Safety and PK of Intrathecal CNTX-3001 for Intractable Chronic Low Back Pain

Inclusion: * Have stable intractable, chronic moderate to severe low back pain * Must have failed all 3 of the following categories of therapies: 1. Physical medicine modalities for at least 6 weeks (e.g., physical therapy, occupational therapy, or chiropractic treatment directed at chronic low back pain) 2. Three or more classes of pharmacologic treatments 3. One or more non-surgical and/or surgical interventions addressing the primary cause of chronic low back pain * If the intractable low back pain is accompanied by radicular pain, back pain must be dominant over leg pain and may not radiate below the knee * Has normal leg strength in both legs (able to stand/walk) * Willing and able to undergo the lumbar puncture * On a stable analgesic regimen, or a stable dose of an opioid medication for \>3 months * Non- or ex-smoker and has not used any nicotine-containing products within 3 months * Men or women able to abide by reproductive and contraceptive requirements * Has a body mass index (BMI) between 18 and 35 kg/m2, with weight ≥60 kg Exclusion * Substantial increase or decrease in pain over the prior 3 months. * Low back pain that only occurs with specific activities or body positions. * Has asthma or other severe respiratory disease requiring daily prescription medication * History of, or current cancer (except basal cell carcinoma), cardiac disease, immunological disorders, meningitis, or bleeding disorders * Confirmed diagnosis of fibromyalgia or myalgic encephalomyelitis Exclusion * Substantial increase or decrease in pain over the prior 3 months * Low back pain that only occurs with specific activities or body positions * Has asthma or other severe respiratory disease requiring daily prescription medication * History of, or current cancer (except basal cell carcinoma), cardiac disease, immunological disorders, meningitis, or bleeding disorders * Confirmed diagnosis of fibromyalgia or myalgic encephalomyelitis