PolyMedix Presents Antibiotic Data at the 50th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC)

PolyMedix, Inc. (OTC BB: PYMX), an emerging biotechnology company focused on developing new therapeutic drugs to treat acute cardiovascular disorders and infectious diseases, today presented five posters at the 50^th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC). The data presented included results from studies focused on identifying compounds from PolyMedix’s library of novel defensin mimetic antibiotics to address foodborne infections and biowarfare pathogens. In addition, results were presented showing antimicrobial activity in human serum collected from subjects in PolyMedix’s Phase 1B clinical trial with its lead defensin mimetic, PMX-30063.

The following posters were presented by PolyMedix and are available on the Company’s website at http://www.polymedix.com/presentations.php:

"Antimicrobial Activity in Human Serum After IV Administration of PMX-30063 in a Phase 1B Study” B. Korczak, E. McAllister, R. Scott

In this study, blood samples were drawn from healthy subjects in PolyMedix’s Phase 1B study after they had been dosed with PMX-30063 to test the antimicrobial activity of PMX-30063. Four different strains of Staphylococcus aureus bacteria, including two MRSA strains, were added to the blood samples. The results showed that PMX-30063 was bactericidal against both MSSA (methicillin-sensitive Staphylococcus aureus) and MRSA (methicillin-resistant Staphylococcus aureus, or drug-resistant Staph) starting at doses as low as 0.1 to 0.3 mg/kg. These data suggest that administration of PMX-30063 below the identified limiting-dose may have a bactericidal effect on MSSA and MRSA in human subjects.

"Antimicrobial Activities of Structurally Diverse Host Defense Protein Mimics” R. Scott, CE Budu, A. Khanna, D. Clements

In this study, compounds from three structurally diverse series of host defense protein mimics were identified that were highly active against recent clinical isolates of Gram-positive Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecalis, and Gram-negative Escherichia coli and Klebsiella pneumoniae. Importantly, the same antimicrobial activities were observed between drug-susceptible and multi-drug resistant isolates of each organism. This indicates that mechanisms used by bacteria to build resistance to current antibiotics are not effective against the PolyMedix defensin-mimics. The PolyMedix defensin-mimetic compounds rapidly kill the bacteria in 30 minutes to 4 hours, with no signs of resistance emerging in laboratory serial passage assays. Results demonstrate that these novel defensin-mimetic compounds exert their antimicrobial activity by a novel mechanism of action, and rapidly kill both Gram-positive and Gram-negative bacterial pathogens while showing a very low risk for development of resistance.

"Antimicrobial Activities of a Novel Host Defense Protein Mimics Against Foodborne Pathogens” R. Scott, S. Mithal, D. Clements

In this study, PolyMedix screened over 125 synthetic defensin-mimetic compounds from its antimicrobial library for activity against many of the bacterial pathogens associated with foodborne infections, including, E. coli, Shigella, Listeria, and Salmonella. Eleven compounds were potently active against all of the pathogens tested, and were also highly selective for bacteria over mammalian cells, indicating a wide safety margin between concentrations needed to kill bacteria and concentrations where damage to host cell types is first observed. The compounds also demonstrated rapid killing properties where >99.9% of bacteria treated with the active compounds were killed in 30 minutes to 4 hours. Results demonstrate that PolyMedix’s defensin-mimetic compounds have potent and rapid antimicrobial activity against foodborne pathogens and low cytotoxicity.

"In Vitro Antimicrobial Activities of Nonpeptidic Mimics of Host Defense Proteins Against Biowarfare Pathogens” R. Scott, H. Heine, D. Clements

In this study, PolyMedix screened over 30 synthetic defensin-mimetic compounds from its antimicrobial library for activity against Category A and B bacterial pathogens that have been identified as potential biowarfare threats, including, B. anthracis, Y. pestis, B. mallei and F. tularensis. Up to 25 compounds were robustly active against B. anthracis and F. tularensis and up to 3 compounds were active against B. mallei and Y. pestis. Many of the active compounds also showed substantial safety indices in mammalian cell cytotoxicity assays. Results demonstrate that PolyMedix’s defensin-mimetic compounds have promising antimicrobial activity and low cytotoxicity against biowarfare pathogens.

"Population Pharmacokinetics of PMX-30063 After Single and Repeated Intravenous Doses” Institute for Clinical Research (M. Melhem et al) and PolyMedix (B. Korczak)

In drug development, population pharmacokinetics is used to better understand the quantitative relationships among drug input patterns, patient characteristics, and drug disposition. In this study a population PK model for PMX-30063 was built using the single and multiple dose data obtained from PolyMedix’s Phase 1A and 1B studies. This model is expected to provide robust and reliable estimates of PMX-30063 pharmacokinetic exposure and will be useful in pharmacokinetic-pharmacodynamic target attainment analyses to support dose selection decisions for future clinical studies.

About ICAAC

The Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) is an annual event hosted by the American Society for Microbiology and is the premier meeting on infectious diseases. For the past 50 years, the meeting has presented late-breaking scientific information featuring physicians, researchers and other healthcare professionals from around the world fostering solutions for the problem of infectious disease.

About PolyMedix, Inc.

PolyMedix is a publicly traded biotechnology company focused on the development of novel drugs and biomaterials for the treatment of serious acute cardiovascular disorders and infectious diseases. PolyMedix uses a rational drug design approach to create non-peptide small molecule drug candidates and polymers that mimic the activity of proteins. PMX-60056, PolyMedix’s lead heptagonist compound, is being developed to reverse the anticoagulant activity of both heparin and low molecular weight heparins. PolyMedix believes that PMX-60056 could potentially be a safer and easier to use anticoagulant reversing agent, with broader activity, than the currently approved therapy for reversing heparin. PMX-30063, PolyMedix’s lead antibiotic compound, is a small molecule that mimics human host-defense proteins and has a mechanism of action distinct from those of current antibiotic drugs, a mechanism which is intended to make bacterial resistance unlikely to develop. PolyMedix plans to develop this compound for serious systemic Staphylococcal infections, including methicillin resistant Staphylococcus aureus (MRSA). Both PMX-60056 heptagonist and PMX-30063 antibiotic are undergoing clinical testing. PolyMedix also plans to continue the development of its PolyCides™, polymeric formulations as antimicrobial biomaterials, which can be used as additives to paints, plastics, and textiles to create self-sterilizing products and surfaces. For more information, please visit our website at www.polymedix.com.

This press release contains forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995 that involve risks, uncertainties and assumptions that could cause PolyMedix’s actual results and experience to differ materially from anticipated results and expectations expressed in these forward looking statements. PolyMedix has in some cases identified forward-looking statements by using words such as "anticipates,” "believes,” "hopes,” "estimates,” "looks,” "expects,” "plans,” "intends,” "goal,” "potential,” "may,” "suggest,” and similar expressions. Among other factors that could cause actual results to differ materially from those expressed in forward-looking statements, PolyMedix’s compounds may not successfully complete clinical testing, or be granted regulatory approval to be sold and marketed in the United States or elsewhere. A more complete description of these risk factors is included in PolyMedix’s filings with the Securities and Exchange Commission. You should not place undue reliance on any forward-looking statements. PolyMedix undertakes no obligation to release publicly the results of any revisions to any such forward-looking statements that may be made to reflect events or circumstances after the date of this press release or to reflect the occurrence of unanticipated events, except as required by applicable law or regulation.