Adults and Adolescents (13 years of age and older)
The recommended dose of RAPIVAB in adult and adolescent patients 13 years of age or older with acute uncomplicated influenza is a single 600 mg dose, administered via intravenous infusion for 15 to 30 minutes.
Pediatric Patients (2 to 12 years of age)
The recommended dose of RAPIVAB in pediatric patients 2 to 12 years of age with acute uncomplicated influenza is a single 12 mg/kg dose (up to a maximum dose of 600 mg), administered via intravenous infusion for 15 to 30 minutes.
Adverse Reactions in Adults (18 years of age and older)
In five randomized, double-blind, controlled trials, 1,399 subjects with acute uncomplicated influenza received a single dose of RAPIVAB, administered intravenously or intramuscularly, at doses up to 600 mg. Among the 664 subjects receiving RAPIVAB 600 mg (intravenous or intramuscular), the most commonly observed adverse reaction was diarrhea, occurring at a rate of 8% versus 7% in subjects receiving placebo. No subject receiving RAPIVAB 600 mg experienced a serious adverse event and less than 1% discontinued study because of an adverse reaction.
Clinically significant laboratory abnormalities (DAIDS Grade 2-4) listed in Table 3 occurred more frequently in subjects treated with RAPIVAB 600 mg (intravenous or intramuscular) than placebo. Only events occurring at ≥2% are included.
Table 3: Laboratory Abnormalities Occurring in ≥2% of Subjects Treated with RAPIVAB 600 mg| Laboratory Parameter Abnormality Frequencies based on treatment-emergent laboratory abnormalities | RAPIVAB 600 mg | Placebo |
|---|
| Alanine Aminotransferase (>2.5 × ULN) | (N=654) 3% | (N=430) 2% |
| Serum Glucose (>160 mg/dL) | (N=660) 5% | (N=433) 3% |
| Creatine Phosphokinase (≥6.0 × ULN) | (N=654) 4% | (N=431) 2% |
| Neutrophils (<1.000 ×109/L) | (N=654) 8% | (N=430) 6% |
In a subset of subjects with serious influenza requiring hospitalization treated with RAPIVAB 600 mg as monotherapy (N=101), the following adverse reactions were also reported more frequently with RAPIVAB as compared to placebo: constipation (4% versus 2%), insomnia (3% versus 0%), AST increased (3% versus 2%), and hypertension (2% versus 0%).
Adverse Reactions in Adolescent and Pediatric Subjects (2 to 17 years of age)
Assessment of adverse reactions is based on a randomized, active-controlled study in which 110 adolescent and pediatric subjects ages 2 to 17 years of age with acute uncomplicated influenza received open-label treatment with a single dose of RAPIVAB (N=88), or 5 days of treatment with oseltamivir (N=22) [see Use In Specific Populations (8.4) and Clinical Studies (14.2)].
The safety profile of RAPIVAB in subjects 2 to 17 years of age was generally similar to that observed in adults. Specific adverse reactions reported in pediatric subjects treated with RAPIVAB (occurring in ≥2% of subjects) and not reported in adults included vomiting (3% versus 9% for oseltamivir), fever and tympanic membrane erythema (2% versus 0%, respectively, for each of these events). The only clinically significant laboratory abnormality (DAIDS Grade 2) occurring in ≥2% of pediatric subjects treated with RAPIVAB was proteinuria by dipstick analysis (3% versus 0% for oseltamivir).
Risk Summary
Limited available data with RAPIVAB use in pregnant women are insufficient to determine a drug-associated risk of adverse developmental outcomes. There are risks to the mother and fetus associated with influenza in pregnancy [see Clinical Considerations]. In animal reproduction studies, no adverse developmental effects were observed in rats when peramivir was administered by intravenous bolus injection during organogenesis at the maximum feasible dose, resulting in systemic drug exposures (AUC) approximately 8 times those in humans at the recommended dose. However, when peramivir was administered to rats by continuous intravenous infusion during the same gestation period, fetal abnormalities of reduced renal papilla and dilated ureters were observed. In rabbits, administration of peramivir during organogenesis at exposures 8 times those in humans at the recommended dose resulted in developmental toxicity (abortion or premature delivery) at a maternally toxic dose [see Data].
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Clinical Considerations
Disease-Associated Maternal and/or Embryo/Fetal Risk
Pregnant women are at higher risk of severe complications from influenza, which may lead to adverse pregnancy and/or fetal outcomes including maternal death, stillbirths, birth defects, preterm delivery, low birthweight, and small for gestational age.
