2013年11月19日,吉利德(Gilead)研发的整合酶抑制剂Vitekta(elvitegravir,85mg和100mg)已获欧盟委员会(EC)批准,用于无任何已知elvitegravir抗性相关突变的HIV-1成人感染者的治疗。
Missed dose If the patient misses a dose of Vitekta within 18 hours of the time it is usually taken, the patient should take Vitekta with food as soon as possible and resume the normal dosing schedule. If a patient misses a dose of Vitekta by more than 18 hours, and it is almost time for their next dose, the patient should not take the missed dose and simply resume the usual dosing schedule. If the patient vomits within 1 hour of taking Vitekta another tablet should be taken. Special populations Elderly No data are available on which to make a dose recommendation for patients over the age of 65 years (see section 5.2). Renal impairment No dose adjustment of Vitekta is required for patients with renal impairment (see section 5.2). Hepatic impairment No dose adjustment of Vitekta is required in patients with mild (Child-Pugh Class A) or moderate hepatic impairment (Child-Pugh Class B). Elvitegravir has not been studied in patients with severe hepatic impairment (Child-Pugh Class C) (see sections 4.4 and 5.2). Paediatric population The safety and efficacy of elvitegravir in children aged 0 to less than 18 years have not yet been established (see section 5.1). No data are available. Method of administration Vitekta should be taken orally, once daily with food (see section 5.2). The film-coated tablet should not be chewed or crushed. 4.3 Contraindications Hypersensitivity to the active substance or to any of the excipients listed in section 6.1. Co-administration with the following medicinal products due to the potential for loss of virologic response and possible development of resistance (see section 4.5): • anticonvulsants: carbamazepine, phenobarbital, phenytoin • antimycobacterials: rifampicin • herbal products: St. John's wort (Hypericum perforatum) 4.4 Special warnings and precautions for use General While effective viral suppression with antiretroviral therapy has been proven to substantially reduce the risk of sexual transmission, a residual risk cannot be excluded. Precautions to prevent transmission should be taken in accordance with national guidelines. The use of Vitekta with HIV-1 protease inhibitors or dosing frequencies other than those presented in Table 1 may result in inadequate or elevated plasma levels of elvitegravir and/or the co-administered medicinal products. Resistance Elvitegravir-resistant viruses show cross-resistance to the integrase strand transfer inhibitor raltegravir in most cases (see section 5.1). Elvitegravir has a relatively low genetic barrier to resistance. Therefore, whenever possible, Vitekta should be administered with a fully active ritonavir-boosted protease inhibitor and a second fully active antiretroviral agent to minimise the potential for virologic failure and the development of resistance (see section 5.1). Co-administration of other medicinal products Elvitegravir is primarily metabolised by CYP3A. Co-administration of Vitekta with strong CYP3A inducers (including St. John's wort [Hypericum perforatum], rifampicin, carbamazepine, phenobarbital and phenytoin) is contraindicated (see sections 4.3 and 4.5). Co-administration of Vitekta with moderate CYP3A inducers (including, but not limited to, efavirenz and bosentan) is not recommended (see section 4.5). Due to the need for co-administration of Vitekta with a ritonavir-boosted protease inhibitor, prescribers should consult the Summary of Product Characteristics of the co-administered protease inhibitor and ritonavir for a description of contraindicated medicinal products and other significant drug-drug interactions that may cause potentially life-threatening adverse reactions or loss of therapeutic effect and possible development of resistance. Atazanavir/ritonavir and lopinavir/ritonavir have been shown to significantly increase the plasma concentrations of elvitegravir (see section 4.5). When used in combination with atazanavir/ritonavir and lopinavir/ritonavir, the dose of Vitekta should be decreased from 150 mg once daily to 85 mg once daily (see section 4.2). Please refer to the Summary of Product Characteristics for Vitekta 85 mg tablets. Co-administration of Vitekta and related active substances: Vitekta must be used in combination with a ritonavir-boosted protease inhibitor. Vitekta should not be used with a protease inhibitor boosted by another agent as dosing recommendations for such combinations have not been established. Boosting elvitegravir with an agent other than ritonavir may result in suboptimal plasma concentrations of elvitegravir and/or the protease inhibitor leading to loss of therapeutic effect and possible development of