This was an interventional, double-blind, placebo controlled, randomized, single dose, proof-of-concept study. It was a single-center clinical trial. The purpose of the study was to explore the clinical efficacy and safety of a single local IM injection of gonyautoxin 2/3 (GTX 2/3) compared to placebo in decreasing pain and improving lumbar functionality at short term follow-up in adult patients with acute low back pain, without radiculopathy.
This was an interventional, double-blind, placebo controlled, randomized, single dose, proof-of-concept study. It was a single-center clinical trial. The primary objective was to determine the clinical efficacy of GTX 2/3 in the decrease of pain and in the functional improvement of adults patients with acute back pain with no associated radiculopathy. The secondary objective was to determine the safety of a local intramuscular injection of GTX 2/3 in adults patients with acute back pain. Thirty subjects were studied in 2 groups, each consisting of 15 subjects. One group received the Investigational Medicinal Product (IMP) and the other group received placebo. The eligible patients were adults, from both sex, aged between 18 and 70 years, with an episode of acute back pain without radiculopathy, with a pain intensity higher than 4 in the VAS scale, with no chronic pain and without any severe pathology. Each subject participated in 1 treatment group only. All subjects received IV administration of 100 mg Ketoprofen before the IMP injection. All patients returned for a follow-up visit at day 4 after dose administration and at day 7 for discharge. Follow up telephone calls were done on day 1, 2 and 3 after the administration. Each subject received only a single dose of GTX 2/3 or placebo during the study. Doses were administered as IM paravertebral injections, 1 mL per site. Total of 2 mL of GTX 2/3 or placebo. The IMP was supplied in glass vials containing 1.2 mL solution at a total GTX 2 and GTX 3 concentration of 40 mcg/mL (at a relative epimer ratio of 62% GTX 2:38% GTX 3). The total concentration of drug administrated was 80 mcg. Placebo was of identical appearance to the IMP. Patients that participated in the study had the possibility of using rescue medication. As a first line medication was Ketoprofen (maximum of 200 mg per day) and as a second line analgesia was Tramadol®. The primary efficacy endpoints were the mean change in pain intensity and lumbar function from baseline to day 4, as measured by VAS and RMDQ scores, respectively. Secondary outcomes were: 1) the mean change in pain intensity and lumbar function from baseline to day 7 as measured by VAS and RMDQ scores, respectively, 2) the frequency of use of rescue pain drugs during Days 1 to 3, and 3) the occurrence of adverse events during the 7 days of the study period.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
30
Hospital San José SSMN
Santiago, Santiago Metropolitan, Chile
Efficacy of GTX 2/3 in the treatment of acute back pain after 4 days of administration.
Change of pain (0- to 10-point on a Visual Analog Scale (VAS), 0 meaning no pain and 10 the worst pain) and/or functional improvement (0- to 24-point on the Roland-Morris Disability Questionnaire (RMDQ). Each question is one point so scores can range from 0 (no disability) to 24 (severe disability)) in patients with acute back pain without radiculopathy from baseline to day 4 day after one local administration of GTX 2/3 or placebo.
Time frame: 4 days after one local administration
Efficacy of GTX 2/3 in the treatment of acute back pain after 7 days of administration.
Change of pain (0- to 10-point on a Visual Analog Scale (VAS), 0 meaning no pain and 10 the worst pain) and/or functional improvement (0- to 24-point on the Roland-Morris Disability Questionnaire (RMDQ). Each question is one point so scores can range from 0 (no disability) to 24 (severe disability)) in patients with acute back pain without radiculopathy from baseline to day 7 day after one local administration of GTX 2/3 or placebo.
Time frame: 7 days after one local administration
Pain evaluation after 2 hours of GTX 2/3 administration (Discharge of the hospital)
Pain evaluation using a Visual Analog Scale (0 no pain and 10 the worst pain) after 2 hours of GTX 2/3 or placebo administration, before the discharge of the patient from the hospital.
Time frame: 2 hours after one local administration
Pain evaluation on day 1 after GTX 2/3 administration.
Pain evaluation using a Visual Analog Scale (0 no pain and 10 the worst pain) after day 1 of GTX 2/3 or placebo administration.
Time frame: 1 day after one local administration
Pain evaluation on day 2 after GTX 2/3 administration.
Pain evaluation using a Visual Analog Scale (0 no pain and 10 the worst pain) after day 2 of GTX 2/3 or placebo administration.
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Time frame: 2 day after one local administration
Pain evaluation on day 3 after GTX 2/3 administration.
Pain evaluation using a Visual Analog Scale (0 no pain and 10 the worst pain) after day 3 of GTX 2/3 or placebo administration.
Time frame: 3 day after one local administration
Use of rescue medication
Use of rescue medication on day 1, 2 and 3 after GTX 2/3 or placebo administration.
Time frame: 3 days
Safety of GTX 2/3 by questioning the patients.
Search of side effects through questioning the patients during all the observation period (7 days). The adverse events questioned included: pain at site injection, perioral paresthesia, limbs paresthesia, headache, nausea, itching at site injection, allergy and ataxia. Indication to notify any event after this period of time.
Time frame: Through the 7 days of the study