Fidaxomicin Reduced C. difficile Recurrence Rate by 45%

SAN FRANCISCO — Patients with Clostridium difficile infection who were treated with the novel macrocylic antibiotic fidaxomicin had a 45% lower rate of recurrence, compared with those who received vancomycin.

“It's encouraging because fidaxomicin is an easier drug to take compared with the current therapies,” Dr. Yoav Golan said in an interview during a poster session at the annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy. “It's only twice a day dosing versus three and four times a day for metronidazole and vancomycin. Also, it seems to have a much smaller impact on emergence of resistance among gut pathogens.”

The analysis involved 432 patients in a multicenter, randomized trial to compare fidaxomicin, 200 mg every 12 hours, with vancomycin, 125 mg every 6 hours for 10 days, in patients with C. difficile. The mean age of patients was 62 years.

Fidaxomicin (Dificid), a minimally absorbed, narrow spectrum antibiotic with limited impact on gut flora, was developed by Optimer Pharmaceuticals, which sponsored the trial. Dr. Golan disclosed that his relationship with Optimer is limited to functioning as an investigator in the fidaxomicin clinical trials. Pamela Sears, Ph.D., executive director of biology and preclinical trials at Optimer, expects the company to file for new drug approval with the Food and Drug Administration by early 2011.

Overall, recurrence of diarrhea and positive toxin within 4 weeks after the end of therapy occurred in 19% of patients. The rate was significantly lower among the 211 patients in the fidaxomicin group (13%) than among the 221 patients in the vancomycin group (24%). This represented a relative reduction of 45% with fidaxomicin, compared with vancomycin.

Recurrence rates were highest in patients aged 75 years and older (31%) and in those aged 65–74 years (18%), and in those who were hospitalized (22% vs. 15% in outpatients).

Of the 81 patients with recurrent C. difficile, recurrence developed later in patients who took fidaxomicin. For example, 25% of patients in the fidaxomicin group had recurrence within 10 days after initial treatment completion vs. 57% of patients in the vancomycin group, while 36% of patients in the fidaxomicin group developed recurrence within 21–30 days after initial treatment vs. 15% of patients in the vancomycin group.

The recurrence rate was significantly lower for patients in the fidaxomicin group who had not received any C. difficile infection-active antibiotics 24 hours prior to study enrollment (11%, compared with a rate of 24% for their counterparts in the vancomycin group). This finding suggests the potential for a high clinical benefit for fidaxomicin when used as a first-line therapy, said Dr. Golan, assistant professor of medicine at Tufts Medical Center, Boston.

“The future for treating C. diff. is [to use] very narrow spectrum antibiotics, compared to the very broad spectrum antibiotics we've been using,” he concluded.

'It's encouraging because fidaxomicin is an easier drug to take compared with the current therapies.'

Source DR. GOLAN

SAN FRANCISCO — Patients with Clostridium difficile infection who were treated with the novel macrocylic antibiotic fidaxomicin had a 45% lower rate of recurrence, compared with those who received vancomycin.

“It's encouraging because fidaxomicin is an easier drug to take compared with the current therapies,” Dr. Yoav Golan said in an interview during a poster session at the annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy. “It's only twice a day dosing versus three and four times a day for metronidazole and vancomycin. Also, it seems to have a much smaller impact on emergence of resistance among gut pathogens.”

The analysis involved 432 patients in a multicenter, randomized trial to compare fidaxomicin, 200 mg every 12 hours, with vancomycin, 125 mg every 6 hours for 10 days, in patients with C. difficile. The mean age of patients was 62 years.

Fidaxomicin (Dificid), a minimally absorbed, narrow spectrum antibiotic with limited impact on gut flora, was developed by Optimer Pharmaceuticals, which sponsored the trial. Dr. Golan disclosed that his relationship with Optimer is limited to functioning as an investigator in the fidaxomicin clinical trials. Pamela Sears, Ph.D., executive director of biology and preclinical trials at Optimer, expects the company to file for new drug approval with the Food and Drug Administration by early 2011.

