KP-457

KP‐457 is a selective ADAM17 inhibitor, which has a reverse-hydroxamate structure. ADAM17, also known as TNF-α-converting enzyme, cleaves various molecules such as GPIbα, GPV, and TNF-α. KP‐457 inhibited cleavages of the TNF‐α sequence with 10 times the potency of GM‐6001 and was >50 times more selective for ADAM17 than for other MMPs and ADAM10 in cell‐free enzyme assays.^[1]

The inhibition of C-terminal cleavage of the GPIbα sequence by ADAM17 was concentration dependent, with an IC50 of 10.6 nmol/l for KP-457. KP-457 at the lower concentration blocks Zn2+ chelation of the catalytic domain of ADAM17. Other studies confirmed that KP-457 exhibited neither genotoxicity nor systemic toxicity at doses up to 3 mg/kg administered to dogs intravenously once a day for 1 month. In vitro study also demonstrated that KP-457 could sustain intact GPIbα at levels seen in platelets freshly isolated from human blood. In addition, KP-457 inhibited GPIbα shedding with a potency 10 times that of GM-6001 in the cellular assay.^[1]

References:
[1]. Hirata S, et al. Selective Inhibition of ADAM17 Efficiently Mediates Glycoprotein Ibα Retention During Ex Vivo Generation of Human Induced Pluripotent Stem Cell-Derived Platelets. Stem Cells Transl Med. 2017 Mar;6(3):720-730.

KP-457 是一种选择性 ADAM17 抑制剂，具有反向异羟肟酸结构。 ADAM17，也称为 TNF-α 转化酶，可裂解各种分子，例如 GPIbα、GPV 和 TNF-α。 KP-457 抑制 TNF-α 序列的裂解，效力是 GM-6001 的 10 倍，并且是 >；在无细胞酶测定中，对 ADAM17 的选择性比对其他 MMP 和 ADAM10 的选择性高 50 倍。^{[1]< /sup>}

ADAM17 对 GPIbα 序列 C 末端裂解的抑制具有浓度依赖性，KP-457 的 IC50 为 10.6 nmol/l。较低浓度的 KP-457 阻断 ADAM17 催化结构域的 Zn2+ 螯合。其他研究证实，KP-457 在剂量高达 3 mg/kg 时每天一次静脉注射给狗，持续 1 个月，既没有表现出遗传毒性，也没有表现出全身毒性。体外研究还表明，KP-457 可以维持完整的 GPIbα，维持在从人体血液中新鲜分离的血小板中所见的水平。此外，在细胞试验中，KP-457 抑制 GPIbα 脱落的效力是 GM-6001 的 10 倍。^[1]