Download Optimer Pharmaceuticals Presents Results From Fidaxomicin Phase

Optimer Pharmaceuticals Presents Results From Fidaxomicin Phase 3 Study for the
Treatment of Clostridium difficile Infection
Optimer Pharmaceuticals, Inc., logo. (PRNewsFoto/Optimer
Pharmaceuticals, Inc.)
SAN DIEGO, CA UNITED STATES
Positive data from subgroup analysis presented at 19th annual European Congress of Clinical
Microbiology and Infectious Diseases (ECCMID) meeting in Helsinki, Finland
SAN DIEGO, May 17 /PRNewswire-FirstCall/ -- Optimer Pharmaceuticals, Inc. (Nasdaq: OPTR)
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.
(Logo: http://www.newscom.com/cgi-bin/prnh/20090413/LA97352LOGO)
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
(microbiologically evaluable)
Fidaxomicin
(200mg bid)
Vancocin(R) capsules
(125mg qid)
Recurrence Rates by Subgroup
Patient Status
In-patient
Out-patient
17.9% (19/106)
8.6% (9/105)
26.1% (29/111)
21.8% (24/110)
Age
< 65
>/= 65
9.5% (12/126)
18.8% (16/85)
18.6% (22/118)
30.1% (31/103)
Strain Type
BI (NAP1/027)
Overall
25.0% (11/44)
13.3% (28/211)
24.1% (13/54)
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.