C. difficile treatment well-tolerated in children

PHILADELPHIA — Clostridium difficile-associated diarrhea treatment fidaxomicin was well-tolerated in a pediatric cohort, according to data presented at IDWeek 2014.

Researchers from Cubist Pharmaceuticals assessed the safety and efficacy of fidaxomicin (Dificid, Cubist) among 38 children, aged 11 months to 17 years, with diarrhea who tested positive for C. difficile. Study participants received 32 mg/kg of the drug per day for 10 days via tablet or oral suspension. Blood samples were collected and evaluated for drug concentration prior to treatment and at two points after treatment between days 5 and 10. Stool samples were collected on the last day of therapy. Most study participants had complex medical histories: 78.9% had gastrointestinal disorders and 23.7% had neoplasms.

Mean fidaxomicin concentration measured in blood samples ranged from 8.87 ng/mL to 16.6 ng/mL. One to 2 hours after dosage, metabolite OP-1118 ranged from 27.5 ng/mL to 130.0 ng/mL, with no age differences. Stool samples had a mean fidaxomicin concentration of 3,230 mcg/g; younger children tended to have higher fidaxomicin concentrations in their stool.

There was an overall clinical response rate of 92.1%. Nearly 29% of participants with a clinical response recurred, but the majority of these children had a history of recurrent C. difficile-associated diarrhea.

Steve Gilman

At least one adverse event occurred among 73.7% of study participants. Most adverse events were mild (44.7%) or moderate (21.1%) in severity and were expected in a cohort with moderate to severe underlying illness, according to researchers. Nine children had severe adverse events but none were associated with fidaxomicin.

“The safety and toleration profile of fidaxomicin looks very encouraging at this point. The study findings supports further evaluation of fidaxomicin in pediatric patients, so we are going to continue to study fidaxomicin in children and see if we can develop more data to help guide physicians who might want to treat children with the severe disease of C. difficile,” Steve Gilman, PhD, executive vice president and chief scientific officer of Cubist, told Infectious Diseases in Children. – by Amanda Oldt

For more information:

Sears P. Abstract LB-8. Presented at: IDWeek 2014; Oct. 8-12; Philadelphia.

Disclosure: The researchers report financial ties with Cubist.