Rapid improvement in symptoms and physical function following ibrutinib initiation in chronic lymphocytic leukemia and the associated changes in plasma cytokines.

A prospective pilot study was carried out on 34 CLL patients treated with ibrutinib, evaluating the effects on symptoms and physical function with changes in plasma exosomes (EXs), ß2-microglobulin (ß2M) and 26 plasma cytokines. The revised Edmonton Symptom Assessment Scale (ESAS-R) demonstrated moderate fatigue, shortness of breath and a sense of unwellness before treatment, which significantly improved within 2 weeks of starting ibrutinib. These changes were associated with a rapid improvement in sit-to-stand and 4 m walking speeds. The plasma levels of CCL11, IL-7, -8 and -10 dropped initially while the levels of TNF-α/-ß, CCL3, CCL4, CCL17, and IL-16 continued to decline for 12 months. Despite the initial lymphocytosis, plasma ß2M levels fell but no consistent change in plasma EXs occurred. Thus, ibrutinib can produce a rapid and sustained improvement in symptoms and physical function in CLL, associated with a decline in multiple plasma cytokines.

Synergistic apoptotic response between valproic acid and fludarabine in chronic lymphocytic leukaemia (CLL) cells involves the lysosomal protease cathepsin B.

Fludarabine, a nucleoside analogue, is commonly used in combination with other agents for the treatment of chronic lymphocytic leukaemia (CLL). In previous studies, valproic acid (VPA), an inhibitor of histone deacetylases, combined with fludarabine to synergistically increase apoptotic cell death in CLL cells. In the present study, we found that the combination of fludarabine and VPA decreases the level of the anti-apoptotic proteins Mcl-1 and XIAP in primary CLL cells. Treatment with fludarabine alone, or in combination with VPA, led to the loss of lysosome integrity, and chemical inhibition of the lysosomal protease cathepsin B, using CA074-Me, was sufficient to reduce apoptosis. VPA treatment increased cathepsin B levels and activities in primary CLL cells, thereby priming CLL cells for lysosome-mediated cell death. Six previously treated patients with relapsed CLL were treated with VPA, followed by VPA/fludarabine combination. The combined therapy resulted in reduced lymphocyte count in five out of six and reduced lymph node sizes in four out of six patients. In vivo VPA treatment increased histone-3 acetylation and cathepsin B expression levels. Thus, the synergistic apoptotic response with VPA and fludarabine in CLL is mediated by cathepsin B activation leading to a decrease in the anti-apoptotic proteins.