emtriva (emtricitabine)  capsule 
emtriva (emtricitabine)  solution 
[Gilead Sciences, Inc.]

Rx Only

DESCRIPTION

EMTRIVA® is the brand name of emtricitabine, a synthetic nucleoside analog with activity against human immunodeficiency virus type 1 (HIV-1) reverse transcriptase.

The chemical name of emtricitabine is 5-fluoro-1-(2R,5S)-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine. Emtricitabine is the (-) enantiomer of a thio analog of cytidine, which differs from other cytidine analogs in that it has a fluorine in the 5-position.

It has a molecular formula of C8H10FN3O3S and a molecular weight of 247.24. It has the following structural formula:

Emtricitabine is a white to off-white powder with a solubility of approximately 112 mg/mL in water at 25 °C. The log P for emtricitabine is -0.43 and the pKa is 2.65.

EMTRIVA is available as capsules or as an oral solution.

EMTRIVA Capsules are for oral administration. Each capsule contains 200 mg of emtricitabine and the inactive ingredients, crospovidone, magnesium stearate, microcrystalline cellulose, and povidone.

EMTRIVA Oral Solution is for oral administration. One milliliter (1 mL) of EMTRIVA Oral Solution contains 10 mg of emtricitabine in an aqueous solution with the following inactive ingredients: cotton candy flavor, FD&C yellow No. 6, edetate disodium, methylparaben, and propylparaben (added as preservatives), sodium phosphate (monobasic), propylene glycol, water, and xylitol (added as a sweetener). Sodium hydroxide and hydrochloric acid may be used to adjust pH.

MICROBIOLOGY

Mechanism of Action

Emtricitabine, a synthetic nucleoside analog of cytosine, is phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate. Emtricitabine 5'-triphosphate inhibits the activity of the HIV-1 reverse transcriptase by competing with the natural substrate deoxycytidine 5'-triphosphate and by being incorporated into nascent viral DNA which results in chain termination. Emtricitabine 5'-triphosphate is a weak inhibitor of mammalian DNA polymerase α, β, ε and mitochondrial DNA polymerase γ.

Antiviral Activity In Vitro

The in vitro antiviral activity of emtricitabine against laboratory and clinical isolates of HIV was assessed in lymphoblastoid cell lines, the MAGI-CCR5 cell line, and peripheral blood mononuclear cells. The 50% inhibitory concentration (IC50) value for emtricitabine was in the range of 0.0013–0.64 µM (0.0003–0.158 µg/mL). In drug combination studies of emtricitabine with nucleoside reverse transcriptase inhibitors (abacavir, lamivudine, stavudine, tenofovir, zalcitabine, zidovudine), non-nucleoside reverse transcriptase inhibitors (delavirdine, efavirenz, nevirapine), and protease inhibitors (amprenavir, nelfinavir, ritonavir, saquinavir), additive to synergistic effects were observed. Most of these drug combinations have not been studied in humans. Emtricitabine displayed antiviral activity in vitro against HIV-1 clades A, C, D, E, F, and G (IC50 values ranged from 0.007–0.075 µM) and showed strain specific activity against HIV-2 (IC50 values ranged from 0.007–1.5 µM).

Drug Resistance

Emtricitabine–resistant isolates of HIV have been selected in vitro. Genotypic analysis of these isolates showed that the reduced susceptibility to emtricitabine was associated with a mutation in the HIV reverse transcriptase gene at codon 184 which resulted in an amino acid substitution of methionine by valine or isoleucine (M184V/I).

Emtricitabine-resistant isolates of HIV have been recovered from some patients treated with emtricitabine alone or in combination with other antiretroviral agents. In a clinical study, viral isolates from 37.5% of treatment-naïve patients with virologic failure showed reduced susceptibility to emtricitabine. Genotypic analysis of these isolates showed that the resistance was due to M184V/I mutations in the HIV reverse transcriptase gene.

Cross Resistance

Cross-resistance among certain nucleoside analog reverse transcriptase inhibitors has been recognized. Emtricitabine-resistant isolates (M184V/I) were cross-resistant to lamivudine and zalcitabine but retained sensitivity to abacavir, didanosine, stavudine, tenofovir, zidovudine, and NNRTIs (delavirdine, efavirenz, and nevirapine). HIV-1 isolates containing the K65R mutation, selected in vivo by abacavir, didanosine, tenofovir, and zalcitabine, demonstrated reduced susceptibility to inhibition by emtricitabine. Viruses harboring mutations conferring reduced susceptibility to stavudine and zidovudine (M41L, D67N, K70R, L210W, T215Y/F, K219Q/E) or didanosine (L74V) remained sensitive to emtricitabine. HIV-1 containing the K103N mutation associated with resistance to NNRTIs was susceptible to emtricitabine.

CLINICAL PHARMACOLOGY

Pharmacodynamics

The in vivo activity of emtricitabine was evaluated in two clinical trials in which 101 patients were administered 25–400 mg a day of EMTRIVA as monotherapy for 10–14 days. A dose-related antiviral effect was observed, with a median decrease from baseline in plasma HIV-1 RNA of 1.3 log10 at a dose of 25 mg QD and 1.7 log10 to 1.9 log10 at a dose of 200 mg QD or BID.

Pharmacokinetics in Adults

The pharmacokinetics of emtricitabine were evaluated in healthy volunteers and HIV-infected individuals. Emtricitabine pharmacokinetics are similar between these populations.

Figure 1 shows the mean steady-state plasma emtricitabine concentration-time profile in 20 HIV-infected subjects receiving EMTRIVA Capsules.

