Research news - February 2005
Open Door - February 2005 pages 2-3
- Tysabri (formerly Antegren) licensed in USA
- Cannabis spray not recommended for licence
- Timing of birth and risk of multiple sclerosis
- Childhood infections and MS risk
- MS in Glasgow
- MS damage repair mechanism found
- Exercise and MS
- Participation in general practice health screening by people with MS
- Drug may improve memory in MS
- Cognitive impairment differences in men and women
Tysabri (formerly Antegren) licensed in USA
On 28 February Elan and Biogen suspended Tysabri after two patients came down with the rare central nervous system condition progressive multifocal leukoencephalopathy, one of them dying from the condition. Both the patients were on a combination therapy regime of Tysabri and Biogen's beta interferon drug, Avonex.
In November, the Food and Drug Administration (FDA), the body that regulates drugs in the USA, granted a licence for Tysabri (natalizumab) as a disease modifying drug for MS. Accelerated approval was granted based on positive one-year data from two trials. Data from the AFFIRM trial, an international study of 942 patients with relapsing remitting MS, showed a significant reduction in relapse rate of 66% for people treated with Tysabri compared with those receiving an inactive placebo. The two-year data from this trial will evaluate the effect of the drug on progression of disability in MS. Data from the SENTINEL trial, studying the effect of Tysabri in 1,171 Avonex (beta interferon 1a) users, showed a 54% reduction in the rate of relapses in those receiving both drugs compared with those receiving Avonex alone. It is anticipated that two-year results of these trials will be available in the first half of 2005. License applications have also been submitted in the EU, Canada and Australia.
Cannabis spray not recommended for licence
The Committee on Safety of Medicines (CSM) announced in December that it would not recommend a licence for the cannabis-derived spray Sativex.
The CSM found the safety and quality of the therapy to be acceptable but felt that the research trials, while showing some positive effect in alleviating spasticity and pain in people with MS, had failed to prove that the drug was sufficiently effective.
The manufacturers, GW Pharmaceuticals, will appeal against the negative recommendation. They will also follow the advice of the CSM and carry out a further spasticity study, which, if positive, may lead to the granting of a licence. Professor Mike Barnes, Chairman of the Royal College of Physicians Rehabilitation Committee commented, "My opinion is that the clinical trials show that Sativex offers sustained benefit to many people with MS who are otherwise unable to find relief from spasticity. I hope the CSM will reconsider their position and give some thought to the impact that this decision will have on the lives of those with painful, chronic disease. I trust common sense will prevail."
Timing of birth and risk of multiple sclerosis
An analysis of data from studies of in excess of 42,000 people with MS in Canada, Britain, Denmark and Sweden has shown that more than the average were born in the spring. In contrast, fewer than the average were born at the end of the year. The effect was similar in all the countries studied but most prominent in Scotland. Although the researchers cannot explain the correlation between birth month and MS, they conjecture that it could be linked to the mother's exposure to sunlight during pregnancy. The body makes vitamin D from sunlight, which has been shown to have a role in reducing the risk of developing MS.
BMJ online first
7 December 2004
Childhood infections and MS risk
Researchers in Denmark have studied health records to determine whether common childhood infections were associated with the development of MS in later life. The study examined the records of 637 people with MS and 2491 controls who had been at school between 1940 and 1975. The results showed no greater risk of MS associated with infection with measles, rubella, mumps, chicken pox, whooping cough or scarlet fever. In addition, the risk of MS was not associated with social class and no clustering of MS in school classes was observed.
Bager P, et al.
Childhood infections and risk of multiple sclerosis.
Brain 2004;127(11): 2491-2497.
MS in Glasgow
The level of MS in Glasgow is in keeping with that in other studies of MS in Scotland according to recent research. Three Local Health Care Cooperatives were studied, with a total population of around 169,000. 245 people with MS were identified, giving the overall prevalence of 145/100,000. The incidence rate, or new cases per year, was 5.7/100,000. A higher prevalence and incidence of MS was found in the more affluent population, although the reasons for this are unclear.
