SAN DIEGO, May 17 /PRNewswire-FirstCall/ -- Optimer Pharmaceuticals, Inc. announced that the results from its North American Phase 3 clinical study of fidaxomicin in patients with Clostridium difficile infection (CDI) were presented today by clinical investigator Thomas J. Louie, M.D. for the first time in an oral presentation at the 19th annual European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Helsinki, Finland.
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Dr. Louie presented the positive top-line results that the Company had previously announced in November 2008. The trial met its primary endpoint with fidaxomicin achieving clinical cure compared to Vancocin(R). In addition, patients treated with fidaxomicin experienced a reduction in CDI recurrence compared to Vancocin (p=0.004) and had a higher global cure (cure with no recurrence within four weeks) compared to Vancocin (p=0.006).
"This study showed that fidaxomicin is as effective as vancomycin for treatment of C. Difficile diarrhea, including treatment of infection by the hyper virulent NAP1/ribotype 027 outbreak strain. Moreover, compared to vancomycin, recurrence of CDI is significantly less likely to occur following fidaxomicin therapy. Combining cure of CDI and freedom from recurrence, fidaxomicin is superior to vancomycin as treatment for this serious and common cause of infectious diarrhea," said Thomas J. Louie, M.D., Medical Director, Infection Prevention and Control for the Calgary Health Region and professor in the Departments of Medicine and Microbiology-Infectious Diseases, University of Calgary. "These findings indicate that fidaxomicin offers both highly effective but more selective therapy that is less damaging to the normal intestinal bacteria that protect against recurrence of CDI."
Additional findings also presented for the first time include a subgroup analysis of clinical cure and recurrence rates for fidaxomicin compared to Vancocin, as well as baseline demographic and disease characteristics. Clinical cure rates for fidaxomicin and Vancocin were similar in each of the following subgroups: patient status (in-patient/out-patient), age (under/over 65) and strain type (BI/NAP1/027). Most notably, fidaxomicin showed a reduction across several subgroups in recurrence rates compared to Vancocin in both out-patient and in-patient settings, as well as in patients both over and under the age of 65. The recurrence rates in the BI/NAP1/027 subgroup were similar between fidaxomicin and Vancocin.
Per Protocol Fidaxomicin Vancocin(R) capsules (microbiologically evaluable) (200mg bid) (125mg qid) Recurrence Rates by Subgroup Patient Status In-patient 17.9% (19/106) 26.1% (29/111) Out-patient 8.6% (9/105) 21.8% (24/110) Age < 65 9.5% (12/126) 18.6% (22/118) >/= 65 18.8% (16/85) 30.1% (31/103) Strain Type BI (NAP1/027) 25.0% (11/44) 24.1% (13/54) Overall 13.3% (28/211) 24.0% (53/221)
Baseline demographic and disease characteristics of study participants were similar between the fidaxomicin and Vancocin arms. The BI/NAP1/027 hyper virulent strain of C. difficile was present in 36% of patients in the study. 46% of the patients were over the age of 65, 56% were in-patients, 17% had a prior episode of CDI and study participants had an average of 8.3 bowel movements per day.
The incidence of adverse events and serious adverse events between the fidaxomicin and Vancocin arms was similar.
Additional detailed data from the study will be presented at medical conferences throughout the year.
Fidaxomicin Clinical Study Design
629 adult subjects were enrolled in this multi-center, randomized, double-blind Phase 3 clinical trial, which was the largest such trial for the treatment of CDI. Subjects with confirmed CDI received either 200 mg fidaxomicin dosed orally twice daily or 125 mg Vancocin dosed orally four times daily. This study was conducted in more than 100 clinical sites throughout North America. The objective of the study was to show that a 10-day course of fidaxomicin was at least as efficacious (non-inferior) and safe as a 10-day course of Vancocin (vancomycin hydrochloride capsules, USP) for the treatment of CDI.
The primary endpoint of the study was clinical cure defined as patients requiring no further CDI therapy two days after completion of study medication, as determined by the investigator. The secondary endpoint evaluated CDI recurrence up to four weeks post therapy with recurrence defined as the return of diarrhea associated with CDI confirmed by a positive toxin test. Global cure was defined as patients who were cured and did not have a recurrence.
About Clostridium Difficile Infection
CDI has become a growing problem in hospitals, long-term care facilities and in the community. It is a serious illness caused by infection of the inner lining of the colon by C. difficile bacteria, which produce toxins that cause inflammation of the colon, severe diarrhea and, in the most serious cases, death. CDI typically develops from the use of broad-spectrum antibiotics that disrupt normal gastrointestinal (gut) flora, allowing C. difficile bacteria to flourish.
Current therapeutic options for CDI include metronidazole and oral vancomycin. However, approximately 20% to 30% of CDI patients who initially respond to these treatments experience a clinical recurrence following cessation of antibiotic administration.
Primary risk factors for CDI include broad-spectrum antibiotic use, advanced age (over 65), emerging hyper-virulent strains (NAP1/027, 078, 001) of C. difficile, and previous exposure to CDI that lead to recurrence. Higher incidence, increased treatment failures, and recurrence with standard therapies have resulted in greater awareness and concern of CDI among medical professionals and public health officials.
About Fidaxomicin
Fidaxomicin is the first in a new class of antibiotics called macrocyclics, which inhibit the bacterial enzyme RNA polymerase, resulting in the death of Clostridium difficile. The narrow spectrum profile of fidaxomicin may eradicate Clostridium difficile selectively with minimal disruption to the normal intestinal flora. This may facilitate the return of the normal physiological conditions in the colon and reduce the probability of CDI recurrence.
About Optimer Pharmaceuticals
Optimer Pharmaceuticals, Inc. is a biopharmaceutical company focused on discovering, developing and commercializing innovative anti-infective products to treat serious infections and address unmet medical needs. Optimer has two late-stage anti-infective product candidates under development. Fidaxomicin, formerly known as OPT-80, is the only antibiotic therapy currently in Phase 3 worldwide clinical development for Clostridium difficile infection. Prulifloxacin is an antibiotic which has completed two Phase 3 clinical trials for the treatment of travelers' diarrhea, a form of infectious diarrhea. Additional information can be found at http://www.optimerpharma.com/.
Forward-looking Statements
Statements included in this press release that are not a description of historical facts are forward-looking statements, including without limitation all statements related to incidence of CDI and the ability of fidaxomicin to treat CDI and address current treatment limitations. Words such as "believes," "anticipates," "plans," "expects," "intend," "will," "goal" and similar expressions are intended to identify forward-looking statements. The inclusion of forward-looking statements should not be regarded as a representation by Optimer that any of its plans will be achieved. Actual results may differ materially from those set forth in this release due to the risks and uncertainties inherent in Optimer's business including, without limitation, risks relating to: the timing, progress and likelihood of success of its fidaxomicin research and development efforts, the timing and status of its clinical development of fidaxomicin, including the fact that prior clinical results may not predict future results, and other risks detailed in Optimer's filings with the Securities and Exchange Commission.
Contacts Optimer Pharmaceuticals, Inc. John Prunty, CFO & VP, Finance Christina Donaghy, Corporate Communications Manager 858-909-0736 Porter Novelli Life Sciences Jason I. Spark, Vice President 619-849-6005
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Optimer Pharmaceuticals, Inc.
CONTACT: John Prunty, CFO & VP, Finance, or Christina Donaghy, Corporate
Communications Manager, both of Optimer Pharmaceuticals, Inc.,
+1-858-909-0736; or Jason I. Spark, Vice President of Porter Novelli Life
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Web Site: http://www.optimerpharma.com/
