- 1. Name of the medicinal product
- 2. Qualitative and quantitative composition
- 3. Pharmaceutical form
- 4. Clinical particulars
- 4.1 Therapeutic indications
- 4.2 Posology and method of administration
- 4.3 Contraindications
- 4.4 Special warnings and precautions for use
- 4.5 Interaction with other medicinal products and other forms of interaction
- 4.6 Fertility, pregnancy and lactation
- 4.7 Effects on ability to drive and use machines
- 4.8 Undesirable effects
- 4.9 Overdose
- 5. Pharmacological properties
- 5.1 Pharmacodynamic properties
- 5.2 Pharmacokinetic properties
- 5.3 Preclinical safety data
- 6. Pharmaceutical particulars
- 6.1 List of excipients
- 6.2 Incompatibilities
- 6.3 Shelf life
- 6.4 Special precautions for storage
- 6.5 Nature and contents of container
- 6.6 Special precautions for disposal and other handling
- 7. Marketing authorisation holder
- 8. Marketing authorisation number(s)
- 9. Date of first authorisation/renewal of the authorisation
- 10. Date of revision of the text
Caution Strict adherence to dosage recommendations is essential to avoid overdose (see sections 4.4 and 4.9).Valganciclovir is rapidly and extensively metabolised to ganciclovir after oral dosing. Oral valganciclovir 900 mg b.i.d. is therapeutically equivalent to intravenous ganciclovir 5 mg/kg b.i.d. Treatment of cytomegalovirus (CMV) retinitis
Induction treatment of CMV retinitisFor patients with active CMV retinitis, the recommended dose is 900 mg valganciclovir (two Valcyte 450 mg tablets) twice a day for 21 days and, whenever possible, taken with food. Prolonged induction treatment may increase the risk of bone marrow toxicity (see section 4.4).
Maintenance treatment of CMV retinitis:Following induction treatment, or in patients with inactive CMV retinitis, the recommended dose is 900mg valganciclovir (two Valcyte 450 mg tablets) once daily and, whenever possible, taken with food. Patients whose retinitis worsens may repeat induction treatment; however, consideration should be given to the possibility of viral drug resistance.
Paediatric populationThe safety and efficacy of Valcyte in the treatment of CMV retinitis have not been established in adequate and well-controlled clinical studies in paediatric patients.
Prevention of CMV disease in solid organ transplantation:
Adult patientsFor kidney transplant patients, the recommended dose is 900 mg (two Valcyte 450 mg tablets) once daily, starting within 10 days post-transplantation and continuing until 100 days post-transplantation. Prophylaxis may be continued until 200 days post-transplantation (see sections 4.4, 4.8 and 5.1).For patients who have received a solid organ transplant other than kidney, the recommended dose is 900 mg (two Valcyte 450 mg tablets) once daily, starting within 10 days post-transplantation and continuing until 100 days post-transplantation. Whenever possible, the tablets should be taken with food.
Paediatric populationIn paediatric solid organ transplant patients, aged from birth, who are at risk of developing CMV disease, the recommended once daily dose of Valcyte is based on body surface area (BSA) and creatinine clearance (CrCl) derived from Schwartz formula (CrCLS), and is calculated using the equation below:Paediatric Dose (mg) = 7 x BSA x CrCLS (see Mosteller BSA formula and Schwartz Creatinine Clearance formula below). 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 < 2 years, 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. Refer to adult dosing for patients older than 16 years of age.The k values provided are based on the Jaffe method of measuring serum creatinine and may require correction when enzymatic methods are used.*For appropriate sub-populations a lowering of k value may also be necessary (e.g. in paediatric patients with low birth weight). For paediatric kidney transplant patients, the recommended once daily mg dose (7 x BSA x CrCLS) should start within 10 days post-transplantation and continue until 200 days post-transplantation.For paediatric patients who have received a solid organ transplant other than kidney, the recommended once daily mg dose (7x BSA x CrCLS) should start within 10 days post-transplantation and continue until 100 days post-transplantation.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. The oral solution is the preferred formulation since it provides the ability to administer a dose calculated according to the formula above; however, Valcyte film-coated tablets may be used if the calculated doses are within 10% of available tablet doses, and the patient is able to swallow tablets. For example, if the calculated dose is between 405 mg and 495 mg, one 450 mg tablet may be taken. It is recommended to monitor serum creatinine levels regularly and consider changes in height and body weight and adapt the dose as appropriate during the prophylaxis period.