Data
Animal Data
Reproductive toxicity studies have been performed in rats and rabbits. In rats, peramivir was administered once daily by intravenous bolus injection at doses of 200, 400, and 600 mg/kg/day on gestational days 6-17. No treatment-related fetal toxicities were observed when peramivir was administered by intravenous bolus injection at the maximum feasible dose of 600 mg/kg, resulting in exposures approximately 8 times those in humans at the recommended dose.
Peramivir was also administered by continuous intravenous infusion to rats at daily doses of 50, 400, and 1000 mg/kg/day on gestational days 6-17. Dose related increases in the incidence of fetal abnormalities of reduced renal papilla and dilated ureters were observed at 400 and 1000 mg/kg/day. The systemic drug exposure in rats at a dose without fetal effects was less than the exposures in humans at the recommended dose.
In rabbits, peramivir was administered once daily by intravenous bolus injection at doses of 25, 50, 100, and 200 mg/kg/day on gestational days 7-19. Developmental toxicity (abortion or premature delivery) was observed at maternally toxic dose levels (100 and 200 mg/kg/day) resulting in exposures approximately 8 times those in humans at the recommended dose. The exposure in rabbits at doses without developmental toxicity was less than the exposure in humans at the recommended dose.
A pre/post-natal developmental toxicity study was performed in pregnant rats administered peramivir once daily by intravenous infusion at doses of 50, 200, 400 and 600 mg/kg/day on gestational day 6 through lactation day 20. No significant effects of peramivir on developmental outcomes were observed in nursing pups at up to the highest dose tested.
Risk Summary
There are no data on the presence of RAPIVAB in human milk, the effects on the breastfed infant, or the effects on milk production. Peramivir is present in rat milk [see Data]. Limited clinical data during lactation preclude a clear determination of the risk of RAPIVAB to an infant during lactation; therefore, the developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for RAPIVAB and any potential adverse effects on the breastfed child from the drug or from the underlying maternal condition.
Data
A pharmacokinetic study was performed in lactating rats administered a single intravenous dose of peramivir (10 mg/kg) on lactation/postpartum days 11-13. The maximum concentration of peramivir in milk was reached at 0.75 hours post-dose. The milk to plasma AUC ratio of peramivir was approximately 0.5.
Distribution
In vitro binding of peramivir to human plasma proteins is less than 30%.
Based on a population pharmacokinetic analysis, the central volume of distribution was 12.56 L.
Metabolism and Elimination
Peramivir is not a substrate for CYP enzymes, does not affect glucuronidation, and is not a substrate or inhibitor of P-glycoprotein mediated transport.
Peramivir is not significantly metabolized in humans.
The elimination half-life of RAPIVAB following IV administration to healthy subjects of 600 mg as a single dose is approximately 20 hours. The major route of elimination of RAPIVAB is via the kidney. Renal clearance of unchanged peramivir accounts for approximately 90% of total clearance. Negligible accumulation was observed following multiple doses, either once or twice daily, for up to 10 days.
Specific Populations
Race: Pharmacokinetics of peramivir was evaluated primarily in Caucasians and Asians. Based on a population pharmacokinetic analysis including race as a covariate, volume of distribution was dependent on weight and Asian race. No dose adjustment is required based on weight or Asian race.
Gender: Peramivir pharmacokinetics was similar in male and female subjects.
Pediatric Patients: The pharmacokinetics of peramivir has been evaluated in a study in pediatric subjects 2 to 17 years of age with acute uncomplicated influenza. Pharmacokinetic sampling in this study was limited to approximately 3 hours after administration of peramivir. Pharmacokinetics of peramivir in subjects 13 to 17 years of age was similar to those in adult subjects, with a Cmax of 54,300 ng/mL and AUC0-last of 72,400 ng•h/mL after administration of a single 600 mg dose. Pharmacokinetics of peramivir in subjects 2 to 12 years of age (Cmax of 61,300 ng/mL and AUC0-last of 81,700 ng•h/mL) administered a single 12 mg/kg dose was also similar to that in adult subjects administered a single 600 mg dose.
