idelalisib + bortezomib

**Idelalisib + bortezomib** is an experimental combination regimen of two targeted small-molecule drugs developed for treatment of B-cell malignancies. Idelalisib is a selective oral inhibitor of phosphatidylinositol 3-kinase delta (PI3Kδ), primarily expressed in hematopoietic cells, disrupting B-cell receptor (BCR) signaling and inducing apoptosis and inhibition of cell motility in malignant B lymphocytes. Bortezomib is a reversible small-molecule inhibitor of the 26S proteasome, blocking protein degradation, disrupting cell cycle progression, and inducing apoptosis—primarily through NF-κB pathway inhibition. This combination has been evaluated in early phase clinical studies for synergistic anti-tumor activity, particularly in relapsed/refractory mantle cell lymphoma (MCL) and potentially other B-cell lymphomas[1][3][4][5].