IACM-Bulletin of May 1, 2005

Canada/UK — Sativex gets approval in Canada for the treatment of neuropathic pain in multiple sclerosis

On 19 April the British company GW Pharmaceuticals announced that their cannabis extract Sativex has been granted regulatory approval in Canada for the symptomatic relief of neuropathic pain in multiple sclerosis. According to a statement by the company the drug is likely to be launched in May and the price would only be announced shortly before launch.

Dr. Geoffrey Guy, Executive Chairman of the company, said, "We are delighted that Sativex has received regulatory approval in Canada. This event marks the world’s first approval of a cannabis derived medicine. This first regulatory approval has been obtained by GW in just over six years since the Company’s development programme commenced, a highly significant achievement. We are now working with our Canadian marketing partner, Bayer, towards the launch of Sativex throughout Canada in late spring."

The approval had been expected after Canadian regulators said last December that Sativex, which is sprayed under the tongue and contains equal amounts of THC and CBD, qualified to be considered for approval. The company had originally hoped to win British approval for Sativex in 2003 but UK officials said in December they wanted more evidence about the benefits of the medicine. It is not expected to be approved in its home market until later this year or possibly 2006. Nevertheless, Guy said he was confident the drug would win approval in major markets around the world.

The approval of Sativex was welcomed by the MS Society of Canada, whose national medical adviser Dr. William McIlroy said sufferers needed new options to address their pain.

(Sources: Press release by GW Pharmaceuticals of 19 April 2005, Reuters of 19 April 2005)

Science — THC effective in appetite and weight loss in severe lung disease (COPD)

Patients with the severe lung disease COPD (chronic obstructive pulmonary disease) often suffer from appetite loss and cachexia (weight loss) resulting in reduced general well-being and early mortality. In an open clinical study THC improved appetite and well-being and resulted in weight gain.

18 COPD patients aged 49 to 81 years with a mean body weight of 48.5 kg were included in the study under the guidance of Dr. Karl-Christian Bergmann at the Clinic for Allergies and Asthma in Bad Lippspringe, Germany. In the six months before entering the clinic 7 participants had a constant body weight and 11 lost 2.3 kg on average.

They received 3.3-4.2 mg THC two times daily as oily drops delivered by THC Pharm, half an hour before breakfast and dinner. Mean treatment duration was 16 days resulting in a considerable improvement of appetite, general well-being and functional performance (36 per cent mean increase in walking distance) and an average gain in body weight of 1.5 kg, which is much regarding the short treatment period. Side effects were mild.

(Source: Lecture by K-C Bergmann on 17 March 2005 at the Meeting of the German Society of Pulmonology in Berlin)

Economy/Science — THC inhaler offers safe and rapid delivery

On 14 April Solvay Pharmaceuticals announced the results of a Phase I study evaluating the safety and tolerability of pulmonary THC (dronabinol) using a metered dose inhaler. The study, which was presented at the American Academy of Neurology (AAN) Annual Meeting in Miami, USA, included 27 healthy subjects who received doses between 0.3 and 9.6 mg THC.

The study found the new formulation of inhaled THC provided rapid systemic absorption. All dose levels used in the research were considered safe in healthy young and elderly subjects. Dronabinol currently is available as an oral capsule, marketed under the trade name Marinol (Solvay Pharmaceuticals) and in Germany as dronabinol of the companies THC Pharm and Delta 9 Pharma. Dr. Harold H. Shlevin, president of Solvay Pharmaceuticals, said, "Pulmonary dronabinol has potential application in a variety of conditions, such as the treatment of migraines, nausea, pain management and spasticity in patients with multiple sclerosis."

In mid-2005, Solvay Pharmaceuticals will launch a clinical trial to evaluate the efficacy, safety and tolerability of pulmonary THC delivered with a metered dose inhaler for the acute treatment of a single moderate to severe migraine headache attack.

(Source: Press release by Solvay Pharmaceuticals of 14 April 2005)

News in brief

Science — Weight reduction with rimonabant

Rimonabant is a CB1 receptor antagonist that blocks the effects of endocannabinoids at this receptor. In a study with 1507 overweight subjects from Europe and the USA the drug significantly reduced body weight within one year of treatment (5 or 20 mg rimonabant once daily). The lower dose resulted in a mean weight reduction of 3.4 kg, the higher dose in a mean reduction of 6.6 kg, while the placebo group lost 1.8 kg on average. The higher dose also had a significant positive effect on blood lipids. (Source: Van Gaal LF, et al. Lancet 2005;365(9468):1389-97)

UK — No effect of law change on use

Contrary to claims that there has been an explosion in use since the government decriminalized cannabis in January 2004, a new study has found that the increase in regular use fell to just 0.5 per cent in 2004, compared with an increase by 45 per cent at its peak in 1998. "Our first indications are that [the change in the law] has essentially had no effect at all in user levels of cannabis," says Matthew Atha, director of the Independent Drugs Monitoring Unit, which carried out the study. (Source: The Observer of 27 March 2005)

Science — Cannabis in HIV

523 HIV positive subjects were asked about cannabis use with an anonymous questionnaire in the UK. 143 (27 per cent) reported using cannabis for treating symptoms. Patients reported improved appetite (97%), muscle pain (94%), nausea (93%), anxiety (93%), nerve pain (90%), depression (86%), and paresthesia (85%). (Source: Woolridge E, et al. J Pain Symptom Manage 2005;29(4):358-67)

Science — Medical use and driving

The effects of the synthetic cannabinoid nabilone on driving ability was investigated in 6 patients with multiple sclerosis and spasticity. In a crossover design they received either 2 mg nabilone/day or placebo. No indication was found of a deterioration of any of the five investigated neuropsychological functions (reaction time, working memory, divided attention, psychomotor speed and mental flexibility) during the 4-week treatment period with nabilone. Nabilone shows similar effects as THC, 1 mg of nabilone comparing to about 10 mg THC. (Source: Kurzthaler I, et al. Hum Psychopharmacol 2005 Apr 18; [Electronic publication ahead of print])

Science — Pain

A synthetic cannabinoid (GW405833) that only binds to the CB2 receptor reduced neuropathic pain in rats. The study supports the concept that selective CB2 receptor agonists may have the potential to treat pain without eliciting the centrally-mediated side effects associated with non-selective cannabinoids. (Source: Valenzano KJ, et al. Neuropharmacology 2005;48(5):658-72)

Holland — Office of Medicinal Cannabis

Dr. Marco J. van de Velde was appointed head of the Office of Medicinal Cannabis and started his new job on 1 May. He succeeds Dr. Willem Scholten who will work with the World Health Organisation in Geneva. Dr. van de Velde is medical biologist and works in the Dutch Health Ministry since 1995. Dr. Scholten was head of the Office of Medicinal Cannabis since its formation in 2000. (Source: Newsletter of the Office of Medicinal Cannabis of 25 April 2005)