Efficacy and safety of a novel hydrