one we see as a priority as we advance the development of mocravimod in AML patients undergoing allogeneic HCT globally. With this clearance we anticipate a further uptake in patient enrollment in our MO-TRANS trial. We look forward to seeing topline results from MO-TRANS in 2025.”