Figure 1. Mean (± 95% CI) Steady-State Plasma Emtricitabine Concentrations in HIV-Infected Adults (N=20)

Absorption

Emtricitabine is rapidly and extensively absorbed following oral administration with peak plasma concentrations occurring at 1–2 hours post-dose. Following multiple dose oral administration of EMTRIVA Capsules to 20 HIV-infected subjects, the (mean ± SD) steady-state plasma emtricitabine peak concentration (Cmax) was 1.8 ± 0.7 µg/mL and the area-under the plasma concentration-time curve over a 24-hour dosing interval (AUC) was 10.0 ± 3.1 hr∙µg/mL. The mean steady state plasma trough concentration at 24 hours post-dose was 0.09 µg/mL. The mean absolute bioavailability of EMTRIVA Capsules was 93% while the mean absolute bioavailability of EMTRIVA Oral Solution was 75%. The relative bioavailability of EMTRIVA Oral Solution was approximately 80% of EMTRIVA Capsules.

The multiple dose pharmacokinetics of emtricitabine are dose proportional over a dose range of 25–200 mg.

Effects of Food on Oral Absorption

EMTRIVA Capsules and Oral Solution may be taken with or without food. Emtricitabine systemic exposure (AUC) was unaffected while Cmax decreased by 29% when EMTRIVA Capsules were administered with food (an approximately 1000 kcal high-fat meal). Emtricitabine systemic exposure (AUC) and Cmax were unaffected when 200 mg EMTRIVA Oral Solution was administered with either a high-fat or low-fat meal.

Distribution

In vitro binding of emtricitabine to human plasma proteins was <4% and independent of concentration over the range of 0.02–200 µg/mL. At peak plasma concentration, the mean plasma to blood drug concentration ratio was ~1.0 and the mean semen to plasma drug concentration ratio was ~4.0.

Metabolism

In vitro studies indicate that emtricitabine is not an inhibitor of human CYP450 enzymes. Following administration of 14C-emtricitabine, complete recovery of the dose was achieved in urine (~86%) and feces (~14%). Thirteen percent (13%) of the dose was recovered in urine as three putative metabolites. The biotransformation of emtricitabine includes oxidation of the thiol moiety to form the 3'-sulfoxide diastereomers (~9% of dose) and conjugation with glucuronic acid to form 2'-O-glucuronide (~4% of dose). No other metabolites were identifiable.

Elimination

The plasma emtricitabine half-life is approximately 10 hours. The renal clearance of emtricitabine is greater than the estimated creatinine clearance, suggesting elimination by both glomerular filtration and active tubular secretion. There may be competition for elimination with other compounds that are also renally eliminated.

Special Populations

Race, Gender and Elderly

The pharmacokinetics of emtricitabine were similar in adult male and female patients and no pharmacokinetic differences due to race have been identified.

The pharmacokinetics of emtricitabine have not been fully evaluated in the elderly.

Hepatic Impairment

The pharmacokinetics of emtricitabine have not been studied in patients with hepatic impairment, however, emtricitabine is not metabolized by liver enzymes, so the impact of liver impairment should be limited.

Pediatrics

The pharmacokinetics of emtricitabine at steady state were determined in 77 HIV-infected children, and the pharmacokinetic profile was characterized in four age groups (Table 1). The emtricitabine exposure achieved in children receiving a daily dose of 6 mg/kg up to a maximum of 240 mg oral solution or a 200 mg capsule is similar to exposures achieved in adults receiving a once-daily dose of 200 mg.

Table 1 Mean ± SD Pharmacokinetic Parameters by Age Groups for Pediatric Patients Receiving EMTRIVA Capsules and Oral Solution

Age	3–24 mo (N=14)	25 mo–6 yr (N=19)	7–12yr (N=17)	13–17 yr (N=27)
* mean (range)
Formulation
Capsule (n)	0	0	10	26
Oral Solution (n)	14	19	7	1
Dose (mg/kg)*	6.1 (5.5–6.8)	6.1 (5.6–6.7)	5.6 (3.1–6.6)	4.4 (1.8–7.0)
Cmax (µg/mL)	1.9 ± 0.6	1.9 ± 0.7	2.7 ± 0.8	2.7 ± 0.9
AUC (hr∙µg/mL)	8.7 ± 3.2	9.0 ± 3.0	12.6 ± 3.5	12.6 ± 5.4
T1/2 (hr)	8.9 ± 3.2	11.3 ± 6.4	8.2 ± 3.2	8.9 ± 3.3

Renal Impairment

The pharmacokinetics of emtricitabine are altered in patients with renal impairment (see PRECAUTIONS). In adult patients with creatinine clearance <50 mL/min or with end-stage renal disease (ESRD) requiring dialysis, Cmax and AUC of emtricitabine were increased due to a reduction in renal clearance (Table 2). It is recommended that the dosing interval for EMTRIVA be modified in adult patients with creatinine clearance <50 mL/min or in adult patients with ESRD who require dialysis (see DOSAGE AND ADMINISTRATION). The effects of renal impairment on emtricitabine pharmacokinetics in pediatric patients are not known.

Table 2 Mean ± SD Pharmacokinetic Parameters in Adult Patients with Varying Degrees of Renal Function

Creatinine Clearance (mL/min)	>80 (N=6)	50–80 (N=6)	30–49 (N=6)	<30 (N=5)	ESRD* <30 (N=5)
* ESRD patients requiring dialysis † NA = Not Applicable
Baseline creatinine clearance (mL/min)	107 ± 21	59.8 ± 6.5	40.9 ± 5.1	22.9 ± 5.3	8.8 ± 1.4
Cmax (µg/mL)	2.2 ± 0.6	3.8 ± 0.9	3.2 ± 0.6	2.8 ± 0.7	2.8 ± 0.5
AUC (hr∙µg/mL)	11.8 ± 2.9	19.9 ± 1.2	25.1 ± 5.7	33.7± 2.1	53.2 ± 9.9
CL/F (mL/min)	302 ± 94	168 ± 10	138 ± 28	99 ± 6	64 ± 12
CLr (mL/min)	213 ± 89	121 ± 39	69 ± 32	30 ± 11	NA†

Hemodialysis: Hemodialysis treatment removes approximately 30% of the emtricitabine dose over a 3-hour dialysis period starting within 1.5 hours of emtricitabine dosing (blood flow rate of 400 mL/min and a dialysate flow rate of 600 mL/min). It is not known whether emtricitabine can be removed by peritoneal dialysis.

