there are companies working on commercializing phage therapy, though often for rare disease or cancer.

developing new antibiotics in general is difficult in the US because there are many generic antibiotics that work well, so your pricing power is often quite low. but your R&D costs are still just as high as something like cancer, where you can charge hundreds of thousands a year per patient. so R&D dollars go to higher ROI assets. see novartis, which recently axed its antibiotics division

super resistant bugs are a big issue however and there is probably an investment case there, esp at a time like this when capital is so available. i dont know how hard it would be to develop drugs against particular resistant strains, how many patients get each infection / year, how long you have to intervene before pts die, etc, but i can imagine its a tough field

Thoughts on why this hasn't been commercialized?

It's a poor fit for the current economic/political model of drug development, licensing, and commercialization.

It isn't legal to sell a treatment for any disease or condition unless you've conducted multiple rounds of clinical trials proving that it is both safe and effective. Running these trials is fantastically expensive, especially when you don't know ahead of time which treatments will make it out the other side to become sellable products.

Pharma companies are good at getting things through these trial stages. But they can't afford to do it unless there's a patent-protected profit on the other side for the ones that work.

Thus the problem is that phages are essentially a virus picked up out of some pond muck or something. You can't really mass-produce them, and it wouldn't make sense to anyways, as the application for any one phage is very limited. You can't run a particular phage though a set of clinical trials - the effectiveness of a particular strain would be gone long before you got through the first phase. Making enough profit from selling it after commercialization once it made it through the clinical trials that it can't possibly ever pass is a completely absurd notion.

What we need to make phages more widely used isn't economic investment but a complete redo of how we legally require the healthcare industry to operate.

From the standpoint of someone who works in healthcare epidemiology and has always been fond of phage therapy, a few reasons:

1) Even with resistance on the rise, we still have antibiotics that work. Phage therapy is a "someday we're going to need this...we think" type treatment.

2) There's no such thing as a "broad spectrum" phage. They're organism specific, and that means not only would you need to keep a phage library on hand, but you'd have to do a lot of diagnostic tests. That's going to be both expensive and tricky.

3) Phages are living things. Not only is that a weird regulatory framework to be in for a drug, but it also means that you need to be able to keep phage alive. In contrast, antibiotics are inert.

4) Phage therapy is also relatively new in the West, which means there's just less of a R&D infrastructure behind it.

There have been people working on commercializing phage therapy since I was in undergrad (I'm now a tenure-track professor). The problem is it's hard, and antibiotics are so much better as a treatment that there's kind of a ceiling on the excitement that they can generate.

Hard to get regulatory approval and concerns that phages can't be patented so pharmaceutical can't guarantee a monopoly. Plus, the existing way works, so not much incentive to replace it with something speculative. Sort of like why you don't rewrite an existing codebase in C in some other language.

> Plus, the existing way works, so not much incentive to replace it with something speculative.

Except the existing way is quickly no longer working, hence antibiotic resistance. Also, it's not speculative, phage therapy works.

Sure, I'm disputing either of those claims. But if you look at it from the perspective of a drug company the existing way is fine (for now) and it's risky to switch.

Oops should have said "not disputing".

Having talked to a researcher that's used phage therapy on a soldier to combat sepsis, it obviously works, but the hurdle is getting the FDA/others to allow injection of live virus into people. (Edit: that was his quick response to "why is it not being used?")

Somewhat similar: I had to get several injections of the subunit anthrax vaccine that essentially doesn't work (even though live attenuated anthrax is far more effective) because some regulatory committee doesn't like the idea of live (or even whole cell) vaccines.

Difficult to implement, difficult to identify patients.

Phages are specific to particular bacteria, more specific than an antibiotic. This means you need to develop many more varieties of phage to cover the same ground.

These phages are perishable, and alive. That means you have to put much more effort into developing, and maintaining stocks.

Lastly, you need to have specific diagnoses of patients. You need to know which phage to give, based on the bacteria infecting the patient. This means more patient tests, and more time between arrival and treatment.

This all adds up the costs. Phage therapy is better suited to targeted diseases like MRSA than a replacement of chemotherapy.

Here's a good article about phage therapy. Scaling is difficult because the treatment must be customized for each patient.

https://www.motherjones.com/environment/2018/05/the-best-vir...

Difficult to patent. Likely substantial costs to build and maintain a very large phage library. Often each particular patient needs individualized treatment which is a laborious process. I'm sure there are regulatory hurdles in the USA too.

The reason is called the FDA. It just isn’t possible to jump through all the hoops the FDA wants and have a viable product at the end of it.