HK1168552A - Methods for improving pharmacokinetics - Google Patents

Description

Method for improving pharmacokinetics

The present invention relates to improved methods of administering compounds of formula I for the treatment of HCV by co-administration with ritonavir. The invention also relates to pharmaceutical compositions comprising a compound of formula I and ritonavir.

Hepatitis C Virus (HCV) is the leading cause of chronic liver disease worldwide. (Boyer, N. et al, J.hepatol.200032: 98-112). The World Health Organization (WHO) estimates that more than 1.7 million people worldwide (or about 3% of the world's population) are infected with single-stranded ribonucleic acid (RNA) HCV (g.m.lauer and b.d.walker, n.engl.j.med.2001345: 41-52). Approximately one fifth of patients chronically infected with HCV eventually develop cirrhosis of the liver, suffering from considerable morbidity and mortality, including liver failure and hepatocellular carcinoma (T.J.Liang et al, Ann.Intern.Med.2000132: 296-doped 305; M.W.Fried et al, N.Engl.J.Med.2002347: 975-doped 982). HCV infection is the primary indication for liver transplantation in the United states (NIH Consensus statistics Management of Hepatitis C.2002, 10-1219(3) 6 months: 146;

http://www.ncbi.nlm.nih.gov/pubmed/14768714)。

HCV has been classified as a member of The Flaviviridae family of viruses, which includes Flaviviridae (flaviviruses), pestiviruses (pestiviruses) and hapaceviruses including hepatitis C virus (Rice, C.M., Flaviviridae: The viruses and The replication. in The Fields Virology, editors: B.N.fields, D.M.Knipe and P.M.Hoey, Lippincott-Raven Press, Philadelphia, Pa., Chapter 30, 931 959, 1996). HCV is an enveloped virus containing a positive-sense single-stranded RNA genome of approximately 9.4 kb. The viral genome consists of a highly conserved 5 'untranslated region (UTR), a long open reading frame encoding a polyprotein precursor of approximately 3011 amino acids, and a short 3' UTR.

Genetic analysis of HCV has identified 6 major genotypes that differ in DNA sequence by more than 30%. More than 30 subtypes have been distinguished. In the united states, approximately 70% of infected individuals suffer from type 1a and type 1b infections. In asia, type 1b is the most prevalent subtype. (X.Forns and J.Bukh, Clinics in Liver Disease 19993: 693-. Unfortunately, type 1 infections are more resistant to treatment than type 2 or type 3 genotypes (N.N.Zein, Clin. Microbiol. Rev., 200013: 223-.

The HCV genome encodes a polyprotein of 3010-3033 amino acids (Q.L.Choo et al, Proc.Natl.Acad.Sci.USA, 199188: 2451-2455; N.Kato et al, Proc.Natl.Acad.Sci.USA 199087: 9524-9528; A.Takamizawa et al, J.Virol.199165: 1105-1113). The virus structural proteins include a nucleocapsid core protein (C) and two envelope glycoproteins E1 and E2. HCV also encodes two proteases, a zinc-dependent metalloprotease encoded by the NS2-NS3 region and a serine protease encoded in the NS3 region. The HCV NS3 protease is a serine protease that helps process most of the viral enzymes and is therefore thought to be essential for viral replication and infection. These proteases are required to cleave specific regions of the precursor polyprotein into the mature peptide. The carboxy portion of nonstructural protein 5(NS5B) contains an RNA-dependent RNA polymerase.

The number of therapies currently approved for the treatment of HCV infection is limited. New and existing therapeutic approaches to treat HCV infection and to inhibit HCV NS5B polymerase activity have been reviewed: r.g.gish, sen.liver.dis, 199919: 5; di Besceglie, a.m. and Bacon, b.r., Scientific American, 80-85, 10 months 1999; lake-Bakaar, curr, drug targ, infection, dis.20033 (3): 247-253; p. hoffmann et al, exp. opin. ther. patents 200313 (11): 1707-1723; walker et al, exp. opin. investing. drug 200312 (8): 1269-1280; s. l.tan et al, Nature rev.drug discov.20021: 867-881; j.z.wu and z.hong, curr.drug Targ-infect.dis.20033 (3): 207-219.

Ribavirin (1- ((2R, 3R, 4S, 5R) -3, 4-dihydroxy-5-hydroxymethyl-tetrahydro-furan-2-yl) -1H- [1, 2, 4]Triazole-3-carboxylic acid amide;) Is a synthesized non-interferon-induced broad-spectrum antiviral nucleoside analogue. Ribavirin has activity in vitro against several DNA and RNA viruses, including the flaviviridae family (Gary l.davis.gastroenterology, 2000, 118: S104-S114). Although ribavirin reduces serum aminotransferase levels to normal in 40% of patients in monotherapy, it does not reduce serum levels of HCV-RNA. Ribavirin also exhibits significant toxicity, known to induce anemia. Viramidine (Veramelidine)) Is a ribavirin prodrug which is converted to ribavirin by adenosine deaminase in hepatocytes (j.z.wu, antiviral.chem.chemither.200617 (1): 33-9).

Interferons (IFNs) have been used for the treatment of chronic hepatitis for nearly a decade. IFNs are glycoproteins produced by immune cells in response to viral infection. Two different types of interferons were identified: type 1 includes several interferon alphas and one interferon beta, type 2 includes interferon gamma. Type 1 interferons are produced primarily by infected cells, protecting neighboring cells from new infections. IFNs inhibit viral replication of a wide variety of viruses, including HCV, and when used alone to treat hepatitis c infection, IFNs inhibit serum HCV-RNA to undetectable levels. In addition, IFN normalizes serum aminotransferase levels. Unfortunately, the effects of IFN are transient. Discontinuation of therapy resulted in a recurrence rate of 70%, with only 10-15% showing a sustained virologic response and normal serum alanine transferase levels (Davis, Luke-Bakaar, supra).

