1. Subject who received the enough study information and signed informed consent form.
2. Subject who had chronic low back pain accompanying with lower limb pain from the knee
to the ankle.
3. Subject is male or female patient ≥18 years old.
4. Subject who has complained low back pain for 3 months or more before Visit 1.
5. Subject who is refractory to prior analgesics for 3 months and more.
6. Subject who is able and willing to complete all study related assessment and comply
with the study schedule and clinical procedures at clinic.
7. Subject whose pain Numeric Rating Scale(NRS) ≥ 5 at baseline (based on recall over the
1. Subject who, in the opinion of the investigator, was not likely to complete the trial
for whatever reason.
2. Subject who has been already treated by pregabalin