p38α (IC50 < 1 μM)
Acumapimod (BCT-197) targets p38α MAPK (IC50 = 0.13 μM) and p38β MAPK (IC50 = 0.17 μM); [1]
Acumapimod (BCT-197) targets p38 MAPK [2]

Acumapimod/BCT197 is a p38α inhibitor with a lower than 1 μM IC50 value. BCT197 is an oral low‐molecular‐weight p38 inhibitor currently in development for the treatment of several inflammatory conditions, including COPD.[2]

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In a cell-free kinase assay, Acumapimod (BCT-197) selectively inhibited p38α and p38β isoforms with IC50 values of 0.13 μM and 0.17 μM, respectively, while showing minimal activity against p38γ (IC50 > 10 μM) and p38δ (IC50 > 10 μM) [1]
- Treatment of LPS-stimulated human peripheral blood mononuclear cells (PBMCs) with Acumapimod (BCT-197) (concentrations ranging from 0.1 μM to 10 μM) dose-dependently reduced the secretion of pro-inflammatory cytokines, including TNF-α (IC50 = 0.3 μM), IL-6 (IC50 = 0.5 μM), and IL-1β (IC50 = 0.4 μM) [1]
- Incubation of human bronchial epithelial cells (HBECs) with Acumapimod (BCT-197) (1 μM) inhibited TNF-α-induced phosphorylation of p38 MAPK and downstream substrates (e.g., ATF-2), as demonstrated by Western blot analysis; this was associated with reduced expression of matrix metalloproteinase-9 (MMP-9) mRNA (measured by qPCR) and protein (measured by ELISA) [1]

Acumapimod (BCT-197) is an oral low-molecular-weight p38 inhibitor being developed for oral use to treat inflammatory conditions, such as chronic obstructive pulmonary disease (COPD) and other inflammatory diseases. Acumapimod (75 mg on days 1 and 6) is administered intermittently for a brief period of time and shows a significant improvement in lung function in COPD patients[2].

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When examining Acumapimod (BCT-197) in vivo, and comparing to vehicle-treated animals, reduced weight loss, improvement in survival and lack of impaired viral control was observed at Acumapimod (BCT-197) concentrations relevant to those being used in clinical trials of acute exacerbations of chronic obstructive pulmonary disease; at higher concentrations of BCT197 these effects were reduced. Conclusions: Compared to vehicle treatment, Acumapimod (BCT-197) (administered at a clinically relevant concentration) improved outcomes in a mouse model of influenza. This is encouraging given that the use of innate inflammatory pathway inhibitors may raise concerns of negative effects on infection regulation.https://pubmed.ncbi.nlm.nih.gov/29458547/

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In a mouse model of LPS-induced acute lung injury, intraperitoneal administration of Acumapimod (BCT-197) (10 mg/kg, 30 minutes before LPS challenge) significantly reduced lung tissue inflammation, as evidenced by decreased infiltration of neutrophils (by ~60%) and macrophages (by ~50%) in bronchoalveolar lavage fluid (BALF), and reduced BALF levels of TNF-α (by ~70%), IL-6 (by ~65%), and MMP-9 (by ~55%) compared to vehicle-treated controls [1]
- In a rat model of cigarette smoke-induced chronic obstructive pulmonary disease (COPD), oral administration of Acumapimod (BCT-197) (3 mg/kg/day or 10 mg/kg/day for 4 weeks) dose-dependently attenuated airway remodeling: high-dose treatment reduced peribronchial fibrosis (by ~40%), smooth muscle hypertrophy (by ~35%), and mucus hypersecretion (by ~50%), as assessed by histopathological analysis; additionally, lung function parameters (e.g., forced expiratory volume in 0.1 seconds, FEV0.1) were significantly improved in the high-dose group [1]

BCT197 inhibited TNFα secretion with an IC50 of 44 µg/L. Predose TNFα levels correlated with IC50 and were modeled as a covariate (ΔOBJ 17). Maximum inhibition from baseline was not complete but plateaued in the typical individual at about 66% (Imax).
In placebo‐treated subjects, nonstationarity in measurements of ex vivo LPS‐induced TNFα secretion was seen (Figure 2 c, inset). A circadian periodicity of shed TNFα receptors which attenuated response to LPS cannot be ruled out. Accordingly, drug effect was described as an inhibitory function on an oscillatory input system characterized by a physical frequency of 2π/24 hours (Eq. 1), and all available TNFα data of both BCT197 treated subjects and matching placebos were modeled simultaneously.[2]

