Category: Pain

Otsuka and GW Pharmaceuticals cannabis-based drug Sativex failed to show superiority over placebo in two Phase III trials, report Pharmafile.com.*

The studies were testing Sativex (nabiximols) in the treatment of pain in patients with advanced cancer who experience inadequate analgesia during optimised chronic opioid therapy.*

In a previously-reported Phase III trial earlier this year, Sativex also failed to meet the primary endpoint in the additional two trials. The first involved 397 patients from the US, Mexico and Europe, and the second was conducted entirely outside the US and used a different clinical design.*

However, a pre-specified pooled analysis of patients across the two Phase III trials in the US did show a statistically-significant improvement for Sativex compared with placebo, with several secondary efficacy endpoints reaching statistical significance.*

In this study, the US was the largest single recruiting country and represented 30% of the overall trial population. The efficacy data from US sites alone showed more positive trends than those in non-US sites, which the companies say is consistent with data from the first Phase III trial and the Phase IIb trial.*

GW Pharmaceuticals and Otsuka say these more positive US results have led them to request a meeting with the FDA, to discuss the clinical relevance of these data and determine potential paths forward.*

Justin Gover, GW’s chief executive, says: “In light of the missed primary endpoint in the first trial earlier this year, these additional results are not a surprise. Nevertheless, we are encouraged by data across the trials which consistently show positive outcomes for US patients when analysed as a separate cohort. We believe that this finding may provide important guidance in determining the optimal target patient population for Sativex and look forward to a discussion with the FDA on a potential path forward.” *

Dr Marie Fallon, professor of palliative care at the University of Edinburgh and a principal investigator in the Phase III program, comments: “While the results overall have been disappointing, and not necessarily wholly consistent with clinical experience, nonetheless they suggest that Sativex may have a useful role in the treatment of certain subgroups of patients with advanced cancer pain who have exhausted opioid treatments.”*

“In particular, the US patients enrolled in this program showed a useful therapeutic benefit whereas results in European patients were generally not favourable. These US patients were less frail, hence the Sativex intervention was subjected to less ‘noise’, providing clearer results and valuable guidance in determining the optimal target patient population for Sativex. This is a patient population with a significant unmet need and I believe that this important observation for Sativex warrants further investigation.”* 

Sativex, usually used in the treatment of multiple sclerosis, was developed by GW with the Japanese company Otsuka acting as a licensing partner in the US. It was the world’s first plant-derived cannabinoid prescription drug.* 

Joel Levy

* original article

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*** ndlr. : –.