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Priothera Receives First Regulatory Approvals to Start a Global Pivotal Study with Mocravimod in Acute Myeloid Leukemia Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplant

Global Phase 2b/3 trial assessing the efficacy and safety of mocravimod as an adjunctive and maintenance therapy in AML patients undergoing allogeneic HSCT planned to start in H2 202

Dublin, Ireland – 11th April 2022 – Priothera Ltd, a late-clinical stage biotechnology company pioneering the development of its S1P receptor modulator mocravimod, today announces it has received the two first European country approvals from the Swiss and French national health authorities (Swissmedic and ANSM) to begin its planned pivotal study of mocravimod. The company has also received encouraging feedback from the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) on the clinical study design that is closely aligned with earlier feedback from the US Food and Drug Administration (FDA).

Priothera will initiate a global Phase 2b/3 study (MO-TRANS study) in Europe, US and Japan, assessing the efficacy and safety of mocravimod as an adjunctive and maintenance therapy in adult Acute Myeloid Leukemia (AML) patients undergoing allogenic hematopoietic stem cell transplant (HSCT). The MO-TRANS 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, commented “Following on from our recent receipt of orphan drug designations for mocravimod in the US and Europe, we are pleased to have received our first approvals to initiate this key global Phase 2b/3 trial with this highly promising compound. Moreover, the CHMP feedback is encouraging, and is also closely aligned with the feedback we received from the FDA. These first approvals are important regulatory and clinical milestones for Priothera and move us a step closer to bringing mocravimod, an adjunctive and maintenance treatment, to patients with AML and other hematologic malignancies, for whom there remains a significant unmet medical need.”

About mocravimod

Mocravimod(also known as KRP203), is a synthetic, sphingosine 1-phosphate receptor (S1PR) modulator. This novel investigational drug has been assessed in Phase 1 and Phase 2 trials for safety and tolerability, as well as for efficacy in several autoimmune indications. Promising data from a Phase 1b/2a clinical study in patients with hematological malignancies led Priothera to further develop mocravimod for the treatment of blood cancers.

Mocravimod will be investigated as an adjunctive and maintenance treatment in a Phase 2b/3 study as a potential treatment for patients with Acute Myeloid Leukemia (AML) receiving allogeneic hematopoietic stem cell transplantation (HSCT). Allogenic HSCT is the only potentially curative approach for AML patients, but current treatments have unacceptably high mortality and morbidity rates.  

Priothera leverages S1PR modulator’s unique mode of action to maintain anti-leukemia activity – graft-versus leukemia (GVL) while reducing tissue damage resulting from graft-versus-host disease (GVHD), a consequence of allogenic HSCT. This novel treatment approach – mocravimod being the only S1PR modulator treating blood cancers – tackles a high unmet medical need and intends to add quality life to patients.


About Priothera

Priothera is leading the way in developing orally applied sphingosine 1 phosphate (S1P) receptor modulators for the treatment of hematological malignancies. S1P receptor modulators are known to largely reduce egress of T cells from lymphatic tissues. Not being an immunosuppressant, mocravimod maintains the graft-versus-leukemia (GVL) benefits in patients receiving HSCT while inhibiting graft-versus-host-disease (GvHD).

Priothera was founded in 2020 by an experienced team of drug development experts and is headquartered in Dublin, Ireland, and with a subsidiary in Saint-Louis, France. The Company is backed by international founding investors Fountain Healthcare Partners (Dublin, Ireland), funds managed by Tekla Capital Management, LLC (Boston, Massachusetts), HealthCap (Stockholm, Sweden) and EarlyBird Venture Capital (Berlin, Germany).

For more information please visit:


Florent Gros, CEO

MEDiSTRAVA Consulting
Sylvie Berrebi, Sandi Greenwood, Frazer Hall
T: +44 (0)7714 306525

Source: Priothera