GW Pharmaceuticals plc (AIM: GWP) today announces that The International Association of the Study of Pain has published online the results of a study in its official journal Pain, showing that Sativex® successfully treats peripheral neuropathic pain1.
The trial was a multi centre, double-blind, randomised, placebo-controlled parallel group study, conducted in 125 patients with peripheral neuropathic pain characterised by allodynia. The publication of these data follows the previous announcement of preliminary results of this study.
In the study, Sativex demonstrated significant superiority to placebo in reducing pain, as measured on a 0-10 Numeric Rating Scale (p=0.004), the primary endpoint of the study. Statistically significant improvements were also seen in the Neuropathic Pain Scale composite score (p=0.007), sleep disturbance (p=0.001), dynamic allodynia (p=0.042), punctate allodynia (p=0.021), Pain Disability Index (p=0.003) and Patients Global Impression of Change (p<0.0001).
Sativex was well-tolerated in this study, with the majority of adverse events being mild or moderate. There were no treatment-related serious adverse events.
The five week trial was conducted in patients who were experiencing significant levels of neuropathic pain and who had failed to gain adequate relief from currently available analgesic medications. Patients enrolled in the study continued to take their existing medication throughout the trial. Sixty-nine percent of patients were taking opioid analgesics. Hence, improvements obtained on Sativex were over and above those obtained on currently available treatments.
Professor Turo Nurmikko, Principal Investigator, Professor of Pain Science and Consultant Pain Physician at the Walton Centre for Neurology and Neurosurgery, Liverpool, commented,"Peripheral neuropathic pain can be extremely disabling and is one of the most difficult types of chronic pain to treat. This study demonstrates that Sativex is effective in the relief of peripheral neuropathic pain. In particular, considering the refractory nature of their pain and that patients remained on their existing analgesia, the improvements seen on Sativex are very encouraging."
Dr Stephen Wright, Director of Research & Development at GW, noted "We are pleased that this important study has been published in Pain, a highly regarded and influential journal. This recognition of the high quality of GW clinical research and of the importance of these findings provides further evidence of the utility of Sativex in the relief of neuropathic pain, an area of significant unmet medical need."
This study is part of a broad programme of clinical trials aimed at securing future regulatory approval for Sativex in neuropathic pain. It is intended to conduct further Phase III clinical trials targeted at neuropathic pain following initial regulatory approval for Sativex in Multiple Sclerosis in Europe.
1.Nurmikko T, Serpell M, et al. Sativex Successfully Treats Neuropathic Pain Characterised by Allodynia: a Randomised, Double-Blind, Placebo-Controlled Trial. Pain. 2007: doi:10.1016/j.pain.2007.08.028M