Valganciclovir hydrochloride

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# Black Box Warning

# Overview
Valganciclovir hydrochloride is an antiviral agent that is FDA approved for the treatment of cytomegalovirus (CMV) retinitis; prevention of CMV disease in adults and children. There is a Black Box Warning for this drug as shown here.  Common adverse reactions include diarrhea, pyrexia, nausea, tremor, neutropenia, anemia, graft rejection, thrombocytopenia, hypertension, upper respiratory tract infection, cough, vomiting, constipation.

# Adult Indications and Dosage

## FDA-Labeled Indications and Dosage (Adult)
- Valganciclovir Tablets, USP are indicated for the treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS).
- Dosing Information
- Induction: The recommended dose is 900 mg (two 450 mg tablets) twice a day for 21 days.
- Maintenance: Following induction treatment, or in adult patients with inactive CMV retinitis, the recommended dose is 900 mg (two 450 mg tablets) once a day.
- Valganciclovir Tablets, USP are indicated for the prevention of CMV disease in kidney, heart, or kidney-pancreas transplant patients at high risk (Donor CMV seropositive/Recipient CMV seronegative ).
- Dosing Information
- For adult patients who have received a heart or kidney-pancreas transplant, the recommended dose is 900 mg (two 450 mg tablets) 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 dose is 900 mg (two 450 mg tablets) once a day starting within 10 days of transplantation until 200 days post-transplantation.

### Limitations of Use
- Valganciclovir Tablets, USP is not indicated for use in either adult or pediatric liver transplant patients.
- The safety and efficacy of Valganciclovir Tablets, USP have not been established for:
- Prevention of CMV disease in solid organ transplants other than those indicated.
- Prevention of CMV disease in pediatric solid organ transplant patients < 4 months of age.
- Treatment of congenital CMV disease.

## Off-Label Use and Dosage (Adult)

# Pediatric Indications and Dosage

## FDA-Labeled Indications and Dosage (Pediatric)
- Valganciclovir Tablets, USP are indicated for the prevention of CMV disease in kidney or heart transplant patients (4 months to 16 years of age) at high risk.
- Dosing Information
- For pediatric patients 4 months to 16 years of age who have received a kidney or heart transplant, the recommended once daily dose of Valganciclovir Tablets, USP starting within 10 days of transplantation until 100 days post-transplantation 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.
- where k =
- 0.45 for patients aged 4 months to < 1 year,
- 0.45 for patients aged 1 to < 2 years (note k value is 0.45 instead of the typical value of 0.55),
- 0.55 for boys aged 2 to < 13 years and girls aged 2 to 16 years, and
- 0.7 for boys aged 13 to 16 years.
- All calculated doses should be rounded to the nearest 25 mg increment for the actual deliverable dose. If the calculated dose exceeds 900 mg, a maximum dose of 900 mg should be administered. Valganciclovir 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.

## Off-Label Use and Dosage (Pediatric)

### Guideline-Supported Use
- There is limited information regarding Off-Label Guideline-Supported Use of Valganciclovir hydrochloride in pediatric patients.

### NonGuideline-Supported Use
- There is limited information regarding Off-Label NonGuideline-Supported Use of Valganciclovir hydrochloride in pediatric patients.

# Contraindications
- Valganciclovir is contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction (e.g., anaphylaxis) to valganciclovir, ganciclovir, or any component of the formulation.

# Warnings
Hematologic Effects
- Severe leukopenia, neutropenia, anemia, thrombocytopenia, pancytopenia, bone marrow aplasia, and aplastic anemia have been reported in patients treated with Valganciclovir or ganciclovir. Valganciclovir should not be administered if the absolute neutrophil count is less than 500 cells/L, the platelet count is less than 25,000/L, or the hemoglobin is less than 8 g/dL. Valganciclovir should also be used with caution in patients with pre-existing cytopenias, or who have received or who are receiving myelosuppressive drugs or irradiation. Cytopenia may occur at any time during treatment and may worsen with continued dosing. Cell counts usually begin to recover within 3 to 7 days after discontinuing drug.
- Due to the frequency of neutropenia, anemia, and thrombocytopenia in patients receiving valganciclovir, complete blood counts with differential and platelet counts should be performed frequently, especially in patients in whom ganciclovir or other nucleoside analogues have previously resulted in leukopenia, or in whom neutrophil counts are less than 1000 cells/L at the beginning of treatment. Increased monitoring for cytopenias may be warranted if therapy with oral ganciclovir is changed to valganciclovir, because of increased plasma concentrations of ganciclovir after valganciclovir administration.
Impairment of Fertility
- Animal data indicate administration of ganciclovir causes inhibition of spermatogenesis and subsequent infertility. These effects were reversible at lower doses but irreversible at higher doses. In men, valganciclovir at the recommended doses may cause temporary or permanent inhibition of spermatogenesis. Animal data also indicate suppression of fertility in females may occur.
Teratogenesis and Mutagenesis
- Animal data indicate ganciclovir is teratogenic and mutagenic. Therefore, valganciclovir should be considered to have the potential to cause birth defects and cancers in humans. Women of childbearing potential should be advised to use effective contraception during treatment and for at least 30 days following treatment with valganciclovir. Similarly, men should be advised to practice barrier contraception during and for at least 90 days following treatment with valganciclovir.
Carcinogenesis
- Animal data indicate that administration of ganciclovir is carcinogenic. Valganciclovir should therefore be considered a potential carcinogen in humans.
Acute Renal Failure
- Acute renal failure may occur in:
- Elderly patients with or without reduced renal function. Caution should be exercised when administering valganciclovir to geriatric patients, and dosage reduction is recommended for those with impaired renal function.
- Patients receiving potential nephrotoxic drugs. Caution should be exercised when administering valganciclovir to patients receiving potential nephrotoxic drugs.
- Patients without adequate hydration. Adequate hydration should be maintained for all patients.

