Targeting the tumor microenvironment for treating double refractory chronic lymphocytic leukemia.

The introduction of BTK inhibitors and BCL2 antagonists to the treatment of chronic lymphocytic leukemia has revolutionized therapy and improved patient outcomes. These agents have replaced chemoimmunotherapy as standard of care. Despite this progress, a new group of patients is currently emerging, which has become refractory or intolerant to both classes of agents, creating an unmet medical need. Here, we propose that the targeted modulation of the tumor microenvironment provides new therapeutic options for this group of "double refractory" patients. Furthermore, we outline a sequential strategy for tumor microenvironment-directed combination therapies in CLL that can be tested in clinical protocols.