The combination treatment of HCV with ribavirin and interferon alpha is currently the standard of care for the first-treated HCV patients. Ribavirin and PEG-IFN (see below) in combination produced a Sustained Virological Response (SVR) in 54-56% of HCV type 1 patients, defined as undetectable hepatitis c virus ribonucleic acid (HCV RNA) 24 weeks after treatment was completed (m.w. fried et al, supra). SVR is close to 80% for HCV type 2 and 3 (Walker, supra). In addition, PEG-IFN is administered by injection, and the blood and physical toxicity of PEG-IFN and RBV is poorly tolerated for the long duration of treatment required (up to 48 weeks) by many patients. Currently, there is no SOC treatment for patients who are relapsing or who are not responsive (non-responders) to PEG-IFN/RBV treatment. In view of the high prevalence of CHC disease worldwide, the high failure rate of treatment with existing SOCs, and the tolerability issues with existing SOCs, there is a large unmet medical need for these patient populations to improve and expand treatment options. The effectiveness of host defense is hampered by the ability of HCV to disrupt, evade and fight the host immune response, which not only ensures sustained viral infection, but also quite often resists the antiviral effects of IFN therapy (m.gale, jr. and e.m.foy, Nature 2005.436: 939-. Thus, strategies targeting the virus itself may improve the therapeutic outcome compared to existing treatment options.

Several potential new molecular targets for anti-HCV therapeutic drug development have now been identified, including but not limited to NS2-NS3 self protease (autoprotease), NS3 protease, NS3 helicase, and NS5B polymerase. RNA-dependent RNA polymerase is absolutely essential for replication of a single-stranded positive-sense RNA genome. This enzyme has attracted great interest to medicinal chemists.

HCV polymerase inhibitors are another target for drug discovery, and compounds under development include R-1626, R-7128, IDX184/IDX102, PF-868554(Pfizer), VCH-759 (Virocchem), GS-9190(Gilead), A-837093 and A-848837(Abbot), MK-3281(Merck), GSK949614 and GSK625433(Glaxo), ANA598(Anadys), VBY708 (Viroay).

HCV NS3 protease inhibitors have also been identified as potentially useful for the treatment of HCV. Protease inhibitors in clinical trials include VX-950(Telaprevir, Vertex), SCH503034(Broceprevir, Schering), TMC435350(Tibotec/Medivir), and ITMN-191 (Intermune). Other protease inhibitors at an early stage of development include MK7009(Merck), BMS-790052(Bristol Myers Squibb), VBY-376(Virobay), IDXSCA/IDXSCB (Idenix), BI12202(Boehringer), VX-500(Vertex), PHX1766 Phenomix.

In one aspect of the invention, there is provided a method of increasing the bioavailability and or blood levels of a hepatitis C virus NS3 protease inhibitor of formula I in a patient, the method comprising co-administering to the patient a compound of formula I and a cytochrome P450 monooxygenase inhibitor.

In another aspect of the invention, there is provided a pharmaceutical composition comprising a compound of formula I and a cytochrome P450 monooxygenase inhibitor.

The phrase "an" entity as used herein means one or more of the entity(s); for example, a compound means one or more compounds or at least one compound. Thus, the terms "a", "an" or "a" and "at least one" may be used interchangeably herein.

The terms "comprising" or "including" as used in this specification are to be interpreted as having an open-ended meaning, whether in transitional phrases or in the body of the claims. That is, the term is to be construed as synonymous with the phrase "having at least" or "including at least". When used in the context of a method, the term "comprising" means that the method includes at least the recited steps, but may include additional steps. The term "comprising" when used in the context of a compound or composition means that the compound or composition includes at least the recited features or components, but may also include additional features or components.

The term "optionally" is used herein to indicate that the subsequently described event or circumstance may, but need not, occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

As used herein, the recitation of a numerical range for a variable is intended to indicate that the invention can be practiced with the variable equaling any value within the range. Thus, for variables that are non-continuous in nature, the variable may equal any integer value of a range of values, including the endpoints of the range. Similarly, for a variable that is continuous in nature, the variable may be equal to any real value of a range of values, including the endpoints of the range. For example, a variable described as having a value of 0 to 2 may be 0, 1, or 2 for a variable that is non-continuous in nature, and 0.0, 0.1, 0.01, 0.001, or any real value for a variable that is continuous in nature.

There is a need for compositions and therapeutic combinations for the treatment of HCV. Combination chemotherapy has proven effective in treating HCV, however, patient compliance increases with decreasing number of doses and frequency of administration. Improved compounds and dosage regimens would be useful in anti-HCV therapy. The present invention provides methods of administering a compound of formula I (R7227) and a CYP3a4 inhibitor that increases the bioavailability of R7227 and decreases the amount of R7227 that must be administered.

