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Cannabinoids in multiple sclerosis (CAMS) study: safety and efficacy data for 12 months follow up
  1. J P Zajicek2,
  2. H P Sanders1,
  3. D E Wright1,
  4. P J Vickery2,
  5. W M Ingram2,
  6. S M Reilly2,
  7. A J Nunn2,
  8. L J Teare2,
  9. P J Fox2,
  10. A J Thompson3
  1. 1Department of Mathematics and Statistics, University of Plymouth, Plymouth, Devon, UK
  2. 2Peninsula Medical School, Plymouth, Devon, UK
  3. 3National Hospital for Neurology and Neurosurgery, University College Hospitals, London, UK
  1. Correspondence to:
 Professor J P Zajicek Peninsula Medical School
 Room N16, ITTC Building, Tamar Science Park, Plymouth, Devon PL6 8BX, UK;


Objective: To test the effectiveness and long term safety of cannabinoids in multiple sclerosis (MS), in a follow up to the main Cannabinoids in Multiple Sclerosis (CAMS) study.

Methods: In total, 630 patients with stable MS with muscle spasticity from 33 UK centres were randomised to receive oral Δ9-tetrahydrocannabinol (Δ9-THC), cannabis extract, or placebo in the main 15 week CAMS study. The primary outcome was change in the Ashworth spasticity scale. Secondary outcomes were the Rivermead Mobility Index, timed 10 metre walk, UK Neurological Disability Score, postal Barthel Index, General Health Questionnaire-30, and a series of nine category rating scales. Following the main study, patients were invited to continue medication, double blinded, for up to12 months in the follow up study reported here.

Results: Intention to treat analysis of data from the 80% of patients followed up for 12 months showed evidence of a small treatment effect on muscle spasticity as measured by change in Ashworth score from baseline to 12 months (Δ9-THC mean reduction 1·82 (n = 154, 95% confidence interval (CI) 0.53 to 3.12), cannabis extract 0.10 (n = 172, 95% CI −0.99 to 1.19), placebo −0.23 (n = 176, 95% CI −1.41 to 0.94); p = 0.04 unadjusted for ambulatory status and centre, p = 0.01 adjusted). There was suggestive evidence for treatment effects of Δ9-THC on some aspects of disability. There were no major safety concerns. Overall, patients felt that these drugs were helpful in treating their disease.

Conclusions: These data provide limited evidence for a longer term treatment effect of cannabinoids. A long term placebo controlled study is now needed to establish whether cannabinoids may have a role beyond symptom amelioration in MS.

  • Δ9-THC, Δ9-tetrahydrocannabinol
  • BI, Barthel Index
  • CAMS, Cannabinoids in Multiple Sclerosis
  • CBD, cannabidiol
  • GHQ-30, General Health Questionnaire-30
  • MS, multiple sclerosis
  • RMI, Rivermead Mobility Index
  • UKNDS, UK Neurological Disability Score
  • multiple sclerosis
  • spasticity
  • cannabinoids
  • randomised controlled trial
  • follow up

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  • See Editorial Commentary, p 1612

  • Competing interests: Professor Zajicek received support from Solvay Healthcare Ltd and the Institute for Clinical Research, IKF, Berlin to attend meetings with the UK MHRA regarding licensing.

  • The following contributed patients to the CAMS study as part of the UK MS Research Group: Dr S A Ahmed, Dr E J W McClemont (Community Rehabilitation Centre, Lincoln); Dr D Barnes, Dr N Stoy, Dr D Wren (Atkinson Morley’s Hospital, London); Professor D Bates (Royal Victoria Infirmary, Newcastle); Dr M Boggild (Walton Centre, Liverpool); Dr C Constantinescu (University Hospital, Nottingham); Dr E Fathers (Taunton and Somerset Hospital); Dr H Ford, Dr M Johnson (St James’ University Hospital, Leeds); Dr D A Francis, Dr J B Winer (Queen Elizabeth Hospital, Birmingham); Dr C P Hawkins (North Staffordshire Royal Infirmary); Dr S Hawkins, Dr A G Droogan (Royal Victoria Hospital, Belfast); Dr S J L Howell, Dr S Price (Royal Hallamshire Hospital, Sheffield); Dr D Kidd (Hertford County Hospital); Dr L A Loizou (Pinderfields General Hospital, Wakefield); Dr P G Mattison (Ayrshire Central Hospital; Dr B McLean, Dr J Morgan (Royal Cornwall Hospital, Truro); Dr J O‘Riordan, Dr R Swingler, Dr K White (Ninewells Hospital and Medical School, Dundee); Dr J Palace (Radcliffe Infirmary, Oxford); Dr G D Perkin (Charing Cross Hospital, London); Dr I F Pye, Dr B R Kendall (Leicester Royal Infirmary); Dr C Rickards (Morriston Hospital, Swansea); Dr N Robertson, Dr TAT Hughes (University Hospital of Wales and Rookwood Hospital, Cardiff); Professor N J Scolding, Dr J Burrow (Frenchay Hospital, Bristol); Dr M Sharief, Dr O Seidi (Guy’s Hospital, London); Dr A Shehu (Coventry and Warwickshire Hospital, Coventry); Dr E Silber (Queen Elizabeth Hospital, Woolwich); Dr P R Talbot (Hope Hospital, Manchester); Professor A J Thompson (Institute of Neurology, Queen Square, London); Dr J Thorpe, Dr I Bjornson (Addenbrooke’s Hospital, Cambridge); Dr P Tidswell, Dr I Redmond (Royal Preston Hospital); Dr S A Wasti (Community Rehabilitation and Respite Unit, Barnsley); Dr S J Wroe, Dr K Powell (Ipswich Hospital); Professor J P Zajicek (Derriford Hospital, Plymouth).

    Steering Committee: D Chadwick (chair), D Jones, T Meade, T Moffat, A Nunn, M O’Donovan, A Thompson, J Zajicek. Data Monitoring and Ethics Committee: C. Polman (chair), P. Stroner, C. Warlow.

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