- For adult patients who have received a heart or kidney-pancreas transplant, the recommended dosage is 900 mg (two 450 mg tablets) taken orally once a day starting within 10 days of transplantation until 100 days post-transplantation.
- For adult patients who have received a kidney transplant, the recommended dosage is 900 mg (two 450 mg tablets) taken orally once a day starting within 10 days of transplantation until 200 days post-transplantation.
Prevention of CMV Disease in Pediatric Kidney Transplant Patients: For pediatric kidney transplant patients 4 months to 16 years of age, the recommended once daily mg dose (7 × BSA × CrCl) should start within 10 days of post-transplantation until 200 days post-transplantation.
Prevention of CMV Disease in Pediatric Heart Transplant Patients: For pediatric heart transplant patients 1 month to 16 years of age, the recommended once daily mg dose (7 × BSA × CrCl) should start within 10 days of transplantation until 100 days post-transplantation.
The recommended once daily dosage of VALCYTE is based on body surface area (BSA) and creatinine clearance (CrCl) derived from a modified Schwartz formula, and is calculated using the equation below:
Pediatric Dose (mg) = 7 × BSA × CrCl (calculated using a modified Schwartz formula). If the calculated Schwartz creatinine clearance exceeds 150 mL/min/1.73m2, then a maximum value of 150 mL/min/1.73m2 should be used in the equation. The k values used in the modified Schwartz formula are based on pediatric patient age, as shown in Table 1.
|
| Schwartz Creatinine Clearance (mL / min / 1.73m2) = | k × Height (cm) | |
| Serum Creatinine (mg / dL) | |
Table 1 k Values According to Pediatric Patient Age *| k value | Pediatric Patient Age |
|---|
| 0.33 | Infants less than 1 year of age with low birth weight for gestational age |
| 0.45 | Infants less than 1 year of age with birth weight appropriate for gestational age |
| 0.45 | Children aged 1 to less than 2 years |
| 0.55 | Boys aged 2 to less than 13 years Girls aged 2 to less than 16 years |
| 0.7 | Boys aged 13 to 16 years |
Monitor serum creatinine levels regularly and consider changes in height and body weight and adapt the dose as appropriate during prophylaxis period.
All calculated doses should be rounded to the nearest 25 mg increment for the actual deliverable dose. The oral dispenser is graduated in 0.5 mL increments. A 50 mg dose is equivalent to 1 mL. If the calculated dose exceeds 900 mg, a maximum dose of 900 mg should be administered. VALCYTE for oral solution is the preferred formulation since it provides the ability to administer a dose calculated according to the formula above; however, VALCYTE tablets may be used if the calculated doses are within 10% of available tablet strength (450 mg). For example, if the calculated dose is between 405 mg and 495 mg, one 450 mg tablet may be taken. Before prescribing VALCYTE tablets, pediatric patients should be assessed for the ability to swallow tablets.
Adverse Reactions in Adults:
Treatment of CMV Retinitis in AIDS Patients: In a clinical study for the treatment of CMV retinitis in HIV-infected patients, the adverse reactions reported by patients receiving VALCYTE tablets (n=79) or intravenous ganciclovir (n=79) for 28 days of randomized therapy (21 days induction dose and 7 days maintenance dose), respectively, included diarrhea (16%, 10%), nausea (8%, 14%), and headache (9%, 5%). The incidence of adverse reactions was similar between the group who received VALCYTE tablets and the group who received intravenous ganciclovir. The frequencies of neutropenia (ANC less than 500/µL) were 11% for patients receiving VALCYTE tablets compared with 13% for patients receiving intravenous ganciclovir. Anemia (Hgb less than 8 g/dL) occurred in 8% of patients in each group. Other laboratory abnormalities occurred with similar frequencies in the two groups.
Adverse reactions and laboratory abnormalities are available for 370 patients who received maintenance therapy with VALCYTE tablets 900 mg once daily in two open-label clinical trials. Approximately 252 (68%) of these patients received VALCYTE tablets for more than nine months (maximum duration was 36 months). Table 3 and Table 4 show pooled selected adverse reactions and abnormal laboratory values from these patients.
Table 3 Pooled Selected Adverse Reactions Reported in greater than or equal to 5% of Patients who Received VALCYTE Tablets Maintenance Therapy for CMV Retinitis | Patients with CMV Retinitis |
|---|
| Adverse Reactions according to Body System | VALCYTE Tablets (N=370) % |
|---|
| Gastrointestinal system | |
| Diarrhea | 41 |
| Nausea | 30 |
| Vomiting | 21 |
| Abdominal pain | 15 |
| General disorders and administrative site conditions | |
| Pyrexia | 31 |
| Nervous system disorders | |
| Headache | 22 |
| Insomnia | 16 |
| Neuropathy peripheral | 9 |
| Paresthesia | 8 |
| Eye disorders | |
| Retinal detachment | 15 |
Table 4 Pooled Selected Laboratory Abnormalities Reported in Patients Who Received VALCYTE Tablets Maintenance Therapy for the Treatment of CMV Retinitis | Patients with CMV Retinitis |
|---|
| Laboratory Abnormalities | VALCYTE Tablets (N=370) % |
|---|
| Neutropenia: ANC/µL | |
| < 500 | 19 |
| 500 – < 750 | 17 |
| 750 – < 1000 | 17 |
| Anemia: Hemoglobin g/dL | |
| < 6.5 | 7 |
| 6.5 – < 8.0 | 13 |
| 8.0 – < 9.5 | 16 |
| Thrombocytopenia: Platelets/µL | |
| < 25000 | 4 |
| 25000 – < 50000 | 6 |
| 50000 – < 100000 | 22 |
| Serum Creatinine: mg/dL | |
| > 2.5 | 3 |
| > 1.5 – 2.5 | 12 |
Prevention of CMV Disease in Solid Organ Transplant Patients:Table 5 shows selected adverse reactions regardless of severity with an incidence of greater than or equal to 5% from a clinical trial (up to 28 days after study treatment) where heart, kidney, kidney-pancreas and liver transplant patients received VALCYTE tablets (N=244) or oral ganciclovir (N=126) until Day 100 post-transplant. The majority of the adverse reactions were of mild or moderate intensity.