resistance. Vitekta should not be used in combination with products containing elvitegravir or pharmacokinetic boosting agents other than ritonavir. Contraception requirements Female patients of childbearing potential should use either a hormonal contraceptive containing at least 30 µg ethinylestradiol and containing norgestimate as the progestagen or should use an alternative reliable method of contraception (see sections 4.5 and 4.6). Co-administration of elvitegravir with oral contraceptives containing progestagens other than norgestimate have not been studied and, therefore, should be avoided. Patients using oestrogens as hormone replacement therapy should be clinically monitored for signs of oestrogen deficiency (see section 4.5). Opportunistic infections Patients receiving Vitekta or any other antiretroviral therapy may continue to develop opportunistic infections and other complications of HIV infection, and therefore should remain under close clinical observation by physicians experienced in the treatment of patients with HIV associated diseases. Patients with HIV and hepatitis B or C virus co-infection Patients with chronic hepatitis B or C treated with antiretroviral therapy are at an increased risk for severe and potentially fatal hepatic adverse reactions. Physicians should refer to current HIV treatment guidelines for the optimal management of HIV infection in patients co-infected with hepatitis B virus (HBV). Liver disease Elvitegravir has not been studied in patients with severe hepatic impairment (Child-Pugh Class C). No dose adjustment of Vitekta is required in patients with mild (Child-Pugh Class A) or moderate hepatic impairment (Child-Pugh Class B) (see sections 4.2 and 5.2). Patients with pre-existing liver dysfunction, including chronic active hepatitis, have an increased frequency of liver function abnormalities during combination antiretroviral therapy (CART) and should be monitored according to standard practice. If there is evidence of worsening liver disease in such patients, interruption or discontinuation of treatment must be considered. Weight and metabolic parameters An increase in weight and in levels of blood lipids and glucose may occur during antiretroviral therapy. Such changes may in part be linked to disease control and life style. For lipids, there is in some cases evidence for a treatment effect, while for weight gain there is no strong evidence relating this to any particular treatment. For monitoring of blood lipids and glucose reference is made to established HIV treatment guidelines. Lipid disorders should be managed as clinically appropriate. Immune Reactivation Syndrome In HIV infected patients with severe immune deficiency at the time of institution of CART, an inflammatory reaction to asymptomatic or residual opportunistic pathogens may arise and cause serious clinical conditions, or aggravation of symptoms. Typically, such reactions have been observed within the first few weeks or months of initiation of CART. Relevant examples are cytomegalovirus retinitis, generalised and/or focal mycobacterial infections, and Pneumocystis jirovecii pneumonia. Any inflammatory symptoms should be evaluated and treatment instituted when necessary. Autoimmune disorders (such as Graves' disease) have also been reported to occur in the setting of immune reactivation; however, the reported time to onset is more variable and these events can occur many months after initiation of treatment. Osteonecrosis Although the aetiology is considered to be multifactorial (including corticosteroid use, alcohol consumption, severe immunosuppression, higher body mass index), cases of osteonecrosis have been reported particularly in patients with advanced HIV disease and/or long-term exposure to CART. Patients should be advised to seek medical advice if they experience joint aches and pain, joint stiffness or difficulty in movement. Excipients Vitekta contains lactose. Consequently, patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency, or glucose-galactose malabsorption should not take this medicinal product. 