Each bacteriophage typically targets just one or at most few types of bacteria. The targeted treatment in many ways is an advantage because a phage treatment to

Each bacteriophage typically targets just one or at most few types of bacteria. The targeted treatment in many ways is an advantage because a phage treatment to target a pathogen wouldn't also wipe out the symbiotic bacteria that we are increasing finding act as part of our natural defense mechanism against pathogens. The challenge for drug companies is that they would need to isolate and get regulatory approval for each pathogenic bacteria that they wanted to treat. Today one of the challenges that drug companies face with developing new antibiotics is that the profit models for antibiotics are poor compared to drugs that treat chronic conditions. With an antibiotic you sell one course of treatment per patient but with a diabetes drug , for example, you're selling a lifetime supply. With a phage your taking the already small pool of money for antibiotic treatment and dividing it by a hundred or a thousand. The other challenge is that using phages as part of a treatment protocol the diagnosing physician would need to culture and identify the pathogenic bacteria and then order a specific phage for treatment which would increase the cost of diagnosis. One possibility would be creating cocktails of phages that would target many different strains of phages but that would require complex revenue sharing agreements unless all the phages were developed by one drug company. And while phages work great in vitro the don't always work as well in vivo because they are ... viruses ... which the immune system will attempt to identify and destroy them. Phage therapy for a sore throat, for example, requires gargling a phages in liquid. Not as simple as popping a pill to treat a blood infection.