Special dosage instructions
Patients with renal impairment:Serum creatinine levels or creatinine clearance should be monitored carefully. Dosage adjustment is required according to creatinine clearance, as shown in the table below (see sections 4.4 and 5.2).An estimated creatinine clearance (ml/min) can be related to serum creatinine by the following formulae: For females = 0.85 × male value
|CrCl (ml/min)||Induction dose of valganciclovir||Maintenance/Prevention dose of valganciclovir|
|≥ 60||900 mg (2 tablets) twice daily||900 mg (2 tablets) once daily|
|40 59||450 mg (1 tablet) twice daily||450 mg (1 tablet) once daily|
|25 39||450 mg (1 tablet) once daily||450 mg (1 tablet) every 2 days|
|10 24||450 mg (1 tablet) every 2 days||450 mg (1 tablet) twice weekly|
|< 10||Not recommended||Not recommended|
Patients undergoing haemodialysis:For patients on haemodialysis (CrCl < 10 ml/min) a dose recommendation cannot be given. Thus Valcyte film-coated tablets should not be used in these patients (see sections 4.4 and 5.2).
Patients with hepatic impairment:Safety and efficacy of Valcyte tablets have not been studied in patients with hepatic impairment (see section 5.2).
Paediatric population:Dosing of paediatric SOT patients is individualised based on a patient's renal function, together with body length and weight.
Elderly patients:Safety and efficacy have not been established in this patient population.
Patients with severe leucopenia, neutropenia, anaemia, thrombocytopenia and pancytopenia:See section 4.4 before initiation of therapy. If there is a significant deterioration of blood cell counts during therapy with Valcyte, treatment with haematopoietic growth factors and/or dose interruption should be considered (see section 4.4).
Method of administrationValcyte is administered orally, and whenever possible, should be taken with food (see section 5.2).For paediatric patients who are unable to swallow Valcyte film-coated tablets, Valcyte powder for oral solution can be administered.
Precautions to be taken before handling or administering the medicinal productThe tablets should not be broken or crushed. Since Valcyte is considered a potential teratogen and carcinogen in humans, caution should be observed in handling broken tablets (see section 4.4). Avoid direct contact of broken or crushed tablets with skin or mucous membranes. If such contact occurs, wash thoroughly with soap and water, rinse eyes thoroughly with sterile water, or plain water if sterile water is unavailable.
Drug interactions with valganciclovirIn-vivo drug interaction studies with Valcyte have not been performed. Since valganciclovir is extensively and rapidly metabolised to ganciclovir; drug interactions associated with ganciclovir will be expected for valganciclovir.
Drug interactions with ganciclovir
Imipenem-cilastatinConvulsions have been reported in patients taking ganciclovir and imipenem-cilastatin concomitantly. These drugs should not be used concomitantly unless the potential benefits outweigh the potential risks (see section 4.4).
ProbenecidProbenecid given with oral ganciclovir resulted in statistically significantly decreased renal clearance of ganciclovir (20 %) leading to statistically significantly increased exposure (40 %). These changes were consistent with a mechanism of interaction involving competition for renal tubular secretion. Therefore, patients taking probenecid and Valcyte should be closely monitored for ganciclovir toxicity.
TrimethoprimNo clinically significant pharmacokinetic interaction was observed when trimethoprim and oral ganciclovir were given in combination. However, there is a potential for toxicity to be enhanced since both drugs are known to be myelosuppressive and therefore both drugs should be used concomitantly only if the potential benefits outweigh the risks.
Mycophenolate MofetilSince both mycophenolate mofetil (MMF) and ganciclovir have the potential to cause neutropenia and leucopenia, patients should be monitored for additive toxicity.
StavudineNo clinically significant interactions were observed when stavudine and oral ganciclovir were given in combination.
ZidovudineWhen zidovudine was given in the presence of oral ganciclovir there was a small (17 %), but statistically significant increase in the AUC of zidovudine. There was also a trend towards lower ganciclovir concentrations when administered with zidovudine, although this was not statistically significant. However, since both zidovudine and ganciclovir have the potential to cause neutropenia and anaemia, some patients may not tolerate concomitant therapy at full dosage (see section 4.4).
DidanosineDidanosine plasma concentrations were found to be consistently raised when given with ganciclovir (both intravenous and oral). At ganciclovir oral doses of 3 and 6 g/day, an increase in the AUC of didanosine ranging from 84 to 124 % has been observed, and likewise at intravenous doses of 5 and 10 mg/kg/day, an increase in the AUC of didanosine ranging from 38 to 67 % has been observed. There was no clinically significant effect on ganciclovir concentrations. Patients should be closely monitored for didanosine toxicity (see section 4.4).
