HCV NS3/4A protease(Ki=0.36 nM);HCV replication(EC50=7.8 nM);SARS-CoV-2 Mpro(IC50=9.6±2.3 μM);SARS-CoV-2 RdRp(IC50=5.5±0.2 μM)

the antiviral activity of simeprevir (TMC435350) in Huh7-Luc cells is dose dependent, and the EC50 and EC90 values determined for TMC435350 are 8 nM and 24 nM, respectively. Inhibition of TMC435350 on NS3/4A protease is time dependent, and the overall Kis are estimated to be 0.5 nM for genotype 1a and 0.4 nM for genotype 1b, respectively. TMC435350 is a potent inhibitor of HCV NS3/4A protease (Ki=0.36 nM) and viral replication (replicon EC50=7.8 nM).

In rats, TMC435350 (40 mg/kg, p.o.) is extensively distributed to the liver and intestinal tract (tissue/plasma area under the concentration-time curve ratios of >35), and the absolute bioavailability is 44%.

Simeprevir has a rather lengthy in vivo absorption phase; it takes 4-6 hours for the maximum concentration (Cmax) to be reached. 99.9% of it is firmly attached to plasma proteins, primarily albumin. Following a single oral administration, the absolute bioavailability is 44%. Rats with a liver to blood ratio of 29:1 have a well-distributed liver. In preclinical studies, the ratio of liver to plasma concentration is 39 for humans, which is extremely high. With a ratio of 128 in the small intestine, the tissue/plasma AUC ratios are the highest. Plasma concentrations are higher than the EC99 at 8 hours and around the EC50 at 24 hours after dosing, while tissue simeprevir concentrations reach their peak values within 4 hours after dosing.Liver simeprevir concentrations can stay above the EC99 for up to 31 hours after dosing. When simeprevir is given with food, its AUC24h increases by 61%–69%. Thus, it is recommended to take simeprevir with food. Simeprevir is a P-glycoprotein substrate and inhibitor as well. Simeprevir is excreted by the biliary system after being metabolized by CYP3A4. It also inhibits cytochrome 3A4 in the gut, but not CYP3A4 in the liver[1].

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Pharmacology [1]
Absorption[1]
Simeprevir has a relatively long absorption phase, reaching maximum concentration (Cmax) after 4–6 hours. After multiple doses for 5 days, Cmax and area under the plasma concentration-time curve (AUC) after 24 hours (AUC24h) increased more than dose proportionally between 75 mg and 200 mg once daily, suggesting saturation of first-pass metabolism and/or efflux transporters. The AUC 24h for the 200 mg once daily dose group was approximately 10 times higher than that for the 100 mg once daily dose. Steady-state is reached after 7 days of once daily dosing. Exposure to simeprevir in HCV-uninfected subjects with Child–Pugh B and C cirrhosis was 2.4-fold and 5.2-fold higher, respectively, than in HCV uninfected subjects with normal liver function. Plasma Cmax and AUC24h of simeprevir were similar during coadministration of simeprevir with PEG-IFN-α and RBV compared with administration of simeprevir alone. In HCV-infected subjects, the mean steady-state plasma concentration was 1,936 ng/mL, more than 200-fold higher than the EC50 value determined in previous in vitro studies. While plasma exposure dropped to around the EC50 at 24 hours postdosing, the liver concentration remained above the replicon 99% effective concentration (EC99) for up to 31 hours postdosing, thus suggesting the feasibility of once-daily dosing. Moreover, in a Phase I study, it was shown that simeprevir exposure was higher in healthy Japanese volunteers than in Caucasian volunteers. In Phase III trials, mean plasma simeprevir exposure in Asian subjects (n=14) was 3.4-fold higher than in the general population of this trial. The AUC24h of simeprevir was increased by 61%–69% when administered with food; simeprevir should therefore be taken with food. Finally, simeprevir is a substrate and inhibitor of P-glycoprotein.21

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Distribution[1]
Simeprevir is extensively (99.9%) bound to plasma proteins, mainly to albumin. The absolute bioavailability was 44% after a single oral administration. Transport into human hepatocytes is thought to be mediated by OATP1B1/3. In rats, a liver to blood ratio of 29:1 was found, which would mean good distribution to the liver. For humans, in preclinical studies, the liver to plasma concentration ratio was high (ratio of 39). The highest tissue/plasma AUC ratios were observed in the small intestine (ratio of 128). While tissue simeprevir concentrations reached peak values within 4 hours postdosing, simeprevir concentrations in liver remained above the EC99 for up to 31 hours postdosing, and plasma concentrations were higher than the EC99 at 8 hours and around the EC50 at 24 hours postdosing.