Compound I (R7227) is a highly potent and selective macrocyclic peptidomimetic inhibitor of NS3/4A protease activity, selected for oral drug development for the treatment of HCV infection due to its demonstrated potency in inhibiting NS3/4A protease. R7227 shows significant exposure in the liver of animal species (liver is the major or only site of HCV replication in humans) and has acceptable toxicological properties. R7227 is a highly potent NS3/4A proteolytic inhibitor with a 50% Inhibitory Concentration (IC)₅₀) ≦ 0.225nM and is highly specific for the intended target. IC of R7227 in a cell-based potency assay with genotype 1 HCV replicon₅₀It was 1.77 nM. In this same cell-based assay, R7227 additionally showed no detectable change in the activity of interferon alpha-2 a conjugated to polyethylene glycol ("pegylated") (PEG-IFN-alpha 2a,roche) synergistic antiviral action, indicating that R7227 would be useful in HCV treatment.

It has been found that cytochromes, particularly the CYP3a4 isoform, metabolize R7227 resulting in the need for more frequent and higher dosage levels to maintain therapeutically effective blood levels.

In early preclinical studies, the cytochrome P450 phenotype with chemical inhibitors suggested the involvement of a number of CYP isozymes including 3a4, 2C19, 1a2, 2D6 and 2C9 in the metabolism (R7227). Further experiments with recombinant CYP have shown that only CYP3a4 metabolizes R7227 to an extent that can affect pharmacokinetics. Thus, an amount of a cytochrome P450 monooxygenase inhibitor effective to inhibit the metabolism of the protease inhibitor may increase the bioavailability of R7227 compared to administration in the absence of the CYP inhibitor.

Some drugs are metabolized by the enzyme cytochrome P450. These enzymes often oxidize the drug, resulting in unfavorable pharmacokinetic profiles (e.g., reduced blood levels, reduced half-life). In these cases, inhibition of drug metabolism can lead to improved pharmacokinetic properties of the drug (see, e.g., U.S. Pat. No. 6,037,157; D.E. Kempf et al, anti. agents Chemother., 199741: 654-660; W.J. Curatolo and G.Foulds, U.S. Pat. Pub. No. 2004/0091527 and M.G. Cordingley, U.S. Pat. Pub. No. 2004/0152625). In order to determine whether combination therapy with a cytochrome P450 antagonist will improve the pharmacokinetics of the drug, the metabolic pathways involved must be accounted for.

Cytochrome P450(CYP P450) is a very large and diverse superfamily of heme proteins. Both exogenous and endogenous compounds are substrates for cytochrome P450 isoforms. Cytochrome P4503A4(CYP3A 4; EC 1.14.13.97) is one of the most important enzymes involved in metabolism of foreign substances in vivo and in vitro. CYP3a4 is involved in the oxidation of the widest range of substrates for all CYPs. Although CYP3a4 is found primarily in the liver, it is also present in other organs and tissues of the body.

Any CYP inhibitor that improves the pharmacokinetics of the related NS3 protease can be used in the methods of the invention. Such CYP inhibitors include, but are not limited to, ritonavir (WO 94/14436), ketoconazole, oleandomycin, 4-methylpyrazole, cyclosporin, clomerthiazol, cimetidine, itraconazole, fluconazole, miconazole, fluvoxamine, fluoxetine, nefazodone, sertraline, indinavir, nelfinavir, amprenavir, fosamprenavir, saquinavir, lopinavir, delavirdine, and erythromycin. A preferred CYP inhibitor is ritonavir.

Ritonavir is a potent inhibitor of CYP3a4 activity and is currently used at low non-therapeutic doses (e.g., 100mg twice daily) to increase or "boost" the PK of other HIV Protease Inhibitors (PIs). In view of the high prevalence of HIV/HCV co-infection, R7227 can be used to treat HCV in HIV/HCV co-infected patients receiving ritonavir-boosted HIV PIs, resulting in a possible interaction between ritonavir-boosted HIV PI and R7227.

However, in addition to the inhibitory effect on 3a4, ritonavir was shown to induce the activity of other enzymes, including CYP1a2, 2C9 and 2C 19. Although the inhibitory effect of ritonavir will predominate during acute dosing, resulting in elevated R7227 levels, prolonged administration of ritonavir prior to HCV treatment may induce oxidation of other isoforms of R7227, thereby counteracting the expected inhibitory effect.

In one embodiment of the invention, a method is provided for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227 in a patient in need thereof, the method comprising administering R7227 and a cytochrome P450 monooxygenase inhibitor, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level in the absence of the cytochrome P450 monooxygenase inhibitor.

In another embodiment of the invention, there is provided a method of increasing the bioavailability of R7227 in a patient comprising administering R7227 and ritonavir. Ritonavir is known by Abbott laboratories under the nameSold as HIV protease inhibitors (chemical abstracts accession number 1555213-67-5).

In another embodiment of the invention, there is provided a method of increasing the bioavailability of R7227 in a patient comprising co-administering R7227 and ritonavir, wherein R7227 and ritonavir are in separate dosage forms. The respective doses may be administered at the same or about the same time, or the doses may be administered at different time periods.

In another embodiment of the present invention, there is provided a method of increasing the bioavailability of R7227 in a patient comprising co-administering R7227 and ritonavir, wherein R7227 and ritonavir are administered simultaneously. R7227 and ritonavir may be present in a single formulation to increase patient convenience.

In another embodiment of the present invention, there is provided a method of increasing the bioavailability of R7227 in a patient comprising co-administering R7227 and ritonavir, wherein R7227 and ritonavir are administered in a single dosage form.

In another embodiment of the invention, there is provided a method of increasing the bioavailability of R7227 in a patient comprising co-administering a dose of 25 to 600 mg/day, particularly 25 to 500 mg/day, of R7227 and 50 to 400 mg/day of ritonavir.

Use or use in the manufacture of a medicament for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level in the absence of the cytochrome P450 monooxygenase inhibitor.

