p38 MAPK

Dilmapimod (SB-681323) potently inhibits p38 MAPK signaling, measured by inhibition of sorbitol-induced pHSP27 expression[1].

Biomarker Measurements [2]
Upon review of final data, the observed times since trauma were similar enough such that analyses using both time of trauma and time of first dose gave consistent results. Spline-based analyses using time of trauma for key prespecified biomarkers (CXCL8 [IL-8], CRP, IL-6, and MPO) are presented in Figures S1–S4 (Supplemental Digital Content 1, https://links.lww.com/CCM/B328). Changes in IL-6 over time following initial dose are shown in Figure 4A. In the combined placebo arms, mean IL-6 levels rose from 509.4 (95% CI, 404.3, 641.9) at 6 hours from time of first dose to a peak mean of 556.1 (95% CI, 396.8, 779.2) at 24 hours, before falling to a mean level of 250.2 (95% CI, 162.4, 385.4) at 72 hours. As noted in Figure 4A, at all dose levels, Dilmapimod treatment was associated with a trend toward lower levels of IL-6 over time compared with patients who received placebo, with effects present at 24 hours following dosing initiation. The ratio of IL-6 in a given treatment arm relative to placebo is presented in Figure 4A, indicating that the continuous 10-mg infusion yielded values consistently below a ratio of 1, with treatment-related effects present early after the initiation of the infusion.
Changes over time in IL-8 and MPO were not as consistent as IL-6 and CRP (Fig. S5, a and b, Supplemental Digital Content 1, https://links.lww.com/CCM/B328) and did not display consistent treatment effects across all arms, although the highest continuous dose arm had significantly lower IL-8 levels beginning early after study initiation. The sTNFR1 levels were significantly lower than placebo in the highest dose arm (10 mg 24 hr infusion) (Fig. S5c, Supplemental Digital Content 1, https://links.lww.com/CCM/B328), but these effects, while appearing quite different, seemed confined to the highest Dilmapimod doses. Other exploratory biomarkers, listed in Table S2 (Supplemental Digital Content 1, https://links.lww.com/CCM/B328), did not reveal consistent trends or treatment effects (data not shown).

Study Design [2]
Between October 2009 and February 2013, we conducted a phase IIa, randomized, double-blind, placebo-controlled, parallel-group study at six sites in the United States to evaluate the safety, tolerability, systemic PK, and PD profiles of Dilmapimod, compared with placebo in patients with major trauma exclusive of severe head injury and at risk for developing ARDS (ClinicalTrial.gov NCT00996840). Patient eligibility was defined by known or potential contraindications with Dilmapimod and by injury severity, as calculated by Injury Severity Score (ISS) (28). Eligible patients were randomized into the trial within the first 26 hours after known trauma had occurred.
Over the three treatment days, safety tests were performed (detailed in the Primary and Secondary Endpoints section) and blood samples were collected for PK and PD analysis. Patients remained in the hospital for the entire study period. A follow-up visit was conducted on day 7, that is, 4 days after IV dosing had finished or at discharge from the hospital if earlier than day 7 (but no earlier than 12 hr after dosing had completed). The study was 7 days in length for all patients. Study progression to the next cohort only occurred after completion and review of safety, tolerability, and PK data from the previous cohort in conjunction with an Independent Data Monitoring Committee.

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Dose Rationale [2]
To ensure patient safety and to investigate the relationship between drug exposure and biomarkers of p38 inhibition, four separate patient cohorts were recruited to evaluate different dose levels and infusion regimens. Patients in each cohort received either Dilmapimod or placebo as an IV infusion for three consecutive days as follows: cohort 1 received dilmapimod 3 mg infused over 4 hours or placebo; cohort 2 received Dilmapimod7.5 mg infused over 24 hours or placebo; cohort 3 received Dilmapimod 7.5 mg infused over 4 hours or placebo; cohort 4 received dilmapimod 10 mg infused over 24 hours or placebo (Fig. 1). Progression from cohort 1 to 2 was expected to increase area under the concentration-time curve (AUC) and progression from cohort 2 to 3 was expected to increase Cmax, while maintaining safety cover based on preclinical testing and previous studies with dilmapimod. The maximum dose of 10 mg/d was selected based on safety cover margins and to maximize the chance of altering proinflammatory biomarkers in this patient population. As such, cohorts 3 and 4 were expected to provide the best opportunity for detecting a PD signal. Although there is a lack of available data and information to support quantitative prediction of the pharmacology of dilmapimod in trauma patients, doses that result in 50% inhibition of ex vivo TNF-α have been shown to reduce markers of inflammation in other diseases, such as COPD and atherosclerosis (29, 30). Subjects were randomized to receive either dilmapimod or placebo in accordance with the central randomization schedule generated by Discovery Biometrics, prior to the start of the study, using validated internal software.