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Metabolism[1]
Simeprevir, like telaprevir and to a lesser extent boceprevir, is metabolized by CYP3A4. It can therefore be the subject of drug–drug interactions with moderate or strong inhibitors and inducers of CYP3A enzymes, with significant increases or decreases in exposure to simeprevir. Unlike boceprevir and telaprevir, simeprevir is an inhibitor of gut cytochrome 3A4 but not hepatic CYP3A4. The effect of a low dose (600 mg) of a potent CYP3A inducer, rifampicin, on the pharmacokinetics of simeprevir was evaluated and showed that the combination of rifampicin and simeprevir resulted in a 48% decrease in AUC24h while Cmax was increased by 31%. Although simeprevir exposure in subjects with moderate hepatic impairment was higher than in healthy subjects, no dose adjustments are required in patients with moderate hepatic impairment.

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Excretion[1]
Simeprevir is eliminated by biliary excretion. After a single dose of 200 mg of simeprevir, approximately 91% of total radioactivity was recovered in feces and less than 1% in urine, indicating that simeprevir is eliminated from the body via biliary excretion and renal excretion is irrelevant. The elimination half-life in HCV-infected patients was 41 hours, which is almost 3–4 times longer than that in HCV-uninfected individuals. The pharmacokinetic parameters of simeprevir were also not influenced by renal function and no dose adjustments are necessary in patients with mild, moderate, or severe renal impairment. Safety and efficacy, however, have not been studied in patients with end-stage renal disease or on hemodialysis.

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Pharmacodynamics[1]
There was no clear pharmacokinetic/pharmacodynamic relationship between simeprevir exposure and antiviral activity with simeprevir doses of 75 mg once daily (QD) or above. Within the range of exposures to simeprevir in Phase III trials, no clear exposure–response relationships for efficacy (rapid virologic response [RVR], SVR, viral breakthrough [VBT] or relapse) were observed. During clinical trials with simeprevir, higher exposures to simeprevir have been associated with increased frequency of adverse reactions, including rash and photosensitivity.

The in vitro inhibitory activity of simeprevir against NS3/4A is determined using a fluorescence resonance energy transfer cleavage assay with the RetS1 peptide substrate, derived from the genotype 1a NS4A-4B junction, and bacterially expressed full-length NS3 protease domain, supplemented with an NS4A peptide. Briefly, NS3/4A is preincubated in the presence of TMC435350 for 10 min, and then the RetS1 substrate is added and fluorescence is continuously measured for 20 min (excitation, 355 nm; emission, 500 nm). Cleavage of the substrate is expressed as a percentage of the cleavage seen with the vehicle control.

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Biochemical protease assays.[2]
Protease activity for HCV genotype 1 to 6 NS3 proteins was monitored in a continuous FRET-based assay. The assay buffer contained 25 μM NS4A peptide, 50 mM Tris-HCl (pH 7.5), 15% glycerol (vol/vol), 0.6 mM lauryldimethylamine N-oxide, and 10 mM dithiothreitol. This buffer was prepared fresh daily by addition of NS4A peptide and dithiothreitol to a mixture of the other components that was stored at 4°C. The final assay conditions also included 0.5 μM FRET substrate, variable concentrations of NS3/4A and ITMN-8187 as specified, and up to 5% dimethyl sulfoxide (DMSO) (from addition of inhibitor or mock treatment). Assays were conducted at room temperature in black 96-well plates, and fluorescence data were collected using a SpectraMax M5 or SpectraMax EM plate readers (Molecular Devices, Sunnyvale, CA) with excitation and emission wavelengths set to 490 and 520 nm, respectively. The half-maximal inhibitory concentrations (IC50s) for NS3/4A inhibition by ITMN-8187 were determined using NS3-initiated reactions (without preincubation of enzyme and inhibitor). The final 1× assay concentrations of NS3 were 0.05 nM for all genotypic variants tested except 1a and 3a (0.1 nM and 0.4 nM, respectively). Assay wells were prepared by adding and mixing 170 μl of 1× assay buffer, 10 μl of the 20× ITMN-8187 in DMSO (or DMSO blank), 10 μl of 20× substrate, and 10 μl of a 20× NS3/4A stock in the specified order. Data acquisition for 1 h was initiated immediately after NS3/4A addition and mixing. Reaction rates were calculated from progress curve slopes over the first 30 min. Dose-response curves (rate versus log10 concentration of ITMN-8187) were fit to a 4-parameter logistic function to extract IC50s.

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Cytochrome P450 (CYP) inhibition and induction assays.[2]
The drug-drug interaction potential of ITMN-8187 was investigated through in vitro evaluation of CYP inhibition to estimate IC50 and the potential of time-dependent inhibition of CYP enzymes (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A) in human liver microsomes (XenoTech Inc., see Supplemental Methods). Briefly, compounds were incubated with human liver microsomes, CYP probe substrates, and NADP-oxidase (NADPH). The reaction was terminated by protein precipitation with the addition of acetonitrile. After centrifugation, the supernatant was analyzed via LC-MS/MS to quantify the extent of specific metabolite formation for the probe substrate of each CYP enzyme. The potential for ITMN-8187 to induce CYP enzymes activities (CYP1A2, CYP2B6, and CYP3A4) was investigated in fresh human hepatocytes using selective probe substrate.