In another embodiment of the invention, there is provided the use of R7227 and ritonavir in increasing the bioavailability of R7227 or in the manufacture of a medicament for increasing the bioavailability of R7227. Ritonavir is known by Abbott Laboratories under the nameSold as HIV protease inhibitors (chemical abstracts accession number 1555213-67-5).

In another embodiment of the invention, there is provided the use of R7227 and ritonavir in the manufacture of a medicament for increasing the bioavailability of R7227, wherein R7227 and ritonavir are in separate dosage forms. The respective doses may be administered at the same or about the same time, or the doses may be administered at different time periods.

In another embodiment of the invention, there is provided a use of R7227 and ritonavir in the manufacture of a medicament for increasing the bioavailability of R7227, wherein R7227 and ritonavir are administered simultaneously. R7227 and ritonavir may be present in a single formulation to increase patient convenience.

In another embodiment of the invention, there is provided the use of a combination of R7227 and ritonavir in increasing the bioavailability of R7227, wherein R7227 and ritonavir are administered in a single dosage form, or the use of a combination of R7227 and ritonavir in the manufacture of a medicament for increasing the bioavailability of R7227, wherein R7227 and ritonavir are administered in a single dosage form.

In another embodiment of the invention, there is provided the use of R7227 and ritonavir in the manufacture of a medicament comprising a dose of ritonavir for co-administration of 25 to 600 mg/day, particularly 25 to 500 mg/day of R7227 and 50 to 400 mg/day.

In another embodiment of the invention, there is provided the use of R7227 and ritonavir in the manufacture of a medicament for increasing the bioavailability of a dose of ritonavir co-administered at 50 to 300 mg/day and at 100 to 200 mg/day.

In another embodiment of the invention, there is provided the use of a compound of formula I, a free base or other pharmaceutically acceptable salt thereof, and a cytochrome P450 monooxygenase inhibitor in, or in the manufacture of a medicament for, the treatment of HCV.

In another embodiment of the present invention, there is provided the use of a compound of formula I, a free base or other pharmaceutically acceptable salt thereof, and ritonavir in, or in the manufacture of a medicament for, the treatment of HCV.

Combination therapy has proven to be a valuable component of antiviral therapy, and thus HCV therapy with R7227 and ritonavir may include administration of other components including additional substances selected from immunomodulators, antiviral agents, other HCV protease inhibitors, inhibitors of other targets in the HCV life cycle, such as HCV polymerase inhibitors, or combinations thereof.

In another embodiment of the present invention, there is provided the use of a compound of formula I and ritonavir in combination with at least one additional substance selected from the group consisting of: immunomodulators and/or antivirals and/or other hcv NS3/4A protease inhibitors and/or NS5B polymerase inhibitors and/or broad spectrum viral inhibitors and/or other cytochrome P-450 inhibitors.

In another embodiment of the invention, there is provided the use of a compound of formula II (R7128) together with R7227 and ritonavir in, or in the manufacture of a medicament for, the treatment of HCV.

In another embodiment of the invention there is provided the use of alpha-, beta-or gamma-interferon and/or thymosin and/or ribavirin and/or R7128 together with R7227 and ritonavir in, or in the manufacture of a medicament for, the treatment of HCV.

In another embodiment of the present invention, there is provided a pharmaceutical composition comprising R7227 or a pharmaceutically acceptable salt thereof, a cytochrome P450 monooxygenase inhibitor or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient, diluent or carrier.

In another embodiment of the present invention, there is provided a pharmaceutical composition comprising R7227 or a free base or other pharmaceutically acceptable salt thereof, a cytochrome P450 monooxygenase inhibitor and at least one pharmaceutically acceptable excipient, diluent or carrier.

In another embodiment of the present invention, there is provided a pharmaceutical composition comprising R7227 or a free base or other pharmaceutically acceptable salt thereof, a cytochrome P450 monooxygenase inhibitor, an HCV polymerase inhibitor R7128 and at least one pharmaceutically acceptable excipient, diluent or carrier.

In another embodiment of the present invention, there is provided a pharmaceutical composition comprising R7227 or its free base or other pharmaceutically acceptable salt, ritonavir or its pharmaceutically acceptable salt and at least one pharmaceutically acceptable excipient, diluent or carrier.

In another embodiment of the invention, a kit is provided comprising a hepatitis c virus NS3 protease inhibitor of formula I and ritonavir.

In one embodiment of the invention, a pharmaceutical pack is provided comprising a compound of formula I, ritonavir, and optionally an informational insert containing instructions for use of the inhibitor.

Low doses of ritonavir have been reported to increase exposure of the most sensitive CYP3A probe substrate midazolam by approximately 7-fold. (a.a. mathias et al, clin.pharmacol.ther.200985 (1) 64-70).Simulations (symcrypt Limited, Blades Enterprise Centre, john street, Sheffield S24 SU, UK) predicted that ritonavir could increase R7227 exposure by approximately 2-fold to 4-fold, assuming CYP3A contributed to the total elimination of R7227 by 50% and 100%, respectively. When co-administered with ritonavir in this study, the R7227 exposure was expected to increase 4-fold, which is still significantly lower than that observed in the SAD study in the highest safe and tolerated dose of 1600mg in healthy volunteers.

