Experimental Antibiotics Shown to Kill Bacterial Infection Frequently Found in Cystic Fibrosis

Ana Pamplona, PhD avatar

by Ana Pamplona, PhD |

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During the American Thoracic Society 2015 International Conference being held in Denver, Colorado, 15-20 of May, researchers from Oregon State University, Corvallis (OSU), and Aradigm Corporation will present a study entitled “Treatment of Mycobacterium Avium Subsp Hominissuis (MAH) Lung Infections with Liposome-Encapsulated Ciprofloxacin Resulted in Significant Decrease in Bacterial Load in the Lung” where they show the positive effects of Aradigm’s investigational drugs Lipoquin® and Pulmaquin® against pulmonary non-tuberculous mycobacteria infection, a bacterial infection prevalent in cystic fibrosis.

Non-tuberculous mycobacteria (NTM) can be found ubiquitously from tap water to soil. Pulmonary non-tuberculous mycobacteria (PNTM) infections affect mainly individuals with diseases such as cystic fibrosis and chronic obstructive pulmonary disease (COPD). Bronchiectasis, a condition that occurs often after an infectious process, is a common co-morbidity in CF patients infected by non-tuberculous mycobacteria. The standard therapy for PNTM is antibiotics, but mycobacteria can at times be resistant to some antibiotics.

In this study, the researchers showed that Aradigm’s experimental drugs Lipoquin® and Pulmaquin® significantly reduced the growth of the pulmonary non-tuberculous mycobacteria infection (PNTM) after one daily respiratory tract dose in mice for 3 weeks. The antibiotics Lipoquin and Pulmaquin reduced the number of colony forming units of Mycobacterium Avium Subsp Hominissuis by 79% and 77% respectively when compared with saline controls.

The antibiotic Ciprofloxacin is typically used for the treatment of acute lung infections and has a wide-spectrum antibacterial action against several bacteria, like Pseudomonas aeruginosa. Pulmaquin is a dual release formulation composed of a mixture of liposome encapsulated and unencapsulated ciprofloxacin. Pulmaquin is being assessed in two ongoing Phase 3 studies, ORBIT-3 and ORBIT-4, for its safety and efficacy as a daily dose as an inhalator for the chronic therapy of non-cystic fibrosis bronchiectasis (non-CF BE).

Dr. Luiz Bermudez, professor of Biomedical Sciences at OSU, said in the news release that the positive effect of short-term therapy with Lipoquin and Pulmaquin shown previously and now confirmed in animal models is very encouraging. He added that, “We expect that even more profound effects will be seen with the prolonged treatment over several months typically used in humans.”

The U.S. Food and Drug Administration (FDA) has given both ciprofloxacin liposomes and inhalated ciprofloxacin the designations of granted orphan drugs for non-CF BE in the U.S. In addition, Pulmaquin was designated as Qualified Infectious Disease Product (QIDP) for therapy of non-CF BE patients with chronic lung infections with Pseudomonas aeruginosa. The QIDP designation made Pulmaquin suitable for Fast Track designation given by the FDA last September.