A Multicenter, Randomized, Double-blind, Placebo Controlled, Clinical Trial to Evaluate the Safety, Tolerability and Preliminary Effectiveness of 2 Doses of Intradiscal rhGDF-5 (Single Administration) for the Treatment of Early Stage Lumbar Disc Degeneration

Inclusion Criteria:

1. Persistent low back pain with at least 3 months of non-surgical therapy at one
suspected symptomatic lumbar level (L3/L4 to L5/S1) as confirmed using a standardized
provocative discography protocol. The required discography protocol will be provided
by the sponsor. Subjects with multilevel disease must have a provocative discogram
confirming that only 1 level is symptomatic at least 2 weeks prior to administration.
Historical provocative discograms may be used for screening purposes, with an expiry
of 12 calendar months from the date performed. If the study treatment is not
performed within those 12 calendar months, a new discogram will be required.

2. Oswestry Disability Index (ODI) for low back pain of 30 or greater

3. Low Back Pain score greater than or equal to 4 cm as measured by Visual Analog Scale
(VAS) at Visit 1 Baseline

Exclusion Criteria:

1. Persons unable to have a discogram, CT, or MRI

2. Abnormal neurological exam at baseline (e.g., chronic radiculopathy)

3. Active radicular pain due to anatomical compression such as stenosis or disc
herniation (radicular pain is defined as pain below the knee)

4. Extravasation of contrast agent during the discogram, into the epidural space (does
not include leakage of contrast agent along the needle track or leakage to the outer
annular ring at the posterior longitudinal ligament vicinity)

5. Suspected symptomatic facet joints and/or severe facet joint degeneration at the
index level or adjacent segments