Huh7-Luc cells are seeded at a density of 2,500 cells/well in a 384-well plate in Dulbeccos modified Eagles medium plus 10% fetal calf serum and incubated with a range of concentrations of serially diluted simeprevir (TMC435350), in a final DMSO concentration of 0.5% in the absence of G418. After 72 h of incubation, Steady Lite reagent is added in a 1:1 ratio to the medium, and luciferase signal is measured using a ViewLux reader.

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HCV replicon assays.[2]
Huh7 luc/neo ET cells and pFK I389luc-ubi-neo/NS3-3′/ET HCV replicons were licensed from Reblikon GMBH. The stable HCV replicon (pFK I389luc-ubineo/NS3-3′/ET) expresses a firefly luciferase-ubiquitin-neomycin phosphotransferase fusion protein. Expression of the NS3/5B HCV polyprotein containing three cell culture-adaptive mutations (E1202G, T1280I, K1846T) was driven by the encephalomyocarditis virus internal ribosomal entry site. The HCV genotype 1a subgenomic replicon generated at InterMune represents a 1b-to-1a chimera near the N terminus of NS3 distal to the compound binding site. Huh7 cells containing subgenomic HCV replicons were cultured at 37°C in 5% CO2 in DMEM containing 10% heat-inactivated FBS, 2 mM l-glutamine, 1% nonessential amino acids, 50 IU/ml penicillin, 50 μg/ml streptomycin solution, and 0.5 mg/ml G418. HCV replicon-containing Huh7 cells were plated at a density of 5 × 103 cells/well in 96-well tissue culture plates containing 100 μl DMEM with G418. Approximately 24 h later, the medium was removed and replaced with 90 μl DMEM lacking G418. ITMN-8187 or test compounds were serially diluted 3-fold in DMSO in two duplicate rows for each determination of the half-maximal effective concentration (EC50). The serially diluted compound solutions were diluted 10-fold in DMEM lacking serum and G418; 10 μl of these compound solutions in medium were added to duplicate tissue culture plates. The final volume was 100 μl with a DMSO concentration of 1%. Plates were incubated at 37°C for approximately 48 h. At 48 h, a microscopic visual examination of the tissue culture plates was conducted to assess compound solubility. Medium was removed from one of the two duplicate plates, and luciferase activity was measured using the Bright-Glo luciferase assay to determine EC50s. The ATPlite assay kit was used to determine ATP levels of cells and medium in the second plate for determination of half-maximal cytotoxic concentrations (CC50s). Both Bright-Glo and ATPlite assay kits were used according to the manufacturers' instructions. Test compound potency levels against R155K, A156T, and D168V HCV 1b mutant replicons were similarly determined. To assess the effect of concentration in serum on compound potency, the above-described assay was carried out in the presence of 40% FBS. The effect of serum is expressed as fold shift relative to 10% FBS reference conditions.

\n\nSprague-Dawley (SD) rats and cynomolgus monkeys
\n3 mg/kg
\nOral administration\n\n

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\n\nIn vivo preclinical studies.[2]
\nPharmacokinetic properties of ITMN-8187 and simpeprevir were evaluated in Sprague-Dawley (SD) rats, beagle dogs, and cynomolgus monkeys. Procedures were performed under protocols approved by the Institutional Animal Care and Use Committee of the test facility. The animals were fasted overnight and through 4 h after administration of ITMN-8187. SD rats, beagle dogs, and cynomolgus monkeys (three males per species per dosing route) were administered with ITMN-8187 at 3 mg/kg by oral gavage or 0.5 mg/kg by intravenous (i.v.) bolus injection. The formulations used in the i.v. and oral studies were 0.5-mg/ml and 0.6-mg/ml solutions, respectively, in DMSO-solutol-saline (2/2/96, vol/vol/vol). For each species, blood samples were collected at 0.25, 0.5, 1, 2, 4, 8, 12, and 24 h after both i.v. and oral administration. Blood samples were also collected at 5 min after dosing from i.v. studies in all three species. Blood samples were collected in tubes containing tripotassium EDTA (K3EDTA), processed for plasma by centrifugation at 5°C, and stored at −20°C until analysis was performed. In addition, following oral administration of ITMN-8187 at 3 mg/kg, liver tissues were collected from rats and monkeys at predefined time points, rinsed in phosphate-buffered saline, dried, and stored in vials at −80°C until analysis. Drug concentration from each plasma or liver tissue sample at each time point was individually quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Pharmacokinetic analysis of the concentration in plasma-time profiles was performed using Phoenix/WinNonlin version 6.3.\n

