Date: Jul 15, 2013 Source: Company Data (
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Data presented at the STI & AIDS World Congress 2013--
VIENNA, Austria, July 15, 2013 -- Today, Rib-X Pharmaceuticals, Inc. presented in vitro data on the potent activity of delafloxacin against drug-resistant strains of Neisseria gonorrhoeae (gonorrhea). Delafloxacin is an investigational novel fluoroquinolone antibiotic with intravenous (IV) and oral formulations. These data were presented today at the STI & AIDS World Congress 2013 in Vienna, Austria (poster P2.197, Clinical Sciences Track). Rib-X Pharmaceuticals is also evaluating delafloxacin in the ongoing Phase 3 PROCEED (PROve Clinical Efficacy and Effect of Delafloxacin) study in patients with acute bacterial skin and skin structure infections (ABSSSI).
In a poster entitled "In vitro Activity of Delafloxacin Against Neisseria gonorrhoeae Clinical Isolates," researchers from the University of Washington and Rib-X reported the results of two studies in which delafloxacin and other antimicrobial agents were evaluated for their in vitro activity against isolates of N. gonorrhoeae. In the studies, delafloxacin demonstrated in vitro antimicrobial activity against drug resistant N. gonorrhoeae, including ciprofloxacin-resistant isolates, with potency similar to that of ceftriaxone, the currently recommended treatment standard
The first study (Study A) was conducted in the laboratory of Marilyn C. Roberts, Ph.D. at the University of Washington. In this study, 33.6% of the isolates were ciprofloxacin-resistant and 29.3% of the isolates were multidrug-resistant (MDR). Against 113 isolates of N. gonorrhoeae tested in Study A, delafloxacin and ceftriaxone were the most potent antimicrobial agents with MIC90s of 0.06 and 0.03 µg/mL, respectively. Delafloxacin was more than 250 times more active than ciprofloxacin against these isolates.
The second study (Study B) was conducted at the United States Centers for Disease Control and Prevention (CDC). In Study B, 73.1% of the isolates were ciprofloxacin-resistant, whereas 44.4% were MDR. This study evaluated the in vitro antimicrobial activity of 11 agents against 93 isolates of N. gonorrhoeae plus the CDC-control strains. Delafloxacin and several cephalosporins demonstrated robust activity against this group of organisms, with MIC90s of 0.06-0.25 µg/mL. In this study as well, delafloxacin was more than 250 times more active than ciprofloxacin.
"Gonorrhea has become a global health crisis due to rapidly growing resistance, and physicians are now left with only a single recommended drug, which must be given by injection," said Eugene Sun, M.D., Executive Vice President, Research and Development at Rib-X. "In the data presented today, delafloxacin demonstrated promising in vitro activity against multidrug-resistant, including fluoroquinolone-resistant, gonorrhea isolates. We are encouraged that delafloxacin, with its potent activity and an available oral formulation, has the potential to serve a pressing need for an increasingly resistant infection."
According to the World Health Organization (WHO), new gonococcal infections are estimated to be 106 million globally each year. In the US, it is estimated by the CDC that 820,000 Americans contracted gonorrhea in 2011. It is the second most reported notifiable infectious disease in the US as well as in Europe, with the highest incidence in adolescents and young adults. Left untreated, gonorrhea can lead to serious reproductive issues in women, including pelvic inflammatory disease, ectopic pregnancy, and infertility. In addition, gonorrhea may facilitate HIV transmission. N. gonorrhoeae has developed resistance to the common antibiotics previously used to treat it, including sulfonamides, penicillin, tetracycline, macrolides, quinolones, and most cephalosporins. The increase in resistance to cefixime, an oral drug, has resulted in its removal as a recommended treatment by the CDC in the U.S., leaving ceftriaxone injection as the sole remaining treatment recommendation. Worldwide surveillance shows that ceftriaxone resistance is increasing. As a result, gonorrhea has become increasingly difficult to treat, and represents an expanding public health threat for which there is an urgent need for new therapies.
About Rib-X:
Rib-X Pharmaceuticals, Inc. is a biopharmaceutical company developing new antibiotics to provide superior coverage, safety and convenience for the treatment of serious and life-threatening infections. The Company's proprietary drug discovery platform is based on Nobel Prize-winning science and provides an atomic-level, three-dimensional understanding of interactions between drug candidates and their bacterial targets to enable the design of antibiotics with enhanced characteristics. Rib-X's lead antibiotic in development is delafloxacin, a novel fluroquinolone antibiotic, which is currently in a global Phase 3 clinical trial for the treatment of acute bacterial skin and skin structure infections. The Company's pipeline also includes its preclinical RX-04 program t argeting multidrug-resistant and extremely-drug-resistant Gram-negative infections and other discovery stage anti-infective programs. Rib-X is privately held and backed by Vatera Healthcare Partners and Warburg Pincus, among others. For more information, please visit www.rib-x.com.
