AmpliPhi Biosciences’ investigative therapy AB-PA01, in combination with antibiotics, shows significant potential to treat multi-drug resistant Pseudomonas aeruginosa infection in cystic fibrosis (CF), according to the case report of a CF patient with recurrent pneumonia and pulmonary exacerbations.
These positive early results further support the development of the treatment against P. aeruginosa bacteria in larger and controlled clinical trials.
The case study was discussed at the 41st European Cystic Fibrosis Society (ECFS) Conference, held June 6-9 in Belgrade, Serbia, in a poster presentation titled “Bacteriophage treatment of multidrug-resistant Pseudomonas aeruginosa pneumonia in a cystic fibrosis patient.”
AB-PA01 is an investigative therapy based on bacteriophages, also known as phages, which are natural predators of bacteria that can penetrate and disrupt drug-resistant bacteria biofilms. Taking advantage of these unique phage proprieties, AB-PA01 was developed to specifically target P. aeruginosa and restore antibiotic sensitivity to drug-resistant bacteria.
Preclinical studies have shown that AB-PA01 holds a broad activity against 70-80% of global P. aeruginosa clinical isolates and can significantly reduce biofilms. Also, AB-PA01’s phages can survive nebulization, which potentially allows its use in an inhaled formulation to specifically treat lung infections, according to AmpliPhi Biosciences.
After the approval by the U.S. Food and Drug Administration of an emergency Investigational New Drug application, AmpliPhi advanced with a first-in-human test of its AB-PA01 as an adjunct treatment to systemic antibiotics.
The report described the case of a 26-year-old woman with CF who was on the list for a double lung transplant and had suffered multiple episodes of drug-resistant P. aeruginosa pneumonia and CF exacerbations. Before starting treatment with the investigative therapy, she had been treated with multiple courses of antibiotics, which had to be discontinued due to kidney failure.
The patient was given AB-PA01 intravenously every six hours for a total of eight weeks of treatment. During this period, several samples of respiratory bacteria were collected to monitor AB-PA01’s effectiveness.
Results showed the patient tolerated the phage therapy well, with no adverse events being reported. Importantly, her lung infection was resolved after one week of treatment.
Lung bacteria cultures during the treatment period showed ongoing susceptibility to AB-PA01. However, the researchers reported that they “noted a change in microbiological pattern over time,” which may suggest an adjustment of response to treatment.
Still, she did not experience pneumonia or CF exacerbations in the two months after her treatment was completed. Her renal failure was also resolved.
“The patient responded to the combination of AB-PA01 and antibiotic therapy based on an improvement in objective clinical criteria. Furthermore, treatment with AB-PA01 was safe and well-tolerated,” Saima Aslam, MD, director of the Solid Organ Transplant Infectious Diseases service at the University of California San Diego Medical Center and the treating physician, said in a press release.
“In this case study, bacteriophage therapy has demonstrated to hold much promise for patients with cystic fibrosis suffering from multidrug resistant pulmonary bacterial infections,” Aslam added.
Additional controlled clinical studies are warranted to support the approval of AB-PA01 as an option to treat CF pulmonary infections.