Perseus Proteomics Inc. announced that the interim report of phase I clinical trial of PPMX-T003, its anti-transferrin receptor antibody, among polycythemia vera ("PV") patients was presented at the 118th Japanese Society of Hematology Kinki Association Meeting in Osaka on May 29, 2023. This is the interim report of phase I study in 6 PV patients. The results of 3 patients were almost in line with the results of phase I study among healthy volunteers (5 cohorts, total 40) B) No serious adverse events were seen in all the three patients and the same level of safety was confirmed as that among healthy volunteers.

In case 1 and case 3, PPMX-T003 was administered at a dose of 0.25mg/kg, while dose escalated from 0.25mg/kg., 0.4mg/kg, to 0.64mg/kg in case 2. Before the phase I study, the three patients had been treated with phlebotomy every 4 to 9 weeks respectively. The study finished with confirmation that there was no need for phlebotomy for 12 weeks after administration in the three patients. As hematocrit and hemoglobin both decreased, it was also confirmed that administration of PPMX-T001 has a reducing effect on erythroblasts and red blood cells just like healthy volunteers.

The detailed data on safety and promising treatment efficacy data were reported as well. Thus, it was shown that PPMX-T003 has a possibility to be an effective therapeutic drug against PV, a disease characterized by an excessive number of red blood cells.