Tetrodotoxin Open-label Efficacy and Safety Continuation Study
Information source: Wex Pharmaceuticals Inc.
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Pain; Cancer
Intervention: Tetrodotoxin (Biological)
Phase: Phase 3
Status: Completed
Sponsored by: Wex Pharmaceuticals Inc. Official(s) and/or principal investigator(s): Dr. Neil Hagen, MD, FRCPC, Study Chair, Affiliation: Tom Baker Cancer Centre
Summary
Different pathophysiologic mechanisms are responsible for the development of chronic pain
disorders. Pain pathways are triggered in part by ectopic discharges of voltage-sensitive
sodium channels, which are in abundance in both the peripheral and the central nervous
systems. Tetrodotoxin (TTX) is a selective blocker of Na+ channels and causes analgesia
either by decreasing the propagation of action potentials by Na+ channels and/or by blocking
of ectopic discharges associated with chronic pain. TTX is extracted from the puffer fish
(fugu). Results from animal pharmacology studies revealed that TTX is a more potent
analgesic than standard analgesic agents such as aspirin, morphine or meperidine.
At present, the management of severe cancer pain generally includes the use of opiates. This
can often result in undesirable side effects, and treatment with this type of medication is
not always effective. Because currently available pain-relieving therapy is unsatisfactory
for many patients, there is a need for new therapeutic approaches for the management of
moderate or severe cancer pain.
Recent studies indicate that intramuscular (into a muscle) or subcutaneous (under the skin)
injections of tetrodotoxin (TTX) may reduce pain in cancer patients who did not respond to
standard therapies.
The current proposed study (TEC-006OL) is designed to provide the option for all patients
who participated in the TEC-006 study (both tetrodotoxin and placebo-treated) to receive or
continue to receive tetrodotoxin treatment.
Clinical Details
Official title: A Multicentre, Open-label, Long-term Efficacy and Safety Continuation Study of Subcutaneous Tetrodotoxin (TTX) for Moderate to Severe Cancer-related Pain
Study design: Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Primary outcome: Efficacy: long-term efficacy of tetrodotoxin (TTX) in reducing pain and improving quality of life. Safety: long-term safety and tolerability of s.c. TTX
Secondary outcome: For each Treatment Cycle: the total number of days a subject meets the definition of pain response.
Detailed description:
Study Objectives: In cancer patients with moderate to severe pain who participated in the
TEC-006 study:
Primary Objectives:
- To assess the long-term efficacy of subcutaneous tetrodotoxin (TTX) treatment in
reducing the pain outcome and improving the quality of life (physical and emotional
functioning).
- To assess the long-term safety and tolerability of subcutaneous tetrodotoxin (TTX).
Secondary Objective:
• To assess the duration of analgesia following repeated cycles of tetrodotoxin (TTX)
treatment.
Overall Study Design:
This will be a multicentre, open-label, continuation trial of the efficacy and safety of
tetrodotoxin in patients with inadequately controlled moderate to severe pain associated
with cancer. All patients who participated in the TEC-006 study (tetrodotoxin and
placebo-treated), who would like to continue with tetrodotoxin treatment and meet the
inclusion/exclusion criteria, are eligible to receive the First Treatment Cycle for this
continuation study.
The study will be conducted at all centres participating in the TEC-006 study. Patients may
receive repeated cycles of treatment with tetrodotoxin. Each Treatment Cycle will consist of
4 days of treatment with 30 μg b. i.d. of tetrodotoxin injected subcutaneously. Each
Treatment Cycle will last from the start of treatment to the end of the analgesic response.
All patients completing the first Treatment Cycle in this protocol must meet the criteria of
the Responder (First TEC-006OL Treatment Cycle) definition in order to be eligible for a
second Treatment Cycle. Patient eligibility for all subsequent Treatment Cycles will be
determined using the eligibility criteria for a Repeated Treatment Cycle.
Sample Size:
Up to 120 patients.
Investigational Product:
30ug TTX(Tetrodotoxin injectable) injected subcutaneously twice daily for 4 days.
Efficacy Variables:
Worst pain in last 24 hours, average pain in last 24 hours, and/or component-specific pain
intensity in last 24 hours, ATC and breakthrough analgesic use, impact of pain on physical
functioning (general activity, walking ability, or normal work), and emotional functioning
(mood, relations with other people, or enjoyment of life).
