Manufacturing Bacteriophages (Part 1 of 2): Cell Line Development, Upstream, and Downstream Considerations

Abstract

Within this first part of the two-part series on phage manufacturing, we will give an overview of the process leading to bacteriophages as a drug substance, before covering the formulation into a drug product in the second part. The principal goal is to provide the reader with a comprehensive framework of the challenges and opportunities that present themselves when developing manufacturing processes for bacteriophage-based products. We will examine cell line development for manufacture, upstream and downstream processes, while also covering the additional opportunities that engineered bacteriophages present.

Practical Assessment of an Interdisciplinary Bacteriophage Delivery Pipeline for Personalized Therapy of Gram-Negative Bacterial Infections

“…-Titration, plaque, or spot assays for phage-bacteria matches, plaque morphology, change of plaque morphology over time, efficiency of plating, and lysis/growth curves for phage-bacteria matches [18,[39][40][41][42][43]; -Effect of antibiotics, polymicrobial infection assays, and phage cocktail performance assessments [15,39,[44][45][46]; -Phage training for robust phages [30]; and -Neutralization assays for assessing anti-phage immune responses [16].…”

“…The phage laboratory personnel might be trained in further methods, such as ultracentrifugation, dialysis, biofilm formation, and flow analysis. Phage laboratories can find detailed recommendations in the literature [11,18,39].…”

“…The laboratories for steps 2 and 3 should be equipped with certified, maintained, and regularly inspected sterile working facilities, equipment, and technical devices [11,39]. Monitoring of critical parameters, such as fridge and freezer temperatures, is recommended [11].…”

“…Bacterial or chemical residues: Apart from endotoxins, further bacterial or chemical residues in the phage solution, if present, are removed, and the removal is quantified [11,39]. Bacterial residues cover, for example, exotoxins and lipoteichoic acids [34,56].…”

“…The production laboratory provides phage expertise in Conditions for phage storage (cooling, freezing, lyophilization, spray drying, master and working seed lots, and shelf-life monitoring) [11,24,39,53].…”