# Adverse Reactions

## Clinical Trials Experience
- The following serious adverse events are discussed in greater detail in other sections of the labeling:
- Hematologic adverse events.
- Acute renal failure.
- The most common adverse events and laboratory abnormalities reported in at least one indication by  20% of adult patients treated with valganciclovir tablets are diarrhea, pyrexia, nausea, tremor, neutropenia, anemia, graft rejection, thrombocytopenia, and vomiting. The most common reported adverse events and laboratory abnormalities reported in > 10% of pediatric solid organ transplant recipients treated with valganciclovir for oral solution or tablets are diarrhea, pyrexia, hypertension, upper respiratory tract infection, vomiting, anemia, neutropenia, constipation, nausea, and cough.
Clinical Trial Experience in Adult Patients
- Valganciclovir, a prodrug of ganciclovir, is rapidly converted to ganciclovir after oral administration. Adverse events known to be associated with ganciclovir usage can therefore be expected to occur with valganciclovir tablets.
- Because clinical trials are conducted under widely varying conditions, adverse event rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect rates observed in practice.
- Treatment of CMV Retinitis in AIDS Patients: In a clinical study for the treatment of CMV retinitis in HIV-infected patients, the adverse events reported by patients receiving valganciclovir 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%), headache (9%, 5%), and catheter-related infections (3%, 11%). The incidence of adverse events was similar between the group who received valganciclovir tablets and the group who received intravenous ganciclovir, with the exception of catheter-related infections, which occurred with greater frequency in patients randomized to receive intravenous ganciclovir. The frequencies of neutropenia (ANC < 500/L) were 11% for patients receiving valganciclovir tablets compared with 13% for patients receiving intravenous ganciclovir. Anemia (Hgb < 8 g/dL) occurred in 8% of patients in each group. Other laboratory abnormalities occurred with similar frequencies in the two groups.
- Adverse events and abnormal laboratory values data are available for 370 patients who received maintenance therapy with valganciclovir tablets 900 mg once daily in two open-label clinical trials. Approximately 252 (68%) of these patients received valganciclovir tablets for more than nine months (maximum duration was 36 months). Table 2 and Table 3 show the pooled adverse event data and abnormal laboratory values from these patients.
- Prevention of CMV Disease in Selected Solid Organ Transplantation: Table 4 shows selected adverse events regardless of severity and drug relationship with an incidence of  5% from a clinical trial (up to 28 days after study treatment) where heart, kidney, kidney-pancreas and liver transplant patients received valganciclovir tablets (N=244) or oral ganciclovir (N=126) until Day 100 post-transplant. The majority of the adverse events were of mild or moderate intensity.
- The overall safety profile of valganciclovir did not change with the extension of prophylaxis until Day 200 post-transplant in high risk kidney transplant patients (see Table 5).
- Adverse events not included in Table 4 and Table 5, which either occurred at a frequency of  5% in clinical studies with solid organ transplant patients, or were selected serious adverse events reported in studies with patients with CMV retinitis or in studies with solid organ transplant patients with a frequency of < 5% are listed below.
- Allergic reactions: valganciclovir hypersensitivity
- Bleeding complications: potentially life-threatening bleeding associated with thrombocytopenia
- Central and peripheral nervous system: paresthesia, dizziness (excluding vertigo), convulsion
- Gastrointestinal disorders: abdominal pain, constipation, dyspepsia, abdominal distention, ascites
- General disorders and administration site disorders: fatigue, pain, edema, peripheral edema, weakness
- Hemic system: anemia, neutropenia, thrombocytopenia, pancytopenia, bone marrow depression, aplastic anemia
- Hepatobiliary disorders: abnormal hepatic function
- Infections and infestations: pharyngitis/nasopharyngitis, upper respiratory tract infection, urinary tract infection, local and systemic infections and sepsis, postoperative wound infection
- Injury, poisoning, and procedural complications: postoperative complications, postoperative pain, increased wound drainage, wound dehiscence
- Metabolism and nutrition disorders: hyperkalemia, hypokalemia, hypomagnesemia, hyperglycemia, appetite decreased, dehydration, hypophosphatemia, hypocalcemia
- Musculoskeletal and connective tissue disorders: back pain, arthralgia, muscle cramps, limb pain
- Psychiatric disorders: depression, psychosis, hallucinations, confusion, agitation
- Renal and urinary disorders: renal impairment, dysuria, decreased creatinine clearance
- Respiratory, thoracic and mediastinal disorders: cough, dyspnea, rhinorrhea, pleural effusion
- Skin and subcutaneous tissue disorders: dermatitis, pruritus, acne
- Vascular disorders: hypotension
- Laboratory abnormalities reported with valganciclovir tablets in two studies in solid organ transplant patients are listed in Table 6 and Table 7.
Clinical Trial Experience in Pediatric Patients
- Valganciclovir for oral solution and tablets have been studied in 109 pediatric solid organ transplant patients who were at risk for developing CMV disease (aged 4 months 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 100 days. The overall safety profile was similar in pediatric patients as compared to adult patients. However, the rates of certain adverse events and laboratory abnormalities, such as upper respiratory tract infection, pyrexia, nasopharyngitis, anemia, and neutropenia, were reported more frequently in pediatric patients than in adults.