Murray S, et al.
Epidemiology of multiple sclerosis in Glasgow.
Scottish Medical Journal 2004;49(3):100-104.
MS damage repair mechanism found
A gene that controls the body's ability to repair damage to myelin has been identified by researchers at Cambridge and Harvard Universities.
During remissions, damaged nerves in the brain and spinal cord become recovered with myelin. The research shows that a gene called Olig1 triggers this process.
In animal studies, researchers found that Olig1 appears in the nucleus of embryonic nerve cells at the time when myelin-producing cells, oligodendrocytes, are being produced. In adult nerve cells, Olig1 has moved outside the nucleus. However, in animals with MS-type symptoms Olig1 was found back in the nucleus and apparently able to renew production of oligodendrocytes.
In samples taken from people with MS, researchers found that the Olig1 gene appeared inactive in healthy brain areas and active in damaged areas.
Dr Charles Stiles from Harvard said: "Although this finding will not yield direct results in terms of finding treatment for MS, we are confident that it gives new insight and direction for research."
Arnett HA, et al.
bHLH transcription factor Olig1 is required to repair demyelinated lesions in the
CNS.
Science 2004;306(5704):2111-2115.
Exercise and MS
The beneficial effect of exercise has again been shown by research in Finland. Participants were split into two groups. 47 people attended exercise classes for three weeks followed by a home exercise programme lasting for a further 23 weeks. The 48 people in the control group made no lifestyle changes.
The exercise group showed significant improvement in walking speed over 7.62m and 500m and also showed increased upper extremity endurance as compared to those in the control group. The researchers suggest that exercise is recommended for people with MS with mild to moderate disability.
They also observed that adherence to the programme varied considerably. A previous study had suggested that the apparent better response of women to exercise was perhaps due to the fact that women were more likely to stick to the exercise programme.
Romberg A, et al.
Effects of a 6-month exercise program on patients with multiple sclerosis.
Neurology 2004;63:2034-2038.
Surakka J, et al.
Effects of aerobic and strength exercise on motor fatigue in men and women with multiple sclerosis: a randomized controlled trial.
Clinical Rehabilitation 2004;18(7):737-746.
Participation in general practice health screening by people with MS
A study in Northern Ireland examined general health screening given by GPs to people with MS. When looking at blood pressure and cholesterol measurements, lifestyle advice, cervical smears and mammograms, researchers found that those with increased mobility problems seemed to receive less support. Wheelchair users received fewer preventative services with blood pressure monitoring and lifestyle advice in particular found to be less frequent in those people with reduced mobility. Findings were similar for men and women.
Maclurg K, et al.
Participation in general practice health screening by people with multiple sclerosis.
British Journal of General Practice 2004;54(508):853-855.
Drug may improve memory in MS
A small study has shown that donepezil (Aricept) has some effect on people with poor memory due to MS. Memory was tested using the Selective Reminding Test (SRT), which involves learning and then recalling a list of 12 words presented six times in a single session. The scale is scored up to 72 points. On average, those taking donepezil improved their scores by 5 points compared to 1 point for those on an inactive placebo.
Krupp LB, et al.
Donepezil improved memory in multiple sclerosis in a randomized clinical trial.
Neurology 2004;63:1579-1585.
Cognitive impairment differences in men and women
Research in Italy has investigated the variables that can be associated with cognitive problems in MS. Of the 503 participants, 56% were found to have some degree of cognitive impairment. Men were over-represented and cognitive problems were associated with disease duration, level of disability, lower educational level and presence of the 4 APOE allele - a gene associated with an increased risk of Alzheimer's disease and cognitive decline in older people. In contrast, no association was observed with any of the variables.
Savettieri G, et al.
Gender-related effect of clinical and genetic variables on the cognitive impairment in multiple sclerosis.
Journal of Neurology 2004;251(10):1208-1214.
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