Other antiretrovirals (including therapy for HIV, HBV/HCV)At clinically relevant plasma concentrations of ganciclovir and other antivirals for the inhibition of human immunodeficiency virus (HIV) or HBV/HCV, there is unlikely to be a synergistic or antagonistic effect on the activity of either ganciclovir or the other antivirals. The metabolic interaction potential of valganciclovir or ganciclovir is low due to the lack of cytochrome P450 involvement in the metabolism of either valganciclovir or ganciclovir. In addition, ganciclovir is not a substrate to P-glycoprotein, nor does it affect the UDP-glucuronosyltransferase (UGT enzyme). Therefore metabolic and drug transport interactions of valganciclovir or ganciclovir with the following classes of antivirals are considered unlikely:• Non-nucleoside reverse transcriptase inhibitors (NNRTIs), e.g. rilpivirine, etravirine, efavirenz • Protease inhibitors (PIs), e.g. darunavir, boceprevir and telaprevir• Entry inhibitors (fusion inhibitor and CCR5 co-receptor antagonist), e.g. enfuvirtide and maraviroc• HIV integrase strand transfer inhibitor (INSTI), e.g. raltegravirSince ganciclovir is excreted through the kidney via glomerular filtration and active tubular secretion (section 5.2), coadministration of valganciclovir with antiviral drugs that share the tubular secretion pathway may change the plasma concentrations of valganciclovir and/or the coadministered drug. Some examples include nucleos(t)ide analog reverse-transcriptase inhibitors (NRTIs) (including those used for HBV therapy), e.g. lamivudine, emtricitabine, tenofovir, adefovir and entecavir. The renal clearance of ganciclovir may also be inhibited due to nephrotoxicity caused by drugs such as cidofovir, foscarnet, NRTIs (e.g. tenofovir, adefovir). Concomitant use of valganciclovir with any of these drugs should be considered only if the potential benefits outweigh the potential risks (see section 4.4).
Other potential drug interactionsToxicity may be enhanced when valganciclovir is co-administered with, or is given immediately before or after, other drugs that inhibit replication of rapidly dividing cell populations such as occur in the bone marrow, testes and germinal layers of the skin and gastrointestinal mucosa. Examples of these types of drugs are dapsone, pentamidine, flucytosine, vincristine, vinblastine, adriamycin, amphotericin B, trimethoprim/sulpha combinations, nucleoside analogues, hydroxyurea and pegylated interferons/ ribavirin (with or without boceprevir or telaprevir).Concomitant use of valganciclovir with all of these drugs should be considered only if the potential benefits outweigh the potential risks (see section 4.4).
PregnancyThere are no data from the use of Valcyte in pregnant women. Its active metabolite, ganciclovir, readily diffuses across the human placenta. Based on its pharmacological mechanism of action and reproductive toxicity observed in animal studies with ganciclovir (see section 5.3) there is a theoretical risk of teratogenicity in humans.Valcyte should not be used in pregnancy unless the therapeutic benefit for the mother outweighs the potential risk of teratogenic damage to the child.
Breast-feedingIt is unknown if ganciclovir is excreted in breast milk, but the possibility of ganciclovir being excreted in the breast milk and causing serious adverse reactions in the nursing infant cannot be discounted. Therefore, breast-feeding must be discontinued (see section 4.3).
FertilityNo human data on the effect of valganciclovir on fertility are available. Fertility studies have not been repeated with valganciclovir because of the rapid and extensive conversion of valganciclovir to ganciclovir in the body. Ganciclovir is associated with impaired fertility in animal studies (see section 5.3).