4.5 Interaction with other medicinal products and other forms of interaction Interaction studies have only been performed in adults. Interactions with CYP3A inducers Elvitegravir is primarily metabolised by CYP3A (see section 5.2). Medicinal products that are strong (causing a > 5-fold increase in substrate clearance) or moderate (causing a 2-5 fold increase in substrate clearance) inducers of CYP3A are expected to decrease plasma concentrations of elvitegravir. Concomitant use contraindicated Co-administration of Vitekta with medicinal products that are strong inducers of CYP3A is contraindicated as the expected decrease in plasma concentrations of elvitegravir can lead to loss of therapeutic effect and possible development of resistance to elvitegravir (see section 4.3). Concomitant use not recommended Co-administration of Vitekta with medicinal products that are moderate inducers of CYP3A (including, but not limited to, efavirenz and bosentan) is not recommended as the expected decrease in plasma concentrations of elvitegravir can lead to loss of therapeutic effect and possible development of resistance to elvitegravir (see section 4.4). Interactions requiring dose adjustment of Vitekta Elvitegravir undergoes oxidative metabolism by CYP3A (major route), and glucuronidation by UGT1A1/3 enzymes (minor route). Co-administration of Vitekta with medicinal products that are potent inhibitors of UGT1A1/3 may result in increased elvitegravir plasma concentrations and dose modifications may be required. For example, atazanavir/ritonavir and lopinavir/ritonavir (potent UGT1A1/3 inhibitors) have been shown to significantly increase the plasma concentrations of elvitegravir (see Table 2). Accordingly, when used in combination with atazanavir/ritonavir and lopinavir/ritonavir, the dose of Vitekta should be decreased from 150 mg once daily to 85 mg once daily (see sections 4.2 and 4.4). Please refer to the Summary of Product Characteristics for Vitekta 85 mg tablets. Other interactions Elvitegravir is a modest inducer and may have the potential to induce CYP2C9 and/or inducible UGT enzymes. As such, elvitegravir may decrease the plasma concentration of substrates of CYP2C9 (such as warfarin) or UGT (such as ethinyl estradiol). In addition, in vitro studies have shown that elvitegravir is a weak to modest inducer of CYP1A2, CYP2C19 and CYP3A enzymes. Elvitegravir would also have potential to be a weak to modest inducer of CYP2B6 and CYP2C8 enzymes, as these enzymes are regulated in a similar manner to CYP2C9 and CYP3A. However, clinical data have shown there are no clinically relevant changes in the exposure of methadone (which is primarily metabolised by CYP2B6 and CYP2C19) following co-administration with boosted elvitegravir versus administration of methadone alone (see Table 2). Elvitegravir is a substrate for OATP1B1 and OATP1B3, and an inhibitor of OATP1B3 in vitro. The in vivo relevance of these interactions is not clear. Interactions between elvitegravir and potential co-administered medicinal products are listed in Table 2 below (increase is indicated as “↑”, decrease as “↓”, no change as “↔”). These interactions are based on either drug interaction studies or predicted interactions due to the expected magnitude of interaction and potential for serious adverse events or loss of therapeutic effect. Where interactions were studied, the effect on Vitekta was determined by comparing the pharmacokinetics of boosted elvitegravir (using either ritonavir or cobicistat as a pharmacokinetic enhancer) in the absence and presence of the co-administered medicinal product. No interactions were studied using unboosted elvitegravir. Except where indicated in Table 2, the dose of boosted elvitegravir or co-administered medicinal product was the same when administered alone or in combination. The pharmacokinetic parameters of the protease inhibitors presented in Table 2 were assessed in the presence of ritonavir. Although there may be no actual or predicted interactions between a medicinal product and elvitegravir, there may be interactions between a medicinal product and ritonavir and/or the protease inhibitor co-administered with elvitegravir. The prescriber should always refer to the Summary of Product Characteristics for ritonavir, or the protease inhibitor. Table 2: Interactions between elvitegravir and other medicinal products
4.6 Fertility, pregnancy and lactation Women of childbearing potential / contraception in males and females The use of Vitekta must be accompanied by the use of effective contraception (see sections 4.4 and 4.5). Pregnancy There are no or limited clinical data with elvitegravir in pregnant women. Animal studies do not indicate direct or indirect harmful effects of elvitegravir with respect to reproductive toxicity. However, the maximum exposures evaluated in the rabbit were not in excess of those achieved therapeutically (see section 5.3). Vitekta should not be used during pregnancy unless the clinical condition of the woman requires treatment with elvitegravir. Breast-feeding It is unknown whether elvitegravir/metabolites are excreted in human milk. Available pharmacodynamic/toxicological data in rats have shown excretion of elvitegravir in milk. A risk to the newborns/infants cannot be excluded. Therefore, Vitekta should not be used during breast-feeding. In order to avoid transmission of HIV to the infant it is recommended that HIV infected women do not breast-feed their infants under any circumstances. Fertility No human data on the effect of elvitegravir on fertility are available. Animal studies do not indicate harmful effects of elvitegravir on fertility. 