Table 5 Percentage of Selected Grades 1–4 Adverse Reactions Reported in greater than or equal to 5% of Adult Patients From a Study of Solid Organ Transplant Patients| Adverse Reactions | VALCYTE Tablets (N=244) % | Oral Ganciclovir (N=126) % |
|---|
| Gastrointestinal disorders | | |
| Diarrhea | 30 | 29 |
| Nausea | 23 | 23 |
| Vomiting | 16 | 14 |
| Nervous system disorders | | |
| Tremors | 28 | 25 |
| Headache | 22 | 27 |
| Insomnia | 20 | 16 |
| General disorders and administration site conditions | | |
| Pyrexia | 13 | 14 |
Table 6 shows selected adverse reactions regardless of severity with an incidence of greater than or equal to 5% from another clinical trial where kidney transplant patients received either valganciclovir once daily starting within 10 days post-transplant until Day 100 post-transplant followed by 100 days of placebo or valganciclovir once daily until Day 200 post-transplant. The overall safety profile of VALCYTE did not change with the extension of prophylaxis until Day 200 post-transplant in high risk kidney transplant patients.
Table 6 Percentage of Selected Grades 1–4 Adverse Reactions Reported in greater than or equal to 5% of Adult Patients from a Study of Kidney Transplant Patients| Adverse Reactions | VALCYTE Tablets Day 100 Post-transplant (N=164) % | VALCYTE Tablets Day 200 Post-transplant (N=156) % |
|---|
| Gastrointestinal disorders | | |
| Diarrhea | 26 | 31 |
| Nausea | 11 | 11 |
| Vomiting | 3 | 6 |
| Nervous system disorders | | |
| Tremors | 12 | 17 |
| Headache | 10 | 6 |
| Insomnia | 7 | 6 |
| General disorders and administration site conditions | | |
| Pyrexia | 12 | 9 |
Table 7 and Table 8 show selected laboratory abnormalities reported with VALCYTE tablets in two trials in solid organ transplant patients.
Table 7 Selected Laboratory Abnormalities Reported in a Study of Adult Solid Organ Transplant Patients *| Laboratory Abnormalities | VALCYTE Tablets (N=244) % | Ganciclovir Capsules (N=126) % |
|---|
| Neutropenia: ANC/µL | | |
| < 500 | 5 | 3 |
| 500 – < 750 | 3 | 2 |
| 750 – < 1000 | 5 | 2 |
| Anemia: Hemoglobin g/dL | | |
| < 6.5 | 1 | 2 |
| 6.5 – < 8.0 | 5 | 7 |
| 8.0 – < 9.5 | 31 | 25 |
| Thrombocytopenia: Platelets/µL | | |
| < 25000 | 0 | 2 |
| 25000 – < 50000 | 1 | 3 |
| 50000 – < 100000 | 18 | 21 |
| Serum Creatinine: mg/dL | | |
| > 2.5 | 14 | 21 |
| > 1.5 – 2.5 | 45 | 47 |
Table 8 Selected Laboratory Abnormalities Reported in a Study of Adult Kidney Transplant Patients *| Laboratory Abnormalities | VALCYTE Tablets Day 100 Post-transplant (N=164) % | VALCYTE Tablets Day 200 Post-transplant (N=156) % |
|---|
| Neutropenia: ANC/µL | | |
| < 500 | 9 | 10 |
| 500 – < 750 | 6 | 6 |
| 750 – < 1000 | 7 | 5 |
| Anemia: Hemoglobin g/dL | | |
| < 6.5 | 0 | 1 |
| 6.5 – < 8.0 | 5 | 1 |
| 8.0 – < 9.5 | 17 | 15 |
| Thrombocytopenia: Platelets/µL | | |
| < 25000 | 0 | 0 |
| 25000 – < 50000 | 1 | 0 |
| 50000 – < 100000 | 7 | 3 |
| Serum Creatinine: mg/dL | | |
| > 2.5 | 17 | 14 |
| > 1.5 – 2.5 | 50 | 48 |
Other adverse drug reactions from VALCYTE in clinical trials in CMV retinitis and solid organ transplant patients
Other adverse drug reactions with VALCYTE in clinical trials in either patients with CMV retinitis or solid organ transplant patients that occurred in at least 5% of patients are listed below.
Eye disorders: retinal detachment, eye pain
Gastrointestinal disorders: dyspepsia, constipation, abdominal distention, mouth ulceration
General disorders and administration site conditions: fatigue, pain, malaise, asthenia, chills, peripheral edema
Hepatobiliary disorders: hepatic function abnormal
Infections and infestations: candida infections including oral candidiasis, upper respiratory tract infection, influenza, urinary tract infection, pharyngitis/nasopharyngitis, postoperative wound infection
Injury, poisoning, and procedural complications: postoperative complications, wound secretion
Metabolic and nutrition disorders: decreased appetite, hyperkalemia, hypophosphatemia, weight decreased
Musculoskeletal and connective tissue disorders: back pain, myalgia, arthralgia, muscle spasms
Nervous system disorders: insomnia, neuropathy peripheral, dizziness
Psychiatric disorders: depression, anxiety
Renal and urinary disorders: renal impairment, creatinine clearance renal decreased, blood creatinine increased, hematuria
Respiratory, thoracic and mediastinal disorders: cough, dyspnea
Skin and subcutaneous tissues disorders: dermatitis, night sweats, pruritus
Vascular disorders: hypotension
Other adverse reactions with VALCYTE in clinical trials in either patients with CMV retinitis or solid organ transplant patients that occurred in less than 5% of patients are listed below.