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\nHCV chimeric mouse model.[2]
\nChimeric mice were created by transplanting human hepatocytes into immunodeficient transgenic mice carrying Alb-uPA. The immunodeficient homozygous Alb-uPA mice carrying chimeric mouse/human livers with serum were then infected with virus from patients with HCV infection; the inoculum varied by HCV genotype or mutations. The HCV chimeric mouse model used in these studies was provided by Phoenix Bio. Briefly, male uPA+/+-SCID mice 2 to 4 weeks of age were transplanted with human hepatocytes with an estimated replacement index of ≥70%, based on human albumin measurements (>9 mg/ml). After transplantation, the mice were infected at 10 to 14 weeks with HCV genotypes 1a or 1b by inoculation with HCV-positive patient serum. HCV infection in the chimeric mice was confirmed by the presence of serum HCV RNA measurements by real-time PCR (RT-PCR; lower limit of quantification, 4 × 104 copies/ml). uPA+/+-SCID mice confirmed to be infected with HCV genotypes 1a or 1b were dosed for 4 days with vehicle (2% Solutol) or ITMN-8187 at 30 mg/kg once daily by oral gavage. The vehicle and ITMN-8187 dosing solutions were formulated fresh daily. Serum was collected from individual mice on day 0 before treatment with vehicle or ITMN-8187 began (baseline), at 6 and 12 h postdose with vehicle or ITMN-8187 on day 1, and then once daily on days 2 to 4 for measurement of HCV RNA concentration. Data are expressed as the average HCV RNA concentration (copies/milliliter) per experimental group (n = 4); statistical differences (P < 0.05) between the vehicle-treated control mice and ITMN-8187-treated groups were analyzed using the Student t test.

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\n\n

Dosed orally (p.o.) by gastric intubation of a vitamin E acetate-d-α-tocopheryl polyethylene glycol 1000 succinate-polyethylene glycol 400 solution of Simeprevir (TMC435350) at 2 mL/kg body weight to provide a dose of 40 mg/kg.

24 male specific-pathogen-free Sprague-Dawley rats, weighing between 200 and 300 g at the time of dosing, are divided into eight groups of three rats each.

