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.
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.