Geriatric Patients: Peramivir pharmacokinetics in elderly subjects was similar to non-elderly subjects. Peak concentrations of peramivir after a single 4 mg/kg IV dose were approximately 10% higher in elderly subjects when compared to young adults (22,647 vs 20,490 ng/mL, respectively). Exposure (AUC0-12) to peramivir at steady state was roughly 34% higher in elderly subjects compared to young adults (61,572 vs 46,000 ng•hr/mL, respectively). Dose adjustment is not required for elderly patients.
Patients with Impaired Renal Function: A trial was conducted in adult subjects with various degrees of renal impairment. When compared to a concurrent cohort with normal renal function, no change in mean Cmax was observed (6 subjects per cohort). However, mean AUC0-∞ after a single 2 mg/kg IV dose was increased by 28%, by 302%, and by 412% in subjects with creatinine clearance 50-79, 30-49, and 10-29 mL/min, respectively.
Hemodialysis was effective in reducing systemic exposure of peramivir by 73% to 81%.
A reduced dose of RAPIVAB is recommended for patients with creatinine clearance below 50 mL/min [see Dosage and Administration (2.2)].
The pharmacokinetics of peramivir has not been studied in pediatric subjects with renal impairment. Given that the pharmacokinetics in pediatric subjects is comparable to that observed in adults, the same proportional dose reduction in pediatric patients is recommended [see Dosage and Administration (2.2)].
Patients with Hepatic Impairment: The pharmacokinetics of peramivir in subjects with hepatic impairment has not been studied. No clinically relevant alterations to peramivir pharmacokinetics are expected in patients with hepatic impairment based on the route of peramivir elimination.
Assessment of Drug Interactions
The potential for CYP mediated interactions involving RAPIVAB with other drugs is low, based on the known elimination pathway of RAPIVAB, and data from in vitro studies indicating RAPIVAB does not induce or inhibit cytochrome P450.
There was no evidence of drug-drug interactions when RAPIVAB was administered with oral rimantadine, oseltamivir, or oral contraceptives containing ethinyl estradiol and levonorgestrel; or when peramivir IM was administered with oral probenecid.
RAPIVAB is primarily cleared in the urine by glomerular filtration.
Mechanism of Action
Peramivir is an inhibitor of influenza virus neuraminidase, an enzyme that releases viral particles from the plasma membrane of infected cells. The median neuraminidase inhibitory activities (IC50 values) of peramivir in biochemical assays against influenza A/H1N1 virus, influenza A/H3N2 virus, and influenza B virus clinical isolates were 0.16 nM (n=44; range 0.01-1.77 nM), 0.13 nM (n=32; range 0.05-11 nM), and 0.99 nM (n=39; range 0.04-54.2 nM), respectively, in a neuraminidase assay with a fluorescently labeled MUNANA substrate.
Antiviral Activity
The antiviral activity of peramivir against laboratory strains and clinical isolates of influenza virus was determined in cell culture. The concentrations of peramivir required for inhibition of influenza virus in cell culture varied depending on the assay method used and the virus tested. The median 50% effective concentrations (EC50 values) of peramivir in cell culture assays were 2.6 nM (n=13; range 0.09-21 nM), 0.08 nM (n=17; range 0.01-1.9 nM) and 4.8 nM (n=11; range 0.06-120 nM) for influenza A/H1N1 virus, A/H3N2 virus, and B virus strains, respectively.
The relationship between the antiviral activity in cell culture, inhibitory activity in the neuraminidase assay, and the inhibition of influenza virus replication in humans has not been established.
Resistance
Cell culture: Influenza A and B virus isolates with reduced susceptibility to peramivir were recovered by serial passage of virus in cell culture in the presence of increasing concentrations of peramivir. Reduced susceptibility of influenza virus to inhibition by peramivir may be conferred by amino acid substitutions in the viral neuraminidase or hemagglutinin proteins (Table 4).
Table 4: Amino Acid Substitutions Selected by Peramivir in Cell Culture Studies | Type/Subtype |
|---|
| Protein | A/H1N1 Numbering based on A/California/04/2009 | A/H3N2 Numbering based on A/Texas/50/2012 | B Numbering based on B/Massachusetts/02/2012 |
|---|
| HA Numbering begins after the predicted signal peptide. | D125S, R208K | N63K, G78D, N145D, K189E | T139N, G141E, R162M, D195N, T198N, Y319H |
| NA | N58D, I211T, H275Y | - | H273Y |
In vivo: Influenza A and B virus isolates with amino acid substitutions associated with reduced susceptibility to peramivir were observed in clinical isolates collected during clinical trials with peramivir (Table 5). Amino acid substitutions have also been observed in viral isolates sampled during community surveillance studies which may be associated with reduced susceptibility to peramivir (Table 5). The clinical impact of this reduced susceptibility is unknown and may be strain-dependent.
