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Qpex Biopharma to Present its Anti-infective Portfolio at IDWeek 2019


SAN DIEGO, September 25, 2019  Qpex Biopharma today announced scientific presentations on its investigational anti-infectives at the IDWeek 2019 Conference to be held October 2-6 in Washington, DC.

Qpex scientists and external collaborators will be making the first public presentations on QPX9003, a next generation polymyxin antibiotic for multi-drug resistant Acinetobacter and Pseudomonas aeruginosa. In addition, they will present new data on the ultra-broad-spectrum beta-lactamase inhibitor QPX7728, focusing on its first-in- class properties as an inhibitor with potent activity with multiple beta-lactam antibiotics in Acinetobacter and Pseudomonas, as well as in Enterobacteriaceae that produce serine and metallo beta-lactamases.

“We are pleased to report new data at IDWeek on our clinical candidates that demonstrate compelling preclinical properties as best-in-class agents for Acinetobacter, Pseudomonas, and Enterobacteriaceae,” said Michael Dudley, PharmD, FIDSA, President and CEO of Qpex Biopharma. “We welcome the opportunity to engage with the infectious disease community on the excellent progress of these programs as part of our ongoing portfolio collaboration with BARDA,” he added. 


Three poster presentations on the microbiological properties of QPX7728, and two posters on the microbiological properties and preclinical pharmacology of the clinical candidate QPX9003 will be presented by Qpex scientists and external collaborators.  Data show that QPX7728 has potent inhibition of clinically important beta-lactamases from Classes A, B, C, and D that are often present in multi-drug resistant (MDR) Acinetobacter, Pseudomonas, and Enterobacteriaceae. Notably, QPX7728 is active in strains of carbapenem-resistant Enterobacteriaceae (CRE) with resistance to ceftazidime-avibactam. The two posters on QPX9003 will show its improved potency and therapeutic index for Acinetobacter and Pseudomonas aeruginosa in animal models over polymyxin B. 


ID Week is the joint annual meeting of the Infectious Diseases Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), the HIV Medical Association (HIVMA), and the Pediatric Infectious Diseases Society (PIDS). 


The Qpex Biopharma presentations are listed below; additional information may be found at the IDWeek 2019 website at  All times listed below are in Eastern Daylight Time.


Date: Thursday, October 3, 2019

Poster Session: 068 - Novel Antimicrobials and Approaches Against Resistant Bugs

Time: 12:15pm-1:30pm

Place: Poster Area


Presentation Titles (abstract numbers), authors, and summary: 


QPX7728 (Ultra-Broad-Spectrum β-Lactamase Inhibitor) Presentations


Activity of Novel β-Lactamase Inhibitor QPX7728 Combined with β-Lactam Agents When Tested against Carbapenem-Resistant Enterobacteriaceae (CRE) Isolates (#677)

Mariana Castanheira, Jill Lindley, Holly Juynh, Rodrigo Mendes, and Olga Lomovskaya

QPX7728 restored the activity of several BLs when tested against 508 CRE isolates that produce serine and metallo carbapenemases.  


In Vitro Activity of the β-lactamase Inhibitor QPX7728 in Combination with Several β-lactams against Acinetobacter baumannii and Pseudomonas aeruginosa (#681)

Olga Lomovskaya, Jill Lindley, Debora Rubio-Aparicio, Kirk Nelson, and Mariana Castanheira

QPX7728 restored the activity of meropenem against carbapenem-resistant Acinetobacter baumannii, with  >95% of isolates inhibited by ≤8 µg/ml of meropenem. In a representative panel of Pseudomonas aeruginosa, multiple beta-lactam antibiotics tested in combination with QPX7728 resulted in >90% susceptibility. For a challenge panel of highly drug-resistant Pseudomonas aeruginosa, QPX7728 in combination with ceftolozane or piperacillin were the most potent combinations.  


Potency of the Beta-Lactamase Inhibitor QPX7728 Is Minimally Affected by KPC Mutations that Reduce Potency of Ceftazidime-Avibactam (#727)

Kirk Nelson, Debora Rubio-Aparicio, and Olga Lomovskaya

Mutations in the KPC enzyme that result in microbiological and clinical resistance to ceftazidime-avibactam do not affect the potency of QPX7728 in combination with various beta-lactam antibiotics, including ceftazidime. 


QPX9003 (Next Generation Polymyxin) Presentations


Activity of a Novel Polymyxin Analog, QPX9003, Tested against Resistant Gram-Negative Pathogens, including Carbapenem-Resistant Acinetobacter, Enterobacterales, and Pseudomonas (#690)

Mariana Castanheira, Jill Lindley, Holly Juynh, Rodrigo Mendes, and Olga Lomovskaya

QPX9003 had potent activity against the collection of highly resistant gram-negative isolates that included multidrug resistant Pseudomonas aeruginosa, carbapenem-resistant Acinetobacter baumannii and CRE. Against the PSA and CRAB isolates, QPX9003 was four-fold more active than colistin.

QPX9003: Pharmacology of a Novel Polymyxin in Mice and Rats (#707)

Mojgan Sabet, Ziad Tarazi, Jonathan Parkinson, Kade D. Roberts, Philip E. Thompson, Roger L. Nation, Tony Velkov, Scott J. Hecker, Olga Lomovskaya, Michael N. Dudley, Jian Li, and David C. Griffith

The activity and the safety of QPX9003 and polymyxin B was studied in animal models of infection and toxicology. QPX9003 was found to have a wider therapeutic index in being more effective and less toxic than polymyxin B,. 


About Qpex Biopharma, Inc. 

Qpex Biopharma ( is a San Diego-based biopharmaceutical company with a pipeline of best-in-class agents addressing critical needs for treatment of infectious diseases in the inpatient and outpatient settings. Qpex was launched in October 2018 with investments from New Enterprise Associates, Adams Street Partners, LYZZ Capital, Hatteras Venture Partners and Stanford University Draper Fund. The company’s scientists and clinicians have a record of deep expertise in the discovery and development of anti-infective agents, and an extensive record of working with public-private partnerships, including a previous contract with the Biomedical Advanced Research and Development Authority (BARDA) that led to the first approved antimicrobial drug product under that program in 2017. 

Qpex’s partnership with BARDA is funded in whole or in part with federal funds from the Department of Health and Human Services; Office of the Assistant Secretary for Preparedness and Response; Biomedical Advanced Research and Development Authority (BARDA), under OTA number HHSO100201600026C. The agreement provides support for the development of a portfolio of new antibiotics to fight drug- resistant, gram-negative infections. The initial award was for $32 million in funding, and up to an additional $100 million (pending the availability of funding) is available if all options to extend the partnership are exercised by BARDA.

Katherine Smith
Canale Communications 619-849-5378

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