Perseus Proteomics Inc. announced that there will be a delay in the end of the Phase I clinical trial of PPMX-T003, an anti-transferrin receptor 1 (TfR1) antibody, among PV patients from the previous forecast of the end of June 2024 to the end of July 2024. This trial primarily investigates the safety and pharmacokinetics in administering PPMX-T003 to 6 patients suffering from PV, a disease characterized by excess increase in red blood cells (RBCs). The secondary purpose is to confirm the therapeutic effects.

The tests of the 5 patients have already ended and the company has continued the test of the remaining 1 patient. Due to the comprehensive judgement of a doctor considering the background unique to the patient, PPMX-T003 was administered at the increased dosage. The observation period is expected to finish in the end of July 2024.

PPMX-T003 is an antibody targeting TfR1 that is related to iron intake into cells. TfR1 is highly expressed in cells that require much more iron than usual cells. Erythroblasts, which are nucleated cells in bone marrow from which RBCs derive, are one of them.

When PPMX-T003 binds to TfR1, it inhibits cell proliferation by inhibiting iron uptake into erythroblasts. Therefore, it is expected to normalize the number of RBCs of PV patients, who have too many RBCs. TfR1 is also expressed in cancer cells that proliferate at a significant pace.

PPMX-T003 similarly inhibits proliferation of cancer cells due to its function of inhibiting iron intake. Also, investigator-led phase I/II clinical trial of PPMX-T003 among aggressive NK-call leukemia (ANKL) patients is underway.