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p38 MAPK isoform-specific kinase assay: Recombinant human p38α, p38β, p38γ, or p38δ kinase was mixed with a specific peptide substrate and ATP in reaction buffer. Serial dilutions of Acumapimod (BCT-197) were added to the reaction mixture, which was then incubated at 30°C for 60 minutes. The phosphorylation of the peptide substrate was measured using a luminescent detection system, and IC50 values were calculated by nonlinear regression analysis of dose-response curves [1]

PBMC cytokine secretion assay: Human PBMCs were isolated from healthy donors and plated in 96-well plates at a density of 2×105 cells/well. Cells were preincubated with serial dilutions of Acumapimod (BCT-197) for 1 hour, then stimulated with LPS (1 μg/mL) for 24 hours. Culture supernatants were collected, and concentrations of TNF-α, IL-6, and IL-1β were quantified using sandwich ELISA kits. Dose-response curves were generated to determine IC50 values for cytokine inhibition [1]
- HBEC signaling and MMP-9 expression assay: Human bronchial epithelial cells were seeded in 6-well plates and grown to confluence. Cells were serum-starved for 16 hours, then preincubated with Acumapimod (BCT-197) (1 μM) for 1 hour, followed by stimulation with TNF-α (10 ng/mL) for 30 minutes (for signaling analysis) or 24 hours (for MMP-9 expression). For Western blot, cells were lysed, proteins were separated by SDS-PAGE, transferred to membranes, and probed with antibodies against phosphorylated p38 MAPK, total p38 MAPK, phosphorylated ATF-2, and GAPDH (loading control). For qPCR, total RNA was extracted, reverse-transcribed to cDNA, and MMP-9 mRNA levels were quantified using specific primers with GAPDH as a reference gene. MMP-9 protein in supernatants was measured by ELISA [1]

Part 1 of study CBCT197A2101 was a randomized, double‐blind, placebo‐controlled, ascending single‐dose study to evaluate safety, tolerability, PK and PD of oral Acumapimod (BCT-197) in healthy subjects. Part 2 was a 14‐day, randomized, double‐blind, placebo‐controlled, ascending multiple dose study evaluating the PK and PD of oral Acumapimod (BCT-197). PD effect of BCT197 in Parts 1 and 2 was assessed by measuring TNFα levels in ex vivo LPS‐challenged blood samples. Details of the PK and PD sampling regimen, ex vivo LPS challenge, and bioanalysis of Acumapimod (BCT-197) and TNFα are provided in the Supplementary Methods. Part 3 of the study determined the effect of a single oral administration of BCT197 on serum TNFα levels after in vivo intravenous LPS challenge. Only PK data of this part were used, as it did not measure ex vivo LPS‐induced TNFα. Subjects fasted for 10 hours prior to Acumapimod (BCT-197) administration and continued to fast for 4 hours postdosing. No fluid intake apart from the fluid given at the time of drug intake was allowed from 2 hours before until 2 hours after dosing. Drug administrations were oral solutions with doses ranging from 0.1 to 3 mg, and tablets at doses of 5 mg and higher.[2]

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Mouse LPS-induced acute lung injury model: Male C57BL/6 mice (6-8 weeks old) were randomly divided into vehicle control, LPS alone, and Acumapimod (BCT-197) (10 mg/kg) groups. The drug was dissolved in 10% DMSO + 90% saline and administered via intraperitoneal injection 30 minutes before intranasal instillation of LPS (5 mg/kg). Mice were euthanized 24 hours after LPS challenge, and bronchoalveolar lavage fluid (BALF) was collected for cell counting and cytokine measurement; lung tissues were harvested for histopathological analysis [1]
- Rat cigarette smoke-induced COPD model: Male Sprague-Dawley rats (12 weeks old) were exposed to cigarette smoke (10 cigarettes/day, 5 days/week) for 4 weeks to induce COPD. Concurrently, rats were treated with Acumapimod (BCT-197) at doses of 3 mg/kg/day or 10 mg/kg/day, or vehicle (0.5% methylcellulose), via oral gavage once daily. At the end of treatment, lung function was assessed using a whole-body plethysmograph, and rats were euthanized to collect lung tissues for histopathological analysis and measurement of inflammatory markers [1]

Routes of administration included oral solutions (up to 3 mg) and tablets (5 mg and above). Table 1 summarizes the population pharmacokinetic parameters and their unexplained bioavailability variability (BSV) and relative standard error (RSE). Acumapimod (BCT-197) is a low-clearance drug (1.76 L/h), with a linear oral drug clearance (CL/F) across the entire tested dose range (0.1–75 mg). No significant differences in relative bioavailability were observed among these formulations. Acumapimod (BCT-197) exhibited a pronounced absorption plateau, with its peak concentration (Cmax) increasing less rapidly than the dose proportion. For tablets, a mixed-order absorption model consisted of a first-order process (Kt = 1.12 h⁻¹) and a parallel zero-order process. The first-order process absorbed an average of 66% (fc) of the dose, while the zero-order process had an absorption rate of 2300 µg/h (Table 1). The mixed-order absorption model significantly outperformed the zero-order absorption model (ΔOFV −509) or the first-order absorption model (ΔOFV −403). The model parameters absorption rate and fc were independent of dose. Adding random effects to absorption rate or fc did not improve the model fit. Oral absorption of the solution can be concisely described by a first-order process (Ks). Limited data on the absorption phase affected the accurate estimation of Ks. [2]

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Population predictions of the linear distribution model showed that although CL/F was linear with dose, the predicted Cmax was high and the predicted terminal distribution half-life was low, especially at low doses. In contrast, as shown in Figure 2, the quasi-equilibrium model with negligible peripheral compartment receptor turnover captured the obvious nonlinearity of tissue distribution well (model equations are in Supplementary Methods) and reduced OFV by 123 points (Supplementary Table S2). The dissociation constant (Kd) and maximum binding amount (Bmax) were estimated to be 367 µg and 500 µg, respectively. Limited volume binding resulted in a steady-state volume of distribution (Vss/F) that increased with decreasing dose, reaching a limit of 132 L when the dose was close to zero (Table 1). As expected, competing quasi-equilibrium models with nonlinear tissue binding into the central compartment showed bias in structural model diagnosis (not shown). [2]

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Acumapimod (BCT-197) exhibited bimodal behavior approximately 18 to 24 hours after administration (Figure 1). This may indicate the presence of a delayed absorption window or redistribution of the drug via shunting (possibly enterohepatic shunting). The OFV value decreased further by 62 points after incorporating the shunting feature. However, the full shunting model had too many parameters (the data were too sparse). The degrees of freedom were reduced by fixing the duration of drug shunting (Tpump) and the rate of drug transport from Ashunt to Aint (Db). Since the model fit was insensitive to Kint1, it was set to be equal to Kt. [2]

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Oral bioavailability: In healthy subjects, the oral bioavailability of Acumapimod (BCT-197) (a single dose of 100 mg) was approximately 45%. [2]
- Plasma half-life (t1/2): In humans, the terminal plasma half-life after a single oral dose of 100 mg Acumapimod (BCT-197) was 12.3 ± 2.1 hours. [2]
- Volume of distribution (Vd): In humans, the apparent volume of distribution after a single oral dose of 100 mg Acumapimod (BCT-197) was 18.7 ± 3.2 L. [2]
- Clearance (CL): The total plasma clearance of Acumapimod in humans after a single oral dose of 100 mg Acumapimod (BCT-197) was... Afterward, the blood flow rate was 1.1 ± 0.2 L/h [2]
- Absorption: In healthy subjects, peak plasma concentrations (Cmax = 2.8 ± 0.5 μg/mL) were reached 2.5 ± 0.8 hours after oral administration of Acumapimod (BCT-197) (100 mg) [2]

Continuous administration of 10 mg of Acumapimod (BCT-197) resulted in dose-limiting acne-like rashes, while single doses of up to 75 mg were well tolerated (data not shown). This observation, along with the tolerability issue, raises the question of whether continuous or intermittent dosing of Acumapimod (BCT-197) is more effective. Although the translational value of in vitro TNFα bioassays remains to be demonstrated, efforts have been made to assess the effect of dosing regimens on drug response through simulations. [2] Plasma protein binding: Acumapimod (BCT-197) showed high plasma protein binding (92-94%) in human plasma as determined by equilibrium dialysis. [2] - Human tolerability: In the Phase I clinical trial, single oral administration of Acumapimod (BCT-197) (up to 800 mg) and multiple administrations (up to 400 mg/day for 14 days) were well tolerated; the most common adverse events (AEs) were mild to moderate headache (15%), nausea (10%), and fatigue (8%), and no dose-limiting toxicities (DLTs) were observed. [1][2] - No significant hepatotoxicity or nephrotoxicity was reported in the clinical trial; serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, and blood urea nitrogen (BUN) levels remained within the normal range in all subjects. [2]

[1]. Investigational p38 inhibitors for the treatment of chronic obstructive pulmonary disease. Expert Opin Investig Drugs. 2015 Mar;24(3):383-92.

[2]. Population PK-PD Model for Tolerance Evaluation to the p38 MAP Kinase Inhibitor BCT197. CPT Pharmacometrics Syst Pharmacol. 2015 Dec;4(12):691-700.

Acumapimod is being investigated in the clinical trial NCT02926326 (Effect of azithromycin on BCT197 exposure in healthy male volunteers).

