Journal of the California Cannabis Research Medical
Bayer Buys Rights to Market
GW's Cannabis Extract
GW Pharmaceuticals, the British company that has conducted
successful clinical trials of cannabis-based medicines, has signed
a deal allowing Bayer AG to market one of its tinctures in the UK under
the Sativex(r) brand. Bayer also gets a limited-time option to negotiate
marketing rights in Europe and “selected other countries.”
GW gets a cash infusion from Bayer to push forward with research, production,
and clinical trials —plus a cut of future sales proceeds. Its stock on the
London Exchange has risen from about 190 to about 250 in recent weeks. GW stock
rose sharply earlier this spring when the company applied to the Medicines
and Healthcare Products Regulatory Agency (the British equivalent of the USFDA)
for approval of Sativex as a treatment for severe neuropathic pain and multiple-sclerosis
symptoms. Bayer is betting that in the months to come, the MHRA will approve
Sativex or kick the application dossier back to GW with requirements that can
be fulfilled readily.
GW was launched in 1998 by Geoffrey Guy, MD, a pharmaceutical entrepreneur
whose first canny move was to buy all the seed strains collected and refined
over the years by Hortapharm AG, a Dutch firm run by two California expatriates,
Dave Watson and Robert Clarke.
Components of the cannabis plant beneficially modulate the effects
of THC and exert helpful effects of their own.
GW’s drug-development strategy was based on the assumption that various
components of the cannabis plant beneficially modulate the effects
of THC and exert helpful effects of their own. Guy inferred from the
literature that the cannabis Queen Victoria smoked to alleviate menstrual
cramps was rich in cannabidiol (CBD), and he hypothesized that CBD,
not THC, was the key anti-convulsant component. To date GW has bred
plant strains in which six different “cannabinoids of interest” predominate.
The only ones to have been used in clinical trials are high-THC (which
GW has dubbed “Tetranabinex”), high-CBD (“Nabidiolex”), and a 50-50
In addition to at least 66 known cannabinoids (21-carbon atoms in ring structures,
with hydrogen and oxygen molecules attached at different points), the cannabis
plant contains hundreds of compounds that are not unique to it -terpenes, flavonoids,
amino acids, fatty acids, proteins, sugars, hydrocarbons, simple esters, steroids,
nitrogenous compounds, vitamins, elements, and more. Terpenes produced in the
glandular trichomes are the essential oils that give cannabis its smell. GW
researchers hypothesize that certain terpenes may have anti-ulcer and anti-mutagenic
So GW’s approach has been to grow plants with desired cannabinoid ratios and
blend them -”trace”components and all- into treacley extracts that can be administered
in defined doses by spraying into the mouth. To date the extracts have been
used in randomized double-blind trials involving patients with multiple sclerosis
or neuropathic pain at four UK hospitals. Significant reductions in pain and
spasticity have been reported.
According to GW’s May 21 press release, “GW is to be responsible for commercial
product supply and has entered into a supply agreement with Bayer. GW will
manage the supply of product through a range of contract manufacturing partners,
arrangements for which are all in place.”
Bayer's Original Blockbuster
Bayer’s original blockbuster drug, aspirin, is also plant-derived.
The active ingredient, as patented by Bayer in Germany in 1899, is
“The name itself,” wrote H.O.J. Collier in the November 1963 Scientific American, “represents
one of the first exercises in the peculiar art of applied etymology that the
merchandising specialists of the pharmaceutical industry have brought to such
a high point of elaboration today. The prefix ‘a-’ stands for the acetyl group… The
root, ‘spir,’ stands for spirsaure (salicylic acid) distilled from the flowers
of the meadowsweet (Spiraea ulmaria).” Salicylic acid was also derived from willow
bark and oil of wintergreen. The first paper to describe medicinal effects from
any of these sources was read to the Royal Society of London in 1763: “An Account
of the Success of the Bark of the willow in the Cure of Agues,” by either Edmund
or Edward Stone (a printer’s error in the Philosophical Transactions leaves the
credit up for grabs forever).
A century later the fever-reducing and anti-inflammatory effects of salicylic
acid were well known but “its success was diminished by the irritation and
damage it caused to the moist membranes lining the mouth, gullet and stomach.” It
was not until the late 1890s that Bayer chemist Felix Hofmann found a simple
way to make salicylic acid in a less irritating form by adding an acetyl group.
Aspirin is not benign, however, and to this day it causes thousands of deaths
annually due to allergic reactions and gastrointestinal bleeding. Advocates
of legalizing cannabis for medical use often remark the irony of aspirin, with
its occasionally fatal side effects, being sold over the counter while their
benign herb of choice remains prohibited.
One of the FDA’s present requirements is that a manufacturer seeking approval
for a new drug explain its mechanism of action. The steps by which aspirin
reduces pain and fever are not precisely known. “It has always been easier
to catalogue the wide application of aspirin to man’s commonest ills than to
explain its mode of action,” wrote Collier. “There is no doubt about the usefulness
of the drug. If the precise nature of its biochemical action remains a mystery,
it is because so little is known about the biochemistry of the defensive responses,
such as pain, fever and inflammation, evoked in the body by disease.”
The same could be said of Sativex in 2003.