SAN DIEGO – The intravenous echinocandin anidulafungin effectively treated invasive candidiasis in a single-arm, multicenter, open-label trial of 47 children aged 2-17 years.
The overall global response rate of 72% resembled that from the prior adult registry study (76%), Emmanuel Roilides, MD, PhD, and his associates reported in a poster presented at an annual scientific meeting on infectious diseases.
At 6-week follow-up, two patients (4%) had relapsed, both with Candida parapsilosis, which was more resistant to treatment with anidulafungin (Eraxis) than other Candida species, the researchers reported. Treating the children with 3.0 mg/kg anidulafungin on day 1, followed by 1.5 mg/kg every 24 hours, yielded similar pharmacokinetics as the 200/100 mg regimen used in adults. The most common treatment-emergent adverse effects included diarrhea (23%), vomiting (23%), and fever (19%), which also reflected findings in adults, the investigators said. Five patients (10%) developed at least one severe treatment-emergent adverse event, including neutropenia, gastrointestinal hemorrhage, increased hepatic transaminases, hyponatremia, and myalgia. The study (NCT00761267) is ongoing and continues to recruit patients in 11 states in the United States and nine other countries, with final top-line results expected in 2019.
CDC/Dr. William Kaplan
Although rates of invasive candidiasis appear to be decreasing in children overall, the population at risk is expanding, experts have noted. Relevant guidelines from the Infectious Disease Society of America and the European Society of Clinical Microbiology and Infectious Diseases list amphotericin B, echinocandins, and azoles as treatment options, but these recommendations are extrapolated mainly from adult studies, noted Dr. Roilides, who is a pediatric infectious disease specialist at Aristotle University School of Health Sciences and Hippokration General Hospital in Thessaloniki, Greece.
To better characterize the safety and efficacy of anidulafungin in children, the researchers enrolled patients up to 17 years of age who had signs and symptoms of invasive candidiasis and Candida cultured from a normally sterile site. Patients received intravenous anidulafungin (3 mg/kg on day 1, followed by 1.5 mg/kg every 24 hours) for at least 10 days, after which they could switch to oral fluconazole. Treatment continued for at least 14 days after blood cultures were negative and signs and symptoms resolved.
At interim data cutoff in October 2016, patients were exposed to anidulafungin for a median of 11.5 days (range, 1-28 days). Among 47 patients who received at least one dose of anidulafungin, about two-thirds were male, about 70% were white, and the average age was 8 years (standard deviation, 4.7 years). Rates of global success – a combination of clinical and microbiological response – were 82% in patients up to 5 years old and 67% in older children. Children whose baseline neutrophil count was at least 500 per mm3 had a 78% global response rate versus 50% among those with more severe neutropenia. C. parapsilosis had higher minimum inhibitory concentrations than other Candida species, and in vitro susceptibility rates of 85% for C. parapsilosis versus 100% for other species.
All patients experienced at least one treatment-emergent adverse effect. In addition to diarrhea, vomiting, and pyrexia, adverse events affecting more than 10% of patients included epistaxis (17%), headache (15%), and abdominal pain (13%). Half of patients switched to oral fluconazole. Four patients stopped treatment because of vomiting, generalized pruritus, or increased transaminases. A total of 15% of patients died, although no deaths were considered treatment related. The patient who stopped treatment because of pruritus later died of septic shock secondary to invasive candidiasis, despite having started treatment with fluconazole and micafungin, the investigators reported at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
Nearly all patients had bloodstream infections, and catheters also cultured positive in more than two-thirds of cases, the researchers said. Many patients had multiple risk factors for infection such as central venous catheters, broad-spectrum antibiotic therapy, total parenteral nutrition, and chemotherapy. Cultures were most often positive for Candida albicans (38%), followed by C. parapsilosis (26%) and C. tropicalis (13%).
Pfizer makes anidulafungin and sponsored the study. Dr. Roilides disclosed research grants and advisory relationships with Pfizer, Astellas, Gilead, and Merck.