- Fluoroquinolone Compound Demonstrates Potent Activity Against Antibiotic Resistant Gram-Positive Pathogens and MRSA in Skin Infections -
NEW HAVEN, Conn., Dec. 8 /PRNewswire-FirstCall/ -- Rib-X Pharmaceuticals, Inc. ("Rib-X" or the "Company"), a development-stage company focused on the discovery, development and commercialization of novel antibiotics for the treatment of antibiotic-resistant infections, today announced positive topline results from a Phase 2 clinical trial with the intravenous form of its novel anionic quinolone antibiotic, delafloxacin (RX-3341). The double-blind study showed that both doses (300mg BID and 450mg BID) of delafloxacin were as efficacious as the FDA approved dosing regime for tigecycline in the treatment of complicated skin and skin structure infections (cSSSI). Additionally, when evaluated in vitro against the Gram-positive and Gram-negative organisms isolated from patients within this trial, delafloxacin was shown to be the more active compound overall, including its activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) and quinolone-resistant Gram-positive pathogens.
"This is the third Phase 2 clinical trial showing delafloxacin to be both efficacious and safe," said Susan Froshauer, PhD, President and CEO of Rib-X Pharmaceuticals. "The data for delafloxacin continues to show that this broad spectrum compound is likely to be a valuable tool in the armamentarium of agents for treatment of resistant bacterial infections. In fact, delafloxacin has been shown to be extremely effective against resistant Gram-positive bacteria, including MRSA. While we look forward to a complete review of the final data and in particular the subset data, we are encouraged by these results and the two previous Phase 2 studies, and we will continue to focus on the development of this potent antibiotic."
The Company is developing both the oral and intravenous formulations of delafloxacin for the over $9.9 billion hospital antibiotic market. (1)
Delafloxacin cSSSI Clinical Trial Design
This Phase 2 double-blind study evaluated the safety and efficacy of delafloxacin dosed intravenously at 300 mg and 450 mg twice a day to patients with cSSSI for 5 to 14 days, as compared to the FDA approved dosing regime for tigecycline (TYGACIL, Wyeth Pharmaceuticals) for the same time period.
Delafloxacin previously successfully completed two Phase 2 studies with the oral formulation. The first of these studies evaluated the safety and efficacy of delafloxacin in the treatment of community acquired pneumonia (CAP). In this study, the compound was shown to be effective at doses as low as 200 mg once a day. The second study compared delafloxacin to levofloxacin in the treatment of acute bacterial exacerbation of chronic bronchitis (ABECB). A 200 mg once a day dose of delafloxacin for 5 days was shown to be as efficacious as a 500 mg once a day dose for 7 days of levofloxacin.
About Complicated Skin and Skin Structure Infections (cSSSI)
Complicated skin and skin structure infection (cSSSI) is a term used to group a wide range of severe bacterial skin infections involving the deeper soft tissue and includes things like severe cellulitis and major abscesses. These infections may result from infected ulcers, burns, wound infections following surgery, insect bites, and other traumas. Complicated skin infections affect over one million patients in the U.S. annually. The most common cause of cSSSIs are Gram-positive bacteria, specifically Staphylococcus aureus and methicillin-resistant S. aureus (MRSA).
Delafloxacin is a novel, broad spectrum, next-generation fluoroquinolone, which has demonstrated more activity than other quinolones against Gram-positive bacteria, including potent activity against quinolone resistant Gram-positive bacteria including MRSA. The compound has been shown to be at least 16-fold more potent than levofloxacin, ciprofloxacin, gatifloxacin and moxifloxacin against quinolone-resistant MRSA (MIC90 of </= 0.5 ug/ml for delafloxacin versus > 16 ug/ml for all other quinolones). Currently in development for an intravenous formulation, delafloxacin has also been shown to be more potent than existing quinolones against a range of Gram-positive, anaerobic and Gram-negative organisms. Rib-X plans to develop both intravenous and oral formulations of delafloxacin for use in surgical prophylaxis and therapeutic arenas within the hospital setting.
About Rib-X Pharmaceuticals, Inc.
Rib-X Pharmaceuticals, Inc. is a product-driven small molecule drug discovery and development company focused on the structure-based design of new classes of antibiotics. The Company's underlying drug discovery engine capitalizes on its proprietary high-resolution crystal structure of the ribosome, which performs an essential role in protein synthesis. Many known, commercially valuable antibiotics exert their effects by binding to the bacterial ribosome. The Company's integrated research strategy, which combines state-of-the-art, proprietary computational analysis, X-ray crystallography, medicinal chemistry, microbiology and biochemistry, allows it to rapidly synthesize new agents designed to avoid typical antibiotic resistance mechanisms. Rib-X's iterative intelligent engine has yielded several distinctive new antibiotics that can be used for the treatment of either community- or hospital-acquired infections. Delafloxacin is a fluoroquinolone that has demonstrated activity against a broad spectrum of bacteria, including quinolone-resistant Gram-positive bacteria and MRSA. Currently in Phase 2 trials, Rib-X is developing radezolid (RX-1741), an oxazolidinone, as an oral/IV agent for treatment of serious Gram-positive infections. The Rx-04 discovery program is developing novel classes of antibiotics active against multi-drug resistant Gram-negative bacteria and the Rx-02 discovery program is focused on developing an IV/oral macrolide active against methicillin-resistant S. aureus, multidrug-resistant Streptococus pneumonia and S. pyogenes. Additionally, Rib-X is developing delafloxacin, (RX-3341), an anionic fluoroquinolone active against a broad spectrum of bacteria, including quinolone-resistant Gram-positive bacteria and MRSA. Both delafloxacin and radezolid are currently in Phase 2 clinical trials.
For more information on the Rib-X mission and the pipeline, please visit the Company website at www.rib-x.com.
(1) Commercial and Pipeline Insight: Hospital Antibacterials-A market beyond MRSA; DataMonitor; August 24, 2007
|SOURCE Rib-X Pharmaceuticals, Inc.|
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