Duan Rundan, Goldmann Luise, Brandl Richard, Spannagl Michael, Weber Christian, Siess Wolfgang, von Hundelshausen Philipp
Institute for Cardiovascular Prevention, Ludwig-Maximilians-University, Munich, Germany.
Institute for Vascular Surgery and Phlebology am Marienplatz, Munich, Germany.
Front Cardiovasc Med. 2021 Sep 24;8:749022. doi: 10.3389/fcvm.2021.749022. eCollection 2021.
Bruton tyrosine kinase inhibitors (BTKi) are used in B-cell malignancies and in development against various autoimmune diseases. Since Btk is also involved in specific pathways of platelet activation, BTKi might be considered to target platelet GPVI/GPIb-mediated atherothrombosis and platelet FcγRIIA-dependent immune disorders. However, BTKi treatment of patients with B-cell malignancies is frequently associated with mild bleeding events caused possibly by off-target inhibition of Tec. Here, we compared the platelet effects of two novel BTKi that exhibit a high (remibrutinib) or low (rilzabrutinib) selectivity for Btk over Tec. Remibrutinib and rilzabrutinib were pre-incubated with anticoagulated blood. Platelet aggregation and bleeding time (closure time) were studied by multiple electrode aggregometry (MEA) and platelet-function analyzer-200 (PFA-200), respectively. Both BTKi inhibited atherosclerotic plaque-stimulated GPVI-mediated platelet aggregation, remibrutinib being more potent (IC = 0.03 μM) than rilzabrutinib (IC = 0.16 μM). Concentrations of remibrutinib (0.1 μM) and rilzabrutinib (0.5 μM), >80% inhibitory for plaque-induced aggregation, also significantly suppressed (>90%) the Btk-dependent pathways of platelet aggregation upon GPVI, von Willebrand factor/GPIb and FcγRIIA activation stimulated by low collagen concentrations, ristocetin and antibody cross-linking, respectively. Both BTKi did not inhibit aggregation stimulated by ADP, TRAP-6 or arachidonic acid. Remibrutinib (0.1 μM) only slightly prolonged closure time and significantly less than rilzabrutinib (0.5 μM). Remibrutinib and rilzabrutinib inhibit Btk-dependent pathways of platelet aggregation upon GPVI, VWF/GPIb, and FcγRIIA activation. Remibrutinib being more potent and showing a better profile of inhibition of Btk-dependent platelet activation vs. hemostatic impairment than rilzabrutinib may be considered for further development as an antiplatelet drug.
布鲁顿酪氨酸激酶抑制剂（BTKi）用于治疗B细胞恶性肿瘤，并正处于针对各种自身免疫性疾病的研发阶段。由于Btk也参与血小板活化的特定途径，因此BTKi可能被视为靶向血小板糖蛋白VI（GPVI）/糖蛋白Ib（GPIb）介导的动脉粥样硬化血栓形成以及血小板FcγRIIA依赖性免疫紊乱。然而，BTKi治疗B细胞恶性肿瘤患者时，常伴有轻度出血事件，这可能是由对Tec的脱靶抑制所致。在此，我们比较了两种新型BTKi对血小板的影响，这两种药物对Btk的选择性高于Tec，其中一种选择性高（瑞布替尼），另一种选择性低（利扎布替尼）。瑞布替尼和利扎布替尼与抗凝血液预先孵育。分别通过多电极聚集测定法（MEA）和血小板功能分析仪-200（PFA-200）研究血小板聚集和出血时间（闭合时间）。两种BTKi均抑制动脉粥样硬化斑块刺激的GPVI介导的血小板聚集，瑞布替尼（IC = 0.03 μM）比利扎布替尼（IC = 0.16 μM）更有效。瑞布替尼（0.1 μM）和利扎布替尼（0.5 μM）的浓度对斑块诱导的聚集具有>80%的抑制作用，同时也分别显著抑制（>90%）了低浓度胶原蛋白、瑞斯托菌素和抗体交联刺激下GPVI、血管性血友病因子/GPIb和FcγRIIA激活时血小板聚集的Btk依赖性途径。两种BTKi均不抑制由二磷酸腺苷（ADP）、凝血酶受体激活肽-6（TRAP-6）或花生四烯酸刺激引起的聚集。瑞布替尼（0.1 μM）仅轻微延长闭合时间，且显著短于利扎布替尼（0.5 μM）。瑞布替尼和利扎布替尼抑制GPVI、血管性血友病因子（VWF）/GPIb和FcγRIIA激活时血小板聚集的Btk依赖性途径。与利扎布替尼相比，瑞布替尼更有效，并且在抑制Btk依赖性血小板活化与止血损伤方面表现出更好的特性，可考虑作为抗血小板药物进一步研发。
