Rib-X Pharmaceuticals, founded in 2000, is a privately-held biopharmaceutical

Biopharmaceutical

Biopharmaceuticals are medical drugs produced using biotechnology. They include proteins , nucleic acids and living microorganisms like virus and bacteria where the virulence of viruses and bacteria is reduced by the process of attenuation, they can be used for therapeutic or in vivo diagnostic...

 firm that focuses on the design and development of novel broad-spectrum antibiotic

Broad-spectrum antibiotic

The term broad-spectrum antibiotic refers to an antibiotic that acts against a wide range of disease-causing bacteria. A broad-spectrum antibiotic acts against both Gram-positive and Gram-negative bacteria, in contrast to a narrow-spectrum antibiotic, which is effective against specific families of...

s for the treatment of antibiotic-resistant infections in hospital and community settings. The company is located in New Haven, Connecticut

New Haven, Connecticut

New Haven is the second-largest city in Connecticut and the sixth-largest in New England. According to the 2010 Census, New Haven's population increased by 5.0% between 2000 and 2010, a rate higher than that of the State of Connecticut, and higher than that of the state's five largest cities, and...

. Rib-X seeks to exploit expertise in the structural biology

Structural biology

Structural biology is a branch of molecular biology, biochemistry, and biophysics concerned with the molecular structure of biological macromolecules, especially proteins and nucleic acids, how they acquire the structures they have, and how alterations in their structures affect their function...

 (particularly ribosomal structure) and molecular modeling to design new antibiotics. With this technology they hope to design drug candidates with increased target affinity that overcome bacterial resistance, broadened antibacterial spectrum, and increased efficacy and safety.

In November 2011, Rib-X filed with the SEC to raise up to $80 million in an initial public offering.

Pipeline in the clinical phase

Rib-X's pipeline includes the following compounds in the clinical phase:

• Delafloxacin
  Delafloxacin
  Delafloxacin is a fluoroquinolone antibiotic being developed by Rib-X Pharmaceuticals, Inc.It is more active than other quinolones against Gram-positive bacteria such as MRSA....
  
  , a novel fluoroquinolone with activity against range of quinolone
  Quinolone
  The quinolones are a family of synthetic broad-spectrum antibiotics. The term quinolone refers to potent synthetic chemotherapeutic antibacterials....
  
  -resistant Gram-positive
  Gram-positive
  Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
  
   and Gram-negative
  Gram-negative
  Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
  
   bacteria, including MRSA, currently in a Phase 2b studys for hospital use. Delafloxacin was acquired from Wakunaga Pharmaceutical in 2006.
• Radezolid
  Radezolid
  Radezolid is a novel oxazolidinone antibiotic being developed by Rib-X Pharmaceuticals, Inc. for the treatment of serious multi-drug–resistant infections. Radezolid has completed two phase-II clinical trials...
  
  , a next-generation oxazolidinone designed for broader spectrum, enhanced potency and improved safety, has completed two Phase 2 studies. It has been shown to overcome linezolid
  Linezolid
  Linezolid is a synthetic antibiotic used for the treatment of serious infections caused by Gram-positive bacteria that are resistant to several other antibiotics...
  
   resistance.

RX-04 Program

The company has several compounds in a pre-clinical program designated RX-04: Three new classes of compounds have been identified that target a novel site on the bacterial 50S ribosomal subunit. These compounds were designed using the Rib-X proprietary approach to rational drug design based on structural analysis of the bacterial ribosome. Compounds have been identified with antibacterial activity against a number of the most difficult to treat, clinically important multi-drug resistant pathogens, including Methicillin-resistant Staphylococcus aureus (MRSA)

Methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus is a bacterium responsible for several difficult-to-treat infections in humans. It is also called multidrug-resistant Staphylococcus aureus and oxacillin-resistant Staphylococcus aureus...

, Acinetobacter baumannii

Acinetobacter baumannii

Acinetobacter baumannii is a species of pathogenic bacteria, referred to as an aerobic gram-negative bacterium, that is resistant to most antibiotics. As a result of its resistance to drug treatment, some estimates state the disease is killing tens of thousands of U.S...

, Escherichia coli

Escherichia coli

Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...

, Klebsiella pneumoniae

Klebsiella pneumoniae

Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose fermenting, facultative anaerobic, rod shaped bacterium found in the normal flora of the mouth, skin, and intestines....

and Pseudomonas aeruginosa

Pseudomonas aeruginosa

Pseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...

. In mid-2011 Sanofi entered into a global research collaboration and licensing option with Rib-X Pharmaceuticals to develop and commercialize the novel classes of antibiotics resulting from RX-04.

Rib-X also has three programs in the discovery phase designated RX-02, RX-05, and RX-06. RX-06 is a program to develop anti-fungals.

External links

• Rib-X Pharmaceuticals Homepage