Clinical trials of Tomaralimab (OPN-305)

TLR2 is an ideal target for therapeutic intervention, as an important component of the innate immune response with links to an increasing number of major autoimmune diseases, inflammatory diseases and cancers.

As such, Tomaralimab could deliver great medical and commercial benefit through the novel treatment of a broad range of human diseases with unmet medical needs.


Opsona has initiated an open label Phase I/II study to assess the safety and efficacy of Tomaralimab (OPN-305) in patients with low and intermediate-1 risk myelodysplastic syndrome (MDS). Treatment with Tomaralimab (OPN-305) may reduce the need for red blood transfusions (RBC) in MDS patients and help prevent disease progression to high risk MDS or acute myeloid leukemia (AML).
Read more about the current Phase I/II MDS study.

Renal Transplantation

Opsona Therapeutics had identified the prevention of delayed graft function (DGF) following renal transplantation as its initial clinical indication under solid organ transplantation for the development of Tomaralimab (OPN-305), as antagonising TLR2 may reduce the risk of ischaemia/reperfusion injury (I/R injury) and subsequent inflammation of the renal graft in the recipient. This study has been completed. Read more about the results of the Phase I trial, and the Phase II (Renal Transplant) study.