Drug Interactions

At concentrations up to 14-fold higher than those observed in vivo, emtricitabine did not inhibit in vitro drug metabolism mediated by any of the following human CYP 450 isoforms: CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, and CYP3A4. Emtricitabine did not inhibit the enzyme responsible for glucuronidation (uridine-5'-disphosphoglucuronyl transferase). Based on the results of these in vitro experiments and the known elimination pathways of emtricitabine, the potential for CYP450 mediated interactions involving emtricitabine with other medicinal products is low.

EMTRIVA has been evaluated in healthy volunteers in combination with tenofovir disoproxil fumarate (DF), zidovudine, indinavir, famciclovir, and stavudine. Tables 3 and 4 summarize the pharmacokinetic effects of coadministered drug on emtricitabine pharmacokinetics and effects of emtricitabine on the pharmacokinetics of coadministered drug.

Table 3 Drug Interactions: Change in Pharmacokinetic Parameters for Emtricitabine in the Presence of the Coadministered Drug*

Coadministered Drug	Dose of Coadministered Drug (mg)	Emtricitabine Dose (mg)	N	% Change of Emtricitabine Pharmacokinetic Parameters † (90% CI)
				Cmax	AUC	Cmin
* All interaction studies conducted in healthy volunteers. † ↑ = Increase; ↓ = Decrease; = No Effect; NA = Not Applicable
Tenofovir DF	300 once daily × 7 days	200 once daily × 7 days	17			↑ 20 (↑ 12 to ↑ 29)
Zidovudine	300 once daily × 7 days	200 once daily × 7 days	27
Indinavir	800 × 1	200 × 1	12			NA
Famciclovir	500 × 1	200 × 1	12			NA
Stavudine	40 × 1	200 × 1	6			NA

Table 4 Drug Interactions: Change in Pharmacokinetic Parameters for Coadministered Drug in the Presence of Emtricitabine*

Coadministered Drug	Dose of Coadministered Drug (mg)	Emtricitabine Dose (mg)	N	% Change of Coadministered Drug Pharmacokinetic Parameters † (90% CI)
				Cmax	AUC	Cmin
* All interaction studies conducted in healthy volunteers. † ↑= Increase; ↓ = Decrease; = No Effect; NA = Not Applicable
Tenofovir DF	300 once daily × 7 days	200 once daily × 7 days	17
Zidovudine	300 once daily × 7 days	200 once daily × 7 days	27	↑ 17 (↑ 0 to ↑ 38)	↑ 13 (↑ 5 to↑ 20)
Indinavir	800 × 1	200 × 1	12			NA
Famciclovir	500 × 1	200 × 1	12			NA
Stavudine	40 × 1	200 × 1	6			NA

INDICATION AND USAGE

EMTRIVA is indicated, in combination with other antiretroviral agents, for the treatment of HIV-1 infection in patients over three months of age.

This indication is based on analyses of plasma HIV-1 RNA levels and CD4 cell counts from controlled studies of 48 weeks duration in antiretroviral-naïve patients and antiretroviral-treatment-experienced patients who were virologically suppressed on an HIV treatment regimen.

In antiretroviral-treatment-experienced patients, the use of EMTRIVA may be considered for patients with HIV strains that are expected to be susceptible to EMTRIVA as assessed by genotypic or phenotypic testing (see MICROBIOLOGY, Drug Resistance and Cross Resistance).

Description of Clinical Studies in Adult Patients

Study 301A: EMTRIVA QD + Didanosine QD + Efavirenz QD Compared to Stavudine BID + Didanosine QD + Efavirenz QD

Study 301A was a 48 week double-blind, active-controlled multicenter study comparing EMTRIVA (200 mg QD) administered in combination with didanosine and efavirenz versus stavudine, didanosine and efavirenz in 571 antiretroviral naïve adult patients. Patients had a mean age of 36 years (range 18–69), 85% were male, 52% Caucasian, 16% African-American and 26% Hispanic. Patients had a mean baseline CD4 cell count of 318 cells/mm3 (range 5–1317) and a median baseline plasma HIV RNA of 4.9 log10 copies/mL (range 2.6–7.0). Thirty-eight percent of patients had baseline viral loads >100,000 copies/mL and 31% had CD4 cell counts <200 cells/mL. Treatment outcomes are presented in Table 5 below.

Table 5 Outcomes of Randomized Treatment at Week 48 (Study 301A)

Outcome at Week 48	EMTRIVA + Didanosine + Efavirenz (N=286)	Stavudine + Didanosine + Efavirenz (N=285)
* Patients achieved and maintained confirmed HIV RNA <400 copies/mL (<50 copies/mL) through Week 48. † Includes patients who failed to achieve virologic suppression or rebounded after achieving virologic suppression. ‡ Includes lost to follow-up, patient withdrawal, non-compliance, protocol violation and other reasons.
Responder*	81% (78%)	68% (59%)
Virologic Failure†	3%	11%
Death	0%	<1%
Study Discontinuation Due to Adverse Event	7%	13%
Study Discontinuation For Other Reasons‡	9%	8%

The mean increase from baseline in CD4 cell count was 168 cells/mm3 for the EMTRIVA arm and 134 cells/mm3 for the stavudine arm.

Through 48 weeks in the EMTRIVA group, 5 patients (1.7%) experienced a new CDC Class C event, compared to 7 patients (2.5%) in the stavudine group.

Study 303: EMTRIVA QD + Stable Background Therapy (SBT) Compared to Lamivudine BID + SBT

Study 303 was a 48 week, open-label, active-controlled multicenter study comparing EMTRIVA (200 mg QD) to lamivudine, in combination with stavudine or zidovudine and a protease inhibitor or NNRTI in 440 adult patients who were on a lamivudine-containing triple-antiretroviral drug regimen for at least 12 weeks prior to study entry and had HIV-1 RNA ≤400 copies/mL.