Blood and lymphatic disorders: febrile neutropenia, pancytopenia, bone marrow failure (including aplastic anemia)
Cardiovascular disorders: arrhythmia
Ear and labyrinth disorders: deafness
Eye disorders: macular edema
Gastrointestinal disorders: pancreatitis
Hemorrhage: potentially life-threatening bleeding associated with thrombocytopenia
Immune system disorders: hypersensitivity
Infections and infestations: cellulitis, sepsis
Injury, poisoning, and procedural complications: postoperative pain, wound dehiscence
Investigations: aspartate aminotransferase increased, alanine aminotransferase increased
Musculoskeletal and connective tissue disorders: limb pain
Nervous system disorders: seizure, dysguesia (taste disturbance)
Psychiatric disorders: confusional state, agitation, psychotic disorder, hallucinations
Renal and urinary disorders: renal failure
Adverse Reactions in Pediatric Patients:
VALCYTE for oral solution and tablets have been studied in 179 pediatric solid organ transplant patients who were at risk for developing CMV disease (aged 3 weeks to 16 years) and in 24 neonates with symptomatic congenital CMV disease (aged 8 to 34 days), with duration of ganciclovir exposure ranging from 2 to 200 days [see Use in Specific Populations (8.4), Clinical Studies (14.2)].
Prevention of CMV Disease in Pediatric Solid Organ Transplant Patients: The most frequently reported adverse reactions (greater than 10% of patients), regardless of seriousness, in pediatric solid organ transplant patients taking VALCYTE until Day 100 post-transplant were diarrhea, pyrexia, upper respiratory tract infection, vomiting, anemia, neutropenia, constipation and nausea. The most frequently reported adverse reactions (greater than 10% of patients) in pediatric kidney transplant patients treated with valganciclovir until Day 200 post-transplant were upper respiratory tract infection, urinary tract infection, diarrhea, leukopenia, neutropenia, headache, abdominal pain, tremor, pyrexia, anemia, blood creatinine increased, vomiting, and hematuria.
In general, the safety profile was similar in pediatric patients compared to that observed in adult patients. However, the rates of certain adverse reactions, and laboratory abnormalities, such as upper respiratory tract infection, pyrexia, nasopharyngitis, anemia, and abdominal pain were reported more frequently in pediatric patients than in adults [see Use in Specific Populations (8.4), Clinical Studies (14.2)]. Neutropenia was reported at a higher incidence in the two pediatric studies as compared to adults, but there was no correlation between neutropenia and infections observed in the pediatric population.
The overall safety profile of VALCYTE was similar with the extension of prophylaxis until Day 200 post-transplant in high risk pediatric kidney transplant patients. However, the incidence of severe neutropenia (ANC < 500/µL) was higher in pediatric kidney transplant patients treated with VALCYTE until Day 200 (17/57, 30%) compared to pediatric kidney transplant patients treated until Day 100 (3/63, 5%). There were no differences in the incidence of severe (Grade 4) anemia or thrombocytopenia in patients treated 100 or 200 days with VALCYTE.
Risk Summary
After oral administration, valganciclovir (prodrug) is converted to ganciclovir (active drug) and, therefore, VALCYTE is expected to have reproductive toxicity effects similar to ganciclovir. In animal studies, ganciclovir caused maternal and fetal toxicity and embryo-fetal mortality in pregnant mice and rabbits as well as teratogenicity in rabbits at exposures two-times the human exposure. There are no available human data on use of VALCYTE or ganciclovir in pregnant women to establish the presence or absence of drug-associated risk. The background risk of major birth defects and miscarriage for the indicated populations is unknown. However, the background risk in the U.S. general population of major birth defects is 2–4% and the risk of miscarriage is 15–20% of clinically recognized pregnancies. Advise pregnant women of the potential risk to the fetus [see Warnings and Precautions (5.3), Use in Specific Populations (8.3)].
Clinical Considerations
Disease-associated maternal and/or embryo/fetal risk
Most maternal CMV infections are asymptomatic or they may be associated with a self-limited mononucleosis-like syndrome. However, in immunocompromised patients (i.e., transplant patients or patients with AIDS) CMV infections may be symptomatic and may result in significant maternal morbidity and mortality. The transmission of CMV to the fetus is a result of maternal viremia and transplacental infection. Perinatal infection can also occur from exposure of the neonate to CMV shedding in the genital tract. Approximately 10% of children with congenital CMV infection are symptomatic at birth. Mortality in these infants is about 10% and approximately 50–90% of symptomatic surviving newborns experience significant morbidity, including mental retardation, sensorineural hearing loss, microcephaly, seizures, and other medical problems. The risk of congenital CMV infection resulting from primary maternal CMV infection may be higher and of greater severity than that resulting from maternal reactivation of CMV infection.
Data
Animal Data
Doses resulting in two-times the human exposure of ganciclovir (based on the human AUC following a single intravenous infusion of 5 mg per kg of ganciclovir) resulted in maternal and embryo-fetal toxicity in pregnant mice and rabbits as well as teratogenicity in the rabbits. Fetal resorptions were present in at least 85% of rabbits and mice. Rabbits showed increased embryo-fetal mortality, growth retardation of the fetuses and structural abnormalities of multiple organs of the fetuses including the palate (cleft palate), eyes (anophthalmia/microphthalmia), brain (hydrocephalus), jaw (brachygnathia), kidneys and pancreas (aplastic organs). Increased embryo-fetal mortality was also seen in mice. Daily intravenous doses of approximately 1.7 times the human exposure (based on AUC) administered to female mice prior to mating, during gestation, and during lactation caused hypoplasia of the testes and seminal vesicles in the male offspring, as well as pathologic changes in the nonglandular region of the stomach.
