New Treatment for C. difficile in Children Granted FDA Approval

Officials with the FDA have approved a New Drug Application for fidaxomicin (Dificid, Merck) for oral suspension and a supplemental New Drug Application for fidaxomicin tablets for the treatment of Clostridioides difficle-associated diarrhea (CDAD) in children aged 6 months and older.

Fidaxomicin is a macrolide antibacterial medicine indicated to be used to treat infections that are proven or strongly suspected to be caused by C. difficile. In addition, fidaxomicin is contraindicated in patients who have known hypersensitivity to fidaxomicin or any other ingredient in fidaxomicin.

The approval of fidaxomicin is based on a phase 3, randomized parallel group study called the SUNSHINE study, where the safety and efficacy were evaluated in patients from ages 6 months to less than 18 years old. One hundred and forty-eight randomized patients with confirmed C. difficile infection were evaluated; 142 of these patients received either fidaxomicin (suspension or tablets, twice daily) or vancomycin (suspension or tablets, 4 times daily).

The CDAD clinical response in overall pediatric population was similar between the fidaxomicin and vancomycin groups, assessed through 2 days following 10 days of treatment. The proportion of treated patients with confirmed clinical response and no CDAD recurrence through 30 days after the end of treatment was higher for fidaxomicin than for vancomycin.

The safety of fidaxomicin was further evaluated in a Phase 2, single-arm trial of 38 patients and a Phase 3, active-controlled trial of 98 patients treated with fidaxomicin and 44 patients treated with vancomycin. Treatment discontinuation due to adverse reactions occurred in 7.9% of patients in the Phase 2 trial, and in 1% and 2.3% of fidaxomicin- and vancomycin- treated patients in the Phase 3 trial.

The most common adverse reactions in pediatric patients treated with fidaxomicin in the Phase 3 trial were pyrexia, abdominal pain, vomiting, diarrhea, constipation, increased aminotransferases, and rash.

REFERENCE

FDA approves Merck’s DIFICID (fidaxomicin) to treat clostridioides difficile in children aged 6 months and older [news release]. Kenilworth, NJ; BusinessWire: January 27, 2020. https://www.businesswire.com/news/home/20200127005296/en/FDA-Approves-Merck%E2%80%99s-DIFICID%C2%AE-fidaxomicin-Treat-Clostridioides. Accessed January 27, 2020.