Here's a business-section column at the New York Times on the problem of antibiotic drug discovery. To those of us following the industry, the problems of antibiotic drug discovery are big pieces of furniture that we've lived with all our lives; we hardly even notice if we bump into them again. You'd think that readers of the Times or other such outlets would have come across the topic a few times before, too, but there must always be a group for which it's new, no matter how many books and newspaper articles and magazine covers and TV segments are done on it. It's certainly important enough - there's no doubt that we really are going to be in big trouble if we don't keep up the arms race against the bacteria.
This piece takes the tack of "If drug discovery is actually doing OK, where are the new antibiotics?" Here's a key section:
Antibiotics face a daunting proposition. They are not only becoming more difficult to develop, but they are also not obviously profitable. Unlike, say, cancer drugs, which can be spectacularly expensive and may need to be taken for life, antibiotics do not command top dollar from hospitals. What’s more, they tend to be prescribed for only short periods of time.
Importantly, any new breakthrough antibiotic is likely to be jealously guarded by doctors and health officials for as long as possible, and used only as a drug of last resort to prevent bacteria from developing resistance. By the time it became a mass-market drug, companies fear, it could be already off patent and subject to competition from generics that would drive its price down.
Antibiotics are not the only drugs getting the cold shoulder, however. Research on treatments to combat H.I.V./AIDS is also drying up, according to the research at Yale, mostly because the cost and time required for development are increasing. Research into new cardiovascular therapies has mostly stuck to less risky “me too” drugs.
This mixes several different issues, unfortunately, and if a reader doesn't follow the drug industry (or medical research in general), then they may well not realize this. (And that's the most likely sort of reader for this article - people who do follow such things have heard all of this before). The reason that cardiovascular drug research seems to have waned is that we already have a pretty good arsenal of drugs for the most common cardiovascular conditions. There are a huge number of options for managing high blood pressure, for example, and they're mostly generic drugs by now. The same goes for lowering LDL: it's going to be hard to beat the statins, especially generic Lipitor. But there is a new class coming along targeting PCSK9 that is going to try to do just that. This is a very hot area of drug development (as the author of the Times column could have found without much effort), although the only reason it's so big is that PCSK9 is the only pathway known that could actually be more effective at lowering LDL than the statins. (How well it does that in the long term, and what the accompanying safety profile might be, are the subject of ongoing billion-dollar efforts). The point is, the barriers to entry in cardiovascular are, by now, rather high: a lot of good drugs are known that address a lot of the common problems. If you want to go after a new drug in the space, you need a new mechanism, like PCSK9 (and those are thin on the ground), or you need to find something that works against some of the unmet needs that people have already tried to fix and failed (such as stroke, a notorious swamp of drug development which has swallowed many large expeditions without a trace).
To be honest, HIV is a smaller-scale version of the same thing. The existing suite of therapies is large and diverse, and keeps the disease in check in huge numbers of patients. All sorts of other mechanisms have been tried as well, and found wanting in the development stage. If you want to find a new drug for HIV, you have a very high entry barrier again, because pretty most of the reasonable ways to attack the problem have already been tried. The focus now is on trying to "flush out" latent HIV from cells, which might actually lead to a cure. But no one knows yet if that's feasible, how well it will work when it's tried, or what the best way to do it might be. There were headlines on this just the other day.
The barriers to entry in the antibiotic field area similarly high, and that's what this article seems to have missed completely. All the known reasonable routes of antibiotic action have been thoroughly worked over by now. As mentioned here the other day, if you just start screening your million-compound libraries against bacteria to see what kills them, you will find a vast pile of stuff that will kill your own cells, too, which is not what you want, and once you've cleared those out, you will find a still-pretty-vast pile of compounds that work through mechanisms that we already have antibiotics targeting. Needles in haystacks have nothing on this.
In fact, a lot of not-so-reasonable routes have been worked over, too. I keep sending people to this article, which is now seven years old and talks about research efforts even older than that. It's the story of GlaxoSmithKline's exhaustive antibiotics research efforts, and it also tells you how many drugs they got out of it all in the end: zip. Not a thing. From what I can see, the folks who worked on this over the last fifteen or twenty years at AstraZeneca could easily write the same sort of article - they've published all kinds of things against a wide variety of bacterial targets, and I don't think any of it has led to an actual drug.
This brings up another thing mentioned in the Times column. Here's the quote:
This is particularly striking at a time when the pharmaceutical industry is unusually optimistic about the future of medical innovation. Dr. Mikael Dolsten, who oversees worldwide research and development at Pfizer, points out that if progress in the 15 years until 2010 or so looked sluggish, it was just because it takes time to figure out how to turn breakthroughs like the map of the human genome into new drugs.
Ah, but bacterial genomes were sequenced before the human one was (and they're more simple, at that). Keep in mind also that proof-of-concept for new targets can be easier to obtain in bacteria (if you manage to find any chemical matter, that is). I well recall talking with a bunch of people in 1997 who were poring over the sequence data for a human pathogen, fresh off the presses, and their optimism about all the targets that they were going to find in there, and the great new approaches they were going to be able to take. They tried it. None of it worked. Over and over, none of it worked. People had a head start in this area, genomically speaking, with an easier development path than many other therapeutic areas, and still nothing worked.
So while many large drug companies have exited antibiotic research over the years, not all of them did. But the ones that stayed have poured effort and money, over and over, down a large drain. Nothing has come out of the work. There are a number of smaller companies in the space as well, for whom even a small success would mean a lot, but they haven't been having an easy time of it, either.
Now, one thing the Times article gets right is that the financial incentives for new antibiotics are a different thing entirely than the rest of the drug discovery world. Getting one of these new approaches in LDL or HIV to work would at least be highly profitable - the PCSK9 competitors certainly are working on that basis. Alzheimer's is another good example of an area that has yielded no useful drugs whatsoever despite ferocious amounts of effort, but people keep at it because the first company to find a real Alzheimer's drug will be very well rewarded indeed. (The Times article says that this hasn't been researched enough, either, which makes me wonder what areas have been). But any great new antibiotic would be shelved for emergencies, and rightly so.
But that by itself is not enough to explain the shortage of those great new antibiotics. It's everything at once: the traditional approaches are played out and the genomic-revolution stuff has been tried, so the unpromising economics makes the search for yet another approach that much harder.
Note: be sure to see the comments for perspectives from others who've also done antibiotic research, including some who disagree. I don't think we'll find anyone who says it's easy, though, but you never know.