Changes in biomarker levels during therapy with pirtobrutinib. Biomarker levels were obtained from the electronic medical records of the patients at baseline (C1D1) and 1 week (C1D8), 4 weeks/1 cycle (C2D1), and 3 cycles (C4D1) after the initiation of pirtobrutinib. P values were determined using the Kruskal-Wallis test. (A) LDH levels in BTK-WT patients (n = 7) during therapy. (B) LDH levels in patients with mutated BTK (n = 11) during therapy. (C) B2M levels in patients with WT BTK during therapy. (D) B2M levels in patients with mutated BTK during therapy.