Rib-X Pharmaceuticals Initiates Two Phase 2 Studies For Novel Antibiotic Compound RX-1741

Main Category: Respiratory / Asthma
Also Included In: Infectious Diseases / Bacteria / Viruses;  Clinical Trials / Drug Trials;  Pharma Industry / Biotech Industry
Article Date: 05 Jan 2008 - 0:00 PDT

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Rib-X Pharmaceuticals, Inc. ("Rib-X" or the "Company"), a biopharmaceutical company focused on the development of novel antibiotics for the treatment of antibiotic-resistant infections, announced the enrolment of the first patients in two separate Phase 2 clinical trials. The studies will evaluate the safety and efficacy of RX-1741 in the treatment of Community-Acquired Pneumonia (CAP), and separately in the outpatient treatment of Uncomplicated Skin and Skin Structure Infections (uSSSI). RX-1741 is the Company's first antibiotic program developed using its proprietary technology platform.

RX-1741 is an oxazolidinone antibiotic that exhibits activity against methicillin-resistant Staphylococcus aureus (MRSA) and other Gram-positive organisms, and has demonstrated both greater spectrum and potency of activity than the currently marketed product of the same class, Zyvox(R) (linezolid). Discovered using proprietary knowledge of the three dimensional structure of a key area of the ribosome, the 50S subunit, Rib-X believes that RX-1741 will demonstrate a high level of effectiveness against resistant microbes.

"These two studies represent important milestones for Rib-X," said Dr. Susan Froshauer, President and CEO of Rib-X Pharmaceuticals. "RX-1741 is the first of many compounds that Rib-X intends to design and develop in response to the alarming growth of drug resistant microbial pathogens found both in the hospital and in the community. This MRSA-active agent will satisfy a critical need for physicians and their patients because current treatment options are very limited, particularly for orally active agents," said Dr. Froshauer.

CAP Study Design

The CAP study is a Phase 2, multicenter, randomized, double-blind study designed to evaluate the safety and efficacy of RX-1741 in the treatment of adult patients with mild to moderate severity of Community-Acquired Pneumonia (CAP). The study will assess the efficacy of three doses of RX-1741, either once or twice a day, for seven to 10 days in the treatment of adult patients with mild to moderate CAP. It will also evaluate the safety and tolerability profile of the three doses.

The CAP study will enroll approximately 160 patients in 40 study centers across the US, Canada, and Russia, and the Company expects to have preliminary data available when approximately 80 patients (50% of the planned patients) have completed the study. The Company intends to release data from all patients during the first half of 2008.

uSSSI Study Design

The uSSSI study is a Phase 2, multicenter, randomized, open-label, comparative study to evaluate the safety and efficacy of RX-1741 versus linezolid in the outpatient treatment of adult patients with Uncomplicated Skin and Skin Structure Infections (uSSSI). The study will assess the efficacy of a single dose of RX-1741 given either once daily or twice daily compared to linezolid given twice daily for five to ten days in the treatment of ambulatory patients with uSSSI. It will also evaluate the safety and tolerability profile of these two doses compared to linezolid.

The uSSSI study will enroll approximately 150 patients in 25 study centers across the US and the Company expects an interim analysis of the data to be performed when approximately 75 patients (50% of the planned patients) have completed the study. The Company intends to release data from all patients during the first half of 2008.

About Rib-X Pharmaceuticals, Inc.

Rib-X Pharmaceuticals 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 50S subunit of the ribosome, which performs an essential role in the fundamental process of protein synthesis. Many known, commercially valuable antibiotics bind to the 50S subunit, including those used to treat both community-acquired and hospital-acquired pathogens. 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 antibiotic classes. The Company currently has two programs in human clinical trials, the RX-1741 oxazolidinone program as an oral/IV agent to treat serious hospital Gram-positive infections and the RX- 3341 program, a next generation fluoroquinolone, active against a broad spectrum of bacteria, including methicillin-resistant Staphylococcus aureus. Additionally, the Company has two active drug discovery programs. The first of these discovery programs is focused on developing an orally active agent, a macrolide, for community use with activity against MRSA and other skin infections. The second discovery program is directed towards identifying a new chemical class of agents active against multi-drug resistant hospital infections.

For more information on the ribosome and the Rib-X mission, please visit the Company website at http://www.rib-x.com.

Rib-X Pharmaceuticals, Inc.
http://www.rib-x.com