Genesoft Releases Data on Two Novel Antibiotic Classes

CHICAGO -- Genesoft Pharmaceuticals, Inc. presented new data on its portfolio of novel mode-of-action antibiotics at the 43rd Annual Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).

The presentation covered in vitro and in vivo preclinical data on two distinct classes of antibiotics -- Peptide Deformylase Inhibitors and DNA Nanobinderstm. Peptide deformylase (PDF) is one of the most promising new antibiotic targets because they are essential to bacterial survival. Data presented by GeneSoft at ICAAC showed selective inhibition of PDF resulted in potent antibacterial compounds with activity against drug-resistant organisms. GSQ-83698, currently in phase I clinical trials, has been profiled against a variety of clinical isolates and shown to be highly active against S. pneumoniae, the most important respiratory pathogen. A prototype PDF inhibitor in pre-clinical development, GSQ-200061, was reported to have an improved antibacterial spectrum against respiratory pathogens, in particular H. influenzae. The PDF program is advancing in collaboration with scientists at British Biotech LLC.

Preclinical data on two DNA Nanobinder agents from GeneSoft's second novel class, which target bacterial DNA sequences to achieve potent antibiotic activity, were also presented. The first, GSQ-7302, is a prototype that exhibits oral bioavailability in animals and activity against bacteria, protozoa and viruses. Data presented from a proof-of-concept study demonstrated that the compound exhibited significant activity in a S. pneumoniae lung infection murine model. Results demonstrated that GSQ-10547, when administered intravenously (IV), protects mice that are infected by methicillin-resistant S. aureus (MRSA) intraperitoneally, a mouse peritoneal sepsis model. Based on evaluation of survival, behavior, weight loss and serum chemistry, the IV dose in mice was tolerated. GSQ-10547 is a highly potent molecule with a broad spectrum against Gram-positive bacteria, including resistant Staph aureus, which is increasingly seen in hospital-based infections.

"In the years to come, the global medical community will be increasingly desperate for novel mode of action antibiotics that will reduce the chance of resistance," said David B. Singer, chairman and CEO. "Thus, we are particularly excited to share this encouraging progress with the infectious disease community."

Genesoft is an emerging pharmaceutical company based in South San Francisco that offers a deep product portfolio of novel anti-infective agents. Its first commercial product, Factive (gemifloxacin mesylate), was approved for sale in the United States in April 2003 for the treatment of acute bacterial exacerbations of chronic bronchitis (ABECB) and mild to moderate community acquired pneumonia (CAP). Factive should only be used to treat infections that are proven or strongly suspected to be caused by bacteria. It does not treat viral infections. The most common side effects include diarrhea, rash, nausea and headache. Rash is generally mild to moderate in nature, and more likely to occur if taken for longer than the recommended course.

Source: GeneSoft Pharmaceuticals, Inc.