Pharmacokinetics [2]
A total of 471 Dilmapimod concentration records from 56 patients were included in the analysis dataset. A population PK analysis indicated that following IV infusion of v, the plasma concentration versus time profiles were best described by a three compartment model with zero-order input and first-order elimination from the central compartment. The plasma concentration of dilmapimod increased approximately proportionally to the increase in dose. BMI was a significant factor on both the clearance and intercompartmental clearance; the clearance was 21% lower at 1 SD below the mean BMI (23 kg/m2) and 23% higher at 1 SD above the mean BMI (32 kg/m2).
Model-predicted PK curves and the observed concentration data for the different treatment allocation arms are shown in Figure 3. The daily exposure of dilmapimod AUC (0–24) is shown in Table 4. Based on these data, it appeared that continuous dosing arms maintained the most favorable PK profile and that the 10-mg dosing regimen was superior to 7.5 mg.

Safety [2]
A total of 77 patients were randomized; seven patients were withdrawn during the study (Fig. 2). Characteristics of the study population according to treatment allocation are presented in Table 1, and distribution of randomization by site is detailed in Table S5 (Supplemental Digital Content 1, https://links.lww.com/CCM/B328). This was a young, mostly male, severely injured population enrolled within 26 hours of admission.
The overall incidence of adverse events (AEs) was comparable across all treatment groups, and no dose-related effects were identified (Table 2). AEs were common in this critically ill population. The most frequent AEs were pyrexia (20 cases reported by 20 patients), nausea (18 cases reported by 18 patients), and hypertension (19 cases reported by 18 patients), which overall occurred more frequently in placebo patients than treatment group patients. A detailed listing of all adverse events is provided in Table S6 (Supplemental Digital Content 1, https://links.lww.com/CCM/B328). Review of patients’ data that experienced elevations in liver-associated enzymes was not suggestive of drug-related hepatotoxicity. Three patients had elevated liver enzymes. Two patients received active drug and one patient received placebo; two of these AEs were thought to be related to study drug (one each on active or placebo). There were 19 cases of hypertension reported for 18 patients, and all but one was reported as moderate in intensity. The frequency of hypertension was highest in placebo-treated patients and was similar across the different Dilmapimod dose cohorts. Of the cases of hypertension reported in Dilmapimod treatment groups, only one was thought to be drug related by the investigator. The number of clinically significant abnormal ECGs was higher in the placebo group. There were no significant changes observed in mean ECG variables relative to baseline. There were two AEs of “ECG QT prolonged” and “ECG ST segment suppression” reported in one patient that were thought to be related to study drug, however, the patient received placebo.

[1]. A randomized, placebo-controlled study of the effects of the p38 MAPK inhibitor SB-681323 on blood biomarkers of inflammation in COPD patients. J Clin Pharmacol. 2010 Jan;50(1):94-100.

[2]. A Randomized Dose-Escalation Study of the Safety and Anti-Inflammatory Activity of the p38 Mitogen-Activated Protein Kinase Inhibitor Dilmapimod in Severe Trauma Subjects at Risk for Acute Respiratory Distress Syndrome. Crit Care Med . 2015 Sep;43(9):1859-69.

Dilmapimod has been used in trials studying the treatment and diagnostic of Nerve Trauma, Inflammation, Pain, Neuropathic, Arthritis, Rheumatoid, and Coronary Heart Disease, among others. Dilmapimod (SB-681323) is a p38 MAP-kinase inhibitor that has potential uses in inflammatory conditions such as RA (Rheumatoid Arthritis). Previous p38 MAP-kinase inhibitors have been hindered in development by liver toxicity. Methotrexate (common treatment for RA patients) also has potential liver toxicity.}

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Drug Indication
Dilmapimod has been used in trials studying the treatment and diagnostic of Nerve Trauma, Inflammation, Pain, Neuropathic, Arthritis, Rheumatoid, and Coronary Heart Disease, among others.

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Mechanism of Action
Dilmapimod reduces the levels of proinflammatory cytokines and chemokines and reduce cellular infiltration to sites of inflammation, thereby reducing local damage. In diseases such as RA and IBD, TNFα blockade through either anti-TNFα antibodies or use of soluble TNFα receptors. Inhibition of p38α offers significant inhibition of TNFα, and cytokines such as IL-1β and IL-6, which offer additional therapeutic efficacy.