Overall, recurrence of diarrhea and positive toxin within 4 weeks after the end of therapy occurred in 19% of patients. The rate was significantly lower among the 211 patients in the fidaxomicin group (13%) than among the 221 patients in the vancomycin group (24%). This represented a relative reduction of 45% with fidaxomicin, compared with vancomycin.

Recurrence rates were highest in patients aged 75 years and older (31%) and in those aged 65–74 years (18%), and in those who were hospitalized (22% vs. 15% in outpatients).

Of the 81 patients with recurrent C. difficile, recurrence developed later in patients who took fidaxomicin. For example, 25% of patients in the fidaxomicin group had recurrence within 10 days after initial treatment completion vs. 57% of patients in the vancomycin group, while 36% of patients in the fidaxomicin group developed recurrence within 21–30 days after initial treatment vs. 15% of patients in the vancomycin group.

The recurrence rate was significantly lower for patients in the fidaxomicin group who had not received any C. difficile infection-active antibiotics 24 hours prior to study enrollment (11%, compared with a rate of 24% for their counterparts in the vancomycin group). This finding suggests the potential for a high clinical benefit for fidaxomicin when used as a first-line therapy, said Dr. Golan, assistant professor of medicine at Tufts Medical Center, Boston.

“The future for treating C. diff. is [to use] very narrow spectrum antibiotics, compared to the very broad spectrum antibiotics we've been using,” he concluded.

'It's encouraging because fidaxomicin is an easier drug to take compared with the current therapies.'

Source DR. GOLAN

SAN FRANCISCO — Patients with Clostridium difficile infection who were treated with the novel macrocylic antibiotic fidaxomicin had a 45% lower rate of recurrence, compared with those who received vancomycin.

“It's encouraging because fidaxomicin is an easier drug to take compared with the current therapies,” Dr. Yoav Golan said in an interview during a poster session at the annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy. “It's only twice a day dosing versus three and four times a day for metronidazole and vancomycin. Also, it seems to have a much smaller impact on emergence of resistance among gut pathogens.”

The analysis involved 432 patients in a multicenter, randomized trial to compare fidaxomicin, 200 mg every 12 hours, with vancomycin, 125 mg every 6 hours for 10 days, in patients with C. difficile. The mean age of patients was 62 years.

Fidaxomicin (Dificid), a minimally absorbed, narrow spectrum antibiotic with limited impact on gut flora, was developed by Optimer Pharmaceuticals, which sponsored the trial. Dr. Golan disclosed that his relationship with Optimer is limited to functioning as an investigator in the fidaxomicin clinical trials. Pamela Sears, Ph.D., executive director of biology and preclinical trials at Optimer, expects the company to file for new drug approval with the Food and Drug Administration by early 2011.

Overall, recurrence of diarrhea and positive toxin within 4 weeks after the end of therapy occurred in 19% of patients. The rate was significantly lower among the 211 patients in the fidaxomicin group (13%) than among the 221 patients in the vancomycin group (24%). This represented a relative reduction of 45% with fidaxomicin, compared with vancomycin.

Recurrence rates were highest in patients aged 75 years and older (31%) and in those aged 65–74 years (18%), and in those who were hospitalized (22% vs. 15% in outpatients).

Of the 81 patients with recurrent C. difficile, recurrence developed later in patients who took fidaxomicin. For example, 25% of patients in the fidaxomicin group had recurrence within 10 days after initial treatment completion vs. 57% of patients in the vancomycin group, while 36% of patients in the fidaxomicin group developed recurrence within 21–30 days after initial treatment vs. 15% of patients in the vancomycin group.

The recurrence rate was significantly lower for patients in the fidaxomicin group who had not received any C. difficile infection-active antibiotics 24 hours prior to study enrollment (11%, compared with a rate of 24% for their counterparts in the vancomycin group). This finding suggests the potential for a high clinical benefit for fidaxomicin when used as a first-line therapy, said Dr. Golan, assistant professor of medicine at Tufts Medical Center, Boston.

“The future for treating C. diff. is [to use] very narrow spectrum antibiotics, compared to the very broad spectrum antibiotics we've been using,” he concluded.

'It's encouraging because fidaxomicin is an easier drug to take compared with the current therapies.'

Source DR. GOLAN