atezolizumab + guadecitabine

Atezolizumab + guadecitabine is a combination of two pharmaceutical agents: **atezolizumab**, a programmed death-ligand 1 (PD-L1) blocking monoclonal antibody (checkpoint inhibitor), and **guadecitabine**, a next-generation hypomethylating agent (DNA methyltransferase inhibitor). This combination regimen has been studied in clinical trials for hematologic malignancies such as acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and in solid tumors like metastatic urothelial carcinoma that progressed after initial immune checkpoint blockade therapy. - **Atezolizumab** blocks the interaction of PD-L1 with its receptors (PD-1 and CD80) on T cells and antigen-presenting cells, reversing tumor immune evasion and facilitating T cell-mediated antitumor immunity[2][5]. - **Guadecitabine** inhibits DNA methyltransferases, leading to DNA hypomethylation, reactivation of tumor suppressor genes, and potential alteration of tumor immune microenvironment sensitivity[8][7][4]. The rationale for the combination is that epigenetic modulation by guadecitabine may improve responses to immune checkpoint inhibitors by increasing tumor antigenicity and reversing resistance.