MEK (IC50 = 12 nM); Autophagy

ARRY-438162 (625 nM) has an IC50 of 39 nM and prevents osteoclast differentiation in vitro. With an IC50 of 625 nM, ARRY-438162 (10 μM) inhibits in vitro osteoclast resorption. Weakly impairs osteoblast differentiation is ARRY-438162 (2 μM).[2]
ARRY-438162, a recently discovered potent and selective ATP non-competitive MEK1/2 inhibitor, inhibits pERK in cells with an IC50 of 11 nM.[3]
MK-2206 (2 μM) and MEK162 (1 μM) together completely override the resistance of RSK-expressing MCF7 cells.[4]

ARRY-438162 (10 mg/kg, po, bid) reduces disease severity in rat collagen-induced arthritis (CIA) and rat adjuvant-induced arthritis (AIA) models in a dose-dependent manner. In the rat collagen-induced arthritis (CIA) model, ARRY-438162 (po, bid) inhibits increases in ankle diameter by 27% and 50% at 1 mg/kg and 3 mg/kg, whereas ibuprofen has a 46% inhibition. In the rat collagen-induced arthritis (CIA) model, ARRY-438162 (10 mg/kg, po, bid) significantly inhibits lesions (inflammation, cartilage damage, pannus formation, and bone resorption) by 32% and 60% at 1 mg/kg and 3 mg/kg, respectively. In rat adjuvant-induced arthritis (AIA) models, ARRY-438162 inhibits AIA ankle diameter by 11% and 34% at 3 mg/kg and 10 mg/kg, respectively.[1]
ARRY-438162 is significant at 10 mg/kg and 30 mg/kg when compared to vehicle control, demonstrating dose-related inhibition of ankle swelling in rat adjuvant-induced arthritis (AIA) models. In rat adjuvant-induced arthritis (AIA) models, ARRY-438162 exhibits dose-related inhibition of serum IL-6 concentration, with complete inhibition at 10 mg/kg when compared to vehicle control. Rat adjuvant-induced arthritis (AIA) models show dose-related inhibition of relative spleen weights by ARRY-438162 (30 mg/kg). In rat adjuvant-induced arthritis (AIA) models, ARRY-438162 (30 mg/kg) significantly inhibits bone resorption and inflammation with delayed dosing when compared to vehicle.[2]
In immunodeficient mice injected with MCF7 cells, MEK162 (6 mg/kg, BID) and BEZ235 significantly slow tumor growth. [4]

The in vitro osteoclast differentiation inhibitor ARRY-438162 (625 nM) has an IC50 value of 39 nM. The in vitro osteoclast resorption is inhibited by ARRY-438162 (10 μM) with an IC50 of 625 nM. Osteoblast differentiation is only marginally impacted by ARRY-438162 (2 μM). A recently discovered MEK1/2 ATP non-competitive inhibitor, ARRY-438162, inhibits pERK in cells with an IC50 of 11 nM. MCF7 cells that express RSK are completely resistant until MEK162 (1 μM) and MK-2206 (2 μM) are added.

In 12-well plates (2×104), MCF7 cells with the indicated infection level are seeded. Cells are exposed to BEZ235 (100 or 200 nM), BKM120 (0.75 or 1 μM), GDC-0941 (1 μM), or MK2206 (2 μM) alone or in combination with Binimetinib (MEK162) (1 μM), BI-D1870 (10 μM), or AZD6244 (1 μM), as indicated in the text, after 24 hours. Cells are stained with 0.1% crystal violet after being fixed with 4% glutaraldehyde or methanol, in order to determine how many cells are present. The dye is then extracted with 10% acetic acid, and its absorbance (570 nm) is measured. Growth curve analyses are carried out in triplicate. For CellTiter-Glo viability assays, 2,000 cells are plated in 96-well plates, the drug is added at 24 hours, and the assay is conducted 4 to 5 days later. Through the use of flow cytometry, cell-cycle and hypodiploid apoptotic cell numbers can be measured. In a nutshell, cells are PBS-washed, fixed in cold 70% ethanol, and stained with propidium iodide while being subjected to RNase. A FACScalibur cytometer equipped with Cell Quest software is used to quantitatively analyze sub-G1 cells.

