AmpliPhi granted Japanese patent covering the use of phage therapy to resensitize Pseudomonas aeruginosa infections to antibiotics

AB-PA01 designed to broadly target both CF and non-CF Pseudomonas isolates and potentially eradicate the infection instead of merely keeping it at bay.

The patent covers the treatment of Pseudomonas infections through the sequential use of a bacteriophage (phage) therapeutic followed by an antibiotic to which the bacteria were formerly resistant. During the first stage of phage administration, antibiotic-resistant Pseudomonas are placed under extreme selective pressure by the attacking phage. Following the initial assault, most of the bacteria die, but a small portion may evade the phage attack by mutating in a way that protects them from the phage but at the same time resensitizes that population to antibiotics. Antibiotics are then administered to deplete the remaining bacterial population. This resensitization phenomenon has been observed in both in vitro and in vivo experiments, as well as in a few antibiotic-resistant human infections, including a previously-reported case where an antibiotic-resistant Pseudomonas bladder infection was treated and cleared in Australia under a compassionate use exemption.

Pseudomonas infects almost 60% of cystic fibrosis (CF) patients overall, with approximately 80% of patients over the age of 18 chronically infected by the pathogenic bacteria. Recurrent Pseudomonas infections cause severe lung damage and can lead to bronchiectasis and the need for lung transplants. Current standard of care treatment for CF patients include inhaled antibiotics that tamp down but may not eliminate the infection. AmpliPhi’s investigational drug therapy, AB-PA01, is designed to broadly target both CF and non-CF Pseudomonas isolates and potentially eradicate the infection instead of merely keeping it at bay.

“Through a step-wise treatment paradigm of AB-PA01 followed by antibiotics, we envision a treatment modality that effectively clears chronic Pseudomonas infections in CF patients,” said M. Scott Salka, CEO of AmpliPhi Biosciences. “By resensitizing Pseudomonas to antibiotics, we can turn back the clock on currently ineffective antibiotics and make them relevant again. Antibiotic resensitization has the potential to provide patients and caregivers with a new set of weapons to make impactful progress against the growing threat of antibiotic resistance by combining the natural ability of phage to selectively target bacteria with the current arsenal of antibiotics. We look forward to evaluating our proprietary phage cocktail alongside existing antibiotics to address recurrent and resistant Pseudomonas infections in patients with CF.”

AB-PA01 is currently being manufactured in AmpliPhi’s cGMP facility and is in nonclinical studies at the Royal Brompton Hospital, London, UK. AmpliPhi anticipates initiating a Phase 1 clinical trial in 2017 of AB-PA01 for the treatment of CF using a nebulized formulation of the phage cocktail.