SLx-2119

Absorption

Following oral administration, the mean bioavailability of belumosudil is 64% and the median Tmax at steady-state is 1.26 to 2.53 hours. As compared to administration in a fasted state, belumosudil Cmax and AUC increased by 2.2 and 2 times, respectively, when administered with a high-fat, high-calorie meal.

Toxicity

There are no data regarding overdosage with belumosudil.

Description

KD 025 is an inhibitor of Rho-associated kinase 2 (ROCK2; IC₅₀ = 0.105 μM). It is selective for ROCK2 over ROCK1 (IC₅₀ = 24 μM). KD 025 (10 μM) decreases the expression of connective tissue growth factor (CTGF) and induces remodeling of the actin cytoskeleton in isolated human ileal fibrotic smooth muscle cells. It inhibits heat-killed C. albicans- or S. epidermidis-induced production of IL-17 in isolated human peripheral blood mononuclear cells (PBMCs) when used at concentrations ranging from 1.25 to 10 μM. KD 025 (100 and 200 mg/kg) reduces infarct volume in a mouse model of cerebral ischemia induced by transient middle cerebral artery occlusion (MCAO). It decreases disease severity in a mouse model of sclerodermatous chronic graft versus host disease (GVHD) when administered at a dose of 150 mg/kg. Formulations containing KD 025 have been used in the treatment of chronic GVHD.

The Uses of SLx-2119

KD 025 is an inhibitor of Rho-associated protein kinase II (ROCK-II), a serine/threonine kinase that regulates the formation of actin stress fibers and focal adhesions, smooth muscle contraction, and gene expression (1, 2). KD025 has been shown to reduce infarct volume after transient middle cerebral artery occlusion (2).

Background

Belumosudil is used in the treatment of chronic graft-versus-host disease (GVHD) and has been investigated for the treatment of pulmonary arterial hypertension. It is an inhibitor of rho-associated coiled-coil-containing protein kinases (ROCK), with significantly more selectivity for ROCK2 as compared to ROCK1 (IC50 100 nM vs. 3 μM, respectively). In the treatment of GVHD, a condition in which donor T-cells begin to attack recipient tissues following allogeneic hematopoeitic stem cell transplantation (HSCT), belumosudil helps to resolve immune dysregulation by shifting the balance between Th17 cells and T-regulatory cells, thereby dampening the inflammatory cascade that can occasionally be fatal.
Belumosudil was first approved by the FDA in July 2021, under the brand name Rezurock, for the treatment of chronic GVHD in patients who have tried and failed at least two prior lines of systemic therapy. In July 2022, Belumosudil was approved by Health Canada under the brand name RHOLISTIQ to treat the same condition in adult and pediatric patients 12 years or older.

Indications

Belumosudil is indicated for the treatment of chronic graft-versus-host disease (GVHD) in adult and pediatric patients 12 years of age and older following failure of at least two other lines of systemic therapy.

brand name

Rezurock

General Description

Class: serine-threonine kinase; Treatment: chronic GVHD; Other name: SLx-2119, KD025; Oral bioavailability = 64%; Elimination half-life = 19 h; Protein binding = 99.9%

Pharmacokinetics

Belumosudil appears to inhibit several pro-fibrotic and pro-inflammatory processes in order to prevent and treat the damage incurred by graft-versus-host disease. Given its mechanism of action and findings in animal trials, belumosudil is considered to carry embryo-fetal toxicity and may cause significant harm to a developing fetus should a pregnant mother be exposed. Female patients of reproductive potential, or male patients with female partners of reproductive potential, should be advised to use effective contraception during treatment with belumosudil and for one week after the last dose.

Metabolism

The in vitro metabolism of belumosudil occurs primarily via CYP3A4 and to a lesser extent by CYP2C8, CYP2D6, and UGT1A9. The specific metabolites generated by belumosudil metabolism remain unclear.

References

Boerma et al. (2008) Comparative gene expression profiling in three primary human cell lines after treatment with a novel inhibitor of Rho kinase or atorvastatin; Blood Coagul. Fibrinolysis.?19 709 Zanin-Zhorov et al. (2014) Selective oral ROCK2 inhibitor down-regulates IL-21 and IL-17 secretion in human T cells via STAT3-dependent mechanism; Natl. Acad. Sci. USA?111 16814 Flynn et al. (2016) Targeted Rho-associated kinase 2 inhibition suppresses murine and human chronic GVHD through a Stat3-dependent mechanism; 127 2144 Jagasia et al. (2021) ROCK2 Inhibition with Belumosudil (KD025) for the Treatment of Chronic Graft-Versus-Host Disease; Clin. Invest.?39 1888 Diep et al. (2018) Anti-adipogenic effects of KD025 (SLx-2119), a ROCK2-specific inhibitor, in 3T3-L1 cells; Rep.?8 2477 Diep et al. (2019) KD025 (SLx-2119) suppresses adipogenesis at intermediate stage in human adipose-derived stem cells; Adipocyte?9 114 Wei et al. (2020) ROCK2 inhibition enhances the thermogenic program in white and brown fat tissue in mice; FASEB J.?34 474 Tran and Chun (2021) ROCK2-Specific Inhibitor KD025 Suppresses Adipocyte Differentiation by Inhibiting Casein Kinase 2; Molecules?26 4747