(((((((((((OPTIMER'S HAS A SIGNIFICANTLY HIGHER CURE RATE))))))))
Clinical Infectious Diseases Publishes Subgroup Analysis Showing Optimer's DIFICID™ (fidaxomicin) Tablets Exhibited Higher Clinical Cure and Global Cure Rates Than Vancomycin in Patients with Clostridium difficile-Associated Diarrhea (CDAD) Receiving Concomitant Antibiotics
SAN DIEGO, Aug. 16, 2011 /PRNewswire/ -- Optimer Pharmaceuticals, Inc. (NASDAQ: OPTR) announced today that a subgroup analysis of patients receiving concomitant systemic antibiotics in two Phase 3 clinical trials exploring the use of DIFICID™ (fidaxomicin) tablets in the treatment of adult patients with Clostridium difficile-associated diarrhea (CDAD) was published online in the September 1 issue of Clinical Infectious Diseases (CID). The analysis found that in the presence of concomitant systemic antibiotic therapy, which is the use of antibiotics to treat concurrent infections, DIFICID achieved a significantly higher initial clinical cure rate, and higher rate of global cure, compared to oral vancomycin. In the article, approximately 28% of patients in the Phase 3 clinical trials required antibiotic treatment for concurrent infections, primarily lung and urinary tract, and these treatments had an adverse impact on the efficacy of both CDAD therapies.
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Patients with CDAD who received DIFICID while taking concomitant antibiotics demonstrated a significantly higher clinical cure rate of CDAD than patients who received oral vancomycin and concomitant antibiotics (90.0% clinical cure rate vs. 79.4%, respectively; p=0.04).Regardless of concomitant antibiotic use, DIFICID was also statistically superior to oral vancomycin in global cure rate. Global cure is defined as clinical cure with no recurrence through the end of study visit 26 to 30 days after completion of CDAD treatment.
"To date, there has been little research demonstrating the impact of concomitant antibiotic use in patients being treated for CDAD," said Dr. Kathleen Mullane, Associate Professor of Medicine at The University of Chicago Department of Medicine and an author on the study. "Results from this subgroup analysis show that more than one in four patients with CDAD were also taking concomitant antibiotics for other infections and that concomitant antibiotic therapy can significantly compromise CDAD treatment. The results also suggest that DIFICID may help blunt the effect of concomitant antibiotics on response to CDAD treatment and that continued investigation of the impact of concomitant antibiotic use in this patient population is warranted."
Effect of Concomitant Antibiotic Use on Clinical Outcomes
Among patients analyzed in the study, the use of concomitant antibiotics compromised response to CDAD therapy. For the combined DIFICID and vancomycin treatment groups, CDAD patients who received concomitant antibiotics had clinical cure rates of 84.4%, compared to cure rates of 92.6% among patients who did not (p<0.001), and experienced a median extended time to resolution of diarrhea of 97 hours compared to 54 hours in patients who did not receive additional antibiotics (p<0.001). Global cure was observed in 74.7% of patients who did not receive concomitant antibiotics compared to 65.8% of patients receiving concomitants antibiotics at any time during the study (p= 0.005). Use of concomitant antibiotics tended to increase the rate of recurrence but did not reach significance.
Effect of DIFICID vs. Vancomycin with Concomitant Antibiotics
In the absence of concomitant antibiotic use, DIFICID and vancomycin were similar in achievement of clinical cure by the end of treatment (92.3% vs. 92.8%; p= 0.80). However, when patients received one or more antibiotics concurrently with study drug, DIFICID was superior to vancomycin in achieving clinical cure (90.0% vs. 79.4% p = 0.04). When patients received no additional antibiotics at any time during the study, the global cure rate was 80.8% for DIFICID patients and 69.1% for vancomycin patients(p < 0.001). Global cure rates were substantially reduced in both treatment groups when patients received concomitant antibiotics at any time, but 72.7% of DIFICID patients achieved global cure compared to 59.4% for vancomycin (p = 0.02). Concomitant antibiotic use was associated with higher recurrence rates in both the DIFICID and oral vancomycin treatment groups. However, recurrence was consistently less frequent following DIFICID treatment whether patients received concomitant antibiotics or not. In patients receiving concomitant antibiotics at any time during treatment or follow-up, treatment with DIFICID was associated with a recurrence rate of 16.9% compared to 29.2% with oral vancomycin (p=0.048).
"Medical guidelines recommend discontinuation of concomitant antibiotics at the diagnosis of CDAD if possible. However, that may not always be practical because patients need the antibiotics for serious concurrent infections," said Dr. Sherwood Gorbach, Chief Scientific Officer at Optimer and an author on the study. "To the extent treatments for CDAD can help mitigate the adverse impact of concomitant antibiotics on response to treatment, they would offer a much needed treatment option for this patient population."