Data from an ex-vivo human placental model showed that ganciclovir crosses the human placenta. The transfer occurred by passive diffusion and was not saturable over a concentration range of 1 to 10 mg/mL.
Risk Summary
No data are available regarding the presence of valganciclovir (prodrug) or ganciclovir (active drug) in human milk, the effects on the breastfed infant, or the effects on milk production. Animal data indicate that ganciclovir is excreted in the milk of lactating rats. The Centers for Disease Control and Prevention recommend that HIV-infected mothers not breastfeed their infants to avoid risking postnatal transmission of HIV. Advise nursing mothers that breastfeeding is not recommended during treatment with VALCYTE because of the potential for serious adverse events in nursing infants and because of the potential for transmission of HIV [see Boxed Warning, Warnings and Precautions (5.1, 5.3, 5.4, 5.5), Nonclinical Toxicology (13.1)].
Pregnancy Testing
Females of reproductive potential should undergo pregnancy testing before initiation of VALCYTE [see Use in Specific Populations (8.1)].
Contraception
Females
Because of the mutagenic and teratogenic potential of VALCYTE, females of reproductive potential should be advised to use effective contraception during treatment and for at least 30 days following treatment with VALCYTE [see Dosage and Administration (2.6), Warnings and Precautions (5.4, 5.5), Nonclinical Toxicology (13.1)].
Males
Because of its mutagenic potential, males should be advised to use condoms during and for at least 90 days following, treatment with VALCYTE [see Dosage and Administration (2.6), Warnings and Precautions (5.3, 5.5), Nonclinical Toxicology (13.1)].
Infertility
VALCYTE at the recommended doses may cause temporary or permanent female and male infertility [see Warnings and Precautions (5.3), Nonclinical Toxicology (13.1)].
Data
Human Data
In a small, open-label, non-randomized clinical study, adult male renal transplant patients receiving VALCYTE for CMV prophylaxis for up to 200 days post-transplantation were compared to an untreated control group. Patients were followed-up for six months after VALCYTE discontinuation. Among 24 evaluable patients in the VALCYTE group, the mean sperm density at the end of treatment visit decreased by 11 million/mL from baseline; whereas, among 14 evaluable patients in the control group the mean sperm density increased by 33 million/mL. However, at the follow-up visit among 20 evaluable patients in the VALCYTE group the mean sperm density was comparable to that observed among 10 evaluable patients in the untreated control group (the mean sperm density at the end of follow-up visit increased by 41 million/mL from baseline in the VALCYTE group and by 43 million/mL in the untreated group).
Experience with VALCYTE Tablets: An overdose of VALCYTE could possibly result in increased renal toxicity [see Dosage and Administration (2.5), Use in Specific Populations (8.6)]. Because ganciclovir is dialyzable, dialysis may be useful in reducing serum concentrations in patients who have received an overdose of VALCYTE [see Clinical Pharmacology (12.3)]. Adequate hydration should be maintained. The use of hematopoietic growth factors should be considered [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.3)].
Reports of adverse reactions after overdoses with valganciclovir, some with fatal outcomes, have been received from clinical trials and during postmarketing experience. The majority of patients experienced one or more of the following adverse events:
Hematological toxicity: myelosuppression including pancytopenia, bone marrow failure, leukopenia, neutropenia, granulocytopenia
Hepatotoxicity: hepatitis, liver function disorder
Renal toxicity: worsening of hematuria in a patient with pre-existing renal impairment, acute kidney injury, elevated creatinine
Gastrointestinal toxicity: abdominal pain, diarrhea, vomiting
Neurotoxicity: generalized tremor, seizure
Pharmacokinetics in Adults: The pharmacokinetics of ganciclovir after administration of valganciclovir tablets have been evaluated in HIV- and CMV-seropositive patients, patients with AIDS and CMV retinitis, and in solid organ transplant patients (Table 10).
Table 10 Ganciclovir PharmacokineticsData were obtained from single and multiple dose studies in healthy volunteers, HIV-positive patients, and HIV-positive/CMV-positive patients with and without retinitis. Patients with CMV retinitis tended to have higher ganciclovir plasma concentrations than patients without CMV retinitis.
in Healthy Volunteers and HIV-positive/CMV-positive Adults Administered VALCYTE Tablets 900 mg Once Daily with Food| PK parameter | N | Value (Mean ± SD) |
|---|
| AUC0-24h (mcg∙h/mL) | 57 | 29.1 ± 9.7 |
| Cmax (mcg/mL) | 58 | 5.61 ± 1.52 |
| Absolute oral bioavailability (%) | 32 | 59.4 ± 6.1 |
| Elimination half-life (hr) | 73 | 4.08 ± 0.76 |
| Renal clearance (mL/min/kg) | 20 | 3.21 ± 0.75 (1 study, n=20) |
The systemic ganciclovir exposures attained following administration of 900 mg VALCYTE tablets once daily were comparable across kidney, heart and liver transplant recipients (Table 11).
Table 11 Ganciclovir Pharmacokinetics in Solid Organ Transplant Recipients Administered VALCYTE Tablets 900 mg Once Daily with Food| Parameter | Value (Mean ± SD) |
|---|
Heart Transplant Recipients (N=17) | Liver Transplant Recipients (N=75) | Kidney Transplant Recipients Includes kidney-pancreas (N=68) |
|---|
| AUC0-24h (mcg∙h/mL) | 40.2 ± 11.8 | 46.0 ± 16.1 | 48.2 ± 14.6 |
| Cmax (mcg/mL) | 4.9 ± 1.1 | 5.4 ± 1.5 | 5.3 ± 1.5 |
| Elimination half-life (hr) | 6.58 ± 1.50 | 6.18 ± 1.42 | 6.77 ± 1.25 |
The pharmacokinetic parameters of ganciclovir following 200 days of VALCYTE administration in high-risk kidney transplant patients were similar to those in solid organ transplant patients who received VALCYTE for 100 days.