Multiple doses of 100mg ritonavir per 12 hours significantly increased R7227AUC0 → ∞, Cmax and C12h by approximately 5.5-fold, 3.25-fold and 27-42-fold, respectively. The multi-dose effect of ritonavir on R7227C12h was lower than the acute single dose effect of ritonavir, probably because induction of CYP enzymes by ritonavir after multiple dosing counteracted some of the acute inhibitory effects of ritonavir on CYP3a 4. Thus, by co-administration with ritonavir, the pharmacokinetics of R7227 is greatly improved.

The compounds of the present invention may be formulated in a variety of oral administration dosage forms and carriers. Oral administration may be in the form of tablets, coated tablets, dragees, hard and soft gelatin capsules, solutions, emulsions, syrups or suspensions. The compounds of the present invention are effective when administered by other routes of administration, including continuous (intravenous drip) topical parenteral, intramuscular, intravenous, subcutaneous, and suppository administration. The preferred mode of administration is generally oral using a convenient daily regimen which may be adjusted according to the degree of involvement and the response of the patient to the active ingredient.

The compounds of the present invention and their pharmaceutically acceptable salts, together with one or more conventional excipients, carriers or diluents, may be formulated into pharmaceutical compositions and unit dosage forms. The pharmaceutical compositions and unit dosage forms can contain conventional ingredients in conventional proportions, with or without additional active compounds or ingredients, and the unit dosage forms can contain any suitable effective amount of the active ingredient commensurate with the intended daily dosage range to be employed. The pharmaceutical composition may be employed in the form of: solid such as tablets or filled capsules, semi-solid, powder, sustained release formulations or liquid such as solutions, suspensions, emulsions, elixirs or filled capsules for oral use; or suppositories for rectal or vaginal administration; or a sterile injectable solution for parenteral use. Typical formulations will contain from about 5% to about 95% active compound (w/w). The terms "formulation" or "dosage form" are intended to include both solid and liquid formulations of the active compound, and those skilled in the art will appreciate that the active ingredient may be present in different formulations, depending on the target organ or tissue and the desired dosage and pharmacokinetic parameters.

The term "excipient", as used herein, means a compound that is useful in preparing a pharmaceutical composition, is generally safe, non-toxic, neither biologically nor otherwise undesirable, and includes excipients that are acceptable for veterinary use as well as human pharmaceutical use. The compounds of the present invention may be administered alone, but will generally be administered together with one or more suitable pharmaceutical excipients, diluents and carriers selected with regard to the intended route of administration and standard pharmaceutical practice.

"pharmaceutically acceptable" means useful in preparing a pharmaceutical composition that is generally safe, non-toxic, neither biologically nor otherwise undesirable, including those that are acceptable for human pharmaceutical use.

The "pharmaceutically acceptable salt" form of the active ingredient may also initially confer the desired pharmacokinetic properties on the active ingredient in the absence of the non-salt form and may even positively influence the pharmacodynamics of the active ingredient with respect to its therapeutic activity in vivo. The phrase "pharmaceutically acceptable salt" of a compound refers to a salt that is pharmaceutically acceptable and has the intended pharmacological activity of the parent compound. Such salts include: (1) acid addition salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like, or with organic acids; examples of the organic acid include acetic acid, propionic acid, hexanoic acid, cyclopentanepropionic acid, glycolic acid, pyruvic acid, lactic acid, malonic acid, succinic acid, malic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, 3- (4-hydroxybenzoyl) benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, 1, 2-ethane-disulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, 4-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid, 4-toluenesulfonic acid, camphorsulfonic acid, 4-methylbicyclo [2.2.2] oct-2-ene-1-carboxylic acid, glucoheptonic acid, 3-phenylpropionic acid, trimethylacetic acid, tert-butylacetic acid, laurylsulfuric acid, gluconic acid, glutamic acid, hydroxynaphthoic acid, salicylic acid, stearic acid, muconic acid, and the like; or (2) a salt formed when the acidic proton present in the parent compound is replaced by a metal ion, such as an alkali metal ion, an alkaline earth metal ion, or an aluminum ion; or a salt formed when coordinated with an organic base such as ethanolamine, diethanolamine, triethanolamine, tromethamine, N-methylglucamine, or the like.

Solid form preparations include powders, tablets, pills, capsules, cachets, suppositories, and dispersible granules. A solid carrier can be one or more substances that also can act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, preservatives, tablet disintegrating agents, or an encapsulating material. In powders, the carrier is generally a finely divided solid which is in admixture with the finely divided active component. In tablets, the active ingredient is usually mixed with a carrier having the required binding capacity in suitable proportions and compacted in the shape and size desired. Suitable carriers include, but are not limited to, magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, tragacanth, methyl cellulose, sodium carboxymethyl cellulose, a low melting wax, cocoa butter, and the like. Solid form preparations may contain, in addition to the active ingredient, colorants, flavors, stabilizers, buffers, artificial and natural sweeteners, dispersants, thickeners, solubilizing agents, and the like.

Liquid preparations are also suitable for oral administration, and include emulsions, syrups, elixirs, aqueous solutions, and aqueous suspensions. They include solid form preparations which are intended to be converted, shortly before use, to liquid form preparations. Emulsions may be prepared in solution, for example, in aqueous propylene glycol, or may contain emulsifying agents, for example, lecithin, sorbitan monooleate, or acacia. Aqueous solutions can be prepared by dissolving the active ingredient in water and adding suitable colorants, flavors, stabilizers, and thickening agents. Aqueous suspensions may be prepared by dispersing the finely divided active component in water containing viscous material, for example, natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose, and other well-known suspending agents.