Absorption, Distribution and Excretion
Following a single oral dose of 150 mg simexpivir capsules in a fed state, the mean absolute bioavailability of simexpivir is 62%. Peak plasma concentration (Cmax) is typically reached between 4 and 6 hours after oral administration. Simexpivir is primarily excreted via bile. In a radioactive study, 91% of the radiolabeled drug was detected in feces, compared to less than 1% in urine. Of the drug recovered from feces, 31% of the total administered dose was unmetabolized simexpivir. The volume of distribution of simexpivir has not been determined. Animal studies have shown that simexpivir is widely distributed in the intestines and liver (concentration ratio in rat liver to blood is 29:1). The clearance of simexpivir has not been determined. Simexpivir binds highly to plasma proteins (greater than 99.9%), primarily to albumin, and secondarily to α1-acid glycoprotein. Plasma protein binding is not significantly altered in patients with impaired renal or hepatic function. In healthy subjects, administration of simexprevir increased relative bioavailability (AUC) by 61% and 69% with a high-fat, high-calorie (928 kcal) breakfast and a normal-calorie (533 kcal) breakfast, respectively, and delayed absorption time by 1 hour and 1.5 hours, respectively. Due to the increased bioavailability, simexprevir should be taken with food. Food type does not affect simexprevir exposure. Simexprevir is primarily eliminated via bile excretion. Renal clearance plays a minimal role in its elimination process. In healthy subjects, an average of 91% of total radioactivity was recovered in feces following a single oral dose of 200 mg (14)C-simexprevir. Less than 1% of the administered dose was recovered in urine. An average of 31% of the administered dose remained unmetabolized in feces. In animals, simexprevir is widely distributed in the intestines and liver (the concentration ratio in rat liver to blood was 29:1). In vitro data and physiologically based pharmacokinetic models and simulations indicate that hepatic uptake of simexprevir in humans is mediated by OATP1B1/3. For more complete data on absorption, distribution, and excretion of simexprevir (10 items), please visit the HSDB record page. Metabolism/Metabolites Simexprevir is metabolized in the liver. The primary metabolic pathway involves oxidation mediated by the CYP3A system. The involvement of CYP2C8 and CYP2C19 cannot be excluded. Following a single oral dose of 200 mg (1.3 times the recommended dose) (14)C-simexprevir in healthy subjects, most of the radioactivity in plasma (mean 83%) was derived from the parent drug, with a small amount of radioactivity associated with metabolites (no primary metabolite). Metabolites detected in feces are formed by oxidation of the macrocyclic or aromatic moieties or both, and by oxidation following O-demethylation. Simexprevir is metabolized in the liver. In vitro human liver microsomal assays showed that simeprevir is primarily metabolized via the hepatic CYP3A system. The involvement of CYP2C8 and CYP2C19 cannot be ruled out. Co-administration of Olysio with intermediate or potent CYP3A inhibitors may significantly increase simeprevir plasma exposure, while co-administration with intermediate or potent CYP3A inducers may significantly decrease simeprevir plasma exposure. The in vitro metabolism of 14C-TMC435 was investigated in hepatocytes and liver microsomes of mice, rats, rabbits, monkeys, and humans. In vitro metabolic activity was low in both animals and humans. Phase II binding of the phase I metabolite occurs in hepatocytes. In vitro experiments showed that the concentration of parent TMC435 was significantly higher than that of any metabolite. More than 20 metabolites have been identified. The most important phase I metabolic pathways include O-demethylation of the parent drug (especially in animals) and oxidation of the parent drug and its oxidative metabolites (especially in monkeys and humans), while the main phase II pathway for oxidative metabolites is glucuronidation (less common in humans). Only one human metabolite, M22 (oxidized parent drug), was identified in in vitro studies, but it was not found in mice or dogs; however, it was identified in mouse feces. In vivo data show that the major component in rat, dog, and human plasma is parent TMC435. The major metabolites reported in animal and human plasma are M18 and M21. O-Demethyl-TMC435 M21 is the only common circulating metabolite in rat, dog, and human plasma (M21: 8% of the mean plasma TMC435 concentration, with only trace amounts detected in dogs), while M18 was found in both rat and dog plasma, but at lower concentrations relative to the parent compound (M18: 12.5% to 28.9% in rats, with only trace amounts detected in dogs). Only trace amounts of the metabolites M18, M21, and M8 were detected in dog plasma; these metabolites are formed through O-demethylation and oxidation reactions on the aromatic ring. M21 accounts for less than 10% of both the parent compound and total radioactivity; therefore, systemic exposure to M21 was not assessed in safety evaluation studies. M21 does not appear to accumulate in humans. Moderate concentrations of the parent compound (0.11% to 17.2%) were detected in rat bile. In this matrix, the metabolites of TMC435 are primarily formed via hydroxylation, O-demethylation, and glucuronidation. In rats and dogs, the most important metabolic pathway for TMC435 is the O-demethylation of the parent drug to generate M18 (12.8% in male rats – 6.4% in female rats; 18.8% in dogs). In rats, other metabolites are generated by the oxidation of M18 and the oxidation of the parent drug. In dogs, further oxidation of M18 to M14 and M8, as well as oxidation of the parent drug to M21, M16, and M11, have also been reported as secondary metabolic pathways. Human metabolic profiles indicate that TMC435 is primarily metabolized via two pathways: (1) oxidation of the parent drug, with oxidation sites potentially being the cyclic moiety (M27, M21, and M22), the aromatic moiety (M26 and M16), or both (M23, M24, M25, and M11); and (2) O-demethylation of the parent drug to generate M18, followed by oxidation of the cyclic moiety to generate M14 and oxidation of the aromatic moiety to generate M5. This appears to be a secondary metabolic pathway in humans. M21 and M22 are the most significant metabolites in human feces. Other relevant metabolites (1% of the dose) include M11, M16, M27, and M18. All metabolites detected in human feces were also detected in vitro and/or in vivo (rat and/or canine feces). The primary CYP enzyme involved in TMC435 metabolism is CYP3A, but in vitro data suggest that CYP2C8 and CYP2C19 are also involved.
Biological Half-Life
In HCV-positive patients, the elimination half-life after administration of 200 mg simexprevir is approximately 41 hours, while in uninfected individuals it is approximately 10 to 13 hours.
Half-lives vary among species: 4.0 hours in rats, 3.7 hours in rabbits and dogs, and 5 to 6 hours in rhesus monkeys and cynomolgus monkeys.
In uninfected subjects with hepatitis C virus (HCV), the terminal elimination half-life of simexprevir is 10 to 13 hours; while in HCV-infected individuals receiving 200 mg (1.3 times the recommended dose) of simexprevir, the terminal elimination half-life is 41 hours.

