I have read a similar article before. It was about Fidaxomicin and CDAD too. But today this newer one describes more exactly. This article compares fidaxomicin to vancomycin in aspects of cure rate in terms of initial clinical cure, recurrence, and sustained response. According to this article fidaxomicin appears to be better than vancomycin in treating Clostridium difficile-associated diarrhea (CDAD). However, vancomycin also can treat CDAD effiaciously, according to the data shown in these studies.

According to the North American study, clinical cure rate of fidaxomicin was 87.7% and that of vancomycin was 86.8%. From this point both fidaxomicin and vancomycin are able to treat CDAD satisfactorily. However, differ between the two drugs does exist. The incidence of recurrence with vancomycin over fidaxomicin were 26.9% vs 12.7%. And the sustained response rates of fidaxomicin over vancomycin were 76.6% vs 63.4%. Thus from these two aspects fidaxomicin appears to be better than vancomycin.

I want to emphasize that we should compare these two drugs in the specific group population – the cancer survivors. According to the studies, those with cancers treated with fidaxomicin had significantly higher clinical cure and sustained clinical cure rates and significantly lower rates of recurrence than patients treated with vancomycin.

One more thing is that the price of these two drug is not considered in this article. I check the price of fidaxomicin and vancomycin. The dosage of fidaxomicin is 200 mg po Bid, that of vancomycin is 125 mg po Qid. The cheapest vancomycin capsule’s unit price is $27.78 (per 125 mg/capsule, Vancocin-VIROPHARMA INCO), and that of fidaxomicin tablet is $135 (per 200 mg/tablet). So a 10-day course we need $2700 for fidaxomicin vs $1111.2 for vancomycin. From this perspective I think we should use vancomycin to treat CDAD first, fidaxomicin should be the alternative. However considering the lower recurrence rate and higher sustained response rate, the fidaxomicin regimen’s cost may be less than vancomycin’s.

References

  1. Becky McCall. Fidaxomicin Beats Vancomycin for C difficile in Cancer. Medscape News. 22nd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID). 2012 Apr 3. Poster 2289 and abstract O670.
  2. Jason W. Lancaster, PharmD, BCPS. Economic Impact of Fidaxomicin on CDI Treatment in United States. The American Journal of Pharmacy Benefits. 2012 May; 4: 114-117.

April 4, 2012 (London, United Kingdom) — Fidaxomicin (Dificid, Optimer Pharmaceuticals) treatment was superior to vancomycin for initial cure, recurrence, and sustained response, according to a subanalysis of patients with cancer and Clostridium difficile–associated diarrhea (CDAD).

In addition, concomitant antibiotics had less effect on clinical cure rate with fidaxomicin than with vancomycin, according to data from a phase 3 clinical trial conducted in Europe and North America. Both studies were presented here at the 22nd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID).

Oliver A. Cornely, MD, oncologist/hematologist and infectious diseases physician from the University Hospital Cologne in Germany, led the European/North American phase 3 study (OPT-80-004). He presented the results of a subanalysis of data from both studies.

The European/North American multicenter, randomized, controlled, double-blind, noninferiority study was published in February (Lancet Infect Dis. 2012;12:281-289). An earlier phase 3 study of fidaxomicin conducted in the United States and Canada was published last year (N Engl J Med. 2011;364:422-431).

The subanalysis of cancer patients with CDAD was presented here at ECCMID for the first time.

Fidaxomicin is a novel macrocyclic antibiotic with a narrow spectrum of activity against Gram-positive bacteria and minimal activity against normal gut flora. “Fidaxomicin is not absorbed, which makes it like a magic bullet because it stays where it is needed in extremely high concentrations,” Dr. Cornely told Medscape Medical News.

Further to the North American study, results of the second phase 3 trial in 509 patients from Europe and North America also demonstrated that clinical cure for fidaxomicin was noninferior to vancomycin in the modified intent-to-treat population (87.7% vs 86.8%).

Dr. Cornely emphasized the recurrence rates with fidaxomicin. “This is the first point at which we see a difference in the 2 antibiotics, and it is a large difference,” he said. “We see double the incidence of recurrence with vancomycin over fidaxomicin [26.9% vs 12.7%; difference, 14.2%; 95% confidence interval [CI], –21.4% to –6.8%; P < .001]. It cuts the recurrence rate in half. A high recurrence rate is expected with vancomycin in a very sick population, but this is still an extreme.”

These findings were also reflected in the sustained response rates, which showed fidaxomicin was superior to vancomycin (76.6% vs 63.4%; difference, 13.2%; 95% CI, 5.2% to 20.9%; P = .001).

Cancer Patients a Special Population

The subanalysis in cancer patients was drawn from data derived from the 2 phase 3 trials. “Patients with cancer are a population of special interest because of their lower response rates, and they are very prone to recurrent disease,” Dr. Cornely told Medscape Medical News. (more…)