AZD5153 is a potent and selective small molecule inhibitor that targets the bromodomain and extra-terminal (BET) family of proteins, particularly BRD4. It functions by disrupting the interaction between BET proteins and acetylated histones, thereby modulating the expression of key oncogenes such as MYC and BCL-2. This mechanism makes it a promising candidate in cancer therapy, especially in hematological malignancies like acute myeloid leukemia (AML), lymphoma, and multiple myeloma. It has shown strong anti-tumor activity in preclinical models, both as a monotherapy and in combination with other agents such as BCL-2 inhibitors (e.g., venetoclax) or chemotherapy. Its dual inhibition of multiple BET bromodomains enhances transcriptional suppression of pro-survival genes, leading to cancer cell apoptosis. AZD5153 is being investigated in early-phase clinical trials to evaluate its safety, pharmacokinetics, and efficacy in patients with advanced solid tumors and lymphomas. Due to its ability to modulate immune-related gene expression, there is also interest in combining it with immunotherapies to enhance anti-tumor immune responses.