Patients were randomized 1:2 to continue therapy with lamivudine (150 mg BID) or to switch to EMTRIVA (200 mg QD). All patients were maintained on their stable background regimen. Patients had a mean age of 42 years (range 22–80), 86% were male, 64% Caucasian, 21% African-American and 13% Hispanic. Patients had a mean baseline CD4 cell count of 527 cells/mm3 (range 37–1909), and a median baseline plasma HIV RNA of 1.7 log10 copies/mL (range 1.7–4.0).

The median duration of prior antiretroviral therapy was 27.6 months. Treatment outcomes are presented in Table 6 below.

Table 6 Outcomes of Randomized Treatment at Week 48 (Study 303)

Outcome at Week 48	EMTRIVA + ZDV/d4T + NNRTI/PI (N=294)	Lamivudine + ZDV/d4T + NNRTI/PI (N=146)
* Patients achieved and maintained confirmed HIV RNA <400 copies/mL (<50 copies/mL) through Week 48. † Includes patients who failed to achieve virologic suppression or rebounded after achieving virologic suppression. ‡ Includes lost to follow-up, patient withdrawal, non-compliance, protocol violation and other reasons.
Responder*	77% (67%)	82% (72%)
Virologic Failure†	7%	8%
Death	0%	<1%
Study Discontinuation Due to Adverse Event	4%	0%
Study Discontinuation for Other Reasons‡	12%	10%

The mean increase from baseline in CD4 cell count was 29 cells/mm3 for the EMTRIVA arm and 61 cells/mm3 for the lamivudine arm.

Through 48 weeks, in the EMTRIVA group 2 patients (0.7%) experienced a new CDC Class C event, compared to 2 patients (1.4%) in the lamivudine group.

CONTRAINDICATIONS

EMTRIVA is contraindicated in patients with previously demonstrated hypersensitivity to any of the components of the products.

WARNINGS

Lactic Acidosis/Severe Hepatomegaly with Steatosis

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination, including emtricitabine and other antiretrovirals. A majority of these cases have been in women. Obesity and prolonged nucleoside exposure may be risk factors. However, cases have also been reported in patients with no known risk factors. Treatment with EMTRIVA should be suspended in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations).

Patients Co-infected with HIV and Hepatitis B Virus

It is recommended that all patients with HIV be tested for the presence of chronic hepatitis B virus (HBV) before initiating antiretroviral therapy. EMTRIVA is not indicated for the treatment of chronic HBV infection and the safety and efficacy of EMTRIVA have not been established in patients co-infected with HBV and HIV. Severe acute exacerbations of hepatitis B have been reported in patients after the discontinuation of EMTRIVA. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue EMTRIVA and are co-infected with HIV and HBV. If appropriate, initiation of anti-hepatitis B therapy may be warranted.

PRECAUTIONS

Patients with Impaired Renal Function

Emtricitabine is principally eliminated by the kidney. Reduction of the dosage of EMTRIVA is recommended for patients with impaired renal function (see CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION).

Drug Interactions

The potential for drug interactions with EMTRIVA has been studied in combination with zidovudine, indinavir, stavudine, famciclovir, and tenofovir disoproxil fumarate. There were no clinically significant drug interactions for any of these drugs (see CLINICAL PHARMACOLOGY, Drug Interactions).

Fat Redistribution

Redistribution/accumulation of body fat including central obesity, dorsocervical fat enlargement (buffalo hump), peripheral wasting, facial wasting, breast enlargement, and "cushingoid appearance" have been observed in patients receiving antiretroviral therapy.

The mechanism and long-term consequences of these events are unknown. A causal relationship has not been established.

Immune Reconstitution Syndrome

Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including EMTRIVA. During the initial phase of combination antiretroviral treatment, patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia (PCP), or tuberculosis), which may necessitate further evaluation and treatment.

Information for Patients

EMTRIVA is not a cure for HIV infection and patients may continue to experience illnesses associated with HIV infection, including opportunistic infections. Patients should remain under the care of a physician when using EMTRIVA.

Patients should be advised that:

• the use of EMTRIVA has not been shown to reduce the risk of transmission of HIV to others through sexual contact or blood contamination.
• the long term effects of EMTRIVA are unknown.
• EMTRIVA Capsules are for oral ingestion only.
• it is important to take EMTRIVA with combination therapy on a regular dosing schedule to avoid missing doses.
• redistribution or accumulation of body fat may occur in patients receiving antiretroviral therapy and that the cause and long-term health effects of these conditions are not known.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

In long-term oral carcinogenicity studies of emtricitabine, no drug-related increases in tumor incidence were found in mice at doses up to 750 mg/kg/day (26 times the human systemic exposure at the therapeutic dose of 200 mg/day) or in rats at doses up to 600 mg/kg/day (31 times the human systemic exposure at the therapeutic dose).

Mutagenesis

Emtricitabine was not genotoxic in the reverse mutation bacterial test (Ames test), mouse lymphoma or mouse micronucleus assays.

Impairment of Fertility

Emtricitabine did not affect fertility in male rats at approximately 140-fold or in male and female mice at approximately 60-fold higher exposures (AUC) than in humans given the recommended 200 mg daily dose. Fertility was normal in the offspring of mice exposed daily from before birth (in utero) through sexual maturity at daily exposures (AUC) of approximately 60-fold higher than human exposures at the recommended 200 mg daily dose.

Pregnancy

Pregnancy Category B

The incidence of fetal variations and malformations was not increased in embryofetal toxicity studies performed with emtricitabine in mice at exposures (AUC) approximately 60-fold higher and in rabbits at approximately 120-fold higher than human exposures at the recommended daily dose. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, EMTRIVA should be used during pregnancy only if clearly needed.

Antiretroviral Pregnancy Registry

To monitor fetal outcomes of pregnant women exposed to emtricitabine, an antiretroviral Pregnancy Registry has been established. Healthcare providers are encouraged to register patients by calling 1–800–258–4263.