Table 5: Neuraminidase Amino Acid Substitutions Associated with Reduced Susceptibility to Peramivir in Clinical Virus Isolates| Protein | | Type / Subtype |
|---|
| Influenza A/H1N1 Numbering based on A/California/04/2009 | Influenza A/H3N2 Numbering based on A/Texas/50/2012 | Influenza B Numbering based on B/Massachusetts/02/2012 |
|---|
| NA | Clinical Trial | R152K, H275Y | R292K, N294S | - |
| Community Surveillance Studies | G147R, I223R/V, S247N, H275Y | E119V, Q136K, D151A/E/G/N/V | P139S, D197E/N/Y, I221T/V, R374K |
Circulating seasonal influenza strains expressing neuraminidase resistance-associated substitutions have been observed in individuals who have not received RAPIVAB. Prescribers should consider available information from the CDC on influenza virus drug susceptibility patterns and treatment effects when deciding whether to use RAPIVAB.
Cross Resistance
Cross-resistance between peramivir, oseltamivir and zanamivir was observed in neuraminidase biochemical assays and cell culture assays. The amino acid substitutions that resulted in reduced susceptibility to peramivir and either oseltamivir or zanamivir are summarized in Table 6. The clinical impact of this reduced susceptibility is unknown and may be strain-dependent.
Table 6: Summary of Amino Acid Substitutions with Cross-Resistance between Peramivir and Oseltamivir or Zanamivir in Susceptibility Assays | | Type/ Subtype |
|---|
| Protein | A/H1N1 Numbering based on A/California/04/2009 (N1 Numbering) | A/H3N2 Numbering based on A/Texas/50/2012 | B Numbering based on B/Massachusetts/02/2012 |
|---|
| Oseltamivir | HA Numbering begins after the predicted signal peptide. | - | N63K, N145D | - |
| NA | E119V, D151G/N, R152K, Y155H, D199G, I223/R/T/V, S247N, G249R+I267V, H275Y, N295S, Q313R, R368K, I427T | E119I/V, I222V, S247P, R292K, N294S | P139S, G140R, D197E/N/Y, I221T/V, H273Y, R374K, G407S |
| Zanamivir | HA | - | N63K, N145D | - |
| NA | Q136K, R152K, Y155H, D199G, I223T, S247N, G249R+I267V, N295S, Q313R, R368K, I427T | E119G/V, T148I, D151A/G/N/V, I222V, S247P, R292K, N294S | E117A/D/G, P139S, R150K, D197E/N/Y, R292K, R374K, G407S |
No single amino acid substitution has been identified that could confer cross-resistance between the neuraminidase inhibitor class (peramivir, oseltamivir, zanamivir) and the M2 ion channel inhibitor class (amantadine, rimantadine). However, a virus may carry a neuraminidase inhibitor resistance-associated substitution in neuraminidase and an M2 ion channel inhibitor resistance-associated substitution in M2 and may therefore be resistant to both classes of inhibitors. The clinical relevance of phenotypic cross-resistance evaluations has not been established and may be strain-dependent.
Immune Response
No influenza vaccine/peramivir interaction study has been conducted.
Carcinogenesis
Carcinogenicity studies by intravenous injection of peramivir were not performed. However, in an oral carcinogenicity study in Sprague-Dawley rats no drug-related neoplasms were observed at drug exposures 0.2- to 0.5-fold that of humans at the clinically recommended dose of 600 mg/day.
Mutagenesis
Peramivir was not mutagenic or clastogenic in a battery of in vitro and in vivo assays including the Ames bacterial reverse mutation assay, the Chinese hamster ovary chromosomal aberration test, and the in vivo mouse micronucleus test with intravenous administration.
Impairment of Fertility
Peramivir had no effects on mating or fertility in rats up to 600 mg/kg/day, at which exposures were approximately 8-fold of those in humans at the clinically recommended dose.
RAPIVAB is a registered trademark of Seqirus UK Limited.
Manufactured for and distributed by:
BioCryst Pharmaceuticals, Inc.
Durham, NC 27703
206426-GS-002