Ambisome and Management of Culture-negative Neutropenic Fever Unresponsive to Antibiotics

Administration of a single high dose (10 mg/kg) of AmBisome® no later than 72 hours after ARNF onset followed by two 5 mg/kg doses on days 2 and 5 may provide sustained tissue levels of amphotericin B that are as mycologically effective as those provided after administering the standard daily dose of 3 mg/kg/day. The new dosing regimen is anticipated to be equally clinically effective compared with the standard AmBisome® regimen when given for the duration of neutropenic fever in patients with ARNF. In addition, the degree and incidence of nephrotoxicity are predicted to be lower with the 3 sequential dose regimen compared to daily dosing with 3 mg/kg because of the lower cumulative dosage (20 mg/kg versus 42 mg/kg, respectively), which is 1 contributing factor for the development of acute renal failure. Furthermore, the lower cumulative dose may be a cost-effective strategy for the treatment of patients with ARNF.

This is a phase III, multicenter, randomized, open-label study. One center in the United Arab Emirates and 1 center in Turkey will participate in this trial and approximately 50 patients will be recruited. Patients will be adults with hematological malignancies undergoing chemotherapy for leukemia or lymphoma. These patients will be treated with AmBisome® until resolution of fever and neutropenia or for a maximum of 14 days. Patients will be randomized to receive AmBisome 10 mg/kg on treatment day 0 followed by 5 mg/kg on days 2 and 5 or AmBisome 3 mg/kg/day for 14 days. Study medication will be administered during the period of ARNF until resolution of fever and neutropenia and/or a minimum of 14 days. At the end of the 14-day trial period, each patient will be classified as having responded or not responded to the treatment according to the criteria for response given below. Patients will be examined daily for evidence of drug toxicity or intolerance and for the development of an IFI. Vital signs will be recorded every 6 hours if the patient is stable or more frequently if there is evidence of clinical deterioration. In the event of a clinical IFI (i.e., development of a halo sign or positive fungal blood cultures), the patient will be withdrawn from the study, classified as treatment failure, and receive antifungal treatment with either caspofungin or voriconazole. Daily clinical observations will ensure rapid detection of such an event in accordance with standard IDSA guidelines4. Patients who show clinical deterioration (i.e., increasing dyspnea, hypotension) but exhibit no definite evidence of an IFI may also be classified as treatment failures. Patients with evidence of biochemical and/or clinical drug toxicity will be withdrawn from the study and appropriate management will be given. For patients who remain febrile after 14 days but who are otherwise stable and have no discernable cause for the fever, continuation of treatment with AmBisome 3 mg/kg/day or treatment with another antifungal drug treatment, antibiotic, or discontinuation of antimicrobial therapy will be undertaken at the discretion of the investigator. Patients who meet these criteria will have a thorough diagnostic evaluation to investigate the cause of their fever.