Nursing Mothers: The Centers for Disease Control and Prevention recommend that HIV-infected mothers not breast-feed their infants to avoid risking postnatal transmission of HIV

It is not known whether emtricitabine is secreted into human milk. Because of both the potential for HIV transmission and the potential for serious adverse reactions in nursing infants, mothers should be instructed not to breast-feed if they are receiving EMTRIVA.

Pediatric Use

Safety and effectiveness in pediatric patients below the age of 3 months have not been established.

The safety and efficacy of emtricitabine is supported by data from three open-label, non-randomized clinical studies in which emtricitabine was administered to 169 HIV-1 infected treatment naïve and experienced (defined as virologically suppressed on a lamivudine containing regimen for which emtricitabine was substituted for lamivudine) patients between 3 months and 21 years of age. Patients received once-daily EMTRIVA Oral Solution (6 mg/kg to a maximum of 240 mg/day) or EMTRIVA Capsules (a single 200 mg capsule once daily) in combination with at least two other antiretroviral agents.

Patients had a mean age of 7.9 years (range 0.3–21), 49% were male, 15% Caucasian, 61% Black and 24% Hispanic. Patients had a median baseline HIV RNA of 4.6 log10 copies/mL (range 1.7–6.4) and a mean baseline CD4 cell count of 745 cells/mm3 (range 2 – 2650). Through 48 weeks of therapy, the overall proportion of patients who achieved and sustained an HIV RNA <400 copies/mL was 86%, and <50 copies/mL was 73%. The mean increase from baseline in CD4 cell count was 232 cells/mm3 (-945, +1512). The adverse event profile observed during these clinical trials was similar to that of adult patients, with the exception of a higher frequency of hyperpigmentation (see ADVERSE REACTIONS).

Geriatric Use

Clinical studies of EMTRIVA did not contain sufficient numbers of subjects aged 65 years and over to determine whether they respond differently from younger subjects. In general, dose selection for the elderly patient should be cautious, keeping in mind the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy (see PRECAUTIONS, Patients with Impaired Renal Function and DOSAGE AND ADMINISTRATION).

ADVERSE REACTIONS

Adult Patients

More than 2000 adult patients with HIV infection have been treated with EMTRIVA alone or in combination with other antiretroviral agents for periods of 10 days to 200 weeks in Phase I–III clinical trials.

Assessment of adverse reactions is based on data from studies 301A and 303 in which 571 treatment naïve (301A) and 440 treatment experienced (303) patients received EMTRIVA 200 mg (N=580) or comparator drug (N=431) for 48 weeks.

The most common adverse events that occurred in patients receiving EMTRIVA with other antiretroviral agents in clinical trials were headache, diarrhea, nausea, and rash, which were generally of mild to moderate severity. Approximately 1% of patients discontinued participation in the clinical studies due to these events. All adverse events were reported with similar frequency in EMTRIVA and control treatment groups with the exception of skin discoloration which was reported with higher frequency in the EMTRIVA treated group.

Skin discoloration, manifested by hyperpigmentation on the palms and/or soles was generally mild and asymptomatic. The mechanism and clinical significance are unknown.

A summary of EMTRIVA treatment emergent clinical adverse events in studies 301A and 303 is provided in Table 7.

Table 7 Selected Treatment-Emergent Adverse Events (All Grades, Regardless of Causality) Reported in ≥3% of EMTRIVA-Treated Patients in Either Study 301A or 303 (0–48 Weeks)

Adverse Event	303		301A
	EMTRIVA + ZDV/d4T + NNRTI/PI (N=294)	Lamivudine + ZDV/d4T + NNRTI/PI (N=146)	EMTRIVA + didanosine + efavirenz (N=286)	Stavudine + didanosine + efavirenz (N=285)
* Rash event includes rash, pruritus, maculopapular rash, urticaria, vesiculobullous rash, pustular rash, and allergic reaction.
Body as a Whole
Abdominal pain	8%	11%	14%	17%
Asthenia	16%	10%	12%	17%
Headache	13%	6%	22%	25%
Digestive System
Diarrhea	23%	18%	23%	32%
Dyspepsia	4%	5%	8%	12%
Nausea	18%	12%	13%	23%
Vomiting	9%	7%	9%	12%
Musculoskeletal
Arthralgia	3%	4%	5%	6%
Myalgia	4%	4%	6%	3%
Nervous System
Abnormal dreams	2%	<1%	11%	19%
Depressive disorders	6%	10%	9%	13%
Dizziness	4%	5%	25%	26%
Insomnia	7%	3%	16%	21%
Neuropathy/peripheral neuritis	4%	3%	4%	13%
Paresthesia	5%	7%	6%	12%
Respiratory
Increased cough	14%	11%	14%	8%
Rhinitis	18%	12%	12%	10%
Skin
Rash event*	17%	14%	30%	33%

Laboratory Abnormalities

Laboratory abnormalities in these studies occurred with similar frequency in the EMTRIVA and comparator groups. A summary of Grade 3 and 4 laboratory abnormalities is provided in Table 8 below.

Table 8 Treatment-Emergent Grade 3/4 Laboratory Abnormalities Reported in ≥1% of EMTRIVA-Treated Patients in Either Study 301A or 303

Number of Patients Treated	303		301A
	EMTRIVA + ZDV/d4T + NNRTI/PI (N=294)	Lamivudine + ZDV/d4T + NNRTI/PI (N=146)	EMTRIVA + Didanosine + Efavirenz (N=286)	Stavudine + Didanosine + Efavirenz (N=285)
* ULN = Upper limit of normal
Percentage with grade 3 or grade 4 laboratory abnormality	31%	28%	34%	38%
ALT (>5.0 × ULN*)	2%	1%	5%	6%
AST (>5.0 × ULN)	3%	<1%	6%	9%
Bilirubin (>2.5 × ULN)	1%	2%	<1%	<1%
Creatine kinase (>4.0 × ULN)	11%	14%	12%	11%
Neutrophils (<750 mm3)	5%	3%	5%	7%
Pancreatic amylase (>2.0 × ULN)	2%	2%	<1%	1%
Serum amylase (>2.0 × ULN)	2%	2%	5%	10%
Serum glucose <40 or >250 mg/dL)	3%	3%	2%	3%
Serum lipase (>2.0 × ULN)	<1%	<1%	1%	2%
Triglycerides (>750 mg/dL)	10%	8%	9%	6%

Pediatric Patients

Assessment of adverse reactions is based on data from 169 HIV-infected pediatric patients who received emtricitabine through week 48. The adverse event profile in pediatric patients was generally comparable to that observed in clinical studies of EMTRIVA in adult patients.

