"Entry Inhibitors (including Fusion Inhibitors) and CCR5 Co-receptor Antagonist
Entry inhibitors block HIV entry into CD4+ cells.
The only drug in this class "...
Hepatotoxicity with allergic features including life-threatening events has been reported in clinical trials and postmarketing. Severe rash or evidence of systemic allergic reaction including drug-related rash with fever, eosinophilia, elevated IgE, or other systemic symptoms have been reported in conjunction with hepatotoxicity. These events occurred approximately 1 month after starting treatment. Among reported cases of hepatitis, some were observed in the absence of allergic features or with no pre-existing hepatic disease.
Appropriate laboratory testing including ALT, AST, and bilirubin should be conducted prior to initiating therapy with SELZENTRY and at other timepoints during treatment as clinically indicated. Hepatic laboratory parameters should be obtained in any patient who develops rash, or signs or symptoms of hepatitis, or allergic reaction. Discontinuation of SELZENTRY should be considered in any patient with signs or symptoms of hepatitis, or with increased liver transaminases combined with rash or other systemic symptoms.
Caution should be used when administering SELZENTRY to patients with pre-existing liver dysfunction or who are co-infected with viral hepatitis B or C. The safety and efficacy of SELZENTRY have not been specifically studied in patients with significant underlying liver disorders. In trials of treatment-experienced HIV-1-infected subjects, approximately 6% of subjects were co-infected with hepatitis B and approximately 6% were co-infected with hepatitis C. Due to the small number of co-infected subjects studied, no conclusions can be drawn regarding whether they are at an increased risk for hepatic adverse events with administration of SELZENTRY.
Severe Skin and Hypersensitivity Reactions
Severe, potentially life-threatening skin and hypersensitivity reactions have been reported in patients taking SELZENTRY, in most cases concomitantly with other drugs associated with these reactions. These include cases of Stevens-Johnson syndrome (SJS, toxic epidermal necrolysis (TEN), and drug rash with eosinophilia and systemic symptoms (DRESS) [see ADVERSE REACTIONS]. The cases were characterized by features including rash, constitutional findings, and sometimes organ dysfunction, including hepatic failure. Discontinue SELZENTRY and other suspected agents immediately if signs or symptoms of severe skin or hypersensitivity reactions develop (including, but not limited to, severe rash or rash accompanied by fever, malaise, muscle or joint aches, blisters, oral lesions, conjunctivitis, facial edema, lip swelling, eosinophilia). Delay in stopping treatment with SELZENTRY or other suspect drugs after the onset of rash may result in a life-threatening reaction. Clinical status, including liver aminotransferases, should be monitored and appropriate therapy initiated.
Use with caution in patients at increased risk for cardiovascular events. Eleven subjects (1.3%) who received SELZENTRY had cardiovascular events, including myocardial ischemia and/or infarction, during the Phase 3 trials in treatment-experienced subjects (total exposure 609 patient-years [300 on SELZENTRY once daily + 309 on SELZENTRY twice daily]), while no subjects who received placebo had such events (total exposure 111 patient-years). These subjects generally had cardiac disease or cardiac risk factors prior to use of SELZENTRY, and the relative contribution of SELZENTRY to these events is not known.
In the Phase 2b/3 trial in treatment-naive subjects, 3 subjects (0.8%) who received SELZENTRY had events related to ischemic heart diseases and 5 subjects (1.4%) who received efavirenz had such events (total exposure 506 and 508 patient-years for SELZENTRY and efavirenz, respectively).
When SELZENTRY was administered to healthy volunteers at doses higher than the recommended dose, symptomatic postural hypotension was seen at a greater frequency than in placebo. However, when SELZENTRY was given at the recommended dose in HIV-1-infected subjects in Phase 3 trials, postural hypotension was seen at a rate similar to placebo (approximately 0.5%). Caution should be used when administering SELZENTRY in patients with a history of postural hypotension or on concomitant medication known to lower blood pressure.
Postural Hypotension in Patients With Renal Impairment
Patients with impaired renal function may have cardiovascular co-morbidities and could be at increased risk of cardiovascular adverse events triggered by postural hypotension. An increased risk of postural hypotension may occur in patients with severe renal insufficiency or in those with ESRD due to increased maraviroc exposure in some patients. SELZENTRY should be used in patients with severe renal impairment or ESRD only if they are not receiving a concomitant potent CYP3A inhibitor or inducer. However, the use of SELZENTRY in these patients should only be considered when no alternative treatment options are available. If patients with severe renal impairment or ESRD experience any symptoms of postural hypotension while taking 300 mg twice daily, the dose should be reduced to 150 mg twice daily [see DOSAGE AND ADMINISTRATION].