4.7 Effects on ability to drive and use machines No studies on the effects of elvitegravir on the ability to drive and use machines have been performed. 4.8 Undesirable effects Summary of the safety profile Assessment of adverse reactions is based on data from a controlled clinical study (GS-US-183-0145) in which 712 HIV-1 infected, antiretroviral treatment-experienced adults received elvitegravir (n = 354) or raltegravir (n = 358) each administered with a background regimen consisting of a fully active ritonavir-boosted protease inhibitor and other antiretroviral agents. Of these 712 patients, 543 (269 elvitegravir and 274 raltegravir) and 439 (224 elvitegravir and 215 raltegravir) received at least 48 and 96 weeks of treatment, respectively. The most frequently reported adverse reactions to elvitegravir were diarrhoea (7.1%) and nausea (4.0%) (see Table 3). Tabulated summary of adverse reactions Adverse reactions to elvitegravir from clinical study experience are listed in Table 3 below, by body system organ class and frequency. Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness. Frequencies are defined as common (≥ 1/100 to < 1/10) or uncommon (≥ 1/1,000 to < 1/100). Table 3: Tabulated summary of adverse reactions to elvitegravir based on experience for 96 weeks from clinical study GS-US-183-0145
Metabolic parameters Weight and levels of blood lipids and glucose may increase during antiretroviral therapy (see section 4.4). Immune Reactivation Syndrome In HIV infected patients with severe immune deficiency at the time of initiation of CART, an inflammatory reaction to asymptomatic or residual opportunistic infections may arise. Autoimmune disorders (such as Graves' disease) have also been reported; however, the reported time to onset is more variable and these events can occur many months after initiation of treatment (see section 4.4). Osteonecrosis Cases of osteonecrosis have been reported, particularly in patients with generally acknowledged risk factors, advanced HIV disease or long-term exposure to CART. The frequency of this is unknown (see section 4.4). Diarrhoea In study GS-US-183-0145, diarrhoea was reported as an adverse reaction in 7.1% of subjects in the elvitegravir group and in 5.3% of subjects in the raltegravir group. In these subjects, diarrhoea was mild to moderate in severity and did not result in discontinuation of study drug. Paediatric population No data are available for children below 18 years of age. Vitekta is not recommended in this population (see section 4.2). Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system: United Kingdom Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard Ireland HPRA Pharmacovigilance Earlsfort Terrace IRL - Dublin 2 Tel: +353 1 6764971 Fax: +353 1 6762517 Website: www.hpra.ie e-mail: medsafety@hpra.ie Malta ADR Reporting Website: www.medicinesauthority.gov.mt/adrportal 4.9 Overdose If overdose occurs the patient must be monitored for evidence of toxicity. Treatment of overdose with elvitegravir consists of general supportive measures including monitoring of vital signs as well as observation of the clinical status of the patient. There is no specific antidote for overdose with elvitegravir. As elvitegravir is highly bound to plasma proteins, it is unlikely that it will be significantly removed by haemodialysis or peritoneal dialysis. 5. Pharmacological properties 5.1 Pharmacodynamic properties Pharmacotherapeutic group: Antivirals for systemic use, other antivirals, ATC code: J05AX11. Mechanism of action and pharmacodynamic effects Elvitegravir is an HIV-1 integrase strand transfer inhibitor (INSTI). Integrase is an HIV-1 encoded enzyme that is required for viral replication. Inhibition of integrase prevents the integration of HIV-1 DNA into host genomic DNA, blocking the formation of the HIV-1 provirus and propagation of the viral infection. Elvitegravir does not inhibit human topoisomerases I or II. Antiviral activity in vitro The antiviral activity of elvitegravir against laboratory and clinical isolates of HIV-1 was assessed in lymphoblastoid cells, monocyte/macrophage cells, and peripheral blood lymphocytes and the 50% effective concentration (EC50) values were in the range of 0.02 to 1.7 nM. Elvitegravir displayed antiviral activity in cell culture against HIV-1 clades A, B, C, D, E, F, G, and O (EC50 values ranged from 0.1 to 1.3 nM) and activity against HIV-2 (EC50 of 0.53 nM). The in vitro antiviral activity of elvitegravir