VIRACEPT

2.1 Adults and Adolescents (13 years and older)

The recommended dose is 1250 mg (five 250 mg tablets or two 625 mg tablets) twice daily or 750 mg (three 250 mg tablets) three times daily. VIRACEPT should be taken with a meal. Patients unable to swallow the 250 or 625 mg tablets may dissolve the tablets in a small amount of water [see Dosage and Administration (2.3)].

2.2 Pediatric Patients (2 to less than 13 years)

In children 2 years of age and older, the recommended oral dose of VIRACEPT Oral Powder or 250 mg tablets is 45 to 55 mg/kg twice daily or 25 to 35 mg/kg three times daily. All doses should be taken with a meal. Doses higher than the adult maximum dose of 2500 mg per day have not been studied in children.

For children unable to swallow tablets, VIRACEPT 250 mg tablet(s) may be dissolved in a small amount of water or, VIRACEPT Oral Powder may be administered [see Dosage and Administration (2.3)].

The healthcare provider should assess appropriate formulation and dosage for each patient. Tables 1 and 2 provide dosing guidelines for VIRACEPT tablets and powder based on age and body weight.

2.3 Method of Administration

2.4 Hepatic Impairment

VIRACEPT can be used in patients with mild hepatic impairment without any dose adjustment. VIRACEPT should not be used in patients with either moderate or severe hepatic impairment [see Warnings and Precautions (5.2), Use in Specific Populations (8.6), and Clinical Pharmacology (12.3)].

5.1 Risk of Serious Adverse Reactions Due to Drug Interactions

Initiation of VIRACEPT, a CYP3A inhibitor, in patients receiving medications metabolized by CYP3A or initiation of medications metabolized by CYP3A in patients already receiving VIRACEPT, may increase plasma concentrations of medications metabolized by CYP3A. Initiation of medications that inhibit or induce CYP3A may increase or decrease concentrations of VIRACEPT, respectively. These interactions may lead to:

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Clinically significant adverse reactions, potentially leading to severe, life threatening, or fatal events from greater exposures of concomitant medications.

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Clinically significant adverse reactions from greater exposures of VIRACEPT.

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Loss of therapeutic effect of VIRACEPT and possible development of resistance.

See Table 6 for steps to prevent or manage these possible and known significant drug interactions, including dosing recommendations [see Drug Interactions (7)]. Consider the potential for drug interactions prior to and during VIRACEPT therapy; review concomitant medications during VIRACEPT therapy; and monitor for the adverse reactions associated with the concomitant medications [see Contraindications (4) and Drug Interactions (7)].

5.2 Hepatic Impairment

VIRACEPT should not be used in patients with either moderate or severe hepatic impairment (Child-Pugh B or C, score greater than or equal to 7) [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3)].

5.3 Phenylketonurics

Viracept Oral Powder contains phenylalanine, a component of aspartame. Each gram of VIRACEPT powder contains 11.2 mg phenylalanine. Phenylalanine can be harmful to patients with phenylketonuria.

5.4 Diabetes Mellitus/Hyperglycemia

New onset diabetes mellitus, exacerbation of pre-existing diabetes mellitus and hyperglycemia have been reported during post-marketing surveillance in HIV-infected patients receiving protease inhibitor therapy. Some patients required either initiation or dose adjustments of insulin or oral hypoglycemic agents for treatment of these events. In some cases diabetic ketoacidosis has occurred. In those patients who discontinued protease inhibitor therapy, hyperglycemia persisted in some cases. Because these events have been reported voluntarily during clinical practice, estimates of frequency cannot be made and a causal relationship between protease inhibitor therapy and these events has not been established.

5.5 Hemophilia

There have been reports of increased bleeding, including spontaneous skin hematomas and hemarthrosis, in patients with hemophilia type A and B treated with protease inhibitors. In some patients, additional factor VIII was given. In more than half of the reported cases, treatment with protease inhibitors was continued or reintroduced. A causal relationship has not been established.

5.6 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 currently unknown. A causal relationship has not been established.

5.7 Immune Reconstitution Syndrome

Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including VIRACEPT. 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 jiroveci pneumonia (PCP), or tuberculosis], which may necessitate further evaluation and treatment.

Autoimmune disorders (such as Graves' disease, polymyositis, and Guillain-Barré syndrome) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable, and can occur many months after initiation of treatment.