## Postmarketing Experience
- In general, the adverse events reported during the postmarketing use of valganciclovir were similar to those identified during the clinical trials and to those reported during the postmarketing use of ganciclovir. Please also refer to the intravenous ganciclovir product information and ganciclovir capsule product information for more information on postmarketing adverse events associated with ganciclovir.

# Drug Interactions
- In vivo drug-drug interaction studies were not conducted with valganciclovir. However, because valganciclovir is rapidly and extensively converted to ganciclovir, drug-drug interactions associated with ganciclovir will be expected for valganciclovir tablets. Established and other potentially significant drug interactions conducted with ganciclovir are listed in Table 8.

# Use in Specific Populations

### Pregnancy
Pregnancy Category (FDA): C
Teratogenic Effects
- Pregnancy Category C After oral administration, valganciclovir (prodrug) is converted to ganciclovir (active drug) and, therefore, is expected to have reproductive toxicity effects similar to ganciclovir. There are no adequate and well-controlled studies of valganciclovir or ganciclovir use in pregnant women. In animal studies of ganciclovir, embryo-fetal toxicity and structural malformations occurred. Valganciclovir should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
- In animal studies, pregnant mice and rabbits received ganciclovir at doses that produced 2x the human exposure (based on AUC comparison). Treated rabbits had increased rates of fetal resorption, fetal growth retardation, embryolethality, maternal toxicity, cleft palate, anophthalmia/microphthalmia, aplastic organs (kidney and pancreas), hydrocephaly and brachygnathia. In mice, increased fetal resorptions and embryolethality occurred in the presence of maternal/fetal toxicity.
- Daily intravenous doses of approximately 1.7x 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 month-old 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.
Pregnancy Category (AUS):
- Australian Drug Evaluation Committee (ADEC) Pregnancy Category
- There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Valganciclovir hydrochloride in women who are pregnant.

### Labor and Delivery
- There is no FDA guidance on use of Valganciclovir hydrochloride during labor and delivery.

### Nursing Mothers
- It is not known whether valganciclovir (prodrug) or ganciclovir (active drug) are excreted in human milk. Because valganciclovir caused granulocytopenia, anemia and thrombocytopenia in clinical trials and ganciclovir was mutagenic and carcinogenic in animal studies, serious adverse events may occur from ganciclovir exposure in nursing infants. Because of the potential for serious adverse events in nursing infants, a decision should be made whether to discontinue nursing or discontinue drug, taking into consideration the importance of the drug to the mother. The Centers for Disease Control and Prevention recommend that HIV-infected mothers not breast-feed their infants to avoid risking postnatal transmission of HIV.

### Pediatric Use
- Valganciclovir tablets are indicated for the prevention of CMV disease in kidney or heart transplant pediatric patients 4 months to 16 years of age at risk for developing CMV disease.
- The use of valganciclovir tablets for the prevention of CMV disease in pediatric patients 4 months to 16 years of age with kidney or heart transplant is based on pharmacokinetic, safety, and efficacy data from an open-label trial with oral valganciclovir (valganciclovir for oral solution or tablets) in pediatric solid organ transplant recipients at risk for developing CMV disease. The results of this study were supported by previous demonstration of efficacy in adult patients.
- The safety and efficacy of valganciclovir for oral solution and tablets have not been established in children for:
- Prevention of CMV disease in liver transplant patients
- Prevention of CMV disease in solid organ transplants other than those indicated
- Prevention of CMV disease in pediatric solid organ transplant patients < 4 months of age
- Treatment of congenital CMV disease
- The pharmacokinetic profile and safety of valganciclovir for oral solution in children were studied in two open-label studies.
- Study 1 was an open-label trial with oral valganciclovir (valganciclovir for oral solution or tablets) in pediatric solid organ transplant recipients at risk for developing CMV disease.
- Study 2 was a pharmacokinetic and pharmacodynamic evaluation of valganciclovir for oral solution in neonates with congenital CMV infection involving the central nervous system. Twenty-four neonates were enrolled in this study. All patients were treated for 6 weeks with a combination of intravenous ganciclovir 6 mg/kg twice daily and valganciclovir for oral solution at doses ranging from 14 mg/kg to 20 mg/kg twice daily. The pharmacokinetic results showed that in infants > 7 days to 3 months of age, a dose of 16 mg/kg twice daily of valganciclovir for oral solution provided ganciclovir systemic exposures (median AUC0-12h = 23.6  gh/mL; n = 6) comparable to those obtained in infants up to 3 months from a 6 mg/kg dose of intravenous ganciclovir twice daily (AUC0-12h = 25.3  gh/mL; n = 18) or to the ganciclovir systemic exposures obtained in adults from a 900 mg dose of valganciclovir tablets twice daily.
- The safety and efficacy of intravenous ganciclovir have not been established for the treatment of congenital CMV infection in infants and no similar disease occurs in adults; therefore, efficacy cannot be extrapolated from intravenous ganciclovir use in adults.