Selected treatment-emergent adverse events, regardless of causality, reported in patients during 48 weeks of treatment were the following: infection (44%), hyperpigmentation (32%), increased cough (28%), vomiting (23%), otitis media (23%), rash (21%), rhinitis (20%), diarrhea (20%), fever (18%), pneumonia (15%), gastroenteritis (11%), abdominal pain (10%), and anemia (7%). Treatment-emergent grade 3/4 laboratory abnormalities were experienced by 9% of pediatric patients, including amylase >2.0 × ULN (n=4), neutrophils <750/mm3 (n=3), ALT >5 × ULN (n=2), elevated CPK (>4 × ULN) (n=2) and one patient each with elevated bilirubin (>3.0 × ULN), elevated GGT (>10 × ULN), elevated lipase (>2.5 × ULN), decreased hemoglobin (<7 g/dL), and decreased glucose (<40 mg/dL).

OVERDOSAGE

There is no known antidote for EMTRIVA. Limited clinical experience is available at doses higher than the therapeutic dose of EMTRIVA. In one clinical pharmacology study single doses of emtricitabine 1200 mg were administered to 11 patients.

No severe adverse reactions were reported.

The effects of higher doses are not known. If overdose occurs the patient should be monitored for signs of toxicity, and standard supportive treatment applied as necessary.

Hemodialysis treatment removes approximately 30% of the emtricitabine dose over a 3-hour dialysis period starting within 1.5 hours of emtricitabine dosing (blood flow rate of 400 mL/min and a dialysate flow rate of 600 mL/min). It is not known whether emtricitabine can be removed by peritoneal dialysis.

DOSAGE AND ADMINISTRATION

EMTRIVA may be taken without regard to food.

Adult Patients (18 years of age and older):

• EMTRIVA Capsules: one 200 mg capsule administered once daily orally.
• EMTRIVA Oral Solution: 240 mg (24 mL) administered once daily orally.

Pediatric Patients (3 months through 17 years):

• EMTRIVA Oral Solution: 6 mg/kg up to a maximum of 240 mg (24 mL) administered once daily orally.
• EMTRIVA Capsules: for children weighing more than 33 kg who can swallow an intact capsule, one 200 mg capsule administered once daily orally.

Dose Adjustment in Adult Patients with Renal Impairment

Significantly increased drug exposures were seen when EMTRIVA was administered to patients with renal impairment, (see CLINICAL PHARMACOLOGY, Special Populations). Therefore, the dosing interval of EMTRIVA should be adjusted in patients with baseline creatinine clearance <50 mL/min using the following guidelines (see Table 9). The safety and effectiveness of these dose adjustment guidelines have not been clinically evaluated. Therefore, clinical response to treatment and renal function should be closely monitored in these patients.

Table 9 Dose Adjustment in Adult Patients with Renal Impairment

	Creatinine Clearance (mL/min)
Formulation	≥50 mL/min	30–49 mL/min	15–29 mL/min	<15 mL/min or on hemodialysis*
* Hemodialysis Patients: If dosing on day of dialysis, give dose after dialysis.
Capsule (200 mg)	200 mg every 24 hours	200 mg every 48 hours	200 mg every 72 hours	200 mg every 96 hours
Oral Solution (10 mg/mL)	240 mg every 24 hours (24 mL)	120 mg every 24 hours (12 mL)	80 mg every 24 hours (8 mL)	60 mg every 24 hours (6 mL)

Although there are insufficient data to recommend a specific dose adjustment of EMTRIVA in pediatric patients with renal impairment, a reduction in the dose and/or an increase in the dosing interval similar to adjustments for adults should be considered.

HOW SUPPLIED

EMTRIVA is available as capsules and oral solution.

EMTRIVA Capsules, 200 mg, are size 1 hard gelatin capsules with a blue cap and white body, printed with "200 mg" in black on the cap and "GILEAD" and the corporate logo in black on the body.

They are packaged in bottles of 30 capsules (NDC 61958–0601–1) with induction sealed child-resistant closures.

Store at 25 °C (77 °F); excursions permitted to 15 °C–30 °C (59 °F–86 °F)

EMTRIVA Oral Solution is a clear, orange to dark orange liquid.

EMTRIVA Oral Solution is supplied in plastic, amber bottles of 170 mL (NDC 61958–0602–1) with child resistant closures, packaged with a marked dosing cup.

Store refrigerated, 2–8 °C (36–46 °F). Emtriva Oral Solution should be used within 3 months if stored by the patient at 25 °C (77 °F); excursions permitted to 15–30 °C (59–86 °F).

EMTRIVA is manufactured for Gilead Sciences, Inc., Foster City, CA 94404

September 2005

EMTRIVA® is a trademark of Gilead Sciences, Inc.

GS–21–500–896–10

©2003–2005 Gilead Sciences, Inc.

Patient Information
EMTRIVA® (em-treev’-ah) Capsules
EMTRIVA® Oral Solution

Generic name: emtricitabine (em tri SIT uh bean)

Read the Patient Information that comes with EMTRIVA before you start using it and each time you get a refill. There may be new information. This information does not take the place of talking to your healthcare provider about your medical condition or treatment.

You should stay under a healthcare provider's care when taking EMTRIVA. Do not change or stop your medicine without first talking with your healthcare provider. Talk to your healthcare provider or pharmacist if you have any questions about EMTRIVA.