Immune Reconstitution Syndrome
Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including SELZENTRY. 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 infection with Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia [PCP], or tuberculosis, or reactivation of Herpes simplex and Herpes zoster), which may necessitate further evaluation and treatment.
Autoimmune disorders (such as Graves' disease, polymyositis, and Guillain-Barre 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.
Potential Risk of Infection
SELZENTRY antagonizes the CCR5 co-receptor located on some immune cells, and therefore could potentially increase the risk of developing infections. The overall incidence and severity of infection, as well as AIDS-defining category C infections, was comparable in the treatment groups during the Phase 3 treatment-experienced trials of SELZENTRY. While there was a higher rate of certain upper respiratory tract infections reported in the arm receiving SELZENTRY compared with placebo (23% versus 13%), there was a lower rate of pneumonia (2% versus 5%) reported in subjects receiving SELZENTRY. A higher incidence of Herpes virus infections (11 per 100 patient-years) was also reported in the arm receiving SELZENTRY when adjusted for exposure compared with placebo (8 per 100 patient-years).
In the Phase 2b/3 trial in treatment-naive subjects, the incidence of AIDS-defining Category C events when adjusted for exposure was 1.8 for SELZENTRY compared with 2.4 for efavirenz per 100 patient-years of exposure.
Patients should be monitored closely for evidence of infections while receiving SELZENTRY.
Potential Risk of Malignancy
While no increase in malignancy has been observed with SELZENTRY, due to this drug's mechanism of action it could affect immune surveillance and lead to an increased risk of malignancy.
The exposure-adjusted rate for malignancies per 100 patient-years of exposure in treatment-experienced trials was 4.6 for SELZENTRY compared with 9.3 on placebo. In treatment-naive subjects, the rates were 1.0 and 2.4 per 100 patient-years of exposure for SELZENTRY and efavirenz, respectively.
Long-term follow-up is needed to more fully assess this risk.
Patient Counseling Information
See FDA-approved patient labeling (Medication Guide)
Patients should be informed that liver problems including life-threatening cases have been reported with SELZENTRY. Patients should be informed that if they develop signs or symptoms of hepatitis or allergic reaction following use of SELZENTRY (rash, skin or eyes look yellow, dark urine, vomiting, abdominal pain), they should stop SELZENTRY and seek medical evaluation immediately. Patients should understand that laboratory tests for liver enzymes and bilirubin will be ordered prior to starting SELZENTRY, at other times during treatment, and if they develop severe rash or signs and symptoms of hepatitis or an allergic reaction on treatment [see WARNINGS AND PRECAUTIONS].
Patients should be informed that SELZENTRY is not a cure for HIV-1 infection and patients may continue to experience illnesses associated with HIV-1 infection, including opportunistic infections.
Patients should remain under the care of a physician when using SELZENTRY.
Patients should be advised to avoid doing things that can spread HIV-1 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 and razor blades.
- Do not have any kind of sex without protection. Always practice safe sex by using a latex or polyurethane condom to lower the chance of sexual contact with semen, vaginal secretions, or blood.
- Do not breastfeed. We do not know if SELZENTRY can be passed to your baby in your breast milk and whether it could harm your baby. Also, mothers with HIV-1 should not breastfeed because HIV-1 can be passed to the baby in the breast milk.
Patients should be advised that it is important to take all their anti-HIV medicines as prescribed and at the same time(s) each day. SELZENTRY must always be used in combination with other antiretroviral drugs. Patients should not alter the dose or discontinue therapy without consulting their physician. If a dose is missed, patients should take the next dose of SELZENTRY as soon as possible and then take their next scheduled dose at its regular time. If it is less than 6 hours before their next scheduled dose, they should not take the missed dose and should instead wait and take the next dose at the regular time.
Patients should be advised that when their supply of SELZENTRY starts to run low, they should ask their doctor or pharmacist for a refill.
Caution should be used when administering SELZENTRY in patients with a history of postural hypotension or on concomitant medication known to lower blood pressure. Patients should be advised that if they experience dizziness while taking SELZENTRY, they should avoid driving or operating machinery.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Long-term oral carcinogenicity studies of maraviroc were carried out in rasH2 transgenic mice (6 months) and in rats for up to 96 weeks (females) and 104 weeks (males). No drug-related increases in tumor incidence were found in mice at 1,500 mg/kg/day and in male and female rats at 900 mg/kg/day. The highest exposures in rats were approximately 11 times those observed in humans at the therapeutic dose of 300 mg twice daily for the treatment of HIV-1 infection.