### Geriatic Use
- Studies of valganciclovir for oral solution or tablets have not been conducted in adults older than 65 years of age. Clinical studies of valganciclovir did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Valganciclovir is known to be substantially excreted by the kidneys, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection. In addition, renal function should be monitored and dosage adjustments should be made accordingly.

### Gender
- There is no FDA guidance on the use of Valganciclovir hydrochloride with respect to specific gender populations.

### Race
- There is no FDA guidance on the use of Valganciclovir hydrochloride with respect to specific racial populations.

### Renal Impairment
- Dose reduction is recommended when administering valganciclovir to patients with renal impairment.
- For adult patients on hemodialysis (CrCl <10 mL/min) valganciclovir tablets should not be used. Adult hemodialysis patients should use ganciclovir in accordance with the dose-reduction algorithm cited in the Cytovene-IV and ganciclovir capsules complete product information section on DOSAGE AND ADMINISTRATION: Renal Impairment.

### Hepatic Impairment
- The safety and efficacy of valganciclovir have not been studied in patients with hepatic impairment.

### Females of Reproductive Potential and Males
- There is no FDA guidance on the use of Valganciclovir hydrochloride in women of reproductive potentials and males.

### Immunocompromised Patients
- There is no FDA guidance one the use of Valganciclovir hydrochloride in patients who are immunocompromised.

# Administration and Monitoring

### Administration
General Dosing Information
- Valganciclovir tablets should be taken with food.
- The bioavailability of ganciclovir from valganciclovir tablets is significantly higher than from ganciclovir capsules. Therefore, valganciclovir tablets cannot be substituted for ganciclovir capsules on a one-to-one basis.
- Adult patients should use valganciclovir tablets, not valganciclovir for oral solution.
Adult Patients With Normal Renal Function
- For dosage recommendations in adult patients with renal impairment.
- Treatment of CMV Retinitis:
- Induction: The recommended dose is 900 mg (two 450 mg tablets) twice a day for 21 days.
- Maintenance: Following induction treatment, or in adult patients with inactive CMV retinitis, the recommended dose is 900 mg (two 450 mg tablets) once a day.
- Prevention of CMV Disease:
- For adult patients who have received a heart or kidney-pancreas transplant, the recommended dose is 900 mg (two 450 mg tablets) 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 dose is 900 mg (two 450 mg tablets) once a day starting within 10 days of transplantation until 200 days post-transplantation.
Pediatric Patients
- Prevention of CMV Disease: For pediatric patients 4 months to 16 years of age who have received a kidney or heart transplant, the recommended once daily dose of Valganciclovir Tablets, USP starting within 10 days of transplantation until 100 days post-transplantation 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.
- where k =
- 0.45 for patients aged 4 months to < 1 year,
- 0.45 for patients aged 1 to < 2 years (note k value is 0.45 instead of the typical value of 0.55),
- 0.55 for boys aged 2 to < 13 years and girls aged 2 to 16 years, and
- 0.7 for boys aged 13 to 16 years.
- All calculated doses should be rounded to the nearest 25 mg increment for the actual deliverable dose. If the calculated dose exceeds 900 mg, a maximum dose of 900 mg should be administered. Valganciclovir 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.
Renal Impairment
- Dosage recommendations for adult patients with reduced renal function are provided in Table 1. For adult patients on hemodialysis (CrCl <10 mL/min), a dose recommendation for valganciclovir cannot be given.
- Dosing in pediatric patients with renal impairment can be done using the recommended equations because CrCl is a component in the calculation.
Handling and Disposal
- Caution should be exercised in the handling of valganciclovir tablets. Tablets should not be broken or crushed. Because valganciclovir is considered a potential teratogen and carcinogen in humans, caution should be observed in handling broken tablets. Avoid direct contact with broken or crushed tablets with skin or mucous membranes. If such contact occurs, wash thoroughly with soap and water, and rinse eyes thoroughly with plain water.
- Because ganciclovir shares some of the properties of antitumor agents (i.e., carcinogenicity and mutagenicity), consideration should be given to handling and disposal according to guidelines issued for antineoplastic drugs. Several guidelines on this subject have been published. However, there is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate.

### DOSAGE FORMS AND STRENGTHS
- Valganciclovir Tablets:
- 450 mg, pink, convex oval tablets with "E114" on one side and plain on the other side.

### Monitoring
- There is limited information regarding Monitoring of Valganciclovir hydrochloride in the drug label.

# IV Compatibility
- There is limited information regarding IV Compatibility of Valganciclovir hydrochloride in the drug label.

