This is a long-term, 3-year, follow-up study for patients completing the KS-GIG-001-01 Study

This is a long-term, 3-year, follow-up study for patients completing the KS-GIG-001-01 Study (A Phase 1/2a, First-in-Human, Double-Blind, Placebo-Controlled Study to Evaluate the Safety and Therapeutic Activity of Single Ascending Doses of KLS-2031 Administered by Transforaminal Epidural Injection in Patients with Neuropathic Pain from Lumbosacral Radiculopathy). Following the end of the Open-label Safety Extension Period of the KS-GIG-001-01 Study (Visit 14), patients will enter the Long-term Follow-up Period. These patients will continue to be monitored for AEs (including AEs of special interest) and serious AEs (SAEs) via phone call every 6 months and outpatient visits every 52 weeks (annually), over 3 years.

Inclusion Criteria :

To be considered eligible to participate in this study, a patient must meet the inclusion criteria listed below:

1. Patients that have completed the KS-GIG-001-01 Study and were in the Active Treatment group
2. Patients having signed the consent forms for both the KS-GIG-001-01 Study and this Long Term, 3-Year Follow-up Study

Exclusion Criteria :

To be eligible for entry into the study, the patient must not meet any of the exclusion criteria listed below:

1. Enrollment in another AAV or other gene therapy trial

This long-term follow-up study will include up to 12 patients with neuropathic pain from LSR that have completed the KS-GIG-001-01 Study and were randomized to receive KLS-2031.