The treatment of disc-herniation-induced sciatica with infliximab: one-year follow-up results of FIRST II, a randomized controlled trial.

STUDY DESIGN

A randomized controlled trial.

OBJECTIVES

To evaluate the long-term efficacy of infliximab, a monoclonal antibody against tumor necrosis factor alpha (TNF-alpha), in patients with acute/subacute sciatica secondary to herniated disc.

SUMMARY OF BACKGROUND DATA

The results of experimental studies and our open-label trial support the use of infliximab in sciatica. Here we report the 1-year results of a randomized controlled trial (FIRST II, Finnish Infliximab Related STudy) evaluating the efficacy and safety of a single infusion of infliximab for sciatic pain.

METHODS

Inclusion criteria were unilateral sciatic pain with a disc herniation concordant with the symptoms and signs of radicular pain. Patients had to be candidates for discectomy. Criteria for discectomy included (in addition to a symptomatic disc herniation on MRI) neural entrapment (straight leg raising [SLR] < or =60 degrees ) with either a short-term (2-4 weeks) severe or long-term (4-12 weeks) moderate leg pain. Forty patients were allocated to a single intravenous infusion of either infliximab 5 mg/kg or placebo. Differences in the clinical examination parameters (straight leg raise [SLR], muscle strength, sensory defects, tendon reflexes), patient-reported symptoms (leg and back pain using a visual analog scale [VAS], Oswestry disability, quality-of-life [RAND-36]), sick leaves, number of discectomies, and adverse effects between the two treatment groups over the 1-year follow-up were compared using Mann-Whitney U test or Student's t test, repeated-measures analysis, or Cox proportional hazards model. Logistic regression was used to assess the predictors of good response.

RESULTS

Sixty-seven percent of patients in the infliximab group reported no pain at 52 weeks compared with 63% in the control group (P = 0.72). Similar efficacy was observed between treatment groups for other outcomes. Eight patients in each group required surgery. Three nonserious adverse reactions were encountered in the infliximab group. The response (irrespective of the treatment) was significantly better with shorter symptom duration and less SLR restriction at baseline. Patients in the infliximab group appeared to especially benefit in cases of a L4-L5 (or L3-L4) herniation and if a Modic change was colocalized at the symptomatic level.

CONCLUSIONS

Although the long-term results of this randomized trial do not support the use of infliximab compared with placebo for lumbar radicular pain in patients with disc herniation-induced sciatica, further study in a subgroup of patients with L4-L5 or L3-L4 herniations, especially in the presence of Modic changes, appears to be warranted.