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.” 

Dublin, Ireland – January 23, 2023 – Priothera, a late-clinical stage biotechnology company pioneering the development of its S1P receptor modulator compound mocravimod today announced that the first patients have been enrolled in the pivotal MO-TRANS global Phase 2b/3 study evaluating mocravimod in AML patients undergoing allogeneic hematopoietic cell transplant (HCT).

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.

Priothera is initiating the pivotal MO-TRANS global Phase 2b/3 study in Europe, Israel, the US and in additional 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.

Marcos de Lima, M.D., is the Principal Investigator for the MO-TRANS global Phase 2b/3 trial. Dr. de Lima is professor of medicine at The Ohio State University College of Medicine and a hematologist-oncologist at The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute.

Prof de Lima said: “We are excited to be part of the important MO-TRANS global Phase 2b/3 study to investigate mocravimod, a potential new adjunctive and maintenance therapy for patients with Acute Myeloid Leukemia undergoing allogeneic Hematopoietic Cell Transplant. Maintenance therapy is fast becoming the new frontier in the treatment of AML and we are committed to bringing forth new innovative therapies to AML patients.”

Elisabeth Kueenburg, M.D., Chief Medical Officer at Priothera, commented: “This MO-TRANS global Phase 2b/3 study builds on pre-clinical and clinical proof of concept studies which demonstrated mocravimod’s ability to improve survival outcomes for patients with hematological malignancies requiring allogeneic HCT. The mode of action has been well-established in autoimmune indications, but never in hematology. Mocravimod has the potential to be a first-in-class therapy in maintaining the graft-versus-leukemia effect, while preventing graft-versus-host disease, one of the most serious complications of allogeneic HCT. We expect this trial to deliver important clinical data supporting the registration of mocravimod in this indication.”

Florent Gros, Co-Founder and CEO of Priothera, said: “Having successfully enrolled the first AML patients undergoing allogeneic HCT in our MO-TRANS global study represents a significant milestone for Priothera as we believe mocravimod has the potential to address a significant unmet need. Furthermore, we anticipate a strong uptake in patient enrollment with a significant number of patients currently being identified. We look forward to seeing topline results in 2025.”  

Dublin, Ireland – 14^th November 2022 – Priothera, a late-clinical stage biotechnology company pioneering the development of its S1P receptor modulator compound mocravimod, announces that positive data from the Phase 1b clinical trial evaluating mocravimod in allogeneic hematopoietic cell transplantation patients has been published in Transplantation and Cellular Therapy.

The study assessed the safety and tolerability of mocravimod in patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) for hematological malignancies. The secondary objectives were to determine the pharmacokinetic profile of mocravimod in this patient group as well as to assess GvHD-free, relapse-free survival at 6 months after last treatment.

The study found that mocravimod can safely be added to standard treatment regimens in patients with hematological malignancies requiring allo-HCT. CD4+ T cells were more sensitive to mocravimod treatment than CD8+ T cells. Mocravimod resulted in a significant reduction of circulating lymphocyte numbers and had no negative impact on engraftment and transplant outcomes.

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 HCT.

A global Phase 2b/3 study assessing the efficacy and safety of mocravimod as an adjunctive and maintenance therapy in acute myeloid leukemia (AML) patients undergoing allo-HCT is planned to start in the coming months. The trial design for this study will be published as an online abstract as part of the 2022 American Society of Hematology (ASH) conference (December 10-13^th).

Florent Gros, Co-Founder and CEO of Priothera, said: “The positive Phase 1b data reinforce the potential for mocravimod to improve survival outcomes for patients with hematological malignancies requiring HCT. We’re looking forward to building upon this foundation with our upcoming pivotal Phase 2b/3 trial and advancing our lead asset towards its next significant milestones.”

Elisabeth Kueenburg, M.D., Chief Medical Officer at Priothera, commented: “Mocravimod’s mode of action has already been well established in autoimmune indications, and the Phase 1b trial shows that its potential also extends to hematology. We believe mocravimod has the potential to be a first-in-class therapy in maintaining graft-versus-leukemia responses, one of the most serious complications of allogeneic HCT, while preventing graft-versus-host disease.”

References
S. Dertschnig et al. Mocravimod, a selective S1PR modulator in allogeneic hematopoietic stem cell transplantation for malignancy, Transplantation and Cellular Therapy.

Online publication: https://doi.org/10.1016/j.jtct.2022.10.029

Dublin, Ireland – 13^th June 2022 – Priothera, a late-clinical stage biotechnology company pioneering the development of its S1P receptor modulator compound, mocravimod, presented first clinical data on mocravimod (also known as KRP203) in hematological malignancies patients undergoing allogeneic hematopoietic stem cell transplant (HSCT) at the European Hematology Association (EHA) 2022 Congress, which was held in Vienna, Austria, June 9-12^th, 2022.

The oral presentation, which took place on 12^th June, was entitled A two-part, single- and two-arm randomized, open-label study to evaluate the safety, tolerability and pharmacokinetics of KRP203 in subjects with hematological malignancies undergoing allogeneic hematopoietic stem cell transplantation. The study showed that in the Phase 1b/2a study mocravimod was safe and well tolerated with promising overall survival.

Key take aways from the data presentation were:

• The study provided first ever human data of a S1P receptor modulator administered to patients undergoing allogeneic HSCT
• S1PR modulator class effects, such as bradycardia, were of no clinical concern
• Promising overall survival (OS) data
• Limited number of relapses, acute and chronic graft-versus-host disease (GVHD)
• Data supportive for conducting the planned MO-TRANS pivotal study to investigate efficacy (Relapse-free survival and OS) and GVHD in AML patients undergoing allogeneic HSCT

Priothera is initiating the pivotal MO-TRANS global Phase 2b/3 study in Europe, US and Japan, to assess the efficacy and safety of mocravimod as an adjunctive and maintenance therapy in adult AML patients undergoing allogeneic HSCT. The study is expected to start in the second half of 2022 and preliminary data from this study are expected by the end of 2024.

Florent Gros, Co-Founder and CEO of Priothera, said: “We are delighted to have been given the opportunity to present the full first human clinical data on mocravimod at the European Hematology Association Congress this year. Based on these results mocravimod has the potential to be a first-in-class therapy in maintaining graft-versus-leukemia responses while preventing graft-versus-host disease. This novel approach would provide a tremendous benefit to AML patients undergoing an allogeneic hematopoietic stem cell transplant. We are excited about mocravimod which leverages a well-described mode of action in a hematology/oncology setting and has been successfully used in autoimmune indications. Pre-clinical and clinical proof of concept studies have herewith demonstrated mocravimod’s ability to improve survival outcomes for this devastating disease. We look forward to advancing the global pivotal Phase 2/3 trial which is due to start in the second half of 2022.”  

Priothera’s abstract is available on EHA2022 Congress Abstract Book, here: https://journals.lww.com/hemasphere/Documents/EHA2022%20Congress%20Abstract%20Book.pdf