Phage Therapy: Challenges in Its Development and Clinical Implementation

The use of bacteriophages for therapeutic purposes, termed phage therapy was met with inconsistent reports of treatment outcome. Antibiotics were discovered around the same time and were regarded as a magic bullet for the treatment of infectious diseases. This led to the loss of interest in phage therapy. Almost a century later, the non-judicious use of antibiotics has contributed to the rise of drug-resistant bacteria that show increasing resistance to the last line of antibiotics. Consequently, interest has been renewed in phage therapy to treat multidrug-resistant infections. The future of phage therapy looks more promising, as the trials have extended globally. The wider use of phage therapy, however, has to navigate numerous obstacles that are a hurdle to its successful implementation. These include the issues related to the product (phage selection, preparation, extreme specificity for host, emergence of resistance to phages, development of immune response against the phages, pharmacokinetics, and pharmacodynamics), patient (lesser awareness and hesitancy in accepting a live virus based treatment option for combating an infection) and regulatory issues (related to clinical trials, drug/phage manufacturing, licensing, and patents). This chapter discusses various challenges to the use of phage therapy.