a Summary of the safety profileValganciclovir is a prodrug of ganciclovir, which is rapidly and extensively metabolised to ganciclovir after oral administration. The undesirable effects known to be associated with ganciclovir use can be expected to occur with valganciclovir. All of the undesirable effects observed with valganciclovir clinical studies have been previously observed with ganciclovir. The most commonly reported adverse drug reactions following administration of valganciclovir in adults are neutropenia, anaemia and diarrhoea.Valganciclovir is associated with a higher risk of diarrhoea compared to intravenous ganciclovir. In addition, valganciclovir is associated with a higher risk of neutropenia and leucopenia compared to oral ganciclovir. Severe neutropenia (ANC < 500 cells/μl) is seen more frequently in AIDS patients with CMV retinitis undergoing treatment with valganciclovir than in solid organ transplant patients receiving valganciclovir (see section 4.4).The frequency of adverse reactions reported in clinical trials with either valganciclovir, oral ganciclovir, or intravenous ganciclovir is presented in the table below. The adverse reactions listed were reported in clinical trials in patients with AIDS for the induction or maintenance treatment of CMV retinitis, or in liver, kidney or heart transplant patients for the prophylaxis of CMV disease . The term (severe) in parenthesis in the table indicates that the adverse reaction has been reported in patients at both mild/moderate intensity and severe/life-threatening intensity at that specific frequency.The overall safety profile of Valcyte did not change with the extension of prophylaxis up to 200 days in adult kidney transplant patients at high risk of CMV disease (D+/R-). Leucopenia was reported with a slightly higher incidence in the 200 days arm while the incidence of neutropenia, anaemia and thrombocytopenia were similar in both arms.
b Tabulated list of adverse reactionsWithin each frequency grouping, undesirable effects are presented in order of decreasing seriousness.
|Body System||Very Common (≥1/10)||Common (≥1/100 to <1/10)||Uncommon(≥1/1000 to < 1/100)||Rare(≥1/10,000 to < 1/1000)|
|Infections and infestations||Oral candidiasis, sepsis (bacteraemia, viraemia), cellulitis, urinary tract infection|
|Blood and lymphatic system disorders||(Severe) neutropenia, anaemia||Severe anaemia, (severe) thrombocytopenia, (severe) leucopenia, (severe) pancytopenia||Bone marrow failure||Aplastic anaemia|
|Immune system disorders||Anaphylactic reaction|
|Metabolic and nutrition disorders||Decreased appetite, anorexia|
|Psychiatric disorders||Depression, anxiety, confusion, abnormal thinking||Agitation, psychotic disorder, hallucination|
|Nervous system disorders||Headache, insomnia, dysgeusia, (taste disturbance), hypoaesthesia, paraesthesia, peripheral neuropathy, dizziness, convulsion||Tremor|
|Eye disorders||Macular oedema, retinal detachment, vitreous floaters, eye pain||Visual disturbance, conjunctivitis|
|Ear and labyrinth disorders||Ear pain||Deafness|
|Respiratory, thoracic and mediastinal disorders||Dyspnoea||Cough|
|Gastrointestinal disorders||Diarrhoea||Nausea, vomiting, abdominal pain, upper abdominal pain, dyspepsia, constipation, flatulence, dysphagia||Abdominal distension, mouth ulceration, pancreatitis|
|Hepatobiliary disorders||(Severe) hepatic function abnormal, blood alkaline phosphatase increased, aspartate aminotransferase increased||Alanine aminotransferase increased|
|Skin and subcutaneous disorders||Dermatitis, night sweats, pruritus||Alopecia, urticaria, dry skin|
|Musculoskeletal, connective tissue and bone disorders||Back pain, myalgia, arthralgia, muscle spasms|
|Renal and urinary disorder||Creatinine clearance renal decreased, renal impairment||Haematuria, renal failure|
|Reproductive system and breast disorders||Male infertility|
|General disorders and administration site conditions||Fatigue, pyrexia, chills, pain, chest pain, malaise, asthenia|
|Investigations||Weight decreased, blood creatinine increased|
Reporting of suspected adverse reactionsReporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme website: www.mhra.gov.uk/yellowcard.
Overdose experience with ValganciclovirOne 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 degree of renal impairment (decreased creatinine clearance).It is expected that an overdose of valganciclovir could also possibly result in increased renal toxicity (see sections 4.2 and 4.4).Haemodialysis and hydration may be of benefit in reducing blood plasma levels in patients who receive an overdose of valganciclovir (see section 5.2).
Overdose experience with intravenous ganciclovirReports of overdoses with intravenous ganciclovir have been received from clinical trials and during post-marketing experience. In some of these cases no adverse events were reported. The majority of patients experienced one or more of the following adverse events:- Haematological toxicity: pancytopenia, bone marrow depression, medullary aplasia, leucopenia, neutropenia, granulocytopenia.- Hepatotoxicity: hepatitis, liver function disorder.- Renal toxicity: worsening of haematuria in a patient with pre-existing renal impairment, acute renal failure, elevated creatinine.- Gastrointestinal toxicity: abdominal pain, diarrhoea, vomiting.- Neurotoxicity: generalised tremor, convulsion.