6.1 Clinical Trials Experience: Adults and Adolescents (13 years and older)

The safety of VIRACEPT was studied in over 5000 patients who received drug either alone or in combination with nucleoside analogues. The majority of adverse events were of mild intensity. The most frequently reported adverse event among patients receiving VIRACEPT was diarrhea, which was generally of mild to moderate intensity.

Drug-related clinical adverse experiences of moderate or severe intensity in ≥2% of patients treated with VIRACEPT coadministered with d4T and 3TC (Study 542) for up to 48 weeks, or with ZDV plus 3TC (Study 511) for up to 24 weeks are presented in Table 4.

Adverse events occurring in less than 2% of patients receiving VIRACEPT in all phase 2 and 3 clinical trials and considered at least possibly related or of unknown relationship to treatment and of at least moderate severity are listed below.

Body as a Whole: abdominal pain, accidental injury, allergic reaction, asthenia, back pain, fever, headache, malaise, pain, and redistribution/accumulation of body fat [see Warnings and Precautions (5.7)].

Digestive System: anorexia, dyspepsia, epigastric pain, gastrointestinal bleeding, hepatitis, mouth ulceration, pancreatitis, and vomiting.

Hemic/Lymphatic System: anemia, leukopenia, and thrombocytopenia.

Metabolic/Nutritional System: increases in alkaline phosphatase, amylase, creatine phosphokinase, lactic dehydrogenase, SGOT, SGPT, and gamma-glutamyl transpeptidase; hyperlipemia, hyperuricemia, hyperglycemia, hypoglycemia, dehydration, and liver function tests abnormal.

Musculoskeletal System: arthralgia, arthritis, cramps, myalgia, myasthenia, and myopathy.

Nervous System: anxiety, depression, dizziness, emotional lability, hyperkinesia, insomnia, migraine, paresthesia, seizures, sleep disorder, somnolence, and suicide ideation.

Respiratory System: dyspnea, pharyngitis, rhinitis, and sinusitis.

Skin/Appendages: dermatitis, folliculitis, fungal dermatitis, maculopapular rash, pruritus, sweating, and urticaria.

Special Senses: acute iritis and eye disorder.

Urogenital System: kidney calculus, sexual dysfunction, and urine abnormality.

6.2 Clinical Trials Experience: Pediatrics (2 to less than 13 years of age)

VIRACEPT has been studied in approximately 400 pediatric patients in clinical trials from birth to 13 years of age. The adverse event profile seen during pediatric clinical trials was similar to that for adults.

The most commonly reported drug-related, treatment-emergent adverse events reported in the pediatric studies included: diarrhea, leukopenia/neutropenia, rash, anorexia, and abdominal pain. Diarrhea, regardless of assigned relationship to study drug, was reported in 39% to 47% of pediatric patients receiving VIRACEPT in 2 of the larger treatment trials. Leukopenia/neutropenia was the laboratory abnormality most commonly reported as a significant event across the pediatric studies.

6.3 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of VIRACEPT. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Body as a Whole: hypersensitivity reactions (including bronchospasm, moderate to severe rash, fever, and edema).

Cardiovascular System: QTc prolongation, torsades de pointes.

Digestive System: jaundice.

Metabolic/Nutritional System: bilirubinemia, metabolic acidosis.

7.1 Potential for VIRACEPT to Affect Other Drugs

Nelfinavir is an inhibitor of CYP3A. Coadministration of VIRACEPT and drugs primarily metabolized by CYP3A (e.g., dihydropyridine calcium channel blockers, HMG-CoA reductase inhibitors, immunosuppressants, and PDE5 inhibitors) may result in increased plasma concentrations of such drugs that could increase or prolong both its therapeutic and adverse effects (see Tables 3 and 6).

7.2 Potential for Other Drugs to Affect VIRACEPT

Nelfinavir is metabolized by CYP3A and CYP2C19. Coadministration of VIRACEPT and drugs that induce CYP3A or CYP2C19, such as rifampin, may decrease nelfinavir plasma concentrations and reduce its therapeutic effect. Coadministration of VIRACEPT and drugs that inhibit CYP3A or CYP2C19 may increase nelfinavir plasma concentrations.

7.3 Established and Other Potentially Significant Drug Interactions

Table 6 provides the effect on concentrations of VIRACEPT or concomitant drug as a result of coadministration with VIRACEPT. These recommendations 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 efficacy.