Toxicity Summary
Identification and Use: Simeprevir is a white to off-white powder. Simeprevir is used in combination with pegylated interferon-alpha and ribavirin to treat adult patients with compensated liver disease (including cirrhosis) and chronic hepatitis C virus (HCV) genotype 1 infection who have not previously received treatment or have failed previous interferon and ribavirin treatment (including previous non-response, partial response, or relapse). Simeprevir must be used in combination with pegylated interferon-alpha (pegylated interferon-alpha-2a or pegylated interferon-alpha-2b) and ribavirin and must not be used alone to treat chronic HCV infection. Human Exposure and Toxicity: Data on the effects of simeprevir overdose are very limited. In healthy adult subjects, simexprevir was generally well tolerated at single doses up to 600 mg or once-daily doses up to 400 mg for 5 consecutive days. In adult patients with hepatitis C virus (HCV) infection, a once-daily dose of 200 mg for 4 consecutive weeks was also well tolerated. Animal studies: Simexprevir was well tolerated after single doses up to 500 mg/kg in mice, up to 1000 mg/kg in rats, up to 160 mg/kg in dogs, and up to 300 mg/kg in monkeys. In animal studies, simexprevir did not have adverse effects on vital functions (cardiac, respiratory, and central nervous system). Repeated-dose oral toxicity studies of simexprevir were conducted in mice (up to 3 months), rats (up to 6 months), dogs (up to 9 months), and monkeys (up to 28 days). Gastrointestinal reactions were observed in all species. High rates of soft, mucous, or pale stools were observed in mice, rats, and/or dogs. Swelling/vacuolization of apical intestinal cells was observed in the duodenum and jejunum of mice, rats, and dogs. Formulations of this compound caused abnormal gastric contents and/or abdominal distension due to delayed gastric emptying in mice and rats. Hepatic effects were observed in mice, rats, and dogs. These findings were typically accompanied by elevated plasma bilirubin and liver enzymes. In mouse embryo-fetal studies, doses up to 1000 mg/kg of simexprevir resulted in early and late intrauterine fetal loss and early maternal death, at exposures approximately 6 times the mean AUC at the human recommended daily dose of 150 mg. Significantly reduced fetal weight and increased fetal skeletal variation were observed at exposures approximately 4 times the mean AUC at the human recommended daily dose. In a rat prenatal and postnatal study, gestational rats were exposed to simexprevir during pregnancy and lactation at doses up to 1000 mg/kg/day. In pregnant rats, a dose of 1000 mg/kg/day of simexprevir led to early death, equivalent to the mean AUC of the human recommended dose of 150 mg once daily. Significantly reduced weight gain was observed at exposure levels reaching 0.7 times the mean AUC of the human recommended dose of 150 mg once daily. In utero (maternal administration) and lactation (transmission to pups via breast milk) exposure to simexprevir resulted in significantly reduced weight in developing pups and negatively impacted body growth (stunted growth and smaller size) and development (reduced locomotor activity), with maternal exposure levels similar to the mean AUC of the human recommended dose of 150 mg once daily. Subsequent survival, behavior, and reproductive capacity were not affected. In a rat fertility study, at doses up to 500 mg/kg/day, three male rats treated with simexprevir (2/24 rats received 50 mg/kg/day, and 1/24 rats received 500 mg/kg/day) exhibited inactive sperm, reduced testicular and epididymal volume, resulting in infertility in two of the three male rats, with a mean AUC approximately 0.2 times that of humans. Simexprevir did not show genotoxicity in a range of in vitro and in vivo studies, including the Ames test, the mammalian positive mutation assay in mouse lymphoma cells, and the in vivo mammalian micronucleus assay.
Interactions
In vitro studies have shown that simexprevir is a substrate and inhibitor of P-glycoprotein (P-gp) transport. Concomitant use of simexprevir with P-gp substrate drugs may lead to increased concentrations of these drugs.
Pharmacokinetic interactions exist with cyclosporine (increased cyclosporine concentrations). No dose adjustment of cyclosporine is required when used concomitantly with simvastatin; routine monitoring of cyclosporine concentrations is recommended. Simvastatin (single 40 mg dose) concomitantly with simvastatin (150 mg once daily for 10 days) results in a 1.5-fold increase in the AUC of simvastatin due to simvastatin's inhibition of OATP1B1 and/or CYP3A4. If simvastatin is used concomitantly with simvastatin, the dose of simvastatin should be carefully adjusted, using the lowest effective dose. Patient safety should be monitored. Concomitant administration of rosuvastatin (10 mg once daily) and simvastatin (150 mg once daily for 7 days) results in a 2.8-fold increase in the AUC of rosuvastatin due to simvastatin's inhibition of OATP1B1. If rosuvastatin and simvastatin are used concomitantly, the starting dose of rosuvastatin should be 5 mg once daily and should not exceed 10 mg once daily. For more complete data on drug interactions (38 items in total) for simmepvir, please visit the HSDB record page.

[1]. Pharmgenomics Pers Med. 2014; 7: 241–249.

[2]. Antimicrob Agents Chemother. 2016 Dec 27;61(1). pii: e01569-16.

[3]. Bioorg Med Chem Lett.2008 Sep 1;18(17):4853-8.

[4]. Bioorg Med Chem Lett. 2008 Sep 1;18(17):4853-8.

[5]. Antimicrob Agents Chemother. 2009 Apr;53(4):1377-85.

