NanoCarrier Co., Ltd. announced that first participant has been dosed in an investigator-initiated phase I clinical trial of SRN-14/GL2-800, an siRNA/DDS formulation. SRN-14/GL2-800 has been jointly developed by AccuRna Inc., which was integrated into NanoCarrier on September 1, and several institutions. This investigator-initiated clinical trial conducted at the Cancer Institute Hospital of JFCR (Japanese Foundation for Cancer Research), is the first-in-human study of SRN-14/GL2-800 in patients with breast cancer. This pharmaceutical preparation targets the PRDM14 molecule, which is known to be highly expressed in breast cancer. Because PRDM14 is expressed in the cell nucleus, it is extremely difficult to develop low molecular weight drugs or antibody drugs that target it. Thus, the development of nucleic acid drugs targeting PRDM14 has been expected.