Mechanism of actionValganciclovir is an L-valyl ester (prodrug) of ganciclovir. After oral administration, valganciclovir is rapidly and extensively metabolised to ganciclovir by intestinal and hepatic esterases. Ganciclovir is a synthetic analogue of 2'-deoxyguanosine and inhibits replication of herpes viruses in vitro and in vivo. Sensitive human viruses include human cytomegalovirus (HCMV), herpes simplex virus-1 and -2 (HSV-1 and HSV-2), human herpes virus -6, -7 and -8 (HHV-6, HHV-7, HHV8), Epstein-Barr virus (EBV), varicella-zoster virus (VZV) and hepatitis B virus (HBV). 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 metabolised intracellularly. Triphosphate metabolism has been shown to occur in HSV- and HCMV- infected cells with half-lives of 18 and between 6 and 24 hours respectively, after the removal of extracellular ganciclovir. 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 viral DNA synthesis by: (a) competitive inhibition of incorporation of deoxyguanosine-triphosphate into DNA by viral DNA polymerase, and (b) incorporation of ganciclovir triphosphate into viral DNA causing termination of, or very limited, further viral DNA elongation.
Antiviral activityThe in-vitro anti-viral activity, measured as IC50 of ganciclovir against CMV, is in the range of 0.08 μM (0.02 μg/ml) to 14 μM (3.5 μg/ml).The clinical antiviral effect of Valcyte has been demonstrated in the treatment of AIDS patients with newly diagnosed CMV retinitis. CMV shedding was decreased in urine from 46 % (32/69) of patients at study entry to 7 % (4/55) of patients following four weeks of Valcyte treatment.
Clinical efficacy and safety
Treatment of CMV retinitis:Patients with newly diagnosed CMV retinitis were randomised in one study to induction therapy with either Valcyte 900 mg b.i.d or intravenous ganciclovir 5 mg/kg b.i.d. The proportion of patients with photographic progression of CMV retinitis at week 4 was comparable in both treatment groups, 7/70 and 7/71 patients progressing in the intravenous ganciclovir and valganciclovir arms respectively.Following induction treatment dosing, all patients in this study received maintenance treatment with Valcyte given at the dose of 900 mg once daily. The mean (median) time from randomisation to progression of CMV retinitis in the group receiving induction and maintenance treatment with Valcyte was 226 (160) days and in the group receiving induction treatment with intravenous ganciclovir and maintenance treatment with Valcyte was 219 (125) days.
Prevention of CMV disease in transplantation:A double-blind, double-dummy, clinical active comparator study has been conducted in heart, liver and kidney transplant patients (lung and gastro-intestinal transplant patients were not included in the study) at high-risk of CMV disease (D+/R-) who received either Valcyte (900 mg od) or oral ganciclovir (1000 mg t.i.d.) starting within 10 days of transplantation until Day 100 post-transplant. The incidence of CMV disease (CMV syndrome + tissue invasive disease) during the first 6 months post-transplant was 12.1 % in the Valcyte arm (n=239) compared with 15.2 % in the oral ganciclovir arm (n=125). The large majority of cases occurred following cessation of prophylaxis (post-Day 100) with cases in the valganciclovir arm occurring on average later than those in the oral ganciclovir arm. The incidence of acute rejection in the first 6 months was 29.7 % in patients randomised to valganciclovir compared with 36.0 % in the oral ganciclovir arm, with the incidence of graft loss being equivalent, occurring in 0.8 % of patients, in each arm. A double-blind, placebo controlled study has been conducted in 326 kidney transplant patients at high risk of 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 od) within 10 days of transplantation either until Day 200 post-transplant or until Day 100 post-transplant followed by 100 days of placebo.The proportion of patients who developed CMV disease during the first 12 months post-transplant is shown in the table below.Percentage of Kidney Transplant Patients with CMV Disease1, 12 Month ITT Population A
|Valganciclovir 900 mg od100 Days (N = 163)||Valganciclovir 900 mg od200 Days(N = 155)||Between Treatment Group Difference|
|Patients with confirmed or assumed CMV disease2||71 (43.6%) [35.8% ; 51.5%]||36 (23.2%) [16.8% ; 30.7%]||20.3% [9.9% ; 30.8%]|
|Patients with confirmed CMV disease||60 (36.8%) [29.4% ; 44.7%]||25 (16.1%) [10.7% ; 22.9%]||20.7% [10.9% ; 30.4%]|
Viral resistanceVirus resistant to ganciclovir can arise after chronic dosing with valganciclovir by selection of mutations in the viral kinase gene (UL97) responsible for ganciclovir monophosphorylation and/or the viral polymerase gene (UL54). In clinical isolates, seven canonical UL97 substitutions, M460V/I, H520Q, C592G, A594V, L595S, C603W are the most frequently reported ganciclovir resistance-associated substitutions. Viruses containing mutations in the UL97 gene are resistant to ganciclovir alone, whereas viruses with mutations in the UL54 gene are resistant to ganciclovir but may show cross-resistance to other antivirals that also target the viral polymerase.