when combined with antiretroviral drugs from the nucleos(t)ide reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI), protease inhibitor (PI), integrase strand transfer inhibitor, fusion inhibitor, or CCR5 co-receptor antagonist classes showed no antagonism. Elvitegravir did not show inhibition of replication of HBV or HCV in vitro. Resistance In cell culture HIV-1 isolates with reduced susceptibility to elvitegravir have been selected in cell culture. Phenotypic resistance to elvitegravir was most commonly associated with the primary integrase substitutions T66I, E92Q and Q148R. Additional integrase substitutions observed in cell culture selection included H51Y, F121Y, S147G, S153Y, E157Q, and R263K. Cross resistance Elvitegravir-resistant viruses show varying degrees of cross-resistance to the integrase strand transfer inhibitor raltegravir depending on the type and number of substitutions. Viruses expressing the T66I/A substitutions maintain susceptibility to raltegravir, while most other patterns of elvitegravir-associated substitutions are associated with reduced susceptibility to raltegravir. With the exception of Y143C/R/H, HIV-1 with the primary raltegravir-associated substitutions T66K, Q148H/K/R, or N155H in integrase is associated with reduced susceptibility to elvitegravir. In treatment-experienced patients In an analysis of HIV-1 isolates from treatment-failure subjects in study GS-US-183-0145 through week 96, the development of one or more primary elvitegravir resistance-associated substitutions was observed in 23 of the 86 subjects with evaluable genotypic data from paired baseline and elvitegravir treatment-failure isolates (23/351 elvitegravir-treated subjects, 6.6%). Similar rates of raltegravir resistance development occurred in the HIV-1 from subjects treated with raltegravir (26/351 raltegravir-treated subjects, 7.4%). The most common substitutions that emerged in HIV-1 isolates from elvitegravir-treated subjects were T66I/A (n = 8), E92Q/G (n = 7), T97A (n = 4), S147G (n = 4), Q148R (n = 4), and N155H (n = 5) in integrase. In phenotypic analyses of HIV-1 isolates with resistance substitutions from elvitegravir-treated subjects, 14/20 (70%) had reduced susceptibility to elvitegravir and 12/20 (60%) had reduced susceptibility to raltegravir. Clinical experience In treatment-experienced HIV-1 infected patients The efficacy of elvitegravir is primarily based on the analyses through 96 weeks from one randomised, double-blind, active-controlled study, study GS-US-183-0145, in treatment-experienced, HIV-1 infected patients (n = 702). In study GS-US-183-0145, patients were randomised in a 1:1 ratio to receive either elvitegravir (150 mg or 85 mg) once daily or raltegravir 400 mg twice daily, each administered with a background regimen (BR) containing a fully-active ritonavir-boosted protease inhibitor (either atazanavir, darunavir, fosamprenavir, lopinavir or tipranavir) and a second agent. The BR was selected by the investigator based on genotypic/phenotypic resistance testing and prior antiretroviral treatment history. Randomisation was stratified by screening HIV-1 RNA level (≤ 100,000 copies/mL or > 100,000 copies/mL) and the class of the second agent (NRTI or other classes). Virologic response rate was evaluated in both treatment arms. Virologic response was defined as achieving an undetectable viral load (HIV-1 RNA < 50 copies/mL). Baseline characteristics and treatment outcomes through 96 weeks for study GS-US-183-0145 are presented in Tables 4 and 5 respectively. Table 4: Demographic and baseline disease characteristics of antiretroviral treatment-experienced HIV-1 infected adult subjects in study GS-US-183-0145
Table 5: Virologic outcome of randomised treatment of study GS-US-183-0145 at week 48 and week 96 (snapshot analysis)a
b Includes subjects who had ≥ 50 copies/mL in the week 48 or week 96 window, subjects who discontinued early due to lack or loss of efficacy, subjects who had a viral load ≥ 50 copies/mL at time of change in background regimen, subjects who discontinued for reasons other than an adverse event (AE), death or lack or loss of efficacy and at the time of discontinuation had a viral load of ≥ 50 copies/mL. c Includes patients who discontinued due to an AE or death at any time point from day 1 through the time window if this resulted in no virologic data on treatment during the specified window. d Includes subjects who discontinued for reasons other than an AE, death or lack or loss of efficacy, e.g., withdrew consent, loss to follow-up, etc. Elvitegravir was non-inferior in achieving HIV-1 RNA < 50 copies/mL when compared to raltegravir. Among subjects with a genotypic sensitivity score of ≤ 1, 76% and 69% had HIV-1 RNA < 