Good Lord. Do you spend more time in the clinic or the courtroom?
I’m hoping its the former, and you have good representation and a sane judiciary to handle the latter…
I spend little time in court, I’ve not lost any cases. They tend to get thrown out early in the process, as so many of the claims are ludicrous.
Even so I’ve spent more time writing affidavits, being deposed, and appearing in a court (county, state, federal) than I ever planned to. But I get paid the same hourly rate whether I’m seeing patients, doing legal paperwork, or sitting in a courtroom.
How does that work? Suppose the drug is off patent and there are generic versions selling for a few dollars. Now the original company comes up with a new use and get a patent for a “new use for an old substance”. Are all the generic versions now banned? If not, in what form does the new patent apply? And which countries have this “new use for an old substance” patent?
Bottom line and as a practical matter, I am extremely skeptical as to whether either the slightly modified version approach or the new use patent approach are significant in cases like this, in terms of changing the cost/profit considerations of old vs new drugs for pharmacy companies.
The example of taxanes in cancer therapy may be what you’re referring to as a “modified version approach”.
Around 1992 a major advance in treating certain types of cancer came with the introduction of a compound isolated from the Pacific yew tree. Since it took an average of six 100-year-old Pacific yew trees (a slow-growing species) to treat one patient, this was not an environmentally sustainable model. A semi-synthetic process yielded Taxol in 1995, which used needles and twigs of a European yew tree, making it a renewable resource and for a time at least, patentable. Since then, while generic taxol is still in use, new derivatives have been patented and come into production. There have also been patents on cell-culture derived taxanes, eliminating the need to harvest from existing trees.
This is a sizable market in which ingenuity as well as profit motive have come into play.
It always has seemed odd to me that the woo crowd brags about the high percentage of pharmaceuticals that are derived from “natural” substances, while simultaneously complaining that no one will research natural drugs because they can’t be patented. 
New uses often involve new dosages, that often aren’t commercially available, so they often patent a pill, say, made with the new dosage, or combined with other ingredients. See an example here. The notion is, anyone producing the pills with a similar dosage is intending to infringe on the patented use.
Sure, a doctor could prescribe the original drug at its original dose, and it would be hard to prove that it was being done for the patented use, but lots of companies find it profitable to do this anyways. Most doctors want the best possible result for their patients, so won’t go this route without some major reason why, like the person ahs no or bad health insurance.
Generic aren’t banned, because they can still be used for the pre-existing uses. So long as the companies producing them don’t start getting into “wink wink nudge nudge” kind of hijinks, they’re okay to keep selling as they always did.
If you google “patent new use for old drug”, you can see there’s lots of sites out there discussing this, from pro- anti- and neutral perspectives.
Hundreds of millions to billions of dollars suggests your skepticism is misplaced.
And this highlight another argument against the “they can’t patent natural remedies” claims. You can’t patent the substance as it exists in nature, but you can patent a version where the active ingredient has been isolated and purified into a commercially vendible product.
So, sure, you can still go out and chew some twigs and bark, but if you want something a bit more convenient, you can just buy the patented version. Most people in our society opt for he second option.
I wasn’t referring to anything. I was responding to someone else who made a claim, and his/her claim was general. More below.
So bottom line is that the new formulation 1) requires some expense in new studies etc., and 2) is not going to get a monopoly on the market because of all the “wink wink nudge nudge” in people using the generic versions. So there’s a bunch of cost and still not nearly as much return as a new drug.
Your example is of a guy who patented a form of aspirin specifically geared to cardiovascular health. What do you think most doctors are telling their patients? To take this patented version, or to just take X daily dose of generic aspirin? I don’t have any hard data, but I can tell you I’ve known numerous people who’ve been advised by heart doctors to take generic aspirin and never heard of anyone taking this patented drug.
Do any of your examples involve drugs which were off patent at the time they were repurposed for other use? AFAICT, you’re talking about drugs which were in development form at the time of the repurposing or at least under patent at the time. This has nothing at all to do with the situation we’re discussing.
See the last example quoted above. Dextromethorphan has been around since the late 50s, but still made hundreds of millions of dollars for the people who patented the new use.
OK.
But dextromethorphan is one of the two active ingredients of Nuedexta. Would dextromethorphan work on its own and the developers of Nuedexta tinkered with and enhanced the formula in order to get a patent - which is what you’re suggesting to be feasible - or is it only the combination of the two active ingredients which is effective? If someone took Robitussen for pseudobulbar affect, would it work, just not quite as well as Nuedexta?
DXM plus quinidine sulfate, two of the older, cheaper drugs on the planet, together in a high priced pill. Shades of Martin Shkreli!
How about thalidomide? It was not only off patent, but nobody wanted to touch it with a ten-foot pole owing to its sinister history of causing fetal malformations.
Then somebody looked into its potential for treating other diseases (such as leprosy and multiple myeloma) and it wound up as a highly profitable drug for Celgene, reportedly earning the company $7 billion in one recent year (Celgene was accused of using the tight regulatory restrictions governing its marketing of the drug as an excuse to maintain its patent and block generic versions). There are also derivatives of thalidomide now in use and presumably patented.
Apparently there are complex regulatory hoops to jump through before off-patent drugs can be repurposed for treating other ailments, and drug companies have been reluctant to invest in research including expensive large phase III clinical trials. But as the Celgene example shows, if you get a winner there’s a lot of money to be made.
Fascinating. Thank you.
I believe it was off patent but was banned from use altogether, so as a practical matter generic versions were not available. That’s effectively the same as a patent, for purposes of this discussion.
But here’s the thing. I’m not discussing patenting repurposed drugs as a standalone topic. The question in this thread is “What do the people who think ivermectin is effective against COVID-19 believe is the reason health providers do not want to prescribe it?” I pointed out that one rational basis for discounting the reluctance of health providers is because there are economic disincentives to proving the effectiveness for new uses of drugs which are available in generic form. You’re now saying that “there are complex regulatory hoops to jump through before off-patent drugs can be repurposed for treating other ailments, and drug companies have been reluctant to invest in research including expensive large phase III clinical trials”. So it sounds like you agree with me. A guy who says “I think ivermectin probably works and the reason doctors are reluctant to provide it is because it hasn’t gained acceptance, which is in turn because there are complex regulatory hoops to jump through before off-patent drugs can be repurposed for treating other ailments, and drug companies have been reluctant to invest in research including expensive large phase III clinical trials” would be saying something that you agree is not unreasonable?
[Note again, that this is not the same thing as saying that it’s likely that ivermectin is actually effective for covid. But that’s not the question which was raised in this thread.]