We can now answer the question: "Where do new drugs come from?". Well, we can answer it for the period from 1998 on, at any rate. A new paper in Nature Reviews Drug Discovery takes on all 252 drugs approved by the FDA from then through 2007, and traces each of them back to their origins. What's more, each drug is evaluated by how much unmet medical need it was addressed to and how scientifically innovative it was. Clearly, there's going to be room for some argument in any study of this sort, but I'm very glad to have it, nonetheless. Credit where credit's due: who's been discovering the most drugs, and who's been discovering the best ones?
First, the raw numbers. In the 1997-2005 period, the 252 drugs break down as follows. Note that some drugs have been split up, with partial credit being assigned to more than one category. Overall, we have:
58% from pharmaceutical companies.
18% from biotech companies..
16% from universities, transferred to biotech.
8% from universities, transferred to pharma.
That sounds about right to me. And finally, I have some hard numbers to point to when I next run into someone who tries to tell me that all drugs are found with NIH grants, and that drug companies hardly do any research. (I know that this sounds like the most ridiculous strawman, but believe me, there are people - who regard themselves as intelligent and informed - who believe this passionately, in nearly those exact words). But fear not, this isn't going to be a relentless pharma-is-great post, because it's certainly not a pharma-is-great paper. Read on. . .
Now to the qualitative rankings. The author used FDA priority reviews as a proxy for unmet medical need, but the scientific innovation rating was done basically by hand, evaluating both a drug's mechanism of action and how much its structure differed from what had come before. Just under half (123) of the drugs during this period were in for priority review, and of those, we have:
46% from pharmaceutical companies.
30% from biotech companies.
23% from universities (transferred to either biotech or pharma).
That shows the biotech- and university-derived drugs outperforming when you look at things this way, which again seems about right to me. Note that this means that the majority of biotech submissions are priority reviews, and the majority of pharma drugs aren't. And now to innovation - 118 of the drugs during this period were considered to have scientific novelty (46%), and of those:
44% were from pharmaceutical companies.
25% were from biotech companies, and
31% were from universities (transferred to either biotech or pharma).
The university-derived drugs clearly outperform in this category. What this also means is that 65% of the pharma-derived drugs get classed as "not innovative", and that's worth another post all its own. Now, not all the university-derived drugs showed up as novel, either - but when you look closer, it turns out that the majority of the novel stuff from universities gets taken up by biotech companies rather than by pharma.
So why does this happen? This paper doesn't put it one word, but I will: money. It turns out that the novel therapies are disproportionately orphan drugs (which makes sense), and although there are a few orphan-drug blockbusters, most of them have lower sales. And indeed, the university-to-pharma drugs tend to have much higher sales than the university-to-biotech ones. The bigger drug companies are (as you'd expect) evaluating compounds on the basis of their commercial potential, which means what they can add to their existing portfolio. On the other hand, if you have no portfolio (or have only a small one) than any commercial prospect is worth a look. One hundred million dollars a year in revenue would be welcome news for a small company's first drug to market, whereas Pfizer wouldn't even notice it.
So (in my opinion) it's not that the big companies are averse to novel therapies. You can see them taking whacks at new mechanisms and unmet needs, but they tend to do it in the large-market indications - which I think may well be more likely to fail. That's due to two effects: if there are existing therapies in a therapeutic area, they probably represent the low-hanging fruit, biologically speaking, making later approaches harder (and giving them a higher bar to clear. And if there's no decent therapy at all in some big field, that probably means that none of the obvious approaches have worked at all, and that it's just a flat-out hard place to make progress. In the first category, I'm thinking of HDL-raising ideas in cardiovascular and PPAR alpha-gamma ligands for diabetes. In the second, there are CB1 antagonists for obesity and gamma-secretase inhibitors in Alzheimer's (and there are plenty more examples in each class). These would all have done new things in big markets, and they've all gone down in expensive flames. Small companies have certainly taken their cuts at these things, too, but they're disproportionately represented in smaller indications.
There's more interesting stuff in this paper, particularly on what regions of the world produce drugs and why. I'll blog about again, but this is plenty to discuss for now. The take-home so far? The great majority of drugs come from industry, but the industry is not homogeneous. Different companies are looking for different things, and the smaller ones are, other things being equal, more likely to push the envelope. More to come. . .