Vitekta - summary of medicine characteristics

2. QUALITATIVE AND QUANTITATIVE COMPOSITION

Each film-coated tablet contains 85 mg of elvitegravir.

Excipient with known effect: Each tablet contains 6.2 mg lactose (as monohydrate)

For the full list of excipients, see section 6.1.

3. PHARMACEUTICAL FORM

Film-coated tablet (tablet).

Green, pentagon-shaped, film-coated tablet of dimensions 8.9 mm x 8.7 mm, debossed with “GSI” on one side of the tablet and “85” on the other side of the tablet.

4. CLINICAL PARTICULARS4.1 Therapeutic indications

Vitekta co-administered with a ritonavir-boosted protease inhibitor and with other antiretroviral agents, is indicated for the treatment of human immunodeficiency virus-1 (HIV-1) infection in adults who are infected with HIV-1 without known mutations associated with resistance to elvitegravir (see sections 4.2 and 5.1).

4.2 Posology and method of administration

Therapy should be initiated by a physician experienced in the management of HIV infection.

Posology

Vitekta must be administered in combination with a ritonavir-boosted protease inhibitor.

The Summary of Product Characteristics for the co-administered ritonavir-boosted protease inhibitor should be consulted.

The recommended dose of Vitekta is one 85 mg tablet or one 150 mg tablet taken orally once daily with food. The choice of dose of Vitekta depends on the co-administered protease inhibitor (see Table 1 and sections 4.4 and 4.5). For use of the 150 mg tablet, please refer to the Summary of Product Characteristics for Vitekta 150 mg tablets.

Vitekta should be administered once daily as follows:

– Either at the same time as a once daily ritonavir-boosted protease inhibitor – Or with the first dose of a twice daily ritonavir-boosted protease inhibitor.

Table 1: Recommended dosing regimens

Dose of Vitekta	Dose of co-administered ritonavir-boosted protease inhibitor
85 mg once daily	atazanavir 300 mg and ritonavir 100 mg once daily
	lopinavir 400 mg and ritonavir 100 mg twice daily
150 mg once daily	darunavir 600 mg and ritonavir 100 mg twice daily
	fosamprenavir 700 mg and ritonavir 100 mg twice daily

There are no data to recommend the use of Vitekta with dosing frequencies or HIV-1 protease inhibitors other than those presented in Table 1.

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 admini station

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 raltegravi 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). viV

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).

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 qg 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 dose adjustment of Vitekta is required in patients with mild (Child-Pugh Class A impairment (Child-Pugh Class B) (see sections 4.2 and 5.2).

Patients with pre-existing liver dysfunction, including chronic active hepatitis 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        V

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 possi 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).

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 “I”, no change as ‘W’). 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

Medicinal product by therapeutic areas	Effects on drug levels Mean percent change in AUC, C_. C_ '-'max, '-'min	Recommendation concerning co-administration with ritonavir-boosted elvitegravir
Lopinavir/Ritonavir (400/100 mg twice daily) Elvitegravir (125 mg once daily)	Lopinavir/Ritonavir has been shown to significantly increase the plasma concentrations of elvitegravir. Elvitegravir: AUC: T 75% Cmax: T 52% Cmin: T 138% Lopinavir: AUC: ~ Cmax: ^ Cmin: j 8%	When used in combination with lopinavir/rito­navir, the dose of Vitekta should be 85 mg once daily. There are no data available to make dosing recommendations for co-administration with other doses of lopinavir/ritonavir (see section 4.2).
Tipranavir (500 mg twice daily) Elvitegravir (200 mg once daily) Ritonavir (200 mg twice daily)	Elvitegravir: AUC: ~ Cmax: < > Cmin: ^ Tipranavir: AUC: ~ Cmax: < > Cmin: j 11%	Due to insufficient ch. 'ical data, the combination of evátegravir with tipranavir is no. recommended (see section 4.2).
NRTIs
Didanosine (400 mg once daily) Elvitegravir (200 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir: AUC: ~ Cmax: < > Cmin: ^ Didanosine: AUC: j 14 % Cmax: j 16%	As didanosine is administered on an empty stomach, didanosine should be administered at least one hour before or two hours after Vitekta (which is administered with food). Clinical monitoring is recommended.
Zidovudine (300 mg twice daily) Elvitegravir (200 mg once daily) Ritonavir (100 mg once daily) <c	Elvitegravir: AUC:' ••• Cma : ~ Cmin: ^ Zidovudine: AUC: ~ Cmax: < >	No dose adjustment is required when Vitekta is co-administered with zidovudine.
Stavudine (40 mg c.ic daily) Elvitegravir (200 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir: AUC: ~ Cmax: < > Cmin: ^ Stavudine: AUC: ~ Cmax: < >	No dose adjustment is required when Vitekta is co-administered with stavudine.
Abacavir (600 mg once daily) Elvitegravir (200 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir: AUC: ~ Cmax: < > Cmin: ^ Abacavir: AUC: ~ Cmax: ( >	No dose adjustment is required when Vitekta is co-administered with abacavir.