Treatment of CMV retinitis:Genotypic analysis of CMV in polymorphonuclear leucocytes (PMNL) isolates from 148 patients with CMV retinitis enrolled in one clinical study has shown that 2.2 %, 6.5 %, 12.8 %, and 15.3 % contain UL97 mutations after 3, 6, 12 and 18 months, respectively, of valganciclovir treatment.
Prevention of CMV disease in transplantation:
Active comparator studyResistance was studied by genotypic analysis of CMV in PMNL samples collected i) on Day 100 (end of study drug prophylaxis) and ii) in cases of suspected CMV disease up to 6 months after transplantation. From the 245 patients randomised to receive valganciclovir, 198 Day 100 samples were available for testing and no ganciclovir resistance mutations were observed. This compares with 2 ganciclovir resistance mutations detected in the 103 samples tested (1.9 %) for patients in the oral ganciclovir comparator arm.Of the 245 patients randomised to receive valganciclovir, samples from 50 patients with suspected CMV disease were tested and no resistance mutations were observed. Of the 127 patients randomised on the ganciclovir comparator arm, samples from 29 patients with suspected CMV disease were tested, from which two resistance mutations were observed, giving an incidence of resistance of 6.9 %.
Extending prophylaxis study from 100 to 200 days post-transplantGenotypic analysis was performed on the UL54 and UL97 genes derived from virus extracted from 72 patients who met the resistance analysis criteria: patients who experienced a positive viral load (> 600 copies/ml) at the end of prophylaxis and/or patients who had confirmed CMV disease up to 12 months (52 weeks) post-transplant. Three patients in each treatment group had a known ganciclovir resistance mutation.
Treatment of CMV retinitis:The European Medicines Agency has waived the obligation to perform studies with Valcyte in all subsets of the paediatric population in the treatment of infection due to CMV in immuno-compromised patients (see section 4.2 for information on paediatric use).Prevention of CMV disease in transplantationA phase II pharmacokinetic and safety study in paediatric solid organ transplant recipients (aged 4 months to 16 years, n = 63) receiving valganciclovir once daily for up to 100 days according to the paediatric dosing algorithm (see section 4.2) produced exposures similar to that in adults (see section 5.2). Follow up after treatment was 12 weeks. CMV D/R serology status at baseline was D+/R- in 40%, D+/R+ in 38%, D-/R+ in 19% and D-/R- in 3% of the cases. Presence of CMV virus was reported in 7 patients. The observed adverse drug reactions were of similar nature as those in adults (see section 4.8). A phase IV tolerability study in paediatric kidney transplant recipients (aged 1 to 16 years, n=57) receiving valganciclovir once daily for up to 200 days according to the dosing algorithm (see section 4.2) resulted in a low incidence of CMV. Follow up after treatment was 24 weeks. CMV D/R serology status at baseline was D+/R+ in 45%, D+/R- in 39%, D-/R+ in 7%, D-/R- in 7% and ND/R+ in 2% of the cases. CMV viremia was reported in 3 patients and a case of CMV syndrome was suspected in one patient but not confirmed by CMV PCR by the central laboratory. The observed adverse drug reactions were of similar nature to those in adults (see section 4.8).These data support the extrapolation of efficacy data from adults to children and provide posology recommendations for paediatric patients. A phase I pharmacokinetic and safety study in heart transplant patients (aged 3 weeks to 125 days, n=14) who received a single daily dose of valganciclovir according to the paediatric dosing algorithm (see section 4.2) on 2 consecutive days produced exposures similar to those in adults (see section 5.2). Follow up after treatment was 7 days. The safety profile was consistent with other paediatric and adult studies, although patient numbers and valganciclovir exposure were limited in this study.
