Thalidomide-NH-PEG1-NH2 hydrochloride is primarily used in the development of targeted therapies, particularly in the field of cancer treatment. Its structure allows it to act as a linker in antibody-drug conjugates (ADCs), enabling the precise delivery of cytotoxic agents to cancer cells while minimizing damage to healthy tissues. This compound is also explored in proteolysis-targeting chimeras (PROTACs), where it facilitates the degradation of specific proteins involved in disease progression. Additionally, its PEG moiety enhances solubility and stability, making it a valuable component in drug formulation and delivery systems. Research continues to explore its potential in treating inflammatory and autoimmune diseases due to its immunomodulatory properties.