Table 6: Established and Other Potentially Significant Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies [see Clinical Pharmacology (12.3) (Tables 12 and 13) for magnitude of interaction]

8.1 Pregnancy

8.2 Lactation

8.3 Females and Males of Reproductive Potential

8.4 Pediatric Use

The safety, tolerability, pharmacokinetic profile and efficacy of VIRACEPT were evaluated in HIV infected pediatric patients from 2 to 13 years of age in multicenter clinical trials, Study 556 and PACTG 337 [see Clinical Pharmacology (12.3) and Clinical Studies (14.3)]. In patients less than 2 years of age, VIRACEPT was found to be safe at the doses studied, but a reliably effective dose could not be established [see Dosage and Administration (2.2), Adverse Reactions (6.2), and Clinical Pharmacology (12.3)]. The pharmacokinetic profile, safety and antiviral activity of VIRACEPT in adolescent patients 13 years and older is supported by data from the adult clinical trials where some trials allowed enrolment of subjects 13 years and older. Thus, the data for adolescents and adults were analyzed collectively [see Adverse Reactions (6.1)].

8.5 Geriatric Use

Clinical studies of VIRACEPT did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

8.6 Hepatic Impairment

VIRACEPT should not be used in patients with either moderate or severe hepatic impairment (Child-Pugh B or C, score greater than or equal to 7) [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]. No dose adjustment of VIRACEPT is necessary for patients with mild hepatic impairment (Child-Pugh A, score 5–6).

8.7 Renal Impairment

The safety and efficacy of VIRACEPT have not been established in patients with renal impairment.

12.1 Mechanism of Action

Nelfinavir is an inhibitor of the HIV-1 protease [see Microbiology (12.4)].

12.2 Pharmacodynamics

12.3 Pharmacokinetics

The pharmacokinetic properties of nelfinavir were evaluated in healthy volunteers and HIV-infected patients; no substantial differences were observed between the two groups.

12.4 Microbiology

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenicity studies in mice and rats were conducted with nelfinavir at oral doses up to 1000 mg/kg/day. No evidence of a tumorigenic effect was noted in mice at systemic exposures (Cmax) up to 9-fold those measured in humans at the recommended therapeutic dose (750 mg TID or 1250 mg BID). In rats, thyroid follicular cell adenomas and carcinomas were increased in males at 300 mg/kg/day and higher and in females at 1000 mg/kg/day. Systemic exposures (Cmax) at 300 and 1000 mg/kg/day were 1- to 3-fold, respectively, those measured in humans at the recommended therapeutic dose. Repeated administration of nelfinavir to rats produced effects consistent with hepatic microsomal enzyme induction and increased thyroid hormone deposition; these effects predispose rats, but not humans, to thyroid follicular cell neoplasms. Nelfinavir showed no evidence of mutagenic or clastogenic activity in a battery of in vitro and in vivo genetic toxicology assays. These studies included bacterial mutation assays in S. typhimurium and E. coli, a mouse lymphoma tyrosine kinase assay, a chromosomal aberration assay in human lymphocytes, and an in vivo mouse bone marrow micronucleus assay.

Nelfinavir produced no effects on either male or female mating and fertility or embryo survival in rats at systemic exposures comparable to the human therapeutic exposure.

14.1 Studies in Antiretroviral Treatment Naïve Adult Patients

Study 511: VIRACEPT + zidovudine + lamivudine versus zidovudine + lamivudine

Study 511 is a double-blind, randomized, placebo-controlled trial comparing treatment with zidovudine (ZDV; 200 mg TID) and lamivudine (3TC; 150 mg BID) plus 2 doses of VIRACEPT (750 mg and 500 mg TID) to zidovudine (200 mg TID) and lamivudine (150 mg BID) alone in 297 antiretroviral naïve HIV-1 infected patients. The median age was 35 years [range 21 to 63]; 89% were male and 78% were Caucasian. Mean baseline CD4 cell count was 288 cells/mm3 and mean baseline plasma HIV RNA was 5.21 log10 copies/mL (160,394 copies/mL). The proportion of patients with plasma HIV RNA <400 copies/mL at Week 48 was 86%, as summarized in Figure 1. The mean change in CD4 cell count at Week 48 was 207.6 cells/mm3.

Figure 1
Study 511: Percentage of Patients With HIV RNA Below 400 Copies/mL

14.2 Studies in Antiretroviral Treatment Experienced Adult Patients

14.3 Studies in Pediatric Patients

The pharmacokinetic profile, safety and antiviral activity of VIRACEPT in pediatric patients 2 years of age up to 13 years were evaluated in 2 randomized studies.