The compounds of the invention may be formulated for parenteral administration (e.g., by injection, e.g., bolus injection or continuous infusion) and may be presented in unit dosage form in ampoules, pre-filled syringes, small volume infusion or in multi-dose containers with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, for example, solutions in aqueous polyethylene glycol. Examples of oily or nonaqueous carriers, diluents, solvents or vehicles include propylene glycol, polyethylene glycol, vegetable oils (e.g., olive oil) and injectable organic esters (e.g., ethyl oleate), which may contain formulatory agents such as preservatives, wetting, emulsifying or suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form, obtained by aseptic packaging of the sterilized solid or by freeze-drying of the solution, for constitution with a suitable vehicle, e.g. sterile, pyrogen-free water, before use.

The compounds of the present invention may be prepared for administration in the form of suppositories. A low melting wax such as a mixture of fatty acid glycerides or cocoa butter is first melted and the active ingredient is dispersed homogeneously, for example by stirring. The molten homogeneous mixture is then poured into a container of suitable size, cooled and solidified.

The compounds of the invention may be prepared in a form for vaginal administration. Pessaries, tampons, creams, gels, pastes, foams or sprays containing in addition to the active ingredient such carriers as are known in the art to be appropriate.

When desired, the formulations can be prepared with enteric coatings suitable for sustained and controlled release administration of the active ingredient. For example, the compounds of the present invention may be formulated in a transdermal or subcutaneous drug delivery device. These delivery systems are advantageous when sustained release of the compound is necessary and when patient compliance with the treatment regimen is critical. The compounds in transdermal delivery systems are typically attached to a skin-adherent solid support. The compound of interest may also be added with a penetration enhancer such as azone (1-dodecaazacycloheptan-2-one). The sustained release delivery system may be implanted subcutaneously in the subcutaneous layer by surgery or injection. Subcutaneous implants encapsulate the compound in a lipid-soluble membrane such as silicone rubber or a biodegradable polymer such as polylactic acid.

Suitable formulations and pharmaceutical carriers, diluents and excipients are described in Remington: the science and Practice of Pharmacy (1995.E.W.Martin, edited by Mack publishing Co., 19 th edition, Iston, Pa.). The skilled formulation scientist is able to modify the formulation within the teachings of the specification to provide a wide variety of formulations for specific routes of administration without destabilizing the compositions of the invention or otherwise compromising their therapeutic activity.

Modifications of the compounds of the invention to render them more soluble in water or other vehicles can be readily accomplished, for example, by small modifications (salt formation, esterification, etc.), which are well within the ordinary skill of the art. It is also well within the ordinary skill in the art to modify the route of administration and dosage regimen of a particular compound in order to manage the pharmacokinetics of the compounds of the present invention to achieve maximal beneficial effects in the patient.

The methods described herein comprise administering a combination of a hepatitis C virus NS3/4A protease inhibitor and a cytochrome P450 monooxygenase inhibitor. This administration is referred to herein as co-administration. Co-administration includes administering each inhibitor in the same dosage form or in different dosage forms. When administered in different dosage forms, the inhibitors may be administered in any order, at the same or different times. Accordingly, the present invention provides methods wherein a CYP inhibitor and a hepatitis c virus NS3/4A protease inhibitor are administered together in the same dosage form or in separate dosage forms.

If the CYP inhibitor and the protease inhibitor are administered in separate dosage forms, the inhibitors may be administered at about the same time. Alternatively, the CYP inhibitor may be administered at any time period in the vicinity of the administration of the protease inhibitor. That is, the CYP inhibitor may be administered prior to, simultaneously with, or subsequent to the NS3/4A protease inhibitor. The period of administration should be such that the CYP inhibitor can affect the metabolism of the protease inhibitor. For example, if the protease inhibitor is administered first, the CYP inhibitor should be administered before the protease inhibitor is metabolized and/or excreted.

The term "therapeutically effective amount" as used herein means the amount required to reduce the symptoms of a disease in an individual. Therapeutically effective levels in the treatment of HCV are typically determined by measuring the levels of viral RNA. The dosage will be adjusted to the individual needs in each particular case. The dosage may vary within a wide range depending on various factors, such as the severity of the disease being treated, the age and general health of the patient, other medications being used to treat the patient, the route and manner of administration, and the preferences and experience of the attending medical personnel.

Dosage levels of the NS3 protease inhibitor of from about 100 to about 800 mg/day, preferably from about 200 to about 600 mg/day, are useful for the prevention and treatment of HCV-mediated diseases. For CYP inhibitors, dosage levels of from about 50 to about 400 mg/day are typical. More typically at a dosage level of about 100 to about 200 mg/day. Typically, the pharmaceutical composition of and according to the invention will be administered about 1 or 2 times per day. The amount of active ingredient that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. Typically, treatment is initiated at smaller doses than the optimal dose of the compound. The dosage is then gradually increased in small increments until the optimum effect is achieved for the individual patient. The ordinarily skilled artisan, without undue experimentation in treating the diseases described herein, will be able to determine a therapeutically effective amount of a compound of the invention for a given disease and patient, depending on the individual knowledge, experience, and disclosure of the present application.

Preferred dosage forms of ritonavir have been disclosed by l.a. al-Razzak et al in U.S. patent No. 5,484,801 published 1-16, 1996, U.S. patent No. 5,948,436 published 9-7, 1999, WO 95/07696 published 3-23, 1995, and WO 95/09614 published 4-13, 1995.

