Meningitis, Cryptococcal clinical trials

Amphotericin B for Non-HIV Cryptococcal Meningitis Patients

Cryptococcus neoformans and C. gatti are important causes of central nervous system (CNS) infections with significant mortality, remaining a great public health challenge worldwide. Commonly seen as an opportunistic infection in adults with HIV/AIDS, cryptococcal meningitis (CM) accounts for 15% of HIV-related mortality globally [1]. In addition, a growing number of non-HIV CM patients have been observed in recent years with fatality approaching 30% in some areas [2,3]. It occurs in both those with natural or iatrogenic immunosuppression, as well as the apparently immunocompetent individuals. Approximately 65-70% of non-HIV CM patients were without any predisposing factors, particularly in the East Asia [4,5]. With the increasing number of hematopoietic stem cell transplantation, solid organ transplantation recipients and administration of immunosuppressive and corticosteroids agents, this illness will assume even greater public health significance. Current Infectious Disease Society of America (IDSA) guideline suggest the use of combination antifungal therapy: normal dose amphotericin (0.7-1mg/kg/day) combined with flucytosine for a minimum of 4 weeks, followed by fluconazole (600-800 mg/day) for a minimum of 10 weeks in total for HIV patients [6]. However, for non-HIV and immunocompetent patients, the treatment remains controversial. IDSA guideline recommended that the treatment of non-HIV patients could refer to the treatment of HIV patients. That is, amphotericin B combined with flucytosine is still administered in the induction period. However, as amphotericin B have nonspecific effect on ergosterol, it has strong side effects (hepatorenal toxicity, electrolyte disorder, anemia, ventricular fibrillation, etc.). Therefore, the dose of amphotericin B may not be appropriate for Asian patients due to the different drug metabolism and pharmacokinetic. In the prospective studies of Bennett[7] and Dismuke[8], low dose amphotericin B (0.3 mg/kg/d) combined with flucytosine achieved response rates of 66% and 85% at 6 weeks, respectively. A similar conclusion was also extracted from a large multicenter retrospective study that low dose amphotericin B (<0.7 mg/kg/d) combined with flucytosine for a minimum of 2 weeks, followed by fluconazole could achieve a response rate of 84%, indicating that the efficacy of low dose amphotericin B (< 0.7 mg/kg/d) may be equivalent with normal dose in non-HIV patients. Therefore, we plan to conduct a prospective, multicenter, open-label randomized controlled study to compare the efficacy and safety of normal dose amphotericin B (0.7 mg/kg/ d) and low dose amphotericin B (0.5 mg/kg/d) in the initial antifungal treatment for non-HIV cryptococcal meningitis patients.