fimepinostat + rituximab

**Fimepinostat + rituximab** is an investigational combination regimen evaluated in clinical trials for relapsed or refractory diffuse large B-cell lymphoma (DLBCL) and other lymphomas. \n- **Fimepinostat** is a synthetic, orally available small molecule that acts as a dual inhibitor of *histone deacetylase (HDAC, class I and II)* and *phosphatidylinositol 3-kinase (PI3K, α, β, and δ)* enzymes. It downregulates MYC protein and MYC-associated genes via HDAC and PI3K inhibition, showing activity in MYC-altered DLBCL[1][3][4][5]. \n- **Rituximab** is a chimeric monoclonal antibody targeting *CD20* on B lymphocytes, mediating B-cell lysis via mechanisms such as antibody-dependent cellular cytotoxicity, complement activation, and direct induction of apoptosis[5]. \nTogether, these agents are combined to exploit potential synergy in B-cell lymphomas, especially in relapsed/refractory settings or MYC-altered cases, with fimepinostat targeting tumor epigenetics and survival pathways, and rituximab targeting malignant B-cells directly[1][5]. \nPreclinical, Phase 1, and Phase 2 clinical data suggest activity for the combination, but the regimen is still under clinical investigation and is not yet approved for routine clinical use[1][3][5].