Medicinal product by therapeutic areas	Effects on drug levels Mean percent change in AUC, C_ . C_ '-'max, '-'min	Recommendation concerning co-administration with ritonavir-boosted elvitegravir
Tenofovir disoproxil fumarate (300 mg once daily) Emtricitabine (200 mg once daily) Elvitegravir (50 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir: AUC: ~ Cmax: < > Cmin: ^ Tenofovir: AUC: ~ Cmax: < > Cmin: ^ Emtricitabine: AUC: ~ Cmax: ^ Cmin: ^	No dose adjustment is required when Vitekta is co-administered with tenofovir disoproxil fumarate or with emtricitabine.
NNRTIs
Efavirenz	Interaction not studied with elvitegravir. Co-administration of efavirenz and elvitegravir is expected to decrease elvitegravir plasma concentrations which may result in loss of therapeutic effect and possible development of resistance.	Co-administration is not recommended (see s ection 4.4).
Etravirine (200 mg twice daily) Elvitegravir (150 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir: AUC: ~ Cmax: ^ Cmin: ~ Etravirine AUC: < + Cmax: ~^ Cmii.: ^	No dose adjustment is required when Vitekta is co-administered with etravirine.
Nevirapine <c	Inte raction not studied with el, itegravir. Co-administration of nevirapine and elvitegravir is expected to decrease elvitegravir plasma concentrations which may result in loss of therapeutic effect and possible development of resistance.	Co-administration is not recommended (see section 4.4).
Rilpivirine	Interaction not studied with elvitegravir.	Co-administration of elvitegravir and rilpivirine is not expected to change elvitegravir plasma concentrations, therefore no dose adjustment of Vitekta is required.
CCR5 antagonists
Maraviroc (150 mg twice daily) Elvitegravir (150 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir: AUC: ~ Cmax: < > Cmin: ^ Maraviroc:§ AUC: t 186% Cmax: t 115% Cmin: t 323%	No dose adjustment is required when Vitekta is co-administered with maraviroc. §Due to inhibition of CYP3 A by ritonavir, maraviroc exposure is significantly increased.

Medicinal product by therapeutic areas	Effects on drug levels Mean percent change in AUC, C_. C_ '-'max, '-'min	Recommendation concerning co-administration with ritonavir-boosted elvitegravir
ANTACIDS
Magnesium/aluminum-containing antacid suspension (20 mL single dose) Elvitegravir (50 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir (antacid suspension given ± 4 hours from elvitegravir administration): AUC: ~ Cmax: ( > Cmin: ^ Elvitegravir (simultaneous antacid administration): AUC: j 45% Cmax: j 47% Cmin: j 41%	Elvitegravir plasma concentrations are lower with antacids due to local complexation in the gastrointestinal tract and not to changes in gastric pH. It is recommended to separate Vitekta and antacid administration by at least 4 hours. xC
FOOD SUPPLEMENTS
Multivitamin supplements	Interaction not studied with elvitegravir.	As the effect of cationi c complexation of e’viiegravir cannot be excluded when co-administered with multivitamin supplements, 't is recommended to separate Vitekta and multivitamin supplements dosing by at least 4 hours.
NARCOTIC ANALGESICS
Methadone (80–120 mg once daily) Elvitegravir (150 mg once daily) Cobicistat (150 mg once daily)	Elvitegravir: AUC: ~ Cmax: ~ Cmin: ^ Methadone: AUC: ~ Cmax: ^ C : ^ '—mill:	No dose adjustment is required when Vitekta is co-administered with methadone.
Buprenorphine/Na­loxone (16/4 mg to 24/6 mg daily) Elvitegravir (150 mg once daily) Cobicistat (150 mg once daily)	Elvitegravir: SUC^ Cma x ( > Cmin: ^ Buprenorphine: AUC: t 35% Cmax: t 12% Cmin: t 66% Naloxone: AUC: j 28% Cmax: j 28%	No dose adjustment is required when Vitekta is co-administered with buprenorphine/na­loxone.
ANTI-INFECTIVES
Antifungals
K etc conazole (200 mg twice daily) Elvitegravir (150 mg once daily) Ritonavir (100 mg once daily)	Elvitegravir: AUC: î 48% Cmax: ^ Cmin: î 67% î Ketoconazole§	No dose adjustment is required when Vitekta is co-administered with ketoconazole. §Due to inhibition of CYP3 A by ritonavir, ketoconazole exposure is increased.

4.6 Fertility, pregnancy and lactation

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 breastfeeding.

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

Frequency	Adverse reaction
Psychiatric disorders:
Uncommon	suicidal ideation and suicide attempt (in patients with a pre-existing history of depression or psychiatric illness), depression, insomnia
Nervous system disorders:
Common	headache
Uncommon	dizziness, paraesthesia, somnolence, dysgeusia
Gastrointestinal disorders:
Common	abdominal pain, diarrhoea, vomiting, nausea
Uncommon	dyspepsia, abdominal distension, flatulence
Skin and subcutaneous tissue disorders:
Common	rash _____________­________________________­________________________­___-
General disorders and administration site conditions:
Common	fatigue

Description of selected adverse reactions

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).