Safety Variables:
Safety assessments will include adverse event reporting, vitals signs, physical and
neurological examinations, 12-lead electrocardiogram, clinical laboratory tests.
Data Analysis Method:
An initial analysis of results of the TEC-006OL study will be completed in parallel with the
TEC-006 study. Further periodic analyses will be completed every 6 months until the study is
closed.
All efficacy and safety analyses will be performed for subjects that are dosed at least once
in protocol TEC-006OL. All analyses performed will be descriptive. No statistics involving
hypothesis testing will be performed.
Eligibility
Minimum age: 18 Years.
Maximum age: N/A.
Gender(s): Both.
Criteria:
Inclusion Criteria:
All patients who participated in the TEC-006 study (tetrodotoxin and placebo-treated) will
be eligible for inclusion in this study provided they wish to continue to receive
treatment and meet the inclusion and exclusion criteria.
NOTE: The blinded treatment assignment of patients in the TEC-006 will not be revealed to
either the investigator or the patient. Patients will not be aware which treatment they
received in the TEC-006 study. All patients will receive tetrodotoxin treatment in the
TEC-006OL study.
A patient will be eligible or continue to be eligible for inclusion in this study (First
Treatment Cycle and subsequent Treatment Cycles) only if all of the following criteria
apply:
1. Male or female 18 years of age and over
2. In-patients or out-patients with a diagnosis of cancer
3. Patients must be experiencing somatic, visceral and/or neuropathic pain related to
cancer.
4. Compliant to the requirements of the TEC-006 Protocol.
5. Inadequately controlled pain: Pain intensity described as 'moderate', 'severe' or
'excruciating', as assessed by the VRS during the screening/baseline period of the
First Treatment Cycle, and a baseline pain intensity score of ≥4 as assessed by NRS
(worst, average, or component-specific pain).
6. Meet the Responder or Clinical Responder definition for repeat cycle treatment (cycle
#2 to cycle #4)
7. Life expectancy of > 3 months.
8. Ability to communicate well with the Investigator and to comply with the requirements
of the entire study.
8. Willingness to give written informed consent (prior to any study-related procedures
being performed) and to be able to adhere to the study restrictions, appointments and
examination schedule.
Exclusion Criteria:
A patient will not be eligible for inclusion in this study if any of the following
criteria apply:
1. Planned initiation of chemotherapy, radiotherapy or bisphosphonates within 30 days
prior to enrolment.
2. Known renal disease.
3. If it has been more than 14 days since their TEC_006 End of Study Visit or their pain
returned to baseline since their last tetrodotoxin treatment cycle (for repeat
cycle).
4. Patient has previously completed 4 cycles of tetrodotoxin
5. If it has been more than 6 months since patient signed consent to participate in the
TEC-006 OL study.
6. Use of anaesthetics.
7. Use of lidocaine, and other types of antiarrhythmic drugs.
8. Use of scopolamine and acetylcholinesterase-inhibiting drugs such as physostigmine.
9. History of CO2 retention, or SaO2 <80% either on room air or O2 of not greater than
2-4 L/min by nasal cannula.
10. Second or third degree heart block or prolonged QTc interval (corrected for rate) on
screening ECG (confirmed > 450 msec on repeated occasion) or any other active cardiac
arrhythmia or abnormality that would constitute a clinical risk.
11. Coagulation or bleeding defects if in the opinion of the Investigator this represents
a risk to the subject considering the subcutaneous (s. c.) route of administration.
12. Known hypersensitivity to puffer fish, tetrodotoxin and/or its derivatives.
13. Received an investigational agent other than tetrodotoxin within 30 days prior to
screening or who is scheduled to receive an investigational drug other than
tetrodotoxin during the course of the study.
14. Females who are lactating or at risk of pregnancy (i. e., sexually active with fertile
males and not using an adequate form of birth control).
15. Females with a positive pregnancy test at screening or on admission to study site.
16. Any other condition that, in the opinion of the investigators, is likely to interfere
with the successful collection of the measures required for the study or poses a risk
to the patient.
Locations and Contacts
WEX Pharmaceuticals Inc., Vancouver, British Columbia V6C 1G8, Canada
Additional Information
Starting date: July 2008
Last updated: October 22, 2012
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