New indication for Valcyte -- prevention of CMV in high-risk kidney, kidney-pancreas, heart transplant patients
NUTLEY, N.J., September 15, 2003 -- The FDA has approved Valcyte (valganciclovir HCl tablets) for the prevention of cytomegalovirus (CMV) disease in high-risk kidney, kidney- pancreas and heart transplant patients, adding another indication to Valcyte's original approval in March 2001 for the treatment of CMV retinitis in AIDS patients. Valcyte is not indicated for use in liver transplant patients.
Valcyte is the oral pro-drug of Roche's Cytovene (ganciclovir), which has been the most widely prescribed anti-CMV medication in the world. Valcyte delivers the same active drug ingredient as Cytovene oral with up to 10 times greater bioavailability than Cytovene. Valcyte also offers the benefit of once-daily dosing, giving immunocompromised patients who often take multiple medications enhanced convenience in treatment.
"CMV disease is one of the most serious infections that can occur after a transplant because it can lead to loss of the transplanted organ and even death," said Richard B. Freeman, Jr., M.D., from the Division of Transplant Surgery at the New England Medical Center, Tufts University School of Medicine. "Valcyte offers higher levels of ganciclovir with once daily dosing, which simplifies the CMV prevention regimen for high-risk kidney, kidney-pancreas and heart transplant patients."
It is estimated that between 50-80 percent of people worldwide have CMV in a latent form. When the immune system is suppressed -- as with transplant patients who are taking immunosuppressive drugs -- the virus can activate, replicate, and lead to disease. CMV can result in opportunistic infections such as pneumonia, hepatitis and a variety of GI conditions. It has been associated with acute and chronic rejection of transplanted organs, as well as atherosclerosis in heart transplant recipients. Studies have also shown that CMV has been correlated with an increased risk of mortality post-transplant.
The 6-month, double-blind, double-dummy, active comparator trial of Valcyte versus Cytovene (oral ganciclovir) involved 364 heart, liver, kidney and kidney-pancreas patients at high-risk for CMV disease (donors were seropositive for CMV; recipients did not have antibodies to CMV). The goal of the study was to compare the efficacy and safety of Valcyte to Cytovene in preventing CMV disease; the study was designed and powered to compare efficacy and safety, and was intended to demonstrate comparability (not superiority) of Valcyte to Cytovene.
The study showed that the proportion of patients who developed CMV disease (CMV syndrome or tissue invasive disease) during the first 6 months post transplant was 12.1% in patients treated with Valcyte compared to 15.2% in Cytovene-treated patients. However, in liver transplant patients the incidence of tissue-invasive CMV disease was significantly higher in the Valcyte group compared to the Cytovene group. The CMV viral load was significantly lower in the Valcyte group while on therapy, but the measurable viral load was comparable in both treatment groups (49% on Valcyte vs. 50% on Cytovene) by 6 months. A greater incidence of neutropenia was observed in Valcyte-treated patients and a greater incidence of anemia in Cytovene-treated patients; however, these differences were not statistically significant.
Adult patients were grouped by organ type and then randomized in a 2 to 1 ratio to Valcyte 900 mg once a day or Cytovene 1000 mg three times a day. Therapy started within ten days post transplant and continued through day 100 with regular follow-up to twelve months.
Valcyte is the pro-drug of Cytovene, which has been the most widely prescribed anti-CMV medication worldwide. A pro-drug is an inactive form of a drug that is converted into its active form in the body by normal metabolic processes. Valcyte delivers the same active drug ingredient as Cytovene oral with up to 10 times greater bioavailability.
The clinical toxicity of Valcyte, which is metabolized to ganciclovir, includes granulocytopenia, anemia and thrombocytopenia. In animal studies, ganciclovir was carcinogenic, teratogenic and cause aspermatogenesis. Valcyte should not be administered if the absolute neutrophil count is less than 500 cells/microliter, the platelet count is less than 25,000/microliter or the hemoglobin is less than 8 g/dL. Didanosine blood levels can be significantly increased when didanosine is taken with Valcyte. Cytopenias may be exacerbated by zidovudine. Other side effects occurring with a frequency of greater than or equal to 5% include diarrhea, tremors, nausea, headache, insomnia, hypertension, vomiting, leukopenia and pyrexia.
Source: Roche www.rocheusa.com
Posted: September 2003