Mice: six-week-old athymic nude female The mice are Foxn1nu mice. Mice are given an oral gavage dose of the following drugs once daily: placebo, BEZ235, BKM120, MK-2206, or binimetinib (MEK162). BKM120 (30 mg/kg, 6IW) and BEZ235 (25-30 mg/kg, 6IW [6 days on, 1 day off]) are freshly formulated in 10% NMP-90% PEG and administered within 30 minutes. Binimetinib (MEK162) (6 mg/kg, BID) is formulated in 0.5% Tween-80 and 1% carboxymethyl cellulose with MK-2206 (100 mg/kg, 3IW) in 30% Captisol. Depending on the xenograft model and treatment regimen, mice are given treatment for 7–24 days in tumor growth studies. Three times per week, tumor xenografts are measured with calipers, and the tumor volume is calculated using the formula: (length×width2)×(π/6). The animals are anesthetized with a 1.5% isofluorane-air mixture before being killed by cervical dislocation at the conclusion of the experiment. Approximately two hours after the last administration, tumors are removed. Rats: The effectiveness in the subacute inflammation setting is evaluated using the rat collagen-induced arthritis (CIA) and rat adjuvant-induced arthritis (AIA) models. In the CIA studies, rats with established disease that was induced by Type II collagen injections were given 0.3, 1 or 3 mg/kg of ARRY-438162 (PO, BID) with or without 30 mg/kg of ibuprofen (PO, QD) for six days. Days 0–7 are used to track disease progression using body weight and ankle diameter. An injection of a lipoidal amine in FCA on day 0 induces the AIA model. The AIA rats are administered 1, 3, or 10 mg/kg of binimetinib (ARRY-438162) (PO, QD) starting on day 8 and continuing for 6 days, with or without the addition of 0.05 mg/kg of CL14377 (PO, QD), which is dosed days 0–13. On days 7 through 14, measurements of the paw diameter and body weight are used to track the disease's progression.

Absorption, Distribution and Excretion
The pharmacokinetics of binimetinib was studied in healthy subjects and patients with solid tumors. After twice-daily dosing, the accumulation is 1.5-fold and the coefficient of variation (CV%) of the area under the concentration-time curve (AUC) is <40% at steady state. The systemic exposure of binimetinib is approximately dose proportional. After oral administration, at least 50% of the binimetinib dose was absorbed with a median time to maximum concentration (Tmax) of 1.6 hours. The administration of a single dose of binimetinib 45 mg with a high-fat, high-calorie meal (consisting of approximately 150 calories from protein, 350 calories from carbohydrate, and 500 calories from fat) in healthy subjects had no effect on binimetinib exposure.
Following a single oral dose of 45 mg radiolabeled binimetinib in healthy subjects, 62% (32% unchanged) of the administered dose was recovered in the feces while 31% (6.5% unchanged) was recovered in the urine.
The geometric mean (CV%) of the apparent volume of distribution of binimetinib is 92 L (45%).
The apparent clearance (CL/F) of binimetinib is is 20.2 L/h (24%).

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Metabolism / Metabolites
The primary metabolic pathway is glucuronidation with UGT1A1 contributing up to 61% of the binimetinib metabolism. Other pathways of binimetinib metabolism include N-dealkylation, amide hydrolysis, and loss of ethane-diol from the side chain. The active metabolite M3 produced by CYP1A2 and CYP2C19 represents 8.6% of the binimetinib exposure. Following a single oral dose of 45 mg radiolabeled binimetinib, approximately 60% of the circulating radioactivity AUC in plasma was attributable to binimetinib.

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Biological Half-Life
The mean (CV%) terminal half-life (t1/2) of binimetinib is 3.5 hours (28.5%).

