Tuesday, November 23, 2010

GW Pharmaceuticals Final Results 2010

GW Pharmaceuticals gave earnings today and I figured it was a good stock to do some equity research on.

http://www.investegate.co.uk/Article.aspx?id=201011230700116258W

and announced that they had ...

http://www.investegate.co.uk/Article.aspx?id=201011230701086266W

"GW Pharmaceuticals plc (AIM: GWP) today announces the initiation of the Phase III clinical trials programme of Sativex® in the treatment of pain in patients with advanced cancer, who experience inadequate analgesia during optimized chronic opioid therapy. This indication represents the initial target indication for Sativex in the United States."

The results were well received by the market and GW Pharmaceuticals continues to demonstrate that they can get Sativex approved across a range of jurisdictions.  My view is that the risk here is not with efficacy nor safety but rather with regards pricing. Will national medical bodies-already facing cutback pressures due to public deficit reduction plans- be willing to pay significantly in order to supply patients with a cannabinoid based treatment such as Sativex?

 Similarly, there are question marks as how to how the US would view a medicine based on cannabis. Similarly, longer term, if cannabis was widely legalised then I suspect there could be pricing pressure for Sativex. I point out the risks, because, actually, GW has made great strides in demonstrating efficacy and safety for pain sufferers with Multiple Sclerosis and Cancer.

I decided to look closer at the issues here.


Information on Multiple Sclerosis and Spasticity

MS is an incurable condition which affects between 2-150 people per 100,000 of population. It causes damage to the Central Nervous System CNS and spasticity is a symptom that affects most sufferers at some point in their lives.

According to Rizzo et al,

“In a survey, 84% of people with MS reported symptoms of spasticity. Moderate, severe or total spasticity is reported in 34% of individuals.“

Symptoms include mobility loss, stiffness, and painful spasms. It is a physically de-habilitating condition.

New Treatment for Multiple Sclerosis Sufferers


Independent research has confirmed that cannabis extracts may provide therapeutic benefit for MS spasticity symptoms. Lakhan reviewed six controlled trials reporting measures of spasticity after tetrahydrocannabinol THC and cannabidiol CBD treatments. THC and CBD are cannabis extracts.

Lakhan concluded: “We found evidence that combined extracts of THC and CBD may reduce symptoms of spasticity in patients with MS. ...The therapeutic potential of cannabinoids in MS is therefore comprehensive and should be given considerable attention.”

Similarly, as reported by Johnson J. et al, GW Pharmaceuticals achieved highly positive results for Sativex (a cannabinoid spray) from their European Phase III trials in MS spasticity. In this trial, 241 responding patients were randomised to be given Sativex or a placebo. The intention was decrease the levels of spasticity according to a numeric rating scale NRS test.

The results were that, after 12 weeks of trials, the treated sample achieved a significant reduction in spasticity. Furthermore, 74% of those treated achieved a greater than 30% response. In comparison the placebo treated group recorded an increase in spasticity and only 51% achieved a greater than 30% response. The data also indicated a reduction in night time incontinence.

Cannabis Based Drug Approved for MS Sufferers


Subsequently, the UK and Spain approved Sativex for MS spasticity sufferers. A decision is due for Canada in 2010. Pam McFarlane, Chief Executive of the MS Trust, welcomed the UK approval in a press release from Bayer Healthcare and said

“ We have been aware for a long time, based on comments from people with MS, that cannabis based medicines can significantly improve spasticity... ... the MS Trust has campaigned for the availability of a licensed medicine that can be properly controlled and prescribed. We have also invested money and resources in developing the body of knowledge by funding clinical research into the effectiveness of cannabis based medicines. The launch of Sativex® is therefore a milestone for the NHS and the MS Trust, and we are delighted.”

Further submissions are believed to be filed by Bayer/GW Pharmaceuticals in the Middle East, Latin America, Africa and Asia.

New Treatment for Cancer Pain Sufferers


Similarly, cannabis based drugs are in trial for cancer pain sufferers. GW pharmaceuticals completed a US phase IIB study for Sativex® in the treatment of pain in patients with advanced cancer, who experience inadequate analgesia during optimized chronic opioid therapy.

The Phase IIb trial results were significant with two of the three analyses showing results in favour of Sativex. According to GW Pharmaceuticals:

“The 30% responder analysis, which was the primary analysis specified in the protocol, was numerically in favor of Sativex but did not show a statistical difference compared to placebo. The “continuous response analysis” (an analysis of all response levels characterized by percent improvement), did show statistically significant results in favor of Sativex for both the Sativex low and mid dose groups versus placebo... ..this continuous response analysis has been the key efficacy parameter discussed in the product labeling of several recently approved medicines for pain.”

Furthermore, the study showed a statistically significant difference in reducing sleep disruption. The successful conclusion of this trial means that a Phase III trial for cancer sufferers, will begin in the US within 2010, with the possibility of a US launch by end 2013.

Source:

Bayer Healthcare Press Release “Sativex® launched in UK for the treatment of spasticity due to Multiple Sclerosis” Bayer Website 2010

GW Pharmaceuticals press release
Johnson J et al, Journal of Pain and Symptom Management, Vol 39, Issue 2, pp 167-179

Lakhan, Shaheen A. and Marie Rowland “Whole plant cannabis extracts in the treatment of spasticity in multiple sclerosis: a systematic review” BMC Neurology, 2009

Rizzo MA, et al. "Prevalence and treatment of spasticity reported by multiple sclerosis patients."Multiple Sclerosis 2004;10:589/595