Researchers at Oregon State University, Corvallis (OSU) and pharmaceutical company Aradigm Corporation have found that Aradigm’s investigational products Lipoquin® and Pulmaquin® are capable of significantly reducing the growth of the pulmonary non-tuberculous mycobacteria (PNTM) infection in mice. The results will be presented at the upcoming American Thoracic Society 2015 International Conference in Denver, on May 20 at Session D108 entitled “Diagnosis and Management of Nontuberculous Mycobacteria Infections” (Abstract ID/Title: #A6293, poster #609 – Treatment of Mycobacterium Avium Subsp Hominissuis (MAH) Lung Infections with Liposome-Encapsulated Ciprofloxacin Resulted in Significant Decrease in Bacterial Load in the Lung).
Ciprofloxacin is a widely prescribed antibiotic with a broad-spectrum of antibacterial activity that is generally used to treat acute and chronic lung infections. Pulmaquin is a dual release formulation comprising a mixture of liposome encapsulated and unencapsulated ciprofloxacin. Pulmaquin is currently being evaluated in two ongoing Phase 3 trials (ORBIT-3 and ORBIT-4) for the treatment of non-cystic fibrosis bronchiectasis (non-CF BE), a severe, chronic and rare disease, frequently associated with chronic lung infection and characterized by an abnormal dilatation of the bronchi and bronchioles. Lipoquin is the liposomal portion of the Pulmaquin formulation.
Aradigm’s inhaled ciprofloxacin formulations are also being investigated as a therapy for patients with PNTM infection, a group of bacteria that can be found almost everywhere, including tap water. Individuals infected with PNTM usually develop fever, night sweats, cough, fatigue and weigh loss or appetite loss. Patients with respiratory disorders are especially vulnerable to infection by PNTM. Treatment is possible through antibiotics, however, they can cause significant side effects and some mycobacteria species can develop resistance to them.
Researchers have now found that a single daily dose of Lipoquin and Pulmaquin in a 3-week treatment can significantly reduce the number of Mycobacterium Avium Subsp Hominissuis colony forming units by 79% and 77%, respectively, in comparison to saline controls in relevant mice models. Unencapsulated ciprofloxacin was found to have no effect.
The team concluded that Lipoquin and Pulmaquin are capable of reducing PNTM growth in mice. “I am very pleased that the encouraging effects of Lipoquin and Pulmaquin against PNTM in the biofilm and macrophage in vitro assays have been now confirmed with this short treatment in our animal model. This test system was previously evaluated and demonstrated to provide results comparable to the results obtained in humans. We expect that even more profound effects will be seen with the prolonged treatment over several months typically used in humans,” concluded Dr. Luiz Bermudez, professor of Biomedical Sciences at OSU, in a news release.