Investigational Intradiscal Injection Improved Pain Associated with Lumbar Disc Herniation

People treated with experimental product SI-6603 (condoliase; Ferring Pharmaceuticals, Parsippany, NJ; Seikagaku, Tokyo, Japan) by a single intradiscal injection showed improvements in the radicular leg pain associated with their lumbar disc herniation (LDH). Early response data from a phase 3 study (NCT03607838) were presented at the American Society of Pain and Neuroscience (ASPN) Annual Meeting. SI-6603 is designed to treat pain by reducing nerve root compression.

Discovery 6603, a double-blind, sham-controlled, parallel phase 3 clinical trial, included 341 participants with radicular leg pain associated with LDH who were randomized 1:1 to receive either a single intradiscal injection of SI-6603 (n=169) or a single sham injection (n=172). Participants were observed for 52 weeks.

• The primary endpoint, defined as significantly greater improvement in worst leg pain at week 13 with SI6603 vs sham, was met (least squares mean [LSM] difference, -7.5; P=.0263).
• Notable differences in worst leg pain were identified as early as week 4 (LSM, 6.0; P=.0418) and week 6 (LSM, 7.4; P=.0146).
• More participants treated with SI6603 vs sham had a negative straight leg raise test beginning at week 1 (P=.0054) sustained to week 52 (P=.0003).
• More participants treated with SI6603 vs sham showed a ≥50% improvement from baseline in worst leg pain at week 4 (P=.0189), week 6 (P=.0297), and week 13 (P=.0165).

Additionally, there were no treatment-related serious adverse events associated with treatment with SI-6603.

“The early treatment response observed in this analysis is promising for those suffering from radicular leg pain resulting from lumbar disc herniation and who may experience severe, debilitating pain which can affect their mobility, and impact their ability to go about their usual activities,” said Raza Ahmed, MD, Senior Director of Medical Affairs, Specialty/Orthopaedics at Ferring USA. “This is an area of significant unmet patient need and if approved, SI-6603, which targets the source of radicular leg pain, may help fill a current treatment gap between conservative pain management and surgery.”