50 copies/mL at week 48 in the elvitegravir and raltegravir treatment arms, respectively. Among subjects with a genotypic sensitivity score > 1, 57% and 56% had HIV-1 RNA < 50 copies/mL at week 48 in the elvitegravir and raltegravir treatment arms, respectively. In study GS-US-183-0145, the mean increase from baseline in CD4+ cell count at week 96 was 205 cells/mm3 in the elvitegravir-treated patients and 198 cells/mm3 in the raltegravir-treated patients. In study GS-US-183-0145, subgroup analyses by co-administered protease inhibitor showed similar rates of virologic success for elvitegravir and raltegravir within each protease inhibitor subgroup at weeks 48 and 96 (HIV-1 RNA < 50 copies/mL) (Table 6). Table 6: Virologic success by co-administered protease inhibitor in study GS-US-183-0145 at week 48 and week 96 (snapshot analysis)
Although limited by the small number of female subjects in study GS-US-183-0145, subgroup analysis by gender showed that the rates of virologic success in female subjects at weeks 48 and 96 (HIV-1 RNA < 50 copies/mL) were numerically lower in the elvitegravir treatment arm than in the raltegravir treatment arm. Virologic success rates at week 48 for elvitegravir and raltegravir were 47.5% (28/59) and 62.7% (42/67) (difference: -12.3% [95% CI: -30.1% to 5.5%]), respectively, for female subjects, and 62.3% (182/292) and 56.3% (160/284) (difference: 5.3% [95% CI: -2.5% to 13.2%]), respectively, for male subjects. Virologic success rates at week 96 for elvitegravir and raltegravir were 39.0% (23/59) and 52.2% (35/67) (difference: -8.4% [95% CI: -26.1% to 9.2%]), respectively, for female subjects, and 55.1% (161/292) and 53.2% (151/284) (difference: 1.5% [95% CI: -6.5% to 9.6%]), respectively, for male subjects. Paediatric population The European Medicines Agency has deferred the obligation to submit the results of studies with elvitegravir in one or more subsets of the paediatric population in the treatment of HIV-1 infection (see section 4.2 for information on paediatric use). 5.2 Pharmacokinetic properties Absorption Following oral administration of ritonavir-boosted elvitegravir with food in HIV-1 infected subjects, elvitegravir peak plasma concentrations were observed 4 hours post-dose. The steady-state mean Cmax, AUCtau, and Ctrough (mean ± SD) following multiple doses of elvitegravir plus a ritonavir-boosted protease inhibitor (150 mg elvitegravir with darunavir or fosamprenavir; 85 mg elvitegravir with atazanavir or lopinavir) in HIV-1 infected subjects were 1.4 ± 0.39 μg/mL, 18 ± 6.8 μg•h/mL, and 0.38 ± 0.22 μg/mL for elvitegravir, respectively. The absolute oral bioavailability has not been determined. Relative to fasting conditions, the administration of boosted elvitegravir as the fixed-dose combination 150 mg elvitegravir/150 mg cobicistat/200 mg emtricitabine/245 mg tenofovir disoproxil with a light meal (approximately 373 kcal, 20% fat) or high-fat meal (approximately 800 kcal, 50% fat) resulted in increased exposures of elvitegravir. The Cmax and AUCtau of elvitegravir increased 22% and 36% with a light meal, while increasing 56% and 91% with a high-fat meal, respectively. Distribution Elvitegravir is 98-99% bound to human plasma proteins and the binding is independent of drug concentration over the range of 1.0 ng/mL to 1.6 µg/mL. The mean plasma to blood drug concentration ratio is 1.37. Biotransformation Elvitegravir undergoes oxidative metabolism by CYP3A (major route), and glucuronidation via UGT1A1/3 enzymes (minor route). Ritonavir inhibits CYP3A, thereby substantially increasing the plasma concentrations of elvitegravir. Administration of once-daily ritonavir (20-200 mg) results in an increased elvitegravir exposure following repeat once-daily administration, with elvitegravir exposure reaching a plateau with approximately 100 mg of ritonavir. Further increases in ritonavir dose do not result in further increases in elvitegravir exposure. Vitekta is indicated for use only when co-administered with ritonavir as a boosting agent. Mean steady-state exposure (AUCtau) of unboosted elvitegravir is ~ 20% lower after multiple dosing versus a single dose, indicating modest autoinduction of its metabolism. Upon boosting with ritonavir (100 mg), net inhibition of elvitegravir metabolism is observed with significantly increased systemic exposures (20-fold higher AUC), high trough concentrations, and longer median elimination half-life (9.5 versus 3.5 hours). Following oral administration of a single dose of ritonavir-boosted [14C]elvitegravir, elvitegravir was the predominant species in plasma, representing approximately 94% and 61% of the circulating radioactivity at 32 and 48 hours, respectively. Metabolites produced by aromatic