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the clinical use of binimetinib during breastfeeding. Because binimetinib is 97% bound to plasma proteins, and the half-life of the drug is 3.5 hours, the amount in milk is likely to be low. However, the manufacturer recommends that breastfeeding be discontinued during binimetinib therapy and for at least 3 days after the final dose. For patients taking the combination with encorafenib, the manufacturer recommends that breastfeeding be discontinued during binimetinib therapy and for at least 2 weeks after the final dose.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
Binimetinib is 97% bound to human plasma proteins and the blood-to-plasma ratio is 0.72.

[1]. 2006, ACR Annual Scientific Meeting. Abst 794.

[2]. 2009, Arraybiopharma. Abstract FRI0063.

[3]. Cancer Biol Ther . 2011 Dec 1;12(11):966-77.

[4]. Chapter 17 MAP Kinase Inhibitors in Inflammation and Autoimmune Disorders.

[5]. J Clin Invest . 2013 Jun;123(6):2551-63.

[6]. Cancer Cell . 2020 Jun 8;37(6):834-849.e13.

Binimetinib is a member of the class of benzimidazoles that is 1-methyl-1H-benzimidazole which is substituted at positions 4, 5, and 6 by fluorine, (4-bromo-2-fluorophenyl)nitrilo, and N-(2-hydroxyethoxy)aminocarbonyl groups, respectively. It is a MEK1 and MEK2 inhibitor (IC50= 12 nM). Approved by the FDA for the treatment of patients with unresectable or metastatic melanoma with a BRAF V600E or V600K mutation in combination with encorafenib. It has a role as an EC 2.7.11.24 (mitogen-activated protein kinase) inhibitor, an antineoplastic agent and an apoptosis inducer. It is a member of benzimidazoles, a member of bromobenzenes, a member of monofluorobenzenes, a hydroxamic acid ester and a secondary amino compound.
Binimetinib, also known as Mektovi, is a potent and selective oral mitogen-activated protein kinase 1/2 (MEK 1/2) inhibitor which is combined with [Encorafenib]. On June 27, 2018, the Food and Drug Administration approved the combination of [Encorafenib] and binimetinib (BRAFTOVI and MEKTOVI, from Array BioPharma Inc.) in combination for patients with unresectable or metastatic melanoma with the BRAF V600E or V600K mutations, as detected by an FDA-approved test.
Binimetinib is an orally available inhibitor of mitogen-activated protein kinase kinase 1 and 2 (MEK1/2) with potential antineoplastic activity. Binimetinib, noncompetitive with ATP, binds to and inhibits the activity of MEK1/2. Inhibition of MEK1/2 prevents the activation of MEK1/2 dependent effector proteins and transcription factors, which may result in the inhibition of growth factor-mediated cell signaling. This may eventually lead to an inhibition of tumor cell proliferation and an inhibition in production of various inflammatory cytokines including interleukin-1, -6 and tumor necrosis factor. MEK1/2 are dual-specificity threonine/tyrosine kinases that play key roles in the activation of the RAS/RAF/MEK/ERK pathway and are often upregulated in a variety of tumor cell types.

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Drug Indication
Binimetinib, in conjunction with encorafenib, is indicated for the treatment of unresectable or metastatic melanoma with BRAF V600E or V600K mutation and metastatic non-small cell lung cancer (NSCLC) with a BRAF V600E mutation.
Binimetinib in combination with encorafenib is indicated for the treatment of adult patients with unresectable or metastatic melanoma with a BRAF V600 mutation.
Treatment of melanoma
Treatment of colorectal carcinoma

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Mechanism of Action
Binimetinib, noncompetitive with ATP, binds reversibly to and inhibits the activity of mitogen-activated extracellular signal-regulated kinase (MEK) 1 and 2. The inhibition of MEK1/2 prevents the activation of MEK1/2-dependent effector proteins and transcription factors, resulting in the inhibition of growth factor-mediated cell signaling such as the downstream extracellular signal-related kinase (ERK) pathway. This may lead to the inhibition of tumor cell proliferation and an inhibition in the production of various inflammatory cytokines including interleukin-1, -6, and tumor necrosis factor. MEK1/2 are themselves threonine and tyrosine kinases that possess a dual specificity. They subsequently contribute critically to the activation of the RAS/RAF/MEK/ERK pathway and are typically upregulated in a number of different tumor cell types.