The methods described herein include the administration of a combination of a hepatitis c virus NS3 protease inhibitor and a cytochrome P450 monooxygenase inhibitor. This administration is referred to herein as co-administration. Co-administration includes administering each inhibitor in the same dosage form or in different dosage forms. When administered in different dosage forms, the inhibitors may be administered in any order, at the same or different times. Accordingly, the present invention provides methods wherein a CYP inhibitor and a hepatitis c virus NS3/4A protease inhibitor are administered together in the same dosage form or in separate dosage forms.

If the CYP inhibitor and the protease inhibitor are administered in separate dosage forms, the inhibitors may be administered at about the same time. Alternatively, the CYP inhibitor may be administered at any time period in the vicinity of the administration of the protease inhibitor. That is, the CYP inhibitor may be administered prior to, simultaneously with, or subsequent to the NS3/4A protease inhibitor. The period of administration should be such that the CYP inhibitor can affect the metabolism of the protease inhibitor. For example, if the protease inhibitor is administered first, the CYP inhibitor should be administered before the protease inhibitor is metabolized and/or excreted.

Combination therapy has proven to be a valuable component of antiviral therapy, and thus HCV therapy with R7227 and ritonavir may include the administration of other components including additional substances selected from immunomodulators, antiviral agents, other HCV protease inhibitors, HCV polymerase inhibitors or inhibitors of other targets in the HCV life cycle, or combinations thereof.

The pharmaceutical compositions may also be administered to the patient in a "patient pack" containing the entire course of treatment in a single package, usually a blister pack. The patient pack has an advantage over traditional prescriptions where a pharmacist divides a patient's supply of medication from a bulk supply in that the patient is always able to see the package inserts contained in the patient pack, where it is always lost. The inclusion of package inserts has been shown to increase patient compliance with physician guidance.

Administration of the combination of the invention by a single patient pack or a patient pack of each formulation containing an insert instructing the patient to use the invention correctly is a desirable additional feature of the invention which improves patient compliance.

According to another aspect of the invention is a pharmaceutical pack comprising at least the NS3 protease inhibitor and the CYP3a4 inhibitor of the invention together with an information insert containing instructions for the use of the combination of the invention. In an alternative embodiment of the invention, the pharmaceutical pack further comprises one or more additional substances as described herein. The additional substances may be provided in the same package or in separate packages.

Another aspect of the invention relates to a kit of parts for use in treating or preventing HCV infection in a patient, comprising: one or more pharmaceutical formulations of each pharmaceutical component; a container containing a pharmaceutical formulation during storage and prior to administration; and instructions for administering the drug in a manner effective to treat or prevent HCV infection.

Accordingly, the present invention provides a kit for the simultaneous or sequential administration of an NS3/4A protease inhibitor and a CYP inhibitor (and optionally additional substances) or derivatives thereof prepared in a conventional manner. Typically, such kits will comprise, for example, a composition of each inhibitor and optionally additional agents in a pharmaceutically acceptable carrier (and in one or more pharmaceutical preparations) and written instructions for simultaneous or sequential administration.

In another embodiment, a kit of parts is provided which: containing one or more dosage forms for self-administration; container means, preferably sealed, for containing the dosage forms during storage and prior to use; and instructions for administration of the drug to a patient. The instructions will typically be written instructions on the package insert, label, and/or other components of the kit, and the dosage form is as described herein. Each dosage form may be contained separately, such as in a sheet of metal foil-plastic laminate, where each dosage form is separated from the other dosage forms in separate units or blisters, or the dosage forms may be contained in a single container, such as in a plastic bottle. The kits of the present invention will also typically include means for packaging the individual kit components, i.e., dosage forms, container means, and written instructions for use. The packaging means may take the form of a cardboard box or carton, a plastic bag or a foil bag or the like.

In order that the invention may be more fully understood, the following preparation examples and test examples are set forth. These examples are for illustrative purposes only and are not to be construed as limiting the scope of the invention in any way.

Examples

Pharmacokinetic enhancement of R7227 in healthy adults

Subjects participating in the study were screened within 21 days prior to dosing. 14 healthy volunteers (each group n-14) were enrolled in the study. The dosing schedule is illustrated below:

r7227 formulationsR7227 is formulated in clear size 10 ovoid soft gelatin capsules for oral administration at an intensity of 100mg per capsule (anhydrous free acid equivalent). The capsule filling solution consisted of R7227-001, polyethylene glycol PEG400(Macrogol 400) and Butylated Hydroxytoluene (BHT). All excipients are pharmacopeia grade (NF or EP). Type 195 gelatin (NF, EP) was used as the main gel raw material for the capsule shell, and a small amount of sorbitol liquid 85/70/00(NF, EP) and water (USP) were used as plasticizers.

All study medications were taken with meals. On the day of administration of R7227 (alone or with ritonavir), study medication was administered after completion of a standard high fat breakfast, and the breakfast on these days was the same. R7227 was administered orally on days 1, 3 and 12 in a single dose of 100mg softgel. On days 3 and 12, R7227 was administered with a morning dose of ritonavir. Ritonavir 100mg was administered orally twice daily (every 12 hours) from day 3 to day 12.

Blood samples (5mL) were collected to determine the plasma concentration of R7227 (and metabolites, when analysable) according to the following schedule:

PK samples (5mL) were collected on day 1, before (pre-dose) and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, 12 and 24 hours after R7227 dosing;

PK samples (5mL) were collected on days 3 and 12, before (pre-dose) and at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, 12, 24, 36 and 48 hours post-dose of R7227.

