Scilex Holding has completed a Phase II study of SP-103 (lidocaine topical system) 5.4% for the treatment of acute lower back pain (LBP).

The aim of the multicentre, parallel group, placebo-controlled, double-blind, randomised study is to evaluate the tolerability and safety of SP-103 in subjects with moderate to severe acute LBP.

Offering treatment effect estimates that can be used in the upcoming trials to treat patient population is the other objective of the study.

Out of the total 75 subjects, 38 received SP-103 and the remaining were given placebo.

In 12-hours ON/ 12-hours OFF pattern, topical systems were applied to the area of most tenderness in the lower back.

In the preliminary analysis, SP-103 demonstrated its safety and tolerability with no serious adverse events or treatment emergent adverse events reported.

No signs of systemic toxicity were observed in patients who received three times increased levels of lidocaine, SP-103 5.4%, compared with ZTLido 1.8%.

Sub-population of patients with higher severity of muscle spasms also showed reduction in pain over the first week.

Scilex Holding chief medical officer Dmitri Lissin said: “We are very pleased to have achieved this important milestone and would like to commend the experienced investigators and advisors for their persistence and diligence in enrolling these patients.

“SP-103 has the potential to meet our core goal of developing leading pain management therapies to significantly improve the lives of patients who are seeking new effective treatments.”

The company plans to evaluate SP-103 in its further trials for the treatment of chronic non-radicular neck pain.