What is the most important information I should know about EMTRIVA?

• Some people who have taken medicines like EMTRIVA(a nucleoside analog) have developed a serious condition called lactic acidosis (buildup of an acid in the blood). Lactic acidosis can be a medical emergency and may need to be treated in the hospital. Call your healthcare provider right away if you get the following signs of lactic acidosis.
  • You feel very weak or tired.
  • You have unusual (not normal) muscle pain.
  • You have trouble breathing.
  • You have stomach pain with nausea and vomiting.
  • You feel cold, especially in your arm and legs.
  • You feel dizzy or lightheaded.
  • You have a fast or irregular heartbeat.
• Some people who have taken medicines like EMTRIVA have developed serious liver problems called hepatotoxicity, with liver enlargement (hepatomegaly) and fat in the liver (steatosis). Call your healthcare provider right away if you get the following signs of liver problems.
  • Your skin or the white part of your eyes turns yellow (jaundice).
  • Your urine turns dark.
  • Your bowel movements (stools) turn light in color.
  • You don't feel like eating food for several days or longer.
  • You feel sick to your stomach (nausea).
  • You have lower stomach area (abdominal) pain.
• You may be more likely to get lactic acidosis or liver problems if you are female, very overweight (obese), or have been taking nucleoside analog medicines, like EMTRIVA, for a long time.
• EMTRIVA is not for the treatment of Hepatitis B Virus (HBV) infection. Patients with both HBV and human immunodeficiency virus (HIV) infection who take EMTRIVA need close medical follow-up for several months after stopping treatment with EMTRIVA. Follow-up includes medical exams and blood tests to check for HBV that is getting worse. Patients with HBV infection, who take EMTRIVA and then stop it, may get "flare-ups" of their hepatitis. A "flare-up" is when the disease suddenly returns in a worse way than before.

What is EMTRIVA?

EMTRIVA is a type of medicine called an HIV (human immunodeficiency virus) nucleoside reverse transcriptase inhibitor (NRTI). EMTRIVA is always used with other anti-HIV medicines to treat people with HIV infection. EMTRIVA is for adults and children 3 months or older. EMTRIVA has not been studied fully in children under 3 months or adults over age 65.

HIV infection destroys CD4 (T) cells, which are important to the immune system. The immune system helps fight infection. After a large number of T cells are destroyed, acquired immune deficiency syndrome (AIDS) develops.

EMTRIVA helps to block HIV reverse transcriptase, a chemical in your body (enzyme) that is needed for HIV to multiply. EMTRIVA may lower the amount of HIV in the blood (viral load). EMTRIVA may also help to increase the number of T cells called CD4 cells. Lowering the amount of HIV in the blood lowers the chance of death or infections that happen when your immune system is weak (opportunistic infections).

EMTRIVA does not cure HIV infection or AIDS. The long-term effects of EMTRIVA are not known at this time. People taking EMTRIVA may still get opportunistic infections or other conditions that happen with HIV infection. Opportunistic infections are infections that develop because the immune system is weak. Some of these conditions are pneumonia, herpes virus infections, and Mycobacterium avium complex (MAC) infections. It is very important that you see your healthcare provider regularly while taking EMTRIVA.

EMTRIVA does not lower your chance of passing HIV to other people through sexual contact, sharing needles, or being exposed to your blood. For your health and the health of others, it is important to always practice safer sex by using a latex or polyurethane condom or other barrier to lower the chance of sexual contact with semen, vaginal secretions, or blood. Never use or share dirty needles.

Who should not take EMTRIVA?

Do not take EMTRIVA if you are allergic to EMTRIVA or any of its ingredients. The active ingredient is emtricitabine. See the end of this leaflet for a complete list of ingredients.

What should I tell my healthcare provider before taking EMTRIVA?

Tell your healthcare provider

• If you are pregnant or planning to become pregnant. We do not know if EMTRIVA can harm your unborn child. You and your healthcare provider will need to decide if EMTRIVA is right for you. If you use EMTRIVA while you are pregnant, talk to your healthcare provider about how you can be on the EMTRIVA Antiviral Pregnancy Registry.
• If you are breast-feeding. You should not breast feed if you are HIV-positive because of the chance of passing the HIV virus to your baby. Also, it is not known if EMTRIVA can pass into your breast milk and if it can harm your baby. If you are a woman who has or will have a baby, talk with your healthcare provider about the best way to feed your baby.
• If you have kidney problems. You may need to take EMTRIVA less often.
• If you have any liver problems including Hepatitis B Virus infection.
• Tell your healthcare provider about all your medical conditions.
• Tell your healthcare provider about all the medicines you take such as prescription and non-prescription medicines and dietary supplements. Keep a complete list of all the medicines that you take. Make a new list when medicines are added or stopped. Give copies of this list to all of your healthcare providers and pharmacist every time you visit or fill a prescription.

How should I take EMTRIVA?

• Take EMTRIVA every day by mouth exactly as your healthcare provider prescribed it. Follow the directions from your healthcare provider, exactly as written on the label.
• Dosing in adults: The usual dose of EMTRIVA is 1 capsule once a day.
• Dosing in children 3 months or older: The child's doctor will calculate the right dose of EMTRIVA (oral solution or capsule) based on the child's weight.
• EMTRIVA is always used with other anti-HIV medicines.
• EMTRIVA may be taken with or without a meal. Food does not affect how EMTRIVA works.
• If you forget to take EMTRIVA, take it as soon as you remember that day. Do not take more than 1 dose of EMTRIVA in a day. Do not take 2 doses at the same time. Call your healthcare provider or pharmacist if you are not sure what to do. It is important that you do not miss any doses of EMTRIVA or your other anti-HIV medicines.
• When your EMTRIVA supply starts to run low, get more from your healthcare provider or pharmacy. This is very important because the amount of virus in your blood may increase if the medicine is stopped for even a short time. The virus may develop resistance to EMTRIVA and become harder to treat.
• Stay under a healthcare provider's care when taking EMTRIVA. Do not change your treatment or stop treatment without first talking with your healthcare provider.
• If you take too much EMTRIVA, call your local poison control center or emergency room right away.