Study 556 was a randomized, double-blind, placebo-controlled trial with VIRACEPT or placebo coadministered with ZDV and ddI in 141 HIV-positive children who had received minimal antiretroviral therapy. The mean age of the children was 3.9 years. Ninety four (67%) children were between 2–12 years, and 47 (33%) were < 2 years of age. The mean baseline HIV RNA value was 5.0 log for all patients and the mean CD4 cell count was 886 cells/mm3 for all patients. The efficacy of VIRACEPT measured by HIV RNA <400 at 48 weeks in children ≥2 years of age was 26% compared to 2% of placebo patients (p=0.0008). In the children < 2 years of age, only 1 of 27 and 2 of 20 maintained an undetectable HIV RNA level at 48 weeks for placebo and VIRACEPT patients, respectively.

PACTG 377 was an open-label study that randomized 181 HIV treatment-experienced pediatric patients to receive: d4T+NVP+RTV, d4T+3TC+NFV, or d4T+3TC+NVP+NFV with NFV given on a TID schedule. The median age was 5.9 years and 46% were male. At baseline the median HIV RNA was 4.4 log and median CD4 cell count was 690 cells/mm3. Substudy PACTG 725 evaluated d4T+3TC+NFV with NFV given on a BID schedule. The proportion of patients with detectable viral load at baseline achieving HIV RNA <400 copies/mL at 48 weeks was: 41% for d4T+NVP+RTV, 42% for d4T+3TC+NFV, 30% for d4T+NVP+NFV, and 52% for d4T+3TC+NVP+NFV. No significant clinical differences were identified between patients receiving VIRACEPT in BID or TID schedules.

VIRACEPT has been evaluated in 2 studies of young infants. The PENTA 7 study was an open-label study to evaluate the toxicity, tolerability, pharmacokinetics, and activity of NFV+d4T+ddI in 20 HIV-infected infants less than 12 weeks of age. PACTG 353 evaluated the pharmacokinetics and safety of VIRACEPT in infants born to HIV-infected women receiving NFV as part of combination therapy during pregnancy.

The following issues should be considered when initiating VIRACEPT in pediatric patients:

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In pediatric patients ≥2 years of age receiving VIRACEPT as part of triple combination antiretroviral therapy in randomized studies, the proportion of patients achieving a HIV RNA level <400 copies/mL through 48 weeks ranged from 26% to 42%.

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Response rates in children <2 years of age appeared to be poorer than those in patients ≥2 years of age in some studies.

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Highly variable drug exposure remains a significant problem in the use of VIRACEPT in pediatric patients. Unpredictable drug exposure may be exacerbated in pediatric patients because of increased clearance compared to adults and difficulties with compliance and adequate food intake with dosing. Pharmacokinetic results from the pediatric studies are reported in Table 11 [see Clinical Pharmacology (12.3)].

The pharmacokinetic profile, safety and antiviral activity of VIRACEPT in adolescent patients 13 years and older is supported by data from the adult clinical trials where some trials allowed enrolment of subjects 13 years and older. Thus, the data for adolescents and adults were analyzed collectively.

VIRACEPT tablets and oral powder should be stored at 15° to 30°C (59° to 86°F).

Keep container tightly closed. Dispense in original container.

Drug Interactions

VIRACEPT may interact with some drugs; therefore, advise patients to report to their healthcare provider the use of any other prescription, non-prescription medication or herbal products, including St. John's wort [see Contraindications (4), Drug Interactions (7.3), and Use in Specific Populations (8.3)].

Hepatic Impairment

Patients should be informed that VIRACEPT should not be used if there is moderate or severe hepatic impairment.

Phenylketonuria

Physicians should alert patients with phenylketonuria that VIRACEPT Oral Powder contains phenylalanine

Fat Redistribution

Patients should be informed that redistribution or accumulation of body fat may occur in patients receiving antiretroviral therapy, including PREZISTA/ritonavir, and that the cause and long-term health effects of these conditions are not known at this time

The most frequent adverse event associated with VIRACEPT is diarrhea, which can usually be controlled with non-prescription drugs, such as loperamide, which slow gastrointestinal motility.

Pregnancy Registry

Advise patients that there is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to VIRACEPT during pregnancy [see Use in Specific Populations (8.1)].

Lactation

Instruct patients with HIV-1 infection not to breastfeed because HIV-1 can be passed to the infant in the breast milk [see Use in Specific Populations (8.2)].

Females and Males of Reproductive Potential

Advise females of reproductive potential that VIRACEPT may reduce the effectiveness of estrogen-based contraceptives, and to use alternative non-hormonal contraception [see Drug Interactions (7.3), Use in Specific Populations (8.3)].