Phase 1b study of tirabrutinib in combination with idelalisib or entospletinib in previously treated B-cell lymphoma

B-cell receptor (BCR) signaling pathway inhibitors (including Bruton’s tyrosine kinase [BTK] inhibitors, and phosphatidylinositol-3 kinase inhibitors [PI3Ki]) have shown clinical efficacy in non-Hodgkin lymphoma (NHL). However, responses to these agents have been limited in depth and duration. This may be due to resistance to PI3Kδ and BTK inhibitors as monotherapy [1,2,3,4,5]. The emergence of resistant clones may be addressed by combining these 2 classes of drugs. Furthermore, tolerability of these drug classes has been a concern. Combination therapy using lower doses of one or more classes of inhibitors may address some limitations.