Intervertebral DXM Gel Injection in Adults With Painful Lumbar Degenerative Disc Disease

The purpose of this study is to assess the safety and the efficacy of an hydrogel (double cross-link microgel - DXM) injection into the intervertebral disc (IVD) space in patients with painful lumbar degenerative disc disease (DDD) over 24 to 48 weeks.

After being informed of the study and the potential risks, all patients matching the eligibility criteria and who have given their written consent will undergo a gel injection at day 0 after a period of screening of up to 14 days.

Then, they will be followed-up for a variable period according to the cohort :

* first cohort of 5 patients with only one disc to be treated will be followed during 48 weeks,
* second cohort of 5 patients with 2 discs to be treated will be followed during 36 weeks,
* third cohort of 10 patients with 1 or 2 discs to be treated will be followed during 24 weeks.

Eligibility Criteria:
Inclusion Criteria:

1. Male or female patient aged between 18 and 55 (inclusive)
2. Discogenic low back pain, confirmed by a history of Low Back Pain, with a minimum of 3 months of continuous pain or 6 months of acute episodes of pain despite the conservative treatment including painkillers and physiotherapy
3. Oswestry Disability Index (ODI) ≥ 30% and ≤ 60%,
4. Painful disc(s) between L1 and S1 represented

   1. For cohort 1L: at a single disc level
   2. For cohort 2L: at 2 disc levels
   3. For cohort 1-2L: at 1 or 2 disc levels
5. Patients with a Zung depression score ≤ 49, Note: Patients with a Zung depression score between ≥ 50 and ≤ 64 may be included if deemed suitable for trial inclusion by the investigator
6. Partial dehydration (grey disc) confirmed by MRI, grade II/III Pfirrmann classification

   Note:
   * Pfirrmann Grade I lesions are not contra-indications to recruitment, but can never be the target of any intervention in this trial. Patients featuring grade I disc(s) in conjunction with a grade II/III meet the inclusion criteria for his(her) disc Grade II/III disc to be treated
   * Pfirrmann Grade IV and V disc lesions are absolute contra-indications for inclusion
7. Female patients of childbearing potential must have a negative urine pregnancy test at screening and use an effective birth control during the follow up period after the injection procedure
8. Patients who are willing and capable of understanding the investigator's explanations, following his instructions and adhering to the follow-up visits according to the study protocol, including a willingness and ability to undergo MRI scanning,
9. Patient giving informed consent to take part in the study

Exclusion Criteria:

1. Averted nerve root pain and potential root compression Note: Referred leg pain authorised
2. Presence of posterior bone spurs (osteophytes)
3. Partial or total Modic signal grade 1 at the considered disc level
4. Patients with active systemic infection or infection localized to the site of the proposed implantation.
5. Any conditions not described in the indications for use.
6. Any mental conditions or neuromuscular disease that may generate an unacceptable risk of failure or postoperative complication.
7. Patients with existing disc herniation at the considered level and on adjacent discs
8. Endplate disease, defect or weakness, e.g. Schmorl nodule
9. Vertebral bone abnormalities with active angioma
10. Disc collapse ≥ 15% when disc height is compared to the height of the upper adjacent disc
11. One lumbar disc rated grade IV or V on the Pfirrmann classification
12. Imaging showing facet arthrosis
13. Lytic spondylolisthesis
14. Degenerative spondylolisthesis grade \> grade I Meyerding
15. Congenital or idiopathic deformities of the spine (e.g. Scoliosis \>20° Cobb or Kyphosis)
16. Old or acute vertebral fractures in the lumbar spine
17. Patients with any prior spine procedure in the lumbar spine
18. Any skin disease or inadequate tissue coverage at the site of the injection
19. Any medical or surgical conditions that could preclude the potential benefit of disc injection must be carefully analysed before the procedure, such as congenital abnormalities, immunosuppressive disease, elevation of erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) concentration not explained by other diseases, elevation of white blood cell (WBC) count, or marked left shift in the WBC differential count, should be carefully taken into consideration prior to the surgical procedure.

    Note: These contra-indications can be relative or absolute and must be taken into account by the physician when making his decision. The above list is not exhaustive.
20. Tumours with any metastatic potential, or known metastases, in any part of the body
21. Known infection with HIV or Hepatitis B, C or E
22. Patient that has received or is seeking employee compensation
23. Zung depression score ≥ 65
24. Substance abuse or dependency (pharmaceuticals, drugs, alcohol)
25. Disabling obesity (BMI \> 35kg/m²)
26. History of chemical dependency (e.g. illicit drugs, or opiates) or significant emotional or psychosocial disturbance which may have an effect on treatment outcome
27. Patients who are pregnant, breast feeding or planning pregnancy during the study
28. Anticoagulation (beyond low level prophylactic doses of single anti-platelet agents)
29. Inability to undertake or known contra-indications to MRI scanning
30. Known hypersensitivity to barium sulphate