In December 2023, the Food and Drug Administration approved Pirtobrutinib for the treatment of relapsed or refractory CLL patients who have received at least two lines of systemic therapy, including a BTK inhibitor and a Bcl-2 inhibitor, based on results from the phase 1/2 BRUIN trial [41,42]. This evidence concerns the gene BTK and B-cell chronic lymphocytic leukemia.