But researchers are not necessarily paid by corporations, and governments, foundations, and such are generally more willing to hand out grants that forego short-term profitability for long-term gains. And while a company might not be interested investing in research that could undermine one of their core products, that obviously does not apply to competing companies that do not already have corresponding products. What better way to break into a market, than to render your competitors' products obsolete?

I've hung out with a lot of pharma folks, and the business is really complicated. Most of the companies aim to both help people and to make a lot of money, and will choose projects based on some balance of those -- sometimes in dubiously ethical ways (e.g. tweaking formulations of existing products to extend the patent) and sometimes in basically fine ways (e.g. lots of the improvements in diabetes management which have helped a ton of people; at least the targeting is fine here though often not the pricing). Obviously chronic diseases that affect lots of rich people are a prime target to make money, so drug companies make lots of drugs for these, and they usually aren't curative because chronic diseases are hard to cure (but see e.g. Hep C which is now curable). There are also companies with rich investors who want to cure death, or at least cure particular diseases that they fear or have a genetic predisposition to (lots of unethical behavior from a certain now-defunct company that tried to do this).

For cancer in particular, pharmas don't (and mostly can't) just target a drug to chronically treat some cancer over the long term but not cure it. Instead they pick some target that's believed to contribute to development (/ metastasis / treatment resistance / whatever) in whatever cancer, and make a drug to interfere with it or to target an immune response to cells that make it. If it's stable, nontoxic, and looks potentially effective enough they'll take it to clinical trials. During clinical trials they'll find out whether it does nothing, gives you a few extra months, or has a chance at curing the disease. Usually the answer is that it does nothing or almost nothing, or isn't worth the side effects, and then the company wasted its time and money. Drugs with a chance to cure common types of cancer can be enormous successes -- see eg Herceptin.

Cancers are difficult diseases and it's rare to find something that reliably cures them. But drug companies aren't pulling their punches. Like they would never say "oh this drug clears breast cancer too reliably, we should make it less effective so that people will be more likely to die but also might take it for longer".

> Which illnesses have been cured? Diabetes, cancer?

Chicken pox, polio, hepatitis C, dracunculiasis, yaws, malaria (on the way of it), tuberculosis, syphilis, everything that can be killed with antibiotics, rubella...

> Which illnesses have been cured? Diabetes, cancer?

Type I diabetes - no, but this is a condition in which the body attacks the part of itself that makes insulin. So by the time it happens, it's too late. Sadly, we're generally bad at understanding and preventing autoimmune diseases, but this needs more basic research, not drugs.

Type II diabetes - essentially a lifestyle condition. May be functionally cured in some/many cases with strict lifestyle interventions. Ironically, GLP-1s may help move some people towards a functional cure.

Cancer - yes, where possible. The open secret is that the best way to fight cancer is to not get it in the first place, or failing that to catch it very early, but these are issues of lifestyle and public health policy - both of which we're currently very bad at optimising, as a species.

> All the financial upside for pharmaceuticals is in prolonged treatments.

Except for the examples to the contrary.

Imagine your role is allocating spending on $10B/year of medical research and you are presented with two strategies: spend everything searching for the cure for one poorly understood condition, or allocate to treatments improving standard of care for 100 conditions.

Improving standard of care for 100 is less risky/more profitable because you have more shots at an expensive process with a high failure rate. And it is a lower bar to improve patient care than to permanently fix a medical mystery. But there is another factor. Focusing on treatment/management over cure most likely maximizes the positive impact on patients within the the constraints you work under.

There have been at least three new major treatments for a chronic thing I have that received FDA approval over my lifetime. Those treatments have had a massive impact on my quality of life, ability to have a career, etc. I don't believe that happens for me if we allocate to cures.