Absorption, Distribution, Metabolism, and Excretion
The pharmacokinetic (PK) properties of VALCYTE are provided in Table 12.
Table 12 Pharmacokinetic Properties of Ganciclovir and Valganciclovir Associated with VALCYTE | Valganciclovir | Ganciclovir |
|---|
| Absorption |
Tmax (h) median (min-max) (fed conditions) | | 2.18 1.7h to 3.0h |
| Food effect (high fat meal/fasting): PK parameter ratio and 90% confidence interval Steady state ganciclovir PK was assessed after administration of VALCYTE tablets (875 mg once daily) with a high fat meal containing approximately 600 total calories (31.1 g fat, 51.6 g carbohydrates and 22.2 g protein) to 16 HIV-positive subjects. | | Cmax: 1.14 (0.95, 1.36) AUC: 1.30 (1.07, 1.51) Tmax: ↔ |
| Distribution |
| % Bound to human plasma proteins (ex vivo) | Unknown | 1–2% over 0.5– 51 mcg/mL |
| Cerebrospinal fluid penetration | Unknown | Yes |
| Metabolism |
| Hydrolyzed by intestinal and liver esterases | No significant metabolism |
| Elimination |
| Dose proportionality | | AUC was dose proportional under fed conditions across a valganciclovir dose range of 450 to 2625 mg |
| Major route of elimination | Metabolism to ganciclovir | Glomerular filtration and active tubular secretion |
| t1/2 (h) | | See Tables 10 and 11 |
| % Of dose excreted in urine | Unknown |
| % Of dose excreted in feces | Unknown |
Specific Populations:
Renal Impairment: The pharmacokinetics of ganciclovir from a single oral dose of 900 mg VALCYTE tablets were evaluated in 24 otherwise healthy individuals with renal impairment. Decreased renal function results in decreased clearance of ganciclovir and increased terminal half-life (Table 13).
Table 13 Pharmacokinetics of Ganciclovir from a Single Oral Dose of 900 mg VALCYTE Tablets| Estimated Creatinine Clearance Creatinine clearance calculated from 24-hour urine collection. (mL/min) | N | Apparent Clearance (mL/min) Mean ± SD | AUClast (mcg∙h/mL) Mean ± SD | Half-life (hours) Mean ± SD |
|---|
| 51-70 | 6 | 249 ± 99 | 49.5 ± 22.4 | 4.85 ± 1.4 |
| 21-50 | 6 | 136 ± 64 | 91.9 ± 43.9 | 10.2 ± 4.4 |
| 11-20 | 6 | 45 ± 11 | 223 ± 46 | 21.8 ± 5.2 |
| ≤ 10 | 6 | 12.8 ± 8 | 366 ± 66 | 67.5 ± 34 |
Hemodialysis reduces plasma concentrations of ganciclovir by about 50% following VALCYTE administration. Adult patients receiving hemodialysis (CrCl less than 10 mL/min) cannot use VALCYTE tablets because the daily dose of VALCYTE tablets required for these patients is less than 450 mg [see Dosage and Administration (2.5) and Use in Specific Populations (8.6)].
Pharmacokinetics in Pediatric Patients: The pharmacokinetics of ganciclovir were evaluated following the administration of valganciclovir in 63 pediatric solid organ transplant patients aged 4 months to 16 years, and in 16 pediatric heart transplant patients less than 4 months of age. In these studies, patients received oral doses of valganciclovir (either VALCYTE for oral solution or tablets) to produce exposure equivalent to an adult 900 mg dose [see Dosage and Administration (2.3), Adverse Reactions (6.1), Use in Specific Populations (8.4), Clinical Studies (14.2)].
In studies using the pediatric valganciclovir dosing algorithm, the pharmacokinetics of ganciclovir were similar across organ types and age ranges (Table 14). Relative to adult transplant patients (Table 11), AUC values in pediatric patients were somewhat increased, but were within the range considered safe and effective in adults.
Table 14 Ganciclovir Pharmacokinetics by Age in Pediatric Solid Organ Transplant Patients Administered VALCYTE| Organ | PK Parameter mean (SD) | Age Group |
|---|
| < 4 months | 4 months to ≤ 2 years | > 2 to < 12 years | ≥ 12 years |
|---|
| N=number of patients, NA=not applicable |
Heart (N=26) | N | 14 Ages ranged from 26 to 124 days. | 6 | 2 | 4 |
| AUC0-24h (mcg∙h/mL) | 66.3 (20.5) | 55.4 (22.8) | 59.6 (21.0) | 60.6 (25.0) |
| Cmax (mcg/mL) | 10.8 (3.30) | 8.2 (2.5) | 12.5 (1.2) | 9.5 (3.3) |
| t1/2 (h) | 3.5 (0.87) | 3.8 (1.7) | 2.8 (0.9) | 4.9 (0.8) |
Kidney (N=31) | N | NA | 2 | 10 | 19 |
AUC0-24h (mcg∙h/mL) | 67.6 (13.0) | 55.9 (12.1) | 47.8 (12.4) |
| Cmax (mcg/mL) | 10.4 (0.4) | 8.7 (2.1) | 7.7 (2.1) |
| t1/2 (h) | 4.5 (1.5) | 4.8 (1.0) | 6.0 (1.3) |
Liver (N=17) | N | NA | 9 | 6 | 2 |
| AUC0-24h (mcg∙h/mL) | 69.9 (37.0) | 59.4 (8.1) | 35.4 (2.8) |
| Cmax (mcg/mL) | 11.9 (3.7) | 9.5 (2.3) | 5.5 (1.1) |
| t1/2 (h) | 2.8 (1.5) | 3.8 (0.7) | 4.4 (0.2) |
Pharmacokinetics in Geriatric Patients: The pharmacokinetic characteristics of VALCYTE in elderly patients have not been established.
