Condoliase chemonucleolysis for lumbar disc herniation: A post-hoc follow-up study of patients in previous clinical trials

Background: Chemonucleolysis with condoliase significantly improved clinical symptoms in patients with lumbar disc herniation. We evaluated the surgical intervention rate and outcomes for >1 year after condoliase treatment.

Methods: This was a follow-up study of patients who received condoliase or placebo in two previous randomized, placebo-controlled clinical trials with 1-year follow-ups. A post-treatment surgery survey and on-site examination were administered and patients' data from the clinical trial records and additional interview data were analyzed to evaluate the surgical intervention rate. Patients' lumbar disease symptoms, Oswestry Disability Index, and imaging features were evaluated.

Results: Among the patients (condoliase, n = 228; placebo, n = 128) enrolled in the clinical trials, additional post-treatment surgery data were available for 231 patients after the clinical trials ended, and 179 patients underwent post-trial examinations, at least 5 years and 17 months after the end of the clinical trials. The surgical intervention rate in the placebo and condoliase groups was 20.7% (95% confidence interval: 14.2-29.7) and 13.4% (95% confidence interval: 8.8-20.2), respectively. The mean change in Oswestry Disability Index score from pre-injection in placebo and condoliase groups was -24.7 ± 15.0 and -32.7 ± 18.6 (between-group difference: -8.0 ± 17.3; 95% confidence interval: -13.2 to -2.7). Modic Type 2 changes were observed, particularly in the condoliase group. No relationship between lumbar disease symptoms and change in imaging features was found.

Conclusions: This follow-up study more than 1 year revealed no new safety concerns of condoliase. However, because the study had several limitations, such as large loss of follow-up, further research is needed.