Enzon Pharmaceuticals, Inc., a biotechnology company, engages in the research and development of therapeutics for cancer patients with unmet medical needs primarily in the United States. The company’s drug development programs utilize PEGylation Linker technology and third-generation messenger ribonucleic acid (mRNA) antagonists utilizing the Locked Nucleic Acid (LNA) technology. Its development pipeline comprises various novel compounds, including PEG-SN38, which is in Phase II clinical trials for the treatment of metastatic colorectal and breast cancer; and Phase I trial for pediatric patients with cancer. Its development pipeline also includes mRNA antagonists, such as hypoxia-inducible factor-1 alpha that is in Phase I study in patients with solid tumors and lymphoma to evaluate various dosing schedules; Survivin, which is in Phase I study in patients with solid tumors and lymphoma; and androgen receptor, a novel antagonist that is in Phase I study in patients with castration-resistant prostate cancer. In addition, the company has LNA targets in various stages of preclinical research. It has collaboration agreement with National Cancer Institute for conducting a pilot study in patients with tumors in the liver; and has a license and collaboration agreement with Santaris Pharma A/S for mRNA antagonists. Enzon Pharmaceuticals, Inc. has a strategic alliance with Zhejiang Hisun Pharmaceuticals Co. Ltd for the research and development of therapeutics using the company’s customized PEGylation linker technology. The company was founded in 1981 and is headquartered in Piscataway, New Jersey.