Priothera – Positive mocravimod Phase 1b clinical data published in Transplantation and Cellular Therapy

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