Congenital CMVThe efficacy and safety of ganciclovir and/or valganciclovir was studied in neonates and infants with congenital symptomatic CMV infection in two studies.In the first study, the pharmacokinetics and safety of a single dose of valganciclovir (dose range 14-16-20 mg/kg/dose) was studied in 24 neonates (aged 8 to 34 days) with symptomatic congenital CMV disease (see section 5.2). The neonates received 6 weeks of antiviral treatment, whereas 19 of the 24 patients received up to 4 weeks of treatment with oral valganciclovir, in the remaining 2 weeks they received i.v. ganciclovir. The 5 remaining patients received i.v. ganciclovir for the most time of the study period. In the second study the efficacy and safety of six weeks versus six months of valganciclovir treatment was studied in 109 infants aged 2 to 30 days with symptomatic congenital CMV disease. All infants received oral valganciclovir at a dose of 16 mg/kg b.i.d. for 6 weeks. After 6 weeks of treatment the infants were randomized 1:1 to continue treatment with valganciclovir at the same dose or receive a matched placebo to complete 6 months of treatment.This treatment indication is not currently recommended for valganciclovir. The design of the studies and results obtained are too limited to allow appropriate efficacy and safety conclusions on valganciclovir.
AbsorptionValganciclovir is a prodrug of ganciclovir. It is well absorbed from the gastrointestinal tract and rapidly and extensively metabolised in the intestinal wall and liver to ganciclovir. Systemic exposure to valganciclovir is transient and low. The bioavailability of ganciclovir from oral dosing of valganciclovir is approximately 60 % across all the patient populations studied and the resultant exposure to ganciclovir is similar to that after its intravenous administration (please see below). For comparison, the bioavailability of ganciclovir after administration of 1000 mg oral ganciclovir (as capsules) is 6 - 8 %.Valganciclovir in HIV positive, CMV positive patients:Systemic exposure of HIV positive, CMV positive patients after twice daily administration of ganciclovir and valganciclovir for one week is:
|Parameter||Ganciclovir (5 mg/kg, i.v.) n = 18||Valganciclovir (900 mg, p.o.) n = 25|
|AUC(0 - 12 h) (μg.h/ml)||28.6 ± 9.0||32.8 ± 10.1||0.37 ± 0.22|
|Cmax (μg/ml)||10.4 ± 4.9||6.7 ± 2.1||0.18 ± 0.06|
Valganciclovir in solid organ transplant patients:Steady state systemic exposure of solid organ transplant patients to ganciclovir after daily oral administration of ganciclovir and valganciclovir is:
|Parameter||Ganciclovir (1000 mg t.i.d.) n = 82||Valganciclovir (900 mg, od) n = 161|
|AUC(0 - 24 h) (μg.h/ml)||28.0 ± 10.9||46.3 ± 15.2|
|Cmax (μg/ml)||1.4 ± 0.5||5.3 ± 1.5|
Distribution:Because of rapid conversion of valganciclovir to ganciclovir, protein binding of valganciclovir was not determined. Plasma protein binding of ganciclovir was 1 2 % over concentrations of 0.5 and 51 μg/ml. The steady state volume of distribution (Vd) of ganciclovir after intravenous administration was 0.680 ± 0.161 l/kg (n=114).
BiotransformationValganciclovir is rapidly and extensively metabolised to ganciclovir; no other metabolites have been detected. No metabolite of orally administered radiolabelled ganciclovir (1000 mg single dose) accounted for more than 1 2 % of the radioactivity recovered in the faeces or urine.
EliminationFollowing dosing with Valcyte, renal excretion, as ganciclovir, by glomerular filtration and active tubular secretion is the major route of elimination of valganciclovir. Renal clearance accounts for 81.5 % ± 22 % (n=70) of the systemic clearance of ganciclovir. Post-hoc Bayesian estimates for population mean apparent clearance of ganciclovir in patients with CrCl > 60 ml/min is 14.05 ± 4.13 l/h. In patients with renal impairment, the mean apparent clearance of ganciclovir is 8.46 ± 1.67 l/h (CrCl between 40 and 60 ml/min) and 7.00 ± 1.08 l/h (CrCl between 25 and 40 ml/min). The half-life of ganciclovir from valganciclovir is 4.1 ± 0.9 hours in HIV- and CMV-seropositive patients.
Pharmacokinetics in special clinical situations
Patients with renal impairmentDecreasing renal function resulted in decreased clearance of ganciclovir from valganciclovir with a corresponding increase in terminal half-life. Therefore, dosage adjustment is required for renally impaired patients (see sections 4.2 and 4.4).