and aliphatic hydroxylation or glucuronidation are present in very low levels and do not contribute to the overall antiviral activity of elvitegravir. Elimination Following oral administration of ritonavir-boosted [14C]elvitegravir, 94.8% of the dose was recovered in faeces, consistent with the hepatobiliary elimination of elvitegravir; 6.7% of the administered dose was recovered in urine as metabolites. The median terminal plasma half-life of ritonavir-boosted elvitegravir is approximately 8.7 to 13.7 hours. Linearity/non-linearity Elvitegravir plasma exposures are non-linear and less than dose-proportional, likely due to solubility-limited absorption. Elderly Pharmacokinetics of elvitegravir have not been fully evaluated in the elderly (over 65 years of age). Gender No clinically relevant pharmacokinetic differences due to gender have been identified for boosted elvitegravir. Ethnicity No clinically relevant pharmacokinetic differences due to ethnicity have been identified for boosted elvitegravir. Paediatric population The pharmacokinetics of elvitegravir in paediatric subjects have not been established. Renal impairment A study of the pharmacokinetics of boosted elvitegravir was performed in non HIV-1 infected subjects with severe renal impairment (estimated creatinine clearance below 30 mL/min). No clinically relevant differences in elvitegravir pharmacokinetics were observed between subjects with severe renal impairment and healthy subjects. No dose adjustment of Vitekta is required for patients with renal impairment. Hepatic impairment Elvitegravir is primarily metabolised and eliminated by the liver. A study of the pharmacokinetics of boosted elvitegravir was performed in non-HIV-1 infected subjects with moderate hepatic impairment (Child-Pugh Class B). No clinically relevant differences in elvitegravir pharmacokinetics were observed between subjects with moderate impairment and healthy subjects. No dose adjustment of Vitekta is necessary for patients with mild to moderate hepatic impairment. The effect of severe hepatic impairment (Child-Pugh Class C) on the pharmacokinetics of elvitegravir has not been studied. Hepatitis B and/or hepatitis C virus co-infection Limited data from population pharmacokinetic analysis (n = 56) indicated that hepatitis B and/or C virus infection had no clinically relevant effect on the exposure of boosted elvitegravir. 5.3 Preclinical safety data Non-clinical data reveal no special hazard for humans based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity, carcinogenic potential, toxicity to reproduction and development. The maximum doses of elvitegravir tested in the development toxicity studies in rats and rabbits corresponded to exposures that are approximately 29-fold and 0.2-fold the human therapeutic exposure, respectively. Elvitegravir was negative in an in vitro bacterial mutagenicity test (Ames test) and negative in an in vivo rat micronucleus assay at doses up to 2,000 mg/kg. In an in vitro chromosomal aberration test, elvitegravir was negative with metabolic activation; however, an equivocal response was observed without activation. Elvitegravir did not show any carcinogenic potential in long-term oral carcinogenicity studies in mice and rats. The active substance elvitegravir is persistent in the environment. 6. Pharmaceutical particulars 6.1 List of excipients Tablet core Croscarmellose sodium Hydroxypropyl cellulose Lactose monohydrate Magnesium stearate Microcrystalline cellulose Sodium lauryl sulfate Film-coating Indigo carmine aluminium lake (E132) Macrogol 3350 (E1521) Polyvinyl alcohol (partially hydrolysed) (E1203) Talc (E553B) Titanium dioxide (E171) Iron oxide yellow (E172) 6.2 Incompatibilities Not applicable. 6.3 Shelf life 4 years. 6.4 Special precautions for storage This medicinal product does not require any special storage conditions. 6.5 Nature and contents of container High density polyethylene (HDPE) bottle with a child-resistant closure containing 30 film-coated tablets. Pack size: 1 bottle of 30 film-coated tablets. 6.6 Special precautions for disposal and other handling Any unused medicinal product or waste material should be disposed of in accordance with local requirements. 7. Marketing authorisation holder Gilead Sciences International Limited Cambridge CB21 6GT United Kingdom 8. Marketing authorisation number(s) EU/1/13/883/002 9. Date of first authorisation/renewal of the authorisation Date of first authorisation: 13 November 2013 10. Date of revision of the text 01/2016 Detailed information on this medicinal product is available on the website of the European Medicines Agency http://www.ema.europa.eu. 附:Vitekta 85mg film coated tablets(http://www.medicines.org.uk/emc/medicine/28410) |