to some list members. It's about an assumed obstacles to finding
cancer cures: the inability to patent natural compounds.
==
re: "Methadone joins a long list of molecules that have shown
activity in the lab but will never see the light of day as drugs as
either they were not patentable in the first place (naturally
occuring molecules) or their patient has expired. The list is endless
and includes over the counter compounds such as resveratrol, curcumin
and even tetracycline antibiotics." - comment from list member.
Hi,
I've heard this reason cited often as the reason natural compounds
are not developed - and believed it for quite a while. But there are
many examples of cancer drugs derived from plants, vincristine and
etoposide to name but two. And many other drugs for other conditions.
Also, those in the field will tell you that the original compounds
often don't have the highest affinity to the target, and need to be
modified to improve activity ,or bioavailability, or decrease
toxicity.
Also, it does seem that patent protection is a challenge for natural
products development, but not an insurmountable obstacle as described
here:
"You cannot patent a natural compound as a structure (but you can
make the simplest semisynthetic analog - and if it was never
disclosed you can stake your claim on it). With a natural compound
you can patent its use, a process of isolation/manufacture, a
specific drug formulation, etc but it is obviously a much weaker
protection." http://totallysynthetic.com/blog/?p=956
I don't know for sure, but strongly suspect that the so-called
patent obstacle is a false argument used to justify unproven
alternative practices ... the reason this and that natural "cure" is
not FDA approved and never will be. That's not to say nature doesn't
provide useful compounds of course, but I think we should take such
arguments with a grain of salt, particularly when doses and blood
levels are not even accounted for in alt med promotions.
Regarding product development: "Only five in 5,000 compounds that
enter preclinical testing make it to human testing. One of these five
tested in people is approved." ~ Food and Drug Administration: From
Test Tube to Patient
=
But I wrote to an expert to confirm:
Many things to say here Karl. The highlights would be:
1. Methadone is not a natural product although it binds opiate
receptors - it is a synthetic diphenyl compound developed by the
Nazis in WWII because of fears that opium extract (the source of
morphine and codeine) would be subject to Allied blockade from SE
Asia.
2. Regardless of whether methadone is natural, natural products are
indeed patentable but, as the writer notes, use patents are weaker.
However, there are some cases where strong patents can be used to
protect natural products. Taxol (paclitaxel) is a great example: one
could not extract enough taxol from Pacific yew trees without sending
them (and a species of spotted owl) into extinction. Bob Holton at
Florida State came up with a 5-step synthesis satrated with 10-DAB, a
chemical precursor derived from European yew needles (a renewable
resource). Bristol-Myers Squibb licensed Holton's patented synthesis
for their manufacture of Taxol and Dr, Holton is now a very wealthy
man.
3. I would pay very close attention to the final statement by Scott
Kaufmann from Mayo Clinic - Scott is a MD/PhD who treats cancer
patients and has his own basic science laboratory. Many, many
compounds kill all kinds of cancer cells in flasks (i.e., cell
culture) yet few people (and medical writers) consider that the
concentrations of drug required to do so are either unable to be
achieved in patients and/or are so high as to be even more toxic than
conventional chemotherapy. Hence, Dr. Kaufmann's point is that the
concentrations of methadone required to kill leukemia cells are so,
so high that the patient would be dead from a major side effect of
opiate drugs: respiratory depression (i.e., the patient's breathing
center in the brainstem would be depressed such that one would stop
breathing).
~ David Kroll, PhD, cancer pharmacologist at North Carolina Central
University
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