Project Summary Lung metastasis is the 2nd most common metastasis and accounts for 30% of all metastatic diseases in human cancer patients. Patients with lung metastases have a very short survival time. For example, the 5- year survival rate for colorectal cancer patients with lung metastases, if left untreated, is only 5%. Surgical lung metastases resection (pulmonary metastasectomy) is a “curative” treatment for cancer patients with lung metastases. For example, pulmonary metastasectomy increases the 5-year survival rate of colorectal cancer patients with lung metastases from 50.3-66%. However, pulmonary metastasectomy is currently performed only in a very small population of cancer patients with lung metastases due to the risk-related highly selective criteria. For example, only 5% of colorectal cancer patients with lung metastases are treated with pulmonary metastasectomy. A neoadjuvant therapy that can effectively reduce lung metastases number and/or size is therefore expected to significantly increase the eligible patient population for this life-saving pulmonary metastasectomy. ChemMedImmune Inc. is developing IFNA2-LNP001, a lipid nanoparticle-encapsulated IFN2-encoding mini-plasmid DNA for treatment of patients with lung metastases. IFNA2-LNP01 will be administered in the clinically neoadjuvant setting, where it activates the type I interferon (IFN-I) signaling pathways in lung metastases to increase the expression of T cell chemokines CXCL9 and CXCL10, resulting in enhanced T cell recruitment to the tumor site to reduce the size and number of lung metastases. A key differentiating feature of IFNA2-LNP01 is its administration in the neoadjuvant setting, which is necessary to give patients the best chance to fight their metastatic tumor ahead of other lines of therapies that can negatively affect T cells. IFNA2-LNP01 is designed based on our recent published data showing that loss of IFN-I expression and function is a major mechanism underlying lung metastases immune evasion and growth. Two aims will be pursued in this project: 1) determine the efficacy of IFNA2-LNP01 in suppression of tumor lung metastases in vivo; and 2) determine IFNA2-LNP01 biodistribution and toxicology in vivo. This project is expected to generate sufficient efficacy and toxicology data for a Phase II IND-enabling study of IFNA2- LNP01.