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Pain Research and Management
Volume 2017 (2017), Article ID 7212713, 7 pages
Clinical Study

Tetrodotoxin for Moderate to Severe Cancer-Related Pain: A Multicentre, Randomized, Double-Blind, Placebo-Controlled, Parallel-Design Trial

1Tom Baker Cancer Centre and Division of Palliative Medicine, University of Calgary, 1331 29 Street NW, Calgary, AB, T2N4N2, Canada
2ClinForce Services Inc., Vancouver, BC, Canada
3PRA Health Sciences, Victoria, 655 Tyee Rd., Victoria, BC, Canada V9A 6X5
4Statcon Consulting Services, 6 Matson Drive, Caledon, ON, Canada L7E 0A3
5Département d’Anesthésiologie, CHUM, 1560, rue Sherbrooke Est, Pavillon Deschamps, Local FS-1136, Montréal, QC, Canada H2L 4M1
6St. Paul’s Hospital, 1081 Burrard Street, Vancouver, BC, Canada V6Z 1Y6
7Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, CP 6128 Centre-Ville, Montréal, QC, Canada H3C 3J7
8WEX Pharmaceuticals Inc., 420-1090 West Pender Street, Vancouver, BC, Canada V6E 2N7
9Clinical Research Unit, Jewish General Hospital, Room E-872 3755, Chemin de la Côte Sainte-Catherine, Montréal, QC, Canada H3T 1E2

Correspondence should be addressed to Neil A. Hagen

Received 15 September 2016; Accepted 23 March 2017; Published 7 May 2017

Academic Editor: Jacob Ablin

Copyright © 2017 Neil A. Hagen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objective. This study evaluated subcutaneous injections of tetrodotoxin (TTX) for the treatment of moderate to severe, inadequately controlled cancer-related pain. Methods. Eligible patients were randomized to receive TTX (30?µg) or placebo subcutaneously twice daily for four consecutive days. Efficacy was assessed using pain and composite endpoints (including pain and quality of life measures), and safety was evaluated using standard measures. Results. 165 patients were enrolled at 19 sites in Canada, Australia, and New Zealand, with 149 patients in the primary analysis “intent-to-treat” population. The primary analysis supports a clinical benefit of TTX over placebo based on the pain endpoint alone with a clinically significant estimated effect size of 16.2% (). The value was nominally statistically significant after prespecified (Bonferroni Holm) adjustment for the two primary endpoints but not at the prespecified two-sided 5% level. The mean duration of analgesic response was 56.7 days (TTX) and 9.9 days (placebo). Most common adverse events were nausea, dizziness, and oral numbness or tingling and were generally mild to moderate and transient. Conclusions. Although underpowered, this study demonstrates a clinically important analgesic signal. TTX may provide clinically meaningful analgesia for patients who have persistent moderate to severe cancer pain despite best analgesic care. This clinical study is registered with (NCT00725114).