Rep orti ng 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 listed in

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 PROPERTIES5.1 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.

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

rossres s ance

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.

<AJ

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

	Elvitegravir + background regimen n = 351	Raltegravir + background regimen n = 351
Demographic characteristics
Median age, years (min-max)	44 (20–78)	45 (19–74)
Sex
Male	83.2%	80.9%
Female	X 16.8%	19.1%
Ethnicity
White	60.1%	64.4%
Black/African American	35.6%	32.2%
Asian	2.6%	1.4%
Other	J          1.7%	2.0%
Baseline disease characteristics
Median baseline plasma HIV-1 RNA (range) logio copies/mL	4.35 (1.69–6.63)	4.42 (1.69–6.10)
Percentage of subjects with viral load > ioo,000 copies/mL	25.6	25.6
Median base’ine CD4+ cell count (range), cells/mm3	227.0 (2.0–1,374.0)	215.0 (1.0–1,497.0)
Percent age of subjects with CD4+ cell counts S 200 cells/mm3	44.4	44.9
Baseline genotypic sensitivity scorea 0 1 2 3	1% 14% 81% 3%	< 1% 15% 83% 2%

a Genotypic sensitivity scores are calculated by summing up drug susceptibility values (1 = sensitive; 0 = reduced

susceptibility) on all drugs in the baseline background regimen.

Table 5: Virologic outcome of randomised treatment of study GS-US-183–0145 at week 48 and week 96 (snapshot analysis) a

	Week 48		Week 96
	Elvitegravir + background regimen n = 351	Raltegravir + background regimen n = 351	Elvitegravir + background regimen n = 351	Raltegravir + background regimen n = 351
Virologie success HIV-1 RNA < 50 copies/mL	60%	58%	52%	53%
Treatment difference	2.2% (95% CI =	–5.0%, 9.3%)	–0.5% (95% CI =	–7.9%, 6.8%) I
Virologie failure b	33%	32%	36%	31% y
No virologie data at week 48 or week 96 window	7%	11%	12%	'6%
Discontinued study drug due to AE or deathc	2%	5%	3%	7%
Discontinued study drug due to other reasons and last available HIV-1 RNA < 50 copies/mLd	4%	5%	8% c/	9%
Missing data during window but on study drug	1%	1% \ď	1%	1%

a Week 48 window is between day 309 and 364 (inclusive), week 96 window is between day 645 and 700 (inclusive).

b Includes subjects who had > 50 copies/mL in the week 48 or wee k 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 geno ypic 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)

			Elvitegravir versus raltegravir
HIV-1 RNA < 50 copies/mL, n/N (%)	Elvitegravir (N = 351)	Raltegravir (N = 351)	Difference in percentages (95% CI) a
Virologie success at week 48
Darunavir/ritonavir	126/202 (62.4%)	122/207 (58.9%)	3.4% (-6.0% to 12.9%)
Lopinavir/ritonavir	39/68 (57.4%)	37/68 (54.4%)	2.9% (-13.7% to 19.6%) Q
Atazanavir/ri­tonavir	34/61 (55.7%)	28/51 (54.9%)	0.8% (-17.7% to 19.3%)
Fosamprenavir/ri­tonavir	8/14 (57.1%)	10/18 (55.6%)	1.6% (-33.0% to 36 2%)
Tipranavir/ri­tonavir	3/6 (50.0%)	5/7 (71.4%)	–21.4% (-73.6% to 30.7%)
Virologie success at week 96			vxO
Darunavir/ritonavir	105/202 (52.0%)	112/207 (54.1%)	–2.1% (-11 8% to 7.5%)
Lopinavir/ritonavir	36/68 (52.9%)	37/68 (54.4%)	–1.5% (-18 2% to 15.3%)
Atazanavir/ri­tonavir	33/61 (54.1%)	23/51 (45.1%)	9.0% (-9.5% to 27.5%)
Fosamprenavir/ri­tonavir	7/14 (50.0%)	11/18 (61.1%)	–11.1% (-45.7% to 23.4%)
Tipranavir/ri­tonavir	3/6 (50.0%)	3/7 (42.9%)	7.1% (-47.1% to 61.4%)

a The difference in proportions and its 95% CIs between randomised treatment groups is based on normal approximation.

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

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 ^g/mL, 18 ± 6.8 |ig^h/mL, and 0.38 ± 0.22 ^g/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 ^g/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.

OOvOOv

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 solubilitylimited 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.

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 an 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 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 PARTICULARS6.1 List of excipients

• Tablet core •K Croscarmellose sodium Hydroxypropyl cellulose Lactose monohydrate Magnesium stearate Microcrystalline cellulose

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.