Therapeutic Uses

Antiviral Drug; Protease Inhibitor
Olysio is a hepatitis C virus (HCV) NS3/4A protease inhibitor indicated for the treatment of chronic hepatitis C (CHC) genotype 1 infection as part of a combination antiviral therapy regimen. /US product label contains/
Olysio is not recommended for monotherapy.
Olysio in combination with pegylated interferon-alpha and ribavirin: NS3 Q80K polymorphism screening is strongly recommended for patients with HCV genotype 1a infection. If HCV genotype 1a carrying Q80K is detected, other treatment options should be considered.
Olysio is not recommended for patients who have previously failed treatment regimens containing Olysio or other hepatitis C virus (HCV) protease inhibitors.
Drug Warnings
Simeprevir contains sulfonamides. In clinical trials of simeprevir, no increased incidence of rash or photosensitivity was observed in 16 patients with a history of sulfonamide allergy. However, the available data are insufficient to rule out an association between sulfonamide allergy and the frequency or severity of adverse reactions to simeprevir. During a 12-week course of Olysio treatment, 12% of subjects in the Olysio treatment group reported dyspnea, compared to 8% in the placebo group (all grades; pooled phase 3 clinical trial data). All reported dyspnea events were mild or moderate (grade 1 or 2). No grade 3 or 4 dyspnea events were reported, and no subjects discontinued Olysio treatment due to dyspnea. 61% of dyspnea events occurred within the first 4 weeks of Olysio treatment. In clinical trials, adverse reactions were reported in over 20% of patients treated with simexprevir in combination with pegylated interferon-alpha and ribavirin, at an incidence at least 3% higher than in patients treated with placebo in combination with pegylated interferon-alpha and ribavirin. These adverse reactions included rash (including photosensitivity), pruritus, and nausea. Rash has been reported in patients treated with simexprevir in combination with pegylated interferon-alpha and ribavirin. Rash most commonly occurs during the first 4 weeks of treatment, but can occur at any time during treatment. Rash is usually mild to moderate, but there have been reports of severe rashes and rashes requiring discontinuation of treatment. Patients with mild to moderate rashes should be closely monitored for disease progression (e.g., oral lesions, conjunctivitis, systemic symptoms). If the rash worsens, simexprevir should be discontinued. Patients should be monitored until the rash resolves. For more complete data on drug warnings for simexprevir (12 in total), please visit the HSDB record page. Pharmacodynamics Simeprevir is a direct-acting antiviral drug and an inhibitor of the HCV NS3/4A protease, an essential enzyme required for viral replication. Unlike [DB08873] and [DB05521], simeprevir is a competitive, reversible, macrocyclic, non-covalent inhibitor. The macrocyclic portion of this molecule enhances its affinity and selectivity, enabling it to rapidly bind to and slowly dissociate to the target protein via non-covalent binding. Simeprevir (TMC435, Olysio™) is a second-generation hepatitis C virus (HCV) protease inhibitor, recently approved for use in combination with pegylated interferon and ribavirin for the treatment of genotype 1 chronic hepatitis C. This molecule exhibits significantly different properties from first-generation protease inhibitors. Clinical trial results demonstrate that simeprevir is highly effective and safe with few adverse reactions. This article will explore the specific characteristics of this novel HCV infection treatment regimen from the perspectives of in vitro data, pharmacological data, and clinical trials. In addition, the impact of baseline Q80K polymorphism is discussed. Currently, studies are underway to evaluate simexprevir-free treatment regimens. In the future, combinations of two or more antiviral drugs that act directly on different viral enzymes and have synergistic antiviral effects will be approved, enabling the treatment of pan-genotypic hepatitis C virus infection with optimized sustained virological responses. Simexprevir will undoubtedly be part of the future treatment strategy. [1]

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The current paradigm for treating chronic hepatitis C virus (HCV) infection is the combination of drugs that act directly on each stage of the HCV life cycle. This article reports the preclinical characteristics of ITMN-8187, a non-macrocyclic HCV protease NS3/4A inhibitor. X-ray crystallography of ITMN-8187 and simexprevir in combination with NS3/4A protease showed good structural consistency. ITMN-8187 maintained low nanomolar biochemical activity against NS3/4A proteins derived from HCV genotypes 1, 2b, 4, 5 and 6. In cell-based activity assays, ITMN-8187 at doses of 11 nM and 4 nM reduced the levels of HCV replicon RNA in genotypes 1a and 1b by half, respectively. In vitro studies demonstrated that ITMN-8187, when used in combination with other direct-acting antiviral agents, exhibits additive antiviral efficacy. In an HCV chimeric mouse model, administration of 30 mg/kg body weight of ITMN-8187 for four consecutive days significantly reduced viral load until day 5. In rats, dogs, or monkeys, oral administration of 3 mg/kg ITMN-8187 resulted in plasma concentrations exceeding the half-maximal effective concentration (MCD) of ITMN-8187 16 hours after administration. Human microdose pharmacokinetic studies showed low inter-subject variability, long oral absorption time, and first-order elimination kinetics consistent with once-daily dosing. These preclinical characteristics offer advantages over other NS3/4A inhibitors already approved for the treatment of chronic HCV infection. [2]

