Foscarnet for pre-emptive therapy of CMV infection detected by a leukocyte-based nested PCR in allogeneic bone marrow transplant patients.

Fifteen allogeneic BMT patients in a phase II study were given foscarnet 60 mg/kg twice daily for 14 days as pre-emptive therapy against CMV disease. CMV infection was diagnosed by a leukocyte-based nested PCR. All 15 patients were evaluable for toxicity. One patient did not fulfill the inclusion criteria of two consecutively positive CMV PCR tests and therefore was not evaluable for efficacy. Thus, 14 of 15 patients were evaluable for development of CMV disease. None of the patients developed CMV disease and all 14 assessable patients had a negative CMV isolation at the end of therapy. None of the 15 patients had to discontinue therapy due to toxicity. Six patients reported mild gastrointestinal disturbances, three patients headaches, and three patients mild urethritis or hemorrhagic cystitis. Serum-electrolyte disturbances were common including abnormal magnesium, potassium and calcium levels. Two patients developed mild serum-creatinine increases requiring adjustment of the foscarnet dosage according to protocol. We conclude that a dosage of foscarnet of 60 mg/kg given twice daily seems to be safe and effective in preventing CMV disease in allogeneic BMT recipients. A study comparing foscarnet and ganciclovir is indicated.