Why you won't see phage therapy in the US any time soon

[unixronin]

Phage therapy, in brief, is the therapeutic use of virus phages (aka bacteriophages), instead of antibiotics, to treat pathogenic bacterial infections.  Phage therapy has a number of advantages over antibiotics, among which are:

• Virus phage strains are specific to just a handful of bacterial strains, so they don't also wipe out beneficial bacteria as antibiotics often do;
• Bacteria do not develop resistance to virus phages, because the phages evolve right along with them;
• Virus phages attack only their bacterial targets, and do not damage human cells;
• Phage therapy typically has few or no undesirable side effects, unlike antibiotics which often have severe side effects.

There's some further information in a USAToday article from 2006.  But what neither of these sources really point out is that you won't be seeing phage therapy in the US any time soon, unless FDA rules are changed.

Virus phages are already used in supermarkets — sprayed on meat to kill listeria, for example, to prevent food poisoning and extend freshness.  But when sprayed on foodstuffs, phages are considered a food additive.  Under FDA rules for food additives, that basically means that it's easy to gain approval and the approval only needs to be done once.  Once approved, one phage-spray food additive is considered much like another.

But the moment you use it therapeutically on a human, that means the phage becomes a drug.  And that entails a whole different approval process.  Every new drug must be separately approved, with clinical trials that may take years and can easily cost millions of dollars per trial.  If you plan on using multiple drugs in combination, each planned combination must be separately tested and separately approved.

There are hundreds of pathogenic bacterial species and strains, and hundreds of phage strains specific to them, which must be blended into a specific mixture to combat the bacterial strains present in any given infection.  Under FDA rules, every individual mixture must be tested.  You do the math.

...OK, I'll help you out a little with the math.  Let's simplify the math, a lot, and pretend there are only 50 phage strains (there aren't; there are hundreds) and that no therapeutic mixture will ever contain more than five strains (in reality it may contain less than five, or it may contain dozens).

There are 2,118,760 unique ways of selecting five phage strains out of fifty.  FDA rules say each one of these combinations must be separately tested for safety and efficacy.  With real-world numbers, the total is many times higher ... and I don't mean fifteen or twenty times higher, I mean fifteen or twenty orders of magnitude higher.

Do you begin to see the problem?

Phage therapy could get us out of the hole we're in now, with ever-dwindling numbers of antibiotics still effective against ever-increasing numbers of multi-resistant "superbug" strains.  Many doctors and bacteriologists agree it's only a matter of time before an infectious pathogenic bacterial strain arises that is resistant to all known antibiotics.

But under current FDA rules, phage therapy in humans will never be approved, because under current FDA testing rules, the test regimen required is quite simply impossible.  There literally are not enough people on the planet to conduct clinical trials of every therapeutic phage combination, even if we could test a million combinations per person.

This isn't the only problem with FDA drug testing rules.  Many experimental therapies for hard-to-treat medical conditions are unavailable in the US because, outside of a clinical trial environment, you cannot use an experimental treatment on a human that has not been proven safe in clinical trials, even if their condition is otherwise terminal and it's their only chance.  (Some limited exceptions to this rule have been allowed in recent years.)

When FDA rules and policies are blocking even testing valuable treatments, the FDA needs to change.

Comments

[lebo-superman.livejournal.com]

"When FDA rules and policies are blocking even testing valuable treatments, the FDA needs to change."

I'd go so far as to say that the FDA needs to change anyhow. They aren't operating as safety preservers. For a very long time, they have been in the business of protecting the profit margins of the drug companies. Which is why, every few years (ever since I was a teen 3 decades ago) you hear whispers about a new attempt to place all nutritional supplements under regulation and require a prescription to obtain them. Even vitamins.

[unixronin.livejournal.com]

Yup. There's that too.

The first priority of ANY government agency is to ensure its own continued survival. The second is to increase its power.

[ithildae.livejournal.com]

When your regulations are in place to handle linear growth, and science increases exponentially, things are going to break down. The FDA is entering a crunch time, they can adapt, or they will be bypassed. The aging baby boomers are not going to tolerate not having treatments available to them that could improve their quality of life. There is some time yet. Maybe President Obama can make it a priority, everything else is.