The primary PK parameter determined for R7227 was C_maxAnd AUC_0→∞. The secondary PK parameters determined for R7227 include T_maxAnd AUC_0→last、CL/F、t_1/2、C_12hrAnd C_24h。

Application of analysis of variance (ANOVA) to Log-transform oncePharmacokinetic parameters. Deriving primary parameters (AU of R7227)_C0→∞And C_max) The two 90% confidence intervals on both sides of the ratio of the geometric mean values of (a) were used for the following comparisons: (R7227+ ritonavir) day 3 versus day 1 of R7227 and (R7227+ ritonavir) day 12 versus day 1 of R7227;

analysis of variance (ANOVA) was used to analyze all primary study parameters using the following model:

Yij＝μ+τi+sj+εij

where Yij refers to the PK parameter to be analyzed and μ refers to the total mean of the transformed variables; τ i, fixed effect of treatment; sj, random effects of the subject; ε ij (error). Assume that the random deviations ε ij are independent and have a zero mean and a common variance σ²A normal distribution. Group comparison τ R7227+ ritonavir- τ R7227, residual variance σ was estimated by ANOVA model²And a 90% confidence limit for group comparisons. For log-transformed variables (AUC)_0→∞And C_max) The ratio of the true group mean and the confidence limits for the corresponding ratios of the mean values of the unconverted variables are calculated by least squares mean difference exponentiation and confidence limits for the converted values.

The foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding. It will be apparent to those skilled in the art that changes and modifications may be made within the scope of the appended claims. Accordingly, it is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

All patents, patent applications, and publications cited in this application are incorporated herein by reference in their entirety for all purposes to the same extent as if each patent, patent application, or publication were individually indicated to be so incorporated.

Claims (18)

1. A method of increasing the bioavailability of a hepatitis C virus NS3/4A protease inhibitor of formula I in a patient, the method comprising co-administering to the patient a compound of formula I and a cytochrome P450 monooxygenase inhibitor, wherein the monooxygenase inhibitor is present in an amount sufficient to elevate blood levels of I,

2. the method of claim 1 wherein the cytochrome P450 monooxygenase inhibitor is ritonavir.

3. The method of claim 2, wherein the compound of formula I and ritonavir are in separate dosage forms.

4. The method of claim 3, wherein the separate dosage forms are administered at about the same time.

5. The method of claim 2, wherein the compound of formula I and ritonavir are administered in a single dosage form.

6. A method of treating a hepatitis c virus infection in a patient in need thereof, the method comprising administering to a patient in need thereof a compound of formula I, a free base or a pharmaceutically acceptable salt thereof, and a cytochrome P450 monooxygenase inhibitor or a pharmaceutically acceptable salt thereof.

7. The method of claim 6, wherein the cytochrome P450 monooxygenase inhibitor is ritonavir or a pharmaceutically acceptable salt thereof.

8. The method of claim 7 comprising co-administering at least one additional agent selected from an immunomodulator and/or an antiviral agent and/or other HCV NS3/4A protease inhibitor and/or NS5B polymerase inhibitor and/or a broad spectrum viral inhibitor and/or other cytochrome P-450 inhibitors with the compound of formula I and ritonavir.

Use of R7227 and a cytochrome P450 monooxygenase inhibitor for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level of R7227 in the absence of the cytochrome P450 monooxygenase inhibitor.

Use of R7227 and a cytochrome P450 monooxygenase inhibitor in the manufacture of a medicament for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level of R7227 in the absence of the cytochrome P450 monooxygenase inhibitor.

11. Use according to claim 9 or 10, wherein the inhibitor of cytochrome P450 monooxygenase is ritonavir or a pharmaceutically acceptable salt thereof.

12. The use according to claim 11, wherein R7227 and ritonavir are in separate dosage forms.

13. The use of claim 11, wherein R7227 and ritonavir are administered simultaneously.

Use according to claim 11 of R7227 and ritonavir and at least one further substance selected from the group consisting of immunomodulators, antivirals, other HCV NS3/4A protease inhibitors, NS5B polymerase inhibitors, broad spectrum viral inhibitors and other cytochrome P-450 inhibitors.

15. A pharmaceutical composition comprising a compound of formula I or a free base or other pharmaceutically acceptable salt thereof and a cytochrome P450 monooxygenase inhibitor or a pharmaceutically acceptable salt thereof and at least one pharmaceutically acceptable excipient, diluent or carrier. Use of R7227 and a cytochrome P450 monooxygenase inhibitor in the manufacture of a medicament for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level of R7227 in the absence of the cytochrome P450 monooxygenase inhibitor.

16. The pharmaceutical composition of claim 13, wherein the cytochrome P450 monooxygenase inhibitor is ritonavir or a pharmaceutically acceptable salt thereof. Use of R7227 and a cytochrome P450 monooxygenase inhibitor in the manufacture of a medicament for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level of R7227 in the absence of the cytochrome P450 monooxygenase inhibitor.

17. A kit comprising a hepatitis c virus NS3 protease inhibitor of formula I and ritonavir. Use of R7227 and a cytochrome P450 monooxygenase inhibitor in the manufacture of a medicament for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level of R7227 in the absence of the cytochrome P450 monooxygenase inhibitor.

18. A pharmaceutical pack comprising a compound of formula I, ritonavir and an information insert containing instructions for use of the inhibitor. Use of R7227 and a cytochrome P450 monooxygenase inhibitor in the manufacture of a medicament for increasing the bioavailability of the hepatitis c virus NS3/4A protease inhibitor R7227, wherein the amount of cytochrome P450 monooxygenase inhibitor is sufficient to increase the blood level of R7227 compared to the blood level of R7227 in the absence of the cytochrome P450 monooxygenase inhibitor.