What should I avoid while taking EMTRIVA?

• Do not breast-feed. See "What should I tell my healthcare provider before taking EMTRIVA?"Talk with your healthcare provider about the best way to feed your baby.
• Avoid doing things that can spread HIV infection since EMTRIVA doesn't stop you from passing the HIV infection to others.
• Do not share needles or other injection equipment.
• Do not share personal items that can have blood or body fluids on them, like toothbrushes or razor blades.
• Do not have any kind of sex without protection. Always practice safer sex by using a latex or polyurethane condom or other barrier to reduce the chance of sexual contact with semen, vaginal secretions, or blood.

What are the possible side effects of EMTRIVA?

EMTRIVA may cause the following serious side effects (see "What is the most important information I should know about EMTRIVA?"):

• lactic acidosis (buildup of an acid in the blood). Lactic acidosis can be a medical emergency and may need to be treated in the hospital. Call your doctor right away if you get signs of lactic acidosis. (see "What is the most important information I should know about EMTRIVA?")
• serious liver problems (hepatotoxicity), with liver enlargement (hepatomegaly) and fat in the liver (steatosis). Call your healthcare provider right away if you get any signs of liver problems. (see "What is the most important information I should know about EMTRIVA?")
• "flare-ups" of hepatitis B virus infection, in which the disease suddenly returns in a worse way than before, can occur if you stop taking EMTRIVA. EMTRIVA is not for the treatment of Hepatitis B Virus (HBV) infection.

Other side effects with EMTRIVA when used with other anti-HIV medicines Include:

• Changes in body fat have been seen in some patients taking EMTRIVA and other anti-HIV medicines. These changes may include increased amount of fat in the upper back and neck ("buffalo hump"), breast, and around the main part of your body (trunk). Loss of fat from the legs, arms and face may also happen. The cause and long term health effects of these conditions are not known at this time.

The most common side effects of EMTRIVA used with other anti-HIV medicines are headache, diarrhea, nausea and rash. Skin discoloration may also happen with EMTRIVA.

There have been other side effects in patients taking EMTRIVA. However, these side effects may have been due to other medicines that patients were taking or to HIV itself. Some of these side effects can be serious.

This list of side effects is not complete. If you have questions about side effects, ask your healthcare provider or pharmacist. You should report any new or continuing symptoms to your healthcare provider right away. Your healthcare provider may be able to help you manage these side effects.

How do I store EMTRIVA?

• Keep EMTRIVA and all other medicines out of reach of children.
• Store EMTRIVA Capsules between 59 °F and 86 °F (15 °C to 30 °C).
• Store EMTRIVA Oral Solution in a refrigerator between 36 °F and 46 °F (2–8 °C). Do not freeze. Alternatively, the product may be stored at room temperature for up to 3 months and any remaining solution in the bottle must be discarded after the 3 months.
• Do not keep your medicine in places that are too hot or cold.
• Do not keep medicine that is out of date or that you no longer need. If you throw any medicines away make sure that children will not find them.

General information about EMTRIVA:

Medicines are sometimes prescribed for conditions that are not mentioned in patient information leaflets. Do not use EMTRIVA for a condition for which it was not prescribed. Do not give EMTRIVA to other people, even if they have the same symptoms you have. It may harm them.

This leaflet summarizes the most important information about EMTRIVA. If you would like more information, talk with your doctor. You can ask your healthcare provider or pharmacist for information about EMTRIVA that is written for health professionals. For more information, you may also call 1-800-GILEAD5.

What are the ingredients of EMTRIVA?

Active Ingredient: emtricitabine

Inactive Ingredients for EMTRIVA Capsules: crospovidone, magnesium stearate, microcrystalline cellulose, and povidone.

Inactive Ingredients for EMTRIVA Oral Solution: Cotton candy flavor, FD&C yellow No. 6, edetate disodium, methylparaben and propylparaben, sodium phosphate (monobasic), propylene glycol, water, and xylitol. Sodium hydroxide and hydrochloric acid may be used to adjust pH.

Rx Only

September 2005

GS–21–500–896–10

©2003–2005 Gilead Sciences, Inc.

Emtriva (emtricitabine)

PRODUCT INFO Product Code 61958-0601 Dosage Form CAPSULE Route Of Administration ORAL DEA Schedule

INGREDIENTS Name (Active Moiety) Type Strength emtricitabine (emtricitabine) Active 200 MILLIGRAM  In 1 CAPSULE crospovidone Inactive   magnesium stearate Inactive   microcrystalline cellulose Inactive   povidone Inactive

IMPRINT INFORMATION Characteristic Appearance Characteristic Appearance Color BLUE (Blue) , WHITE (WHITE) Score 1 Shape CAPSULE (Capsule shaped) Symbol true Imprint Code 200;mg;GILEAD Coating false Size 19mm

PACKAGING # NDC Package Description Multilevel Packaging 1 61958-0601-1 30 CAPSULE In 1 BOTTLE, PLASTIC None

Emtriva (emtricitabine)

PRODUCT INFO Product Code 61958-0602 Dosage Form SOLUTION Route Of Administration ORAL DEA Schedule

INGREDIENTS Name (Active Moiety) Type Strength emtricitabine (emtricitabine) Active 10 MILLIGRAM  In 1 MILLILITER cotton candy flavor Inactive   FD&C yellow No 6 Inactive   edetate disodium Inactive   methylparaben Inactive   propylparaben Inactive   sodium phosphate Inactive   propylene glycol Inactive   water Inactive   xylitol Inactive

IMPRINT INFORMATION Characteristic Appearance Characteristic Appearance Color Score Shape Symbol Imprint Code Coating Size

PACKAGING # NDC Package Description Multilevel Packaging 1 61958-0602-1 170 MILLILITER In 1 BOTTLE, DISPENSING None

Revised: 10/2006Gilead Sciences, Inc.