RNS Number:3518L
GW Pharmaceuticals PLC
21 May 2003



Embargoed until 0700                                               21 May 2003

                             GW Pharmaceuticals plc
                            ("GW" or "the Company")

            GW and Bayer Announce Marketing Agreement on Pioneering
                          New Cannabis-based Treatment

GW Pharmaceuticals plc ("GW") and Bayer AG ("Bayer") have entered into an
exclusive marketing agreement for GW's cannabis-based medicinal extract product,
to be marketed under the Sativex(R) brand name.

Bayer has obtained exclusive rights to market Sativex in the UK. In addition,
Bayer has the option for a limited period of time to negotiate the marketing
rights in other countries in European Union and selected other countries around
the world.

The financial terms of this partnership have been established to yield equal
long term value to each partner. GW has maintained a significant share of long
term product revenues whilst benefiting from a signature fee, an innovative
advance working capital facility and milestone payments in the near term to
further enhance GW's cash position.

The medicine has been developed by GW to provide a medically acceptable
cannabis-derived product for the treatment of the debilitating symptoms of
Multiple Sclerosis ("MS") and severe neuropathic pain. The product is a whole
plant medicinal cannabis extract containing Tetranabinex (tetrahydrocannabinol
("THC")) and Nabidiolex (cannabidiol ("CBD")) as its principal components. The
medicine is administered by means of a spray into the mouth.

GW submitted a product licence application for Sativex to the UK Medicines and
Healthcare Products Regulatory Agency ("MHRA") in March 2003.

Sativex and a THC medicine are also undergoing Phase III trials for the
treatment of cancer pain. If approved, Bayer will also market these medicines
for cancer pain.

In addition to a share of product revenues, GW has received a signature fee and
will receive additional fees on regulatory approval in the UK of the initial
indications of MS, neuropathic pain and cancer pain, totalling #25 million. In
the event that Bayer exercise the option for countries outside the UK,
additional milestones shall be payable on a country by country basis.

Of the #25 million milestone payments, #10 million can be drawn by GW in advance
as an interest-free working capital facility to support ongoing preparations for
market launch of Sativex. The facility can be drawn by GW at GW's discretion
until MHRA approval is obtained. On approval, Bayer has the option to convert
the facility into a milestone payment or to convert into GW shares at an agreed
premium to the share price at the time of conversion. The facility is subject to
additional conditions if MHRA approval is not obtained by 30 September 2004.

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.

Dr Geoffrey Guy, Executive Chairman of GW, said: "We are delighted to have
entered into this partnership with Bayer. Having recently submitted the
regulatory dossier for Sativex to the UK regulatory authorities, this
announcement is a further significant achievement for GW. It is GW's first
commercial collaboration and marks the start of a new phase in the company's
history. As a leading global pharmaceutical company, Bayer is well placed to
maximise the market opportunity for GW's product."

Commenting on the commercial terms of the agreement between the two companies,
Dr Guy added: "GW's commercial strategy is to maximise the value of its products
by entering into agreements at a late stage of development. The terms of this
agreement reflect the merits of this strategy. Most importantly, GW retains a
significant interest in revenues from product sales."

Dr. Christa Kreuzburg, Head of Europe for Bayer HealthCare's Pharmaceuticals
Division, said: "We are delighted that GW has selected Bayer as its marketing
partner to bring this innovative medicine to market. Supporting medical
professionals with effective therapies for the management of MS and severe
neuropathic pain is an area of largely unmet need. I am therefore very excited
that Bayer will be bringing a product to market with the potential to make a
significant contribution in this area. Our two companies are now working closely
to prepare for market launch in the UK. Sativex will enhance our portfolio in
the UK extremely well and strengthen the market position of Bayer
Pharmaceuticals".
                                    - Ends -

Notes to editors:

Bayer HealthCare, a forthcoming subgroup of Bayer AG, is one of the world's
leading innovative companies in the health care and medical products industry.
More than 34,000 employees work for Bayer HealthCare worldwide.

Bayer HealthCare combines the global activities of the Animal Health, Biological
Products, Consumer Care, Diagnostics and Pharmaceuticals divisions. Our work at
Bayer HealthCare is to discover and manufacture innovative products for the
purpose of improving human and animal health worldwide. Our products enhance
well-being and quality of life by diagnosing, preventing and treating disease.

Enquiries:

GW Pharmaceuticals plc                            (21/05/03) + 44 20 7067 0700
Dr Geoffrey Guy, Executive Chairman             (Thereafter) + 44 1980 557 000
Justin Gover, Managing Director
Mark Rogerson, Press and PR                                  + 44 7885 638 810

Weber Shandwick Square Mile                                  + 44 20 7067 0700
Kevin Smith

Bayer AG                                                     + 49 214 30 66102
Christina Sehnert

Bayer plc                                                    + 44 1635  563607
Sylvia Barber







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