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Pharmacodynamics
In vitro, binimetinib inhibited extracellular signal-related kinase (ERK) phosphorylation in cell-free assays as well as viability and MEK-dependent phosphorylation of BRAF-mutant human melanoma cell lines. Binimetinib also inhibited in vivo ERK phosphorylation and tumor growth in BRAF-mutant murine xenograft models. MEK is an enzyme that regulates the biosynthesis of inflammatory cytokines such as TNF, IL-6 and IL-1; therefore, binimetinib anti-tumor activity can be mediated through the interference of cytokines biosynthesis. Binimetinib and [encorafenib] target two different kinases in the RAS/RAF/MEK/ERK pathway. Compared to either drug alone, coadministration of [encorafenib] and binimetinib resulted in greater anti-proliferative activity in vitro in BRAF mutation-positive cell lines and greater anti-tumor activity with respect to tumor growth inhibition in BRAF V600E mutant human melanoma xenograft studies in mice. Additionally, the combination of binimetinib and [encorafenib] delayed the emergence of resistance in BRAF V600E mutant human melanoma xenografts in mice compared to either drug alone. In a BRAF V600E mutant NSCLC patient-derived xenograft model in mice, coadministration of [encorafenib] and binimetinib resulted in greater anti-tumor activity compared to binimetinib alone, with respect to tumor growth inhibition. Increased tumor growth delay after dosing cessation was also observed with the coadministration compared to either drug alone. Following MEKTOVI 45 mg twice daily, no clinically meaningful QT prolongation was observed.

C17H15BRF2N4O3

441.23

440.029

C, 46.28; H, 3.43; Br, 18.11; F, 8.61; N, 12.70; O, 10.88

606143-89-9

10288191

White to off-white solid powder

1.67

1.652

5.42

3

7

6

27

521

0

BrC1C([H])=C([H])C(=C(C=1[H])F)N([H])C1=C(C2=C(C([H])=C1C(N([H])OC([H])([H])C([H])([H])O[H])=O)N(C([H])([H])[H])C([H])=N2)F

ACWZRVQXLIRSDF-UHFFFAOYSA-N

InChI=1S/C17H15BrF2N4O3/c1-24-8-21-16-13(24)7-10(17(26)23-27-5-4-25)15(14(16)20)22-12-3-2-9(18)6-11(12)19/h2-3,6-8,22,25H,4-5H2,1H3,(H,23,26)

6-(4-bromo-2-fluoroanilino)-7-fluoro-N-(2-hydroxyethoxy)-3-methylbenzimidazole-5-carboxamide

MEK162; ARRY 162; ARRY-162; MEK162; Mektovi; ARRY-162; ARRY-438162; 5-[(4-Bromo-2-fluorophenyl)amino]-4-fluoro-N-(2-hydroxyethoxy)-1-methyl-1H-benzimidazole-6-carboxamide; ARRY-438162; ARRY438162; MEK-162; MEK 162; ARRY162; ARRY-162; ARRY-438162; Binimetinib; Brand name: Mektovi.

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.67 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (5.67 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (5.67 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: ≥ 2.5 mg/mL (5.67 mM) (saturation unknown) in 5% DMSO + 40% PEG300 + 5% Tween80 + 50% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 5: ≥ 2.5 mg/mL (5.67 mM) (saturation unknown) in 5% DMSO + 95% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 6: 1% CMC+0.5% Tween-80: 30mg/mL

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Solubility in Formulation 7: 10 mg/mL (22.66 mM) in 1% CMC 0.5% Tween-80 (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)