Impairment of Fertility
Maraviroc did not impair mating or fertility of male or female rats and did not affect sperm of treated male rats at approximately 20-fold higher exposures (AUC) than in humans given the recommended 300-mg twice-daily dose.
Use In Specific Populations
Pregnancy Category B
The incidence of fetal variations and malformations was not increased in embryofetal toxicity studies performed with maraviroc in rats at exposures (AUC) approximately 20-fold higher and in rabbits at approximately 5-fold higher than human exposures at the recommended daily dose (up to 1,000 mg/kg/day in rats and 75 mg/kg/day in rabbits). During the pre- and postnatal development studies in the offspring, development of the offspring, including fertility and reproductive performance, was not affected by the maternal administration of maraviroc.
However, there are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, SELZENTRY should be used during pregnancy only if clearly needed.
Antiretroviral Pregnancy Registry
To monitor maternal-fetal outcomes of pregnant women exposed to SELZENTRY and other antiretroviral agents, an Antiretroviral Pregnancy Registry has been established. Physicians are encouraged to register patients by calling 1-800258- 4263.
The Centers for Disease Control and Prevention recommend that HIV-infected mothers not breastfeed their infants to avoid risking postnatal transmission of HIV infection. Studies in lactating rats indicate that maraviroc is extensively secreted into rat milk. It is not known whether maraviroc is secreted into human milk. Because of the potential for both HIV transmission and serious adverse reactions in nursing infants, mothers should be instructed not to breastfeed if they are receiving SELZENTRY.
The pharmacokinetics, safety and efficacy of maraviroc in patients younger than 16 years have not been established. Therefore, maraviroc should not be used in this patient population.
There were insufficient numbers of subjects aged 65 and over in the clinical trials to determine whether they respond differently from younger subjects. In general, caution should be exercised when administering SELZENTRY in elderly patients, also reflecting the greater frequency of decreased hepatic and renal function, of concomitant disease and other drug therapy.
Recommended doses of SELZENTRY for patients with impaired renal function (CrCl ≤ 80 mL/min) are based on the results of a pharmacokinetic trial conducted in healthy subjects with various degrees of renal impairment. The pharmacokinetics of maraviroc in subjects with mild and moderate renal impairment was similar to that in subjects with normal renal function [see CLINICAL PHARMACOLOGY]. A limited number of subjects with mild and moderate renal impairment in the Phase 3 clinical trials (n = 131 and n = 12, respectively) received the same dose of SELZENTRY as that administered to subjects with normal renal function. In these subjects there was no apparent difference in the adverse event profile for maraviroc compared with subjects with normal renal function.
If patients with severe renal impairment or ESRD not receiving a concomitant potent CYP3A inhibitor or inducer experience any symptoms of postural hypotension while taking SELZENTRY 300 mg twice daily, the dose should be reduced to 150 mg twice daily. No trials have been performed in subjects with severe renal impairment or ESRD co-treated with potent CYP3A inhibitors or inducers. Hence, no dose of SELZENTRY can be recommended, and SELZENTRY is contraindicated for these patients [see DOSAGE AND ADMINISTRATION, CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS, CLINICAL PHARMACOLOGY].
Maraviroc is principally metabolized by the liver; therefore, caution should be exercised when administering this drug to patients with hepatic impairment, because maraviroc concentrations may be increased. Maraviroc concentrations are higher when SELZENTRY 150 mg is administered with a potent CYP3A inhibitor compared with following administration of 300 mg without a CYP3A inhibitor, so patients with moderate hepatic impairment who eceive SELZENTRY 150 mg with a potent CYP3A inhibitor should be monitored closely for maraviroc-associated adverse events. Maraviroc has not been studied in subjects with severe hepatic impairment [see WARNINGS AND PRECAUTIONS, CLINICAL PHARMACOLOGY].
Population pharmacokinetic analysis of pooled Phase ½a data indicated gender (female: n = 96, 23.2% of the total population) does not affect maraviroc concentrations. Dosage adjustment based on gender is not necessary.
Population pharmacokinetic analysis of pooled Phase ½a data indicated exposure was 26.5% higher in Asians (N = 95) as compared with non-Asians (n = 318). However, a trial designed to evaluate pharmacokinetic differences between Caucasians (n = 12) and Singaporeans (n = 12) showed no difference between these 2 populations. No dose adjustment based on race is needed.
Last reviewed on RxList: 2/26/2013
This monograph has been modified to include the generic and brand name in many instances.
Additional Selzentry Information
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