Azeen Ghorayshi has a very good article about phage therapy–the use of bacterial viruses to treat bacterial infections (the bacterial viruses only infect bacterial, not human cells). There’s a long history of using phage to stop bacterial disease (d’Herelle’s use of phage to stop cholera outbreaks and treat sick patients is the classic example). While it doesn’t always work (as is the case with antbiotic therapy), it’s a promising therapy, especially since many bacteria are resistant to many (or all) traditional antibiotics.

To me, the real hurdle isn’t technological, but, well, this (boldface mine):

But the biggest obstacle for phage therapy in the U.S. may ultimately have less to do with the science than its implementation into the medical system.

Rachel George and Roger Mintey both received personalized phage treatments, meaning that the viruses were selected to specifically attack their particular infections. It’s uncertain whether the FDA would be able to adopt such a tailor-made approach, which stands in such stark contrast to the one-size-fits-most approach of antibiotics.

What’s more, because of the number and diversity of phages — and a regulatory system that’s been set up to deal with manufactured chemicals rather than the messiness of nature — each phage would have to be tested as its own drug, even if it’s used in combination. In a concoction of nine phages designed to treat a mixture of three bacteria, that could mean hundreds of trials. Depending on who you ask, this is viewed as anything from costly to impossible.

Regulation is one issue. But related to this is the ability to monetize it: making a chemical, once you figure out how to do it, is straightforward. But selecting a tailored mixture of different phage is not. Importantly, for companies, it’s harder to make money from this ‘loosy-goosey’ system. How do you patent a phage, or a mixture of phage? And if determining the correct phage cocktail is required, what are the legal liabilities if you make it incorrectly (i.e., don’t stop the infection due to a misdiagnosis)?

In a sense, we’re viewing this as a de facto drug development problem (it’s not–the phage are commonplace), when it should probably be viewed as the microbiological equivalent of surgery: ultimately, a doctor has to make an informed therapeutic decision. The phage manufacturers, such as they are, should be viewed as medical supply companies. The problem is most medical supply companies aren’t making blockbuster profits (compared to a successful medical startup, anyway…).

Of course, if bacterial resistance continues to rise, we’ll probably figure this out eventually….