# Overdosage
- Experience With Valganciclovir Tablets: One adult developed fatal bone marrow depression (medullary aplasia) after several days of dosing that was at least 10-fold greater than recommended for the patient's estimated degree of renal impairment.
- An overdose of valganciclovir could also possibly result in increased renal toxicity.
- Because ganciclovir is dialyzable, dialysis may be useful in reducing serum concentrations in patients who have received an overdose of valganciclovir. Adequate hydration should be maintained. The use of hematopoietic growth factors should be considered.
- Experience With Intravenous Ganciclovir: Reports of overdoses with intravenous ganciclovir 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: pancytopenia, bone marrow depression, medullary aplasia, leukopenia, neutropenia, granulocytopenia
- Hepatotoxicity: hepatitis, liver function disorder
- Renal toxicity: worsening of hematuria in a patient with pre-existing renal impairment, acute renal failure, elevated creatinine
- Gastrointestinal toxicity: abdominal pain, diarrhea, vomiting
- Neurotoxicity: generalized tremor, convulsion

# Pharmacology

## Mechanism of Action
- Valganciclovir is an antiviral drug.

## Structure
- Valganciclovir Tablets, USP contains valganciclovir hydrochloride (valganciclovir HCl), a hydrochloride salt of the L-valyl ester of ganciclovir that exists as a mixture of two diastereomers. Ganciclovir is a synthetic guanine derivative active against CMV.
- Valganciclovir Tablets, USP is available as a 450 mg tablet for oral administration. Each tablet contains 496.3 mg of valganciclovir HCl (corresponding to 450 mg of valganciclovir), and the inactive ingredients colloidal silicon dioxide, crospovidone, microcrystalline cellulose, povidone K-30, and stearic acid. The film-coat applied to the tablets contains polyvinyl alcohol, titanium dioxide, polyethylene glycol, talc, and iron oxide red.
- Valganciclovir HCl is a white to off-white amorphous powder with a molecular formula of C14H22N6O5HCl and a molecular weight of 390.83. The chemical name for valganciclovir HCl is L-Valine, 2--3-hydroxypropyl ester, monohydrochloride. Valganciclovir HCl is a polar hydrophilic compound with a solubility of 70 mg/mL in water at 25C at a pH of 7.0 and an n-octanol/water partition coefficient of 0.0095 at pH 7.0. The pKa for valganciclovir HCl is 7.6.
- The chemical structure of valganciclovir HCl is:
- All doses in this insert are specified in terms of valganciclovir.

## Pharmacodynamics
There is limited information regarding Pharmacodynamics of Valganciclovir hydrochloride in the drug label.