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The p38 mitogen-activated protein kinase (MAPK) signaling upregulates inflammation and is known to be increased in chronic obstructive pulmonary disease (COPD). The authors assessed the pharmacology of the novel p38 MAPK inhibitor Dilmapimod/SB-681323 using blood biomarkers in COPD. Seventeen COPD patients (forced expiratory volume in 1 second 50%-80% predicted) using short-acting bronchodilators participated in a double-blind, double-dummy, randomized, crossover study. Patients received single oral doses of SB-681323 7.5 mg and 25 mg, prednisolone 10 mg and 30 mg, and placebo. Blood was obtained predose and at 1, 2, 6, and 24 hours postdose. Whole-blood sorbitol-induced phosphorylated (p) heat shock protein (HSP) 27 levels as a marker of p38 pathway activation and lipopolysaccharide-induced tumor necrosis factor (TNF)-alpha production were assessed. Both doses of SB-681323, but not prednisolone, significantly (P < .0001) reduced weighted mean (WM) pHSP27 (0-6 hours) by 58% compared with placebo. WM TNF-alpha production (0-24 hours) was significantly reduced compared with placebo by SB-681323 25 mg (40%, P = .005) and 7.5 mg (33.4%, P = .02), while prednisolone 30 mg and 10 mg caused 81.5% and 58.2% suppression, respectively (both P < .0001). SB-681323 inhibited the p38 MAPK pathway to a greater degree than prednisolone did. SB-681323 inhibited TNF-alpha production. SB-681323 is a potent p38 MAPK inhibitor that potentially suppresses inflammation in COPD. [1]

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Objectives: There are no current pharmacological therapies for the prevention or treatment of acute respiratory distress syndrome. Early dysregulated inflammation likely plays a role in acute respiratory distress syndrome development and possibly acute respiratory distress syndrome outcomes. p38 mitogen-activated protein kinase is central to the regulation of multiple inflammatory mediators implicated in acute organ dysfunction and is the target for a novel class of cytokine-suppressive anti-inflammatory drugs. In preclinical models, p38 inhibitors reduce lung injury following pancreatitis and burn injury.
Design: We conducted a phase IIa, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the safety and tolerability of Dilmapimod, a novel p38 mitogen-activated protein kinase inhibitor, in patients at risk for developing acute respiratory distress syndrome admitted with an Injury Severity Score more than 16, excluding head trauma. Enrolled patients received 4- or 24-hour IV dilmapimod infusions at different doses or placebo, daily for 3 days, in four separate cohorts.
Setting: Multicenter randomized clinical trial of large, academic trauma centers.
Measurements and Main Results: Seventy-seven patients were enrolled. Although adverse events were common in this critically ill population, Dilmapimod was well tolerated, with no clinically relevant safety findings. Pharmacokinetic models indicated that the higher dose of 10 mg given as continuous infusion over 24 hours had the most favorable plasma concentration profile. Likewise, measures of soluble inflammatory markers including interleukin-6, C-reactive peptide, interleukin-8, and soluble tumor necrosis factor receptor 1 were most different between this dosing arm and placebo. Although the study was not specifically designed with acute respiratory distress syndrome as an outcome, the number of patients who developed acute respiratory distress syndrome was small (2/77).
Conclusions: The novel p38 mitogen-activated protein kinase inhibitor Dilmapimod appears well tolerated and may merit further evaluation for prevention of acute respiratory distress syndrome and other organ injury in larger clinical trials. Furthermore, results of this early-phase trial may aid in design of future studies aimed at prevention of acute respiratory distress syndrome and other organ injury. [2]

C30H27F3N4O6S

628.62

628.1603402

C, 57.32; H, 4.33; F, 9.07; N, 8.91; O, 15.27; S, 5.10

937169-00-1

16070082

Typically exists as solids at room temperature

S(C1C=CC(C)=CC=1)(=O)(=O)O.FC1C=CC=C(C=1N1C(C=CC2=C(C3C=CC(=CC=3C)F)N=C(N=C12)NC(CO)CO)=O)F

SB-681323 tosylate; DILMAPIMOD TOSYLATE; Dilmapimod tosilate; Dilmapimod tosylate [USAN]; 937169-00-1; SB-681323-T; UNII-7R1193W65J; 7R1193W65J; Dilmapimod tosylate (USAN); GW 681323 tosylate

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*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.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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