SAN FRANCISCO, CA—Fidaxomicin was highly effective in patients with cancer treated for the first episode of C. difficile infection (CDI) after failure of standard therapy and in patients with recurrent CDI, as reported by Frank Tverdek, PharmD, from The University of Texas, MD Anderson Cancer Center, Houston, TX, at IDWeek 2013.

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C. difficile infection is a major concern among patients with cancer and can be associated with significant morbidity and mortality. New therapeutic options are needed for recurrent CDIs due to the challenge clinicians face treating these infections.

Dr. Tverdek and his colleagues studied the use of fidaxomicin in cancer patients with CDI after recent clinical trials demonstrated the superiority of fidaxomicin, an oral macrolide antibiotic, compared to oral vancomycin.  The pharmacy database identified 22 episodes of CDI treated with fidaxomicin between May 1, 2011 and January 31, 2013.

The most common underlying malignancies among patients were lymphoma in 9 patients (41%), leukemia in 7 patients (32%), and solid tumors in 6 patients (27%). Also, 9 patients (41%) had a prior stem cell transplant. 

Fidaxomicin was used for recurrent CDI in 16 patients (72%) and for failure of metronidazole in 10 patients (45%), and for failure of oral vancomycin in 15 patients (68%) for a mean duration of 13 days (range: 10–28 days). Most patients (n=19; 86%) were on concomitant antimicrobials during CDI treatment.

Clinical cure occurred in 91% and sustained clinical response occurred in 82% of patients with fidaxomicin. Only 2 patients with documented failures– one patient with severe colitis from both graft vs. host disease continued to have diarrhea and expired 9 days after completing fidaxomicin therapy, and one patient having recovered after successful treatment with oral vancomycin.

Recurrent CDI within 30 days of fidaxomicin therapy was seen in only 2 patients (9%) who had prior recurrences.  Overall fidaxomicin was well tolerated and there were no treatment discontinuations due to drug-related adverse events.

A high cure rate of CDI was shown in cancer patients with recurrent CDI or those treated for first episode of CDI after failure of standard therapy. Dr. Tverdek added, “This was remarkable given the high number of high-risk patients who continued to receive concomitant antimicrobial therapy, which is common in this immunocompromised patient population.” The team further reported that fidaxomicin was well tolerated and there were no discontinuations due to drug-related adverse events.