## Pharmacokinetics
- Because the major elimination pathway for ganciclovir is renal, dosage reductions according to creatinine clearance are required for valganciclovir tablets.
- Pharmacokinetics in Adults: The pharmacokinetics of valganciclovir and 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.
- The ganciclovir pharmacokinetic parameters following administration of 900 mg valganciclovir tablets and 5 mg/kg intravenous ganciclovir and 1000 mg three times daily oral ganciclovir in HIV-positive/CMV-positive patients are summarized in Table 9.
- The area under the plasma concentration-time curve (AUC) of ganciclovir administered as valganciclovir tablets (900 mg once daily) is comparable to the AUC of ganciclovir after administration of intravenous ganciclovir (5 mg/kg once daily). The Cmax of ganciclovir following valganciclovir administration is 40% lower than the Cmax following intravenous ganciclovir administration. During maintenance dosing, ganciclovir AUC0-24h and Cmax following oral ganciclovir administration (1000 mg three times daily) are lower relative to valganciclovir and intravenous ganciclovir. The ganciclovir Cmin following intravenous ganciclovir and valganciclovir administration are less than the ganciclovir Cmin following oral ganciclovir administration. The clinical significance of the differences in ganciclovir pharmacokinetics after administration of valganciclovir tablets, ganciclovir capsules, and intravenous ganciclovir is unknown.
- Plasma concentration-time profiles for ganciclovir (GCV) from valganciclovir (VGCV) and intravenous ganciclovir were obtained from a multiple dose study (n=21 and n=18, respectively) in HIV-positive/CMV-positive patients with CMV retinitis. The plasma concentration-time profile for oral ganciclovir was obtained from a multiple dose study (n=24) in HIV-positive/CMV-positive patients without CMV retinitis.
- In solid organ transplant recipients, the mean systemic exposure to ganciclovir was 1.7x higher following administration of 900 mg valganciclovir tablets once daily versus 1000 mg ganciclovir capsules three times daily, when both drugs were administered according to their renal function dosing algorithms. The systemic ganciclovir exposures attained were comparable across kidney, heart and liver transplant recipients based on a population pharmacokinetics evaluation (see Table 10).
- The pharmacokinetic parameters of ganciclovir following 200 days of valganciclovir administration in high-risk kidney transplant patients were similar to those previously reported in solid organ transplant patients who received valganciclovir for 100 days.
- In a pharmacokinetic study in liver transplant patients, the ganciclovir AUC0-24h achieved with 900 mg valganciclovir was 41.7  9.9 gh/mL (n=28) and the AUC0-24h achieved with the approved dosage of 5 mg/kg intravenous ganciclovir was 48.2  17.3 gh/mL (n=27).
- Absorption: Valganciclovir, a prodrug of ganciclovir, is well absorbed from the gastrointestinal tract and rapidly metabolized in the intestinal wall and liver to ganciclovir. The absolute bioavailability of ganciclovir from valganciclovir tablets following administration with food was approximately 60% (3 studies, n=18; n=16; n=28). Ganciclovir median Tmax following administration of 450 mg to 2625 mg valganciclovir tablets ranged from 1 to 3 hours. Dose proportionality with respect to ganciclovir AUC following administration of valganciclovir tablets was demonstrated only under fed conditions. Systemic exposure to the prodrug, valganciclovir, is transient and low, and the AUC24 and Cmax values are approximately 1% and 3% of those of ganciclovir, respectively.
- Food Effects: When valganciclovir tablets were administered with a high fat meal containing approximately 600 total calories (31.1 g fat, 51.6 g carbohydrates and 22.2 g protein) at a dose of 875 mg once daily to 16 HIV-positive subjects, the steady-state ganciclovir AUC increased by 30% (95% CI 12% to 51%), and the Cmax increased by 14% (95% CI -5% to 36%), without any prolongation in time to peak plasma concentrations (Tmax). Valganciclovir should be administered with food.
- Distribution: Due to the rapid conversion of valganciclovir to ganciclovir, plasma protein binding of valganciclovir was not determined. Plasma protein binding of ganciclovir is 1% to 2% over concentrations of 0.5 and 51 g/mL. When ganciclovir was administered intravenously, the steady-state volume of distribution of ganciclovir was 0.703  0.134 L/kg (n=69).
- After administration of valganciclovir tablets, no correlation was observed between ganciclovir AUC and reciprocal weight; oral dosing of valganciclovir tablets according to weight is not required.
- Metabolism: Valganciclovir is rapidly hydrolyzed to ganciclovir; no other metabolites have been detected. No metabolite of orally administered radiolabeled ganciclovir (1000 mg single dose) accounted for more than 1% to 2% of the radioactivity recovered in the feces or urine.
- Elimination: The major route of elimination of valganciclovir is by renal excretion as ganciclovir through glomerular filtration and active tubular secretion. Systemic clearance of intravenously administered ganciclovir was 3.07  0.64 mL/min/kg (n=68) while renal clearance was 2.99  0.67 mL/min/kg (n=16).
- The terminal half-life (t12) of ganciclovir following oral administration of valganciclovir tablets to either healthy or HIV-positive/CMV-positive subjects was 4.08  0.76 hours (n=73), and that following administration of intravenous ganciclovir was 3.81  0.71 hours (n=69). In heart, kidney, kidney-pancreas, and liver transplant patients, the terminal elimination half-life of ganciclovir following oral administration of valganciclovir was 6.48  1.38 hours, and following oral administration of ganciclovir capsules was 8.56  3.62 hours.
Specific Populations:
- Renal Impairment: The pharmacokinetics of ganciclovir from a single oral dose of 900 mg valganciclovir tablets were evaluated in 24 otherwise healthy individuals with renal impairment.
- Decreased renal function results in decreased clearance of ganciclovir from valganciclovir, and a corresponding increase in terminal half-life. Therefore, dosage adjustment is required for patients with impaired renal function.
- Hemodialysis reduces plasma concentrations of ganciclovir by about 50% following valganciclovir administration. Adult patients receiving hemodialysis (CrCl <10 mL/min) cannot use valganciclovir tablets because the daily dose of valganciclovir tablets required for these patients is less than 450 mg.
- 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. In this study, patients received oral doses of valganciclovir (either valganciclovir for oral solution or tablets) to produce exposure equivalent to an adult 900 mg dose.
- The pharmacokinetics of ganciclovir were similar across organ types and age ranges. Population pharmacokinetic modeling suggested that bioavailability was approximately 60%. Clearance was positively influenced by both body surface area and renal function. The mean total clearance was 5.3 L/hr (88.3 mL/min) for a patient with creatinine clearance of 70.4 mL/min. The mean Cmax and AUC by age and organ type are listed in Table 12.
- Pharmacokinetics in Geriatric Patients: The pharmacokinetic characteristics of valganciclovir in elderly patients have not been established. Because elderly individuals frequently have a reduced glomerular filtration rate, renal function should be assessed before and during administration of valganciclovir.
- Drug Interactions: In vivo drug-drug interaction studies were not conducted with valganciclovir. However, because valganciclovir is rapidly and extensively converted to ganciclovir, interactions associated with ganciclovir will be expected for valganciclovir.
- Drug-drug interaction studies were conducted in patients with normal renal function. Patients with impaired renal function may have increased concentrations of ganciclovir and the coadministered drug following concomitant administration of valganciclovir and drugs excreted by the same pathway as ganciclovir. Therefore, these patients should be closely monitored for toxicity of ganciclovir and the coadministered drug.
- Table 13 and Table 14 provide a listing of established drug interaction studies with ganciclovir. Table 13 provides the effects of coadministered drug on ganciclovir plasma pharmacokinetic parameters, whereas Table 14 provides the effects of ganciclovir on plasma pharmacokinetic parameters of coadministered drug.
Microbiology
- Mechanism of Action: Valganciclovir is an L-valyl ester (prodrug) of ganciclovir that exists as a mixture of two diastereomers. After oral administration, both diastereomers are rapidly converted to ganciclovir by intestinal and hepatic esterases. Ganciclovir is a synthetic analogue of 2'-deoxyguanosine, which inhibits replication of human CMV in cell culture and in vivo.
- In CMV-infected cells ganciclovir is initially phosphorylated to ganciclovir monophosphate by the viral protein kinase, pUL97. Further phosphorylation occurs by cellular kinases to produce ganciclovir triphosphate, which is then slowly metabolized intracellularly (half-life 18 hours). As the phosphorylation is largely dependent on the viral kinase, phosphorylation of ganciclovir occurs preferentially in virus-infected cells. The virustatic activity of ganciclovir is due to inhibition of the viral DNA polymerase, pUL54, synthesis by ganciclovir triphosphate.
- 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 M (0.02 to 5.75 g/mL). The distribution and range in susceptibility observed in one assay evaluating 130 clinical isolates was 0 to 1 M (35%), 1.1 to 2 M (20%), 2.1 to 3 M (27%), 3.1 to 4 M (13%), 4.1 to 5 M (5%), > 5 M ( 1,000 M (10.21 to > 250 g/mL). Bone marrow-derived colony-forming cells are more sensitive .
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, 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 15.
- 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-). 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  versus after therapy: 4/58 ). 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. 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 16.

## Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment of Fertility
- Long-term carcinogenicity studies have not been conducted with valganciclovir. However, upon oral administration, valganciclovir is rapidly and extensively converted to ganciclovir. Therefore, like ganciclovir, valganciclovir is a potential carcinogen.
- Ganciclovir was carcinogenic in the mouse at oral doses that produced exposures approximately 0.1x and 1.4x, respectively, the mean drug exposure in humans following the recommended intravenous dose of 5 mg/kg, based on area under the plasma concentration curve (AUC) comparisons. At the higher dose there was a significant increase in the incidence of tumors of the preputial gland in males, forestomach (nonglandular mucosa) in males and females, and reproductive tissues (ovaries, uterus, mammary gland, clitoral gland and vagina) and liver in females. At the lower dose, a slightly increased incidence of tumors was noted in the preputial and harderian glands in males, forestomach in males and females, and liver in females. Ganciclovir should be considered a potential carcinogen in humans.
- Valganciclovir increases mutations in mouse lymphoma cells. In the mouse micronucleus assay, valganciclovir was clastogenic. Valganciclovir was not mutagenic in the Ames Salmonella assay. Ganciclovir increased mutations in mouse lymphoma cells and DNA damage in human lymphocytes in vitro. In the mouse micronucleus assay, ganciclovir was clastogenic. Ganciclovir was not mutagenic in the Ames Salmonella assay.
- Valganciclovir is converted to ganciclovir and therefore is expected to have similar reproductive toxicity effects as ganciclovir. Ganciclovir caused decreased mating behavior, decreased fertility, and an increased incidence of embryolethality in female mice following intravenous doses that produced an exposure approximately 1.7x the mean drug exposure in humans following the dose of 5 mg/kg, based on AUC comparisons. Ganciclovir caused decreased fertility in male mice and hypospermatogenesis in mice and dogs following daily oral or intravenous administration. Systemic drug exposure (AUC) at the lowest dose showing toxicity in each species ranged from 0.03 to 0.1x the AUC of the recommended human intravenous dose. Valganciclovir caused similar effects on spermatogenesis in mice, rats, and dogs. It is considered likely that ganciclovir (and valganciclovir) could cause inhibition of human spermatogenesis.
Reproductive and Developmental Toxicology
- Valganciclovir is converted to ganciclovir and therefore is expected to have reproductive toxicity effects similar to ganciclovir. Ganciclovir has been shown to be embryotoxic in rabbits and mice following intravenous administration, and teratogenic in rabbits. Fetal resorptions were present in at least 85% of rabbits and mice administered doses that produced 2x the human exposure based on AUC comparisons (all dose comparisons presented are based on the human AUC following administration of a single 5 mg/kg infusion of intravenous ganciclovir). Effects observed in rabbits included: fetal growth retardation, embryolethality, teratogenicity and/or maternal toxicity. Teratogenic changes included cleft palate, anophthalmia/microphthalmia, aplastic organs (kidney and pancreas), hydrocephaly and brachygnathia. In mice, effects observed were maternal/fetal toxicity and embryolethality.
- Daily intravenous doses administered to female mice prior to mating, during gestation, and during lactation caused hypoplasia of the testes and seminal vesicles in the month-old male offspring, as well as pathologic changes in the nonglandular region of the stomach . The drug exposure in mice as estimated by the AUC was approximately 1.7x the human AUC.
- Data obtained using an ex vivo human placental model show that ganciclovir crosses the placenta and that simple diffusion is the most likely mechanism of transfer. The transfer was not saturable over a concentration range of 1 to 10 mg/mL and occurred by passive diffusion.