Antiviral Activity: The quantitative relationship between the cell culture susceptibility of human herpes viruses to antivirals and clinical response to antiviral therapy has not been established, and virus sensitivity testing has not been standardized. Sensitivity test results, expressed as the concentration of drug required to inhibit the growth of virus in cell culture by 50% (EC50), vary greatly depending upon a number of factors including the assay used. Thus, the reported EC50 values of ganciclovir that inhibit human CMV replication in cell culture (laboratory and clinical isolates) have ranged from 0.08 to 22.94 µM (0.02 to 5.75 mcg/mL). The distribution and range in susceptibility observed in one assay evaluating 130 clinical isolates was 0 to 1 µM (35%), 1.1 to 2 µM (20%), 2.1 to 3 µM (27%), 3.1 to 4 µM (13%), 4.1 to 5 µM (5%), less than 5 µM (less than 1%). Ganciclovir inhibits mammalian cell proliferation (CC50) in cell culture at higher concentrations ranging from 40 to greater than 1,000 µM (10.21 to greater than 250 mcg/mL). Bone marrow-derived colony-forming cells are more sensitive [CC50 value = 2.7 to 12 µM (0.69 to 3.06 mcg/mL)].
Viral Resistance:
Cell culture: CMV isolates with reduced susceptibility to ganciclovir have been selected in cell culture. Growth of CMV strains in the presence of ganciclovir resulted in the selection of amino acid substitutions in the viral protein kinase pUL97 (M460I/V, L595S, G598D, and K599T) and the viral DNA polymerase pUL54 (D301N, N410K, F412V, P488R, L516R, C539R, L545S, F595I, V812L, P829S, L862F, D879G, and V946L).
In vivo: Viruses resistant to ganciclovir can arise after prolonged treatment or prophylaxis with valganciclovir by selection of substitutions in pUL97 and/or pUL54. Limited clinical data are available on the development of clinical resistance to ganciclovir and many pathways to resistance likely exist. In clinical isolates, seven canonical pUL97 substitutions, (M460V/I, H520Q, C592G, A594V, L595S, and C603W) are the most frequently reported ganciclovir resistance-associated substitutions. These and other substitutions less frequently reported in the literature, or observed in clinical trials, are listed in Table 17.
Table 17 Summary of Resistance-associated Amino Acid Substitutions Observed in the CMV of Patients Failing Ganciclovir Treatment or Prophylaxis| Note: Many additional pathways to ganciclovir resistance likely exist |
| pUL97 | F342Y, K359E/Q, L405P, A440V, M460I/V/T/L, V466G/M, C480F, C518Y, H520Q, P521L, del 590-593, A591D/V, C592F/G, A594E/G/T/V/P, L595F/S/T/W, del 595, del 595-603, E596D/G/Y, K599E/M, del 600-601, del 597-600, del 601-603, C603W/R/S/Y, C607F/S/Y, I610T, A613V |
| pUL54 | E315D, N408D/K/S, F412C/L/S, D413A/E/N, L501F/I, T503I, K513E/N/R, D515E, L516W, I521T, P522A/L/S, V526L, C539G, L545S/W, Q578H/L, D588E/N, G629S, S695T, I726T/V, E756K, L773V, V781I, V787E/L, L802M, A809V, T813S, T821I, A834P, G841A/S, D879G, A972V, del 981-982, A987G |
The presence of known ganciclovir resistance-associated amino acid substitutions was evaluated in a study that extended valganciclovir CMV prophylaxis from 100 days to 200 days post-transplant in adult kidney transplant patients at high risk for CMV disease (D+/R-) [see Clinical Studies (14.1)]. Five subjects from the 100 day group and four subjects from the 200 day group meeting the resistance analysis criteria had known ganciclovir resistance-associated amino acid substitutions detected. In six subjects, the following resistance-associated amino acid substitutions were detected within pUL97: 100 day group: A440V, M460V, C592G; 200 day group: M460V, C603W. In three subjects, the following resistance-associated amino acid substitutions were detected within pUL54: 100 day group: E315D; 200 day group: E315D, P522S. Overall, the detection of known ganciclovir resistance-associated amino acid substitutions was observed more frequently in patients during prophylaxis therapy than after the completion of prophylaxis therapy (during therapy: 5/12 [42%] versus after therapy: 4/58 [7%]). The possibility of viral resistance should be considered in patients who show poor clinical response or experience persistent viral excretion during therapy.
Cross-Resistance: Cross-resistance has been reported for amino acid substitutions selected in cell culture by ganciclovir, cidofovir or foscarnet. In general, amino acid substitutions in pUL54 conferring cross-resistance to ganciclovir and cidofovir are located within the exonuclease domains and region V of the viral DNA polymerase. Whereas, amino acid substitutions conferring cross-resistance to foscarnet are diverse, but concentrate at and between regions II (codon 696–742) and III (codon 805–845). The amino acid substitutions that resulted in reduced susceptibility to ganciclovir and either cidofovir and/or foscarnet are summarized in Table 18.
Substitutions at amino acid positions pUL97 340–400 have been found to confer resistance to ganciclovir. Resistance data based on assays that do not include this region should be interpreted cautiously.
Table 18 Summary of pUL54 Amino Acid Substitutions with Cross-Resistance between Ganciclovir, Cidofovir, and/or Foscarnet| Cross-resistant to cidofovir | D301N, N408D/K, N410K, F412C/L/S/V, D413E/N, P488R, L501I, T503I, K513E/N, L516R/W, I521T, P522S/A, V526L, C539G/R, L545S/W, Q578H, D588N, I726T/V, E756K, L733V, V787E, V812L, T813S, A834P, G841A, del 981-982, A987G |
| Cross-resistant to foscarnet | F412C, Q578H/L, D588N, V715A/M, E756K, L733V, V776M, V781I, V787E/L, L802M, A809V, V812L, T813S, T821I, A834P, G841A/S, del 981-982 |
Induction Therapy of CMV Retinitis: In one randomized open-label controlled study, 160 patients with AIDS and newly diagnosed CMV retinitis were randomized to receive treatment with either VALCYTE tablets (900 mg twice daily for 21 days, then 900 mg once daily for 7 days) or with intravenous ganciclovir solution (5 mg per kg twice daily for 21 days, then 5 mg per kg once daily for 7 days). Study participants were: male (91%), White (53%), Hispanic (31%), and Black (11%). The median age was 39 years, the median baseline HIV-1 RNA was 4.9 log10, and the median CD4 cell count was 23 cells/mm3. A determination of CMV retinitis progression by the masked review of retinal photographs taken at baseline and Week 4 was the primary outcome measurement of the 3-week induction therapy. Table 19 provides the outcomes at 4 weeks.
Table 19 Week 4 Masked Review of Retinal Photographs in CMV Retinitis Study | Intravenous Ganciclovir | VALCYTE Tablets |
|---|
| Determination of CMV retinitis progression at Week 4 | N=80 | N=80 |
| Progressor | 7 | 7 |
| Non-progressor | 63 | 64 |
| Death | 2 | 1 |
| Discontinuations due to Adverse Events | 1 | 2 |
| Failed to return | 1 | 1 |
| CMV not confirmed at baseline or no interpretable baseline photos | 6 | 5 |
Maintenance Therapy of CMV Retinitis: No comparative clinical data are available on the efficacy of VALCYTE tablets for the maintenance therapy of CMV retinitis because all patients in the CMV retinitis study received open-label VALCYTE tablets after Week 4. However, the AUC for ganciclovir is similar following administration of 900 mg VALCYTE tablets once daily and 5 mg per kg intravenous ganciclovir once daily. Although the ganciclovir Cmax is lower following VALCYTE tablets administration compared to intravenous ganciclovir, it is higher than the Cmax obtained following oral ganciclovir administration. Therefore, use of VALCYTE tablets as maintenance therapy is supported by a plasma concentration-time profile similar to that of two approved products for maintenance therapy of CMV retinitis.
Prevention of CMV Disease in Heart, Kidney, Kidney-Pancreas, or Liver Transplantation: A double blind, double-dummy active comparator study was conducted in 372 heart, liver, kidney, or kidney-pancreas transplant patients at high risk for CMV disease (D+/R-). Patients were randomized (2 VALCYTE: 1 oral ganciclovir) to receive either VALCYTE tablets (900 mg once daily) or oral ganciclovir (1000 mg three times a day) starting within 10 days of transplantation until Day 100 post-transplant. The proportion of patients who developed CMV disease, including CMV syndrome and/or tissue-invasive disease during the first 6 months post-transplant was similar between the VALCYTE tablets arm (12.1%, N=239) and the oral ganciclovir arm (15.2%, N=125). However, in liver transplant patients, the incidence of tissue-invasive CMV disease was significantly higher in the VALCYTE group compared with the ganciclovir group. These results are summarized in Table 20.
Mortality at six months was 3.7% (9/244) in the VALCYTE group and 1.6% (2/126) in the oral ganciclovir group.
Table 20 Percentage of Patients with CMV Disease, Tissue-Invasive CMV Disease or CMV Syndrome by Organ Type: Endpoint Committee, 6 Month ITT Population | CMV Disease Number of patients with CMV disease = Number of patients with tissue-invasive CMV disease or CMV syndrome | Tissue-Invasive CMV Disease | CMV Syndrome CMV syndrome was defined as evidence of CMV viremia accompanied with fever greater than or equal to 38°C on two or more occasions separated by at least 24 hours within a 7-day period and one or more of the following: malaise, leukopenia, atypical lymphocytosis, thrombocytopenia, and elevation of hepatic transaminases |
|---|
| Organ | VGCV (N=239) | GCV (N=125) | VGCV (N=239) | GCV (N=125) | VGCV (N=239) | GCV (N=125) |
|---|
| GCV = oral ganciclovir; VGCV = valganciclovir |
Liver (n=177) | 19% (22/118) | 12% (7/59) | 14% (16/118) | 3% (2/59) | 5% (6/118) | 8% (5/59) |
Kidney (n=120) | 6% (5/81) | 23% (9/39) | 1% (1/81) | 5% (2/39) | 5% (4/81) | 18% (7/39) |
Heart (n=56) | 6% (2/35) | 10% (2/21) | 0% (0/35) | 5% (1/21) | 6% (2/35) | 5% (1/21) |
Kidney/Pancreas (n=11) | 0% (0/5) | 17% (1/6) | 0% (0/5) | 17% (1/6) | 0% (0/5) | 0% (0/6) |
Prevention of CMV Disease in Kidney Transplantation: A double-blind, placebo-controlled study was conducted in 326 kidney transplant patients at high risk for CMV disease (D+/R-) to assess the efficacy and safety of extending VALCYTE CMV prophylaxis from 100 to 200 days post-transplant. Patients were randomized (1:1) to receive VALCYTE tablets (900 mg once daily) within 10 days of transplantation either until Day 200 post-transplant or until Day 100 post-transplant followed by 100 days of placebo. Extending CMV prophylaxis with VALCYTE until Day 200 post-transplant demonstrated superiority in preventing CMV disease within the first 12 months post-transplant in high risk kidney transplant patients compared to the 100 day dosing regimen (primary endpoint). These results are summarized in Table 21.
Table 21 Percentage of Kidney Transplant Patients with CMV Disease, Tissue-Invasive CMV Disease or CMV Syndrome, 12 Month ITT Population | CMV Disease Number of patients with CMV disease = Number of patients with tissue-invasive CMV disease or CMV syndrome | Tissue-Invasive CMV Disease | CMV Syndrome CMV syndrome was defined as evidence of CMV viremia accompanied with at least one of the following: fever (greater than or equal to 38°C), severe malaise, leukopenia, atypical lymphocytosis, thrombocytopenia, and elevation of hepatic transaminases |
|---|
| 100 Days VGCV (N=163) | 200 Days VGCV (N=155) | 100 Days VGCV (N=163) | 200 Days VGCV (N=155) | 100 Days VGCV (N=163) | 200 Days VGCV (N=155) |
|---|
| VGCV = valganciclovir. |
| Cases | 36.8% (60/163) | 16.8% (26/155) | 1.8% (3/163)Two patients in the 100 day group had both tissue-invasive CMV disease and CMV syndrome; however, these patients are counted as having only tissue-invasive CMV disease. | 0.6% (1/155) | 35. 0% (57/163) | 16.1% (25/155) |
The percentage of kidney transplant patients with CMV disease at 24 months post-transplant was 38.7% (63/163) for the 100 day dosing regimen and 21.3% (33/155) for the 200 day dosing regimen.
Prevention of CMV in Pediatric Heart, Kidney, or Liver Transplantation: Sixty-three children, 4 months to 16 years of age, who had a solid organ transplant (kidney 33, liver 17, heart 12, and kidney/liver 1) and were at risk for developing CMV disease, were enrolled in an open-label, safety, and pharmacokinetic study of oral VALCYTE (VALCYTE for oral solution or tablets). Patients received VALCYTE once daily within 10 days after transplant until a maximum of 100 days post-transplant. The daily doses of VALCYTE were calculated at each study visit based on body surface area and a modified creatinine clearance [see Dosage and Administration (2.3)].
The pharmacokinetics of ganciclovir were similar across organ transplant types and age ranges. The mean daily ganciclovir exposures in pediatric patients were somewhat increased relative to those observed in adult solid organ transplant patients receiving VALCYTE 900 mg once daily, but were within the range considered safe and effective in adults [see Clinical Pharmacology (12.3)]. No case of CMV syndrome or tissue-invasive CMV disease was reported within the first six months post-transplantation.
Prevention of CMV in Pediatric Kidney Transplantation: Fifty-seven children, 1 to 16 years of age, who had a renal transplant and were at risk for developing CMV disease, were enrolled in an open-label tolerability study of oral VALCYTE (VALCYTE for oral solution or tablets). Patients received VALCYTE once daily within 10 days after transplant until a maximum of 200 days post-transplant. The daily doses of VALCYTE were calculated at each study visit based on body surface area and a modified creatinine clearance [see Dosage and Administration (2.3)]. No case of CMV syndrome or tissue-invasive CMV disease was reported within the first 12 months post-transplantation.
VALCYTE tablets: Supplied as 450 mg, pink, convex oval tablets with "VGC" on one side and "450" on the other side. Each tablet contains 450 mg valganciclovir. VALCYTE is supplied in bottles of 60 tablets (NDC 61269-480-60).
VALCYTE for oral solution: Supplied as a white to slightly yellow powder blend for constitution, forming a colorless to brownish-yellow tutti-frutti flavored solution. Available in glass bottles containing approximately 100 mL of solution after constitution. Each bottle can deliver up to a total of 88 mL of solution. Each bottle is supplied with a bottle adapter and 2 oral dispensers (NDC 61269-485-10).
Prior to dispensing to the patient, VALCYTE for oral solution must be prepared by the pharmacist [see Dosage and Administration (2.4)].
Serious Adverse Reactions
Inform patients that VALCYTE may cause granulocytopenia (neutropenia), anemia, thrombocytopenia and elevated creatinine levels and that dose modification or discontinuation of dosing may be required. Complete blood counts, platelet counts, and creatinine levels should be monitored frequently during treatment [see Warnings and Precautions (5.1)].
Pregnancy and Contraception
Inform females of reproductive potential that VALCYTE causes birth defects in animals. Advise them to use effective contraception during and for at least 30 days following treatment with VALCYTE. Similarly, advise males to use condoms during and for at least 90 days following treatment with VALCYTE [see Use in Specific Populations (8.1, 8.3)].
Carcinogenicity
Advise patients that VALCYTE is considered a potential carcinogen [see Nonclinical Toxicity (13.1)].
Lactation
Advise mothers not to breast-feed if they are receiving VALCYTE because of the potential for hematologic toxicity and cancer in nursing infants, and because HIV can be passed to the baby in breast milk [see Use in Specific Populations (8.2)].
Infertility
Advise patients that VALCYTE may cause temporary or permanent female and male infertility [see Warnings and Precautions (5.3), Use in Specific Populations (8.3)].
Impairment of Cognitive Ability
Inform patients that tasks requiring alertness may be affected including the patient's ability to drive and operate machinery as seizures, dizziness, and/or confusion have been reported with the use of VALCYTE [see Adverse Reactions (6.1)].
Use in Patients with CMV Retinitis
Inform patients that VALCYTE is not a cure for CMV retinitis, and they may continue to experience progression of retinitis during or following treatment. Advise patients to have ophthalmologic follow-up examinations at a minimum of every 4 to 6 weeks while being treated with VALCYTE. Some patients will require more frequent follow-up.
Administration
Inform adult patients that they should use VALCYTE tablets, not VALCYTE for oral solution [see Dosage and Administration (2.1)].
Inform patients to take VALCYTE with food to maximize bioavailability.
Representative sample of labeling (see the HOW SUPPLIED section for complete listing):