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SAR analysis using a limited number of cyclopentane-containing macrocyclic compounds identified N-[17-[2-(4-isopropylthiazo-2-yl)-7-methoxy-8-methylquinoline-4-yloxy]-13-methyl-2,14-dioxo-3,13-diazatricyclo[13.3.0.0(4,6)]octadec-7-en-4-carbonyl](cyclopropyl)sulfonamide (TMC435350, 32c) as a potent inhibitor of HCV NS3/4A protease (K(i) = 0.36 nM) and viral replication (replicon EC(50) = 7.8 nM). TMC435350 also exhibited low in vitro clearance and high permeability, which has been confirmed by in vivo pharmacokinetic studies. TMC435350 is currently undergoing clinical trials. [3]

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SAR analysis using a limited number of cyclopentane-containing macrocyclic compounds identified N-[17-[2-(4-isopropylthiazo-2-yl)-7-methoxy-8-methylquinoline-4-yloxy]-13-methyl-2,14-dioxo-3,13-diazatricyclo[13.3.0.0(4,6)]octadec-7-en-4-carbonyl](cyclopropyl)sulfonamide (TMC435350, 32c) as a potent inhibitor of HCV NS3/4A protease (K(i) = 0.36 nM) and viral replication (replicon EC(50) = 7.8 nM). TMC435350 also exhibited low in vitro clearance and high permeability, as confirmed by in vivo pharmacokinetic studies. TMC435350 is currently undergoing clinical trials. [4]

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Hepatitis C virus (HCV) NS3/4A serine proteases have been explored as targets for inhibiting viral replication and applied in preclinical models and HCV-infected patients. TMC435350 is a highly specific and active NS3/4A protease inhibitor screened from a series of novel macrocyclic inhibitors. In biochemical assays using 1a and 1b genotype NS3/4A proteases, its inhibition constants were determined to be 0.5 nM and 0.4 nM, respectively. TMC435350 inhibited HCV replication in cell assays (subgenomic 1b replicon) with a half-maximal effective concentration (EC50) of 8 nM and a selectivity index of 5,875. This compound showed synergistic effects with α-interferon and NS5B inhibitors in the replicon model and additive effects with ribavirin. In rats, TMC435350 was widely distributed in the liver and intestine (area under the tissue/plasma concentration-time curve >35), and the absolute bioavailability after a single oral administration was 44%. Eight hours after administration, the concentrations of the compound detected in plasma and liver were higher than the EC99 values measured in the replicon. In conclusion, given the selective and potent in vitro anti-HCV activity of TMC435350, its potential for combination with other anti-HCV drugs, and its favorable pharmacokinetic properties, TMC435350 was selected for clinical development. [5]

C38H46N5O7NAS2

771.92

771.274

C, 59.13; H, 6.01; N, 9.07; Na, 2.98; O, 14.51; S, 8.31

1241946-89-3

Simeprevir;923604-59-5

46866715

Solid powder

7.227

1

11

8

53

1490

5

S(C1CC1)([N-]C([C@@]12CC1C=CCCCCN(C)C([C@@H]1C[C@@H](C[C@H]1C(N2)=O)OC1C=C(C2=NC(C(C)C)=CS2)N=C2C(C)=C(C=CC=12)OC)=O)=O)(=O)=O.[Na+] |c:11|

LLXQGDWGCCKOQP-MVZLLIIPSA-M

InChI=1S/C38H47N5O7S2.Na/c1-21(2)30-20-51-35(40-30)29-18-32(26-13-14-31(49-5)22(3)33(26)39-29)50-24-16-27-28(17-24)36(45)43(4)15-9-7-6-8-10-23-19-38(23,41-34(27)44)37(46)42-52(47,48)25-11-12-25;/h8,10,13-14,18,20-21,23-25,27-28H,6-7,9,11-12,15-17,19H2,1-5H3,(H2,41,42,44,46);/q;+1/p-1/b10-8-;/t23-,24-,27-,28-,38-;/m1./s1

sodium (cyclopropylsulfonyl)((2R,3aR,11aS,12aR,14aR,Z)-2-((2-(4-isopropylthiazol-2-yl)-7-methoxy-8-methylquinolin-4-yl)oxy)-5-methyl-4,14-dioxo-1,2,3,3a,4,5,6,7,8,9,11a,12,12a,13,14,14a-hexadecahydrocyclopenta[c]cyclopropa[g][1,6]diazacyclotetradecine-12a-carbonyl)amide

TMC435 sodium; TMC 435; TMC435; Simeprevir; Olysio.

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)

DMSO : 14.29~100 mg/mL ( 19.05 ~133.34 mM )
Ethanol : ~4 mg/mL

5% DMSO+40% PEG300+5% Tween-80+50% Saline: 2.5 mg/mL (3.33 mM) (Please use freshly prepared in vivo formulations for optimal results.)