Patients undergoing haemodialysisFor patients receiving haemodialysis dose recommendations for Valcyte 450 mg film-coated tablets cannot be given. This is because an individual dose of Valcyte required for these patients is less than the 450 mg tablet strength. Thus, Valcyte film-coated tablets should not be used in these patients (see sections 4.2 and 4.4).
Patients with hepatic impairmentThe safety and efficacy of Valcyte film-coated tablets have not been studied in patients with hepatic impairment. Hepatic impairment should not affect the pharmacokinetics of ganciclovir since it is excreted renally and, therefore, no specific dose recommendation is made.
Patients with cystic fibrosisIn a phase I pharmacokinetic study in lung transplant recipients with or without cystic fibrosis (CF), 31 patients (16 CF/15 non-CF) received post-transplant prophylaxis with 900 mg/day Valcyte. The study indicated that cystic fibrosis had no statistically significant influence on the overall average systemic exposure to ganciclovir in lung transplant recipients. Ganciclovir exposure in lung transplant recipients was comparable to that shown to be efficacious in the prevention of CMV disease in other solid organ transplant recipients.
Paediatric populationIn a phase II pharmacokinetic and safety study in paediatric solid organ transplant recipients (aged 4 months to 16 years, n = 63) valganciclovir was given once daily for up to 100 days. Pharmacokinetic parameters were similar across organ type and age range and comparable with adults. Population pharmacokinetic modeling suggested that bioavailability was approximately 60%. Clearance was positively influenced by both body surface area and renal function. In a phase I pharmacokinetic and safety study in paediatric heart transplant recipients (aged 3 weeks to 125 days, n = 14), valganciclovir was given once daily for two study days. Population pharmacokinetics estimated that mean bioavailability was 64%. A comparison of the results from these two studies and the pharmacokinetic results from the adult population shows that ranges of AUC 0-24h were very similar across all age groups, including adults. Mean values for AUC0-24h and Cmax were also similar across the paediatric age groups < 12 years old, although there was a trend of decreasing mean values for AUC0-24h and Cmax across the entire pediatric age range, which appeared to correlate with increasing age. This trend was more apparent for mean values of clearance and half-life (t1/2); however this is to be expected as clearance is influenced by changes in weight, height and renal function associated with patient growth, as indicated by population pharmacokinetic modelling. The following table summarizes the model-estimated AUC0-24h ranges for ganciclovir from these two studies, as well as mean and standard deviation values for AUC0-24h, Cmax, CL and t ½ for the relevant paediatric age groups compared to adult data:
|≥ 18 years(n=160)||< 4 months (n = 14)||4 months - ≤ 2 years (n=17)||> 2 - < 12 years(n=21)||≥ 12 years 16 years(n=25)|
|AUC0-24h (μg.h/ml)||46.3 ± 15.2||68.1 ± 19.8||64.3 ± 29.2||59.2 ± 15.1||50.3 ± 15.0|
|Range of AUC0-24h||15.4 116.1||34 - 124||34 - 152||36 - 108||22 - 93|
|Cmax (μg/ml)||5.3 ± 1.5||10.5 ± 3.36||10.3 ± 3.3||9.4 ± 2.7||8.0 ± 2.4|
|Clearance (l/h)||12.7 ± 4.5||1.25 ± 0.473||2.5 ± 2.4||4.5 ± 2.9||6.4 ± 2.9|
|t1/2 (h)||6.5 ± 1.4||1.97 ± 0.185||3.1 ±1.4||4.1 ± 1.3||5.5 ± 1.1|
|PK Parameter||Adults||Paediatrics (neonates and infants)|
|5 mg/kg GANSingle dose(n=8)||6 mg/kg GANTwice daily (n=19)||16 mg/kg VALTwice daily(n=19)||16 mg/kg VALTwice daily(n = 100)|
|AUC0-∞ (μg.h/mL)||25.4 ± 4.32||-||-||-|
|AUC0-12h (μg.h/mL)||-||38.2 ± 42.7||30.1 ± 15.1||20.85 ± 5.40|
|Cmax (μg/ml)||9.03 ± 1.26||12.9 ± 21.5||5.44 ± 4. 04||-|
|t1/2 (h)||3.32 ± 0.47||2.52 ± 0. 55||2.98 ± 1. 26||2.98 ± 1.12|
|Tablet core||Tablet film-coat|
|Povidone K30||Opadry Pink 15B24005 containing:|
|Microcrystalline cellulose||Titanium dioxide (E171)|
|Stearic acid||Macrogol 400 Red iron oxide (E172) Polysorbate 80|
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