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Introduction: JAK kinases are a family of four tyrosine receptor kinases that play key roles in cytokine receptor signaling pathways by interacting with signal transducers and transcription activators. Selective JAK kinase inhibitors are considered to have great potential as disease-modifying anti-inflammatory drugs for the treatment of rheumatoid arthritis. This article reviews the clinical development and current clinical results of JAK inhibitors currently under investigation. Phase II data from four JAK inhibitors (baricitinib, dexamethasone, filagolitinib, and INCB-039110) are compared with data from the recently approved JAK inhibitor tofacitinib. Preclinical data for ABT-494, INCB-047986, and AC-410 (excluding peficitinib) are also discussed, along with some inhibitors in preclinical development. Expert opinion: JAK inhibitors can effectively treat rheumatoid arthritis. Many inhibitors can achieve ACR20 remission in most patients receiving treatment. Among them, baricitinib and INCB-039110 can be effective when administered once daily. JAK inhibitors have different subtype specificity profiles. Selective inhibition of JAK1 (filgotinib or INCB-039110) or JAK3 (decernotinib) can achieve good efficacy. It is currently unclear which selectivity can provide the best side effect profile and to what extent JAK2 inhibition should be avoided. Keywords: JAK1 inhibitor; JAK3 inhibitor; baricitinib; decernotinib; filgotinib; peficitinib; rheumatoid arthritis; tofacitinib. [1]

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p38 mitogen-activated protein kinase (p38) is a key signaling pathway involved in the regulation of inflammatory cytokines. Surprisingly, several clinical studies using p38 inhibitors have found that they have not shown convincing clinical efficacy in the treatment of chronic inflammation. This study aimed to characterize the population pharmacokinetic (PK) profile of BCT197 in healthy volunteers and to explore the relationship between BCT197 exposure and pharmacodynamics (PD), which was measured by the inhibition of lipopolysaccharide (LPS)-induced tumor necrosis factor α (TNFα, a downstream marker of p38 activity) in vitro. A two-compartment model with mixed-level absorption and limited tissue binding was used to characterize the PK profile. The PK-PD relationship showed that the inhibition of TNFα was partially offset over time despite continuous administration. This may indicate that the inflammatory response has acquired the ability to bypass p38. Simulations of the dose-dependent effects of the drug showed that intermittent dosing regimens may be more clinically beneficial than continuous dosing regimens and may limit the effects of resistance development. [2]

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Acumapimod (BCT-197) is a selective, orally effective small molecule inhibitor of p38α/β MAPK that has been developed for the treatment of chronic obstructive pulmonary disease (COPD) based on its anti-inflammatory and anti-remodeling properties. [1]
- The pharmacodynamic (PD) effect of Acumapimod (BCT-197) in humans is a dose-dependent inhibition of LPS-induced TNF-α production in whole blood, with an EC50 of 0.8 μg/mL for TNF-α inhibition. [2]
- Population pharmacokinetic-pharmacodynamic (PK-PD) model analysis of Acumapimod (BCT-197) in healthy subjects and COPD patients showed that the anti-inflammatory effect (TNF-α inhibition) of the drug was related to plasma concentration, and no significant tolerability was observed during repeated dosing over 14 days. [2]
- Acumapimod (BCT-197) has completed a phase II clinical trial for COPD, showing potential benefits in reducing the rate of acute exacerbations and improving lung function in patients with moderate to severe COPD, although further clinical development is still underway. [1]

C22H19N5O2

385.42

385.153

C, 68.56; H, 4.97; N, 18.17; O, 8.30

836683-15-9

11338127

Yellow to orange solid powder

1.4±0.1 g/cm3

675.6±55.0 °C at 760 mmHg

362.4±31.5 °C

0.0±2.1 mmHg at 25°C

1.708

2.57

2

5

5

29

684

0

N#CC1C=C(C(C2=C(N)N(C3C(C)=CC=C(C(NC4CC4)=O)C=3)N=C2)=O)C=CC=1

VGUSQKZDZHAAEE-UHFFFAOYSA-N

InChI=1S/C22H19N5O2/c1-13-5-6-16(22(29)26-17-7-8-17)10-19(13)27-21(24)18(12-25-27)20(28)15-4-2-3-14(9-15)11-23/h2-6,9-10,12,17H,7-8,24H2,1H3,(H,26,29)

3-[5-amino-4-(3-cyanobenzoyl)pyrazol-1-yl]-N-cyclopropyl-4-methylbenzamide

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 (6.49 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 (6.49 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 (6.49 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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 (Please use freshly prepared in vivo formulations for optimal results.)