# Clinical Studies
Adult Patients
- 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 valganciclovir tablets (900 mg twice daily for 21 days, then 900 mg once daily for 7 days) or with intravenous ganciclovir solution (5 mg/kg twice daily for 21 days, then 5 mg/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 17 provides the outcomes at 4 weeks.
- Maintenance Therapy of CMV Retinitis: No comparative clinical data are available on the efficacy of valganciclovir tablets for the maintenance therapy of CMV retinitis because all patients in the CMV retinitis study received open-label valganciclovir tablets after Week 4. However, the AUC for ganciclovir is similar following administration of 900 mg valganciclovir tablets once daily and 5 mg/kg intravenous ganciclovir once daily. Although the ganciclovir Cmax is lower following valganciclovir tablets administration compared to intravenous ganciclovir, it is higher than the Cmax obtained following oral ganciclovir administration. Therefore, use of valganciclovir 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 valganciclovir: 1 oral ganciclovir) to receive either valganciclovir 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 valganciclovir 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 valganciclovir group compared with the ganciclovir group. These results are summarized in Table 18.
- Mortality at six months was 3.7% (9/244) in the valganciclovir group and 1.6% (2/126) in the oral ganciclovir group.
- 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 valganciclovir CMV prophylaxis from 100 to 200 days post-transplant.  Patients were randomized (1:1) to receive valganciclovir 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 valganciclovir 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 19.
- 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.
Pediatric Patients
- Prevention of CMV in Pediatric Solid Organ Transplant Recipients: 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 valganciclovir (valganciclovir for oral solution or tablets). Patients received valganciclovir once daily as soon as possible after transplant until a maximum of 100 days post-transplant. The daily doses of valganciclovir were calculated at each study visit based on body surface area and a modified creatinine clearance.
- The pharmacokinetics of ganciclovir were similar across organ transplant types and age ranges. The mean daily ganciclovir exposures in pediatric patients were comparable to those observed in adult solid organ transplant patients receiving valganciclovir 900 mg once daily . No case of CMV disease was reported during the study. CMV viremia was reported in 7 (11%) patients during the study; however, none of these events fulfilled the definition of CMV syndrome. Based on the pharmacokinetic, safety, and efficacy data from this study and extrapolated efficacy data from the adult study, oral valganciclovir is indicated for the prevention of CMV disease in kidney and heart transplant children 4 months to 16 years of age at risk for developing CMV disease. Valganciclovir is not approved in adults for CMV prophylaxis in liver transplant patients; therefore, valganciclovir is not recommended for CMV prophylaxis in pediatric liver transplant patients because efficacy cannot be extrapolated from adults.

# How Supplied
- Valganciclovir Tablets, USP: Supplied as 450 mg, pink, convex oval tablets with "E114" on one side and plain on the other side. Each film-coated tablet contains 450 mg of valganciclovir as valganciclovir hydrochloride. Valganciclovir Tablets, USP, is supplied in bottles of 60 tablets (NDC 0603-6330-20).

## Storage
- Store at 25C (77F); excursions permitted to 15C to 30C (59F to 86F) .

# Images

## Drug Images

## Package and Label Display Panel

# Patient Counseling Information
- See FDA-Approved Patient Labeling
- Valganciclovir tablets cannot be substituted for ganciclovir capsules on a one-to-one basis. Inform patients switching from ganciclovir capsules of the risk of overdosage if they take more than the prescribed number of valganciclovir tablets.
- Adult patients should use valganciclovir tablets, not valganciclovir for oral solution.
- Valganciclovir is changed to ganciclovir once it is absorbed into the body. Inform all patients that the major toxicities of ganciclovir include granulocytopenia (neutropenia), anemia, and thrombocytopenia and that dose modifications may be required, including discontinuation. The importance of close monitoring of blood counts while on therapy should be emphasized. Inform patients that ganciclovir has been associated with elevations in serum creatinine.
- Instruct patients to take valganciclovir tablets with food to maximize bioavailability.
- Advise patients that ganciclovir causes decreased sperm production in animals and may cause decreased fertility in humans. Advise women of childbearing potential that ganciclovir causes birth defects in animals and should not be used during pregnancy. Because of the potential for serious adverse events in nursing infants, instruct mothers not to breast-feed if they are receiving valganciclovir. Advise women of childbearing potential to use effective contraception during and for at least 30 days following treatment with valganciclovir. Similarly, advise men to practice barrier contraception during and for at least 90 days following treatment with valganciclovir.
- Although there is no information from human studies, advise patients that ganciclovir should be considered a potential carcinogen.
- Convulsions, sedation, dizziness, ataxia and/or confusion have been reported with the use of valganciclovir and/or ganciclovir. If they occur, tasks requiring alertness may be affected including the patient's ability to drive and operate machinery.
- Inform patients that ganciclovir 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 valganciclovir. Some patients will require more frequent follow-up.

# Precautions with Alcohol
- Alcohol-Valganciclovir hydrochloride interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

# Brand Names
- Valcyte

# Look-Alike Drug Names
- A  B

# Drug Shortage Status

# Price