Promising Data from Paratek Pharmaceuticals' MAR Inhibitor Program Presented in 'Late Breaker' Session at the 47th Interscience Conference on Antimicrobial Agents and Chemotherapy

Technology Turns Off 'Master Switch' Underlying Bacterial Infection and May

Have Broad Use in Preventing Critical Bacterial Infections

Sep 18, 2007, 01:00 ET from Paratek Pharmaceuticals, Inc.

    BOSTON, Sept. 18 /PRNewswire/ -- Paratek Pharmaceuticals, Inc.
 announced today the most advanced preclinical results of the Company's
 Multiple Adaptation Response (MAR) inhibitor program. MAR proteins in
 bacteria serve as the "master switch" controlling virulence and antibiotic
 resistance. Paratek has shown that shutting down this switch disables
 bacterial virulence and prevents bacteria from causing infection. Paratek
 is developing MAR inhibitors that can prevent serious and life-threatening
 bacterial infections in high-risk patients.
     The results were reported in a "late breaker" poster presentation
 titled, "A Novel Anti-Virulence Approach for Treatment of Pneumonia Caused
 by Pseudomonas aeruginosa," at the 47th Interscience Conference on
 Antimicrobial Agents and Chemotherapy (ICAAC) taking place in Chicago. The
 findings demonstrated that small molecule agents which block the activity
 of ExsA (a MAR protein) in Pseudomonas aeruginosa significantly reduced
 bacterial virulence and were protective in an animal model from pneumonia.
 Lead authors on the research are Michael P. Draper, Ph.D., Director of
 Anti-Infective Drug Discovery at Paratek Pharmaceuticals, and Stuart B.
 Levy, M.D., Chief Scientific Officer and Co-Founder of Paratek.
     In addition, Paratek announced a newly released publication showing
 efficacy of the Company's MAR inhibitors against E. coli in urinary tract
 infection in another animal model of serious bacterial infection. The
 article, titled, "Novel anti-infection agents: Small-molecule inhibitors of
 bacterial transcription factors," is appearing in the current August 2007
 issue of Bioorganic & Medicinal Chemistry Letters.
     Dr. Levy commented, "We are very pleased with the progress of the MAR
 program. We have shown proof of concept in E. coli, Yersinia and now
 Pseudomonas, a gram-negative bacterium with increasing multi-drug
 resistance which is a leading cause of hospital-acquired infections and
 death. We have also supported previous evidence that MAR inhibitors act as
 non-antibacterial compounds, which means they do not inhibit growth of
 bacteria and should therefore be less likely to foster resistance
 development. This new paradigm in infectious diseases will be very useful
 in preventing a broad range of critical bacterial infections."
     Thomas J. Bigger, President and CEO of Paratek Pharmaceuticals, stated,
 "Paratek's MAR program has the potential to reshape the course of existing
 antibiotics and create a new standard in anti-infective therapy by directly
 preventing infection. The Company plans to achieve further proof of concept
 and enter into IND-enabling preclinical studies in 2009."
     About the MAR Proteins
     MAR proteins such as ExsA and its homologues in other bacteria
 constitute a novel "master switch" that controls the expression of multiple
 other proteins involved in serious infections including those caused by
 bacteria such as Escherichia coli, Yersinia, and Pseudomonas aeruginosa.
 When activated, the MAR system initiates a number of bacterial survival and
 defense mechanisms, including processes whereby bacteria establish
 infections and develop resistance to a broad range of antibiotics and other
 toxic substances. MAR inhibitors interfere with protein function,
 specifically eliminating the synthesis of proteins controlling virulence,
 and act as effective agents for preventing infection. MAR inhibitors are
 also non-antibacterial and therefore, not under the same selection pressure
 for multi-drug resistance as traditional antibiotics. Initial potential
 applications include preventing and treating severe pulmonary infections in
 ventilator-assisted patients, other nosocomial infections and recurrent
 urinary tract infections.
     About Paratek Pharmaceuticals
     Paratek Pharmaceuticals, Inc. is engaged in the discovery and
 commercialization of new therapeutics that treat serious and
 life-threatening diseases, with a particular focus on the growing worldwide
 problem of antibiotic resistance. Paratek is advancing novel compounds that
 can circumvent or block bacterial resistance involving technology initially
 developed by Paratek co-founder Dr. Stuart Levy's laboratory at Tufts
 University School of Medicine, and licensed by Paratek. Paratek's lead
 compound, PTK 0796, is a broad spectrum antibiotic derived from the
 tetracycline class with oral and IV formulations that is being developed
 for the treatment of the most common serious and hospital bacterial
 infections, including those caused by resistant strains such as MRSA
 (methicillin resistant Staphylococcus aureus). In addition to PTK 0796 and
 its MAR inhibitor program Paratek is also developing community-targeted
 broad-spectrum antibiotics and narrow-spectrum antibiotics to treat acne
 and C. difficile associated-diarrhea (CDAD).
     Outside the antibacterial therapeutic area, Paratek has also
 established an effort to exploit its novel tetracycline derivatives and
 their unique mechanism of action in selected inflammatory and
 neurodegenerative conditions. Paratek has an active chemical synthesis
 effort to produce novel and diverse small molecules, with the goal of
 developing non-antibacterial compounds with improved activity in serious
 inflammatory and neurodegenerative diseases based upon a growing body of
 clinical research supporting this approach.
     Paratek has active collaborations with Merck, MerckSerono,
 Warner-Chilcott and FSMA to develop orally available small molecule drugs
 for community bacterial infections, multiple sclerosis, acne & rosacea, and
 spinal muscular atrophy (SMA), respectively. Paratek is privately held and
 headquartered in Boston, Massachusetts, USA. For more information about
 Paratek and its research and development initiatives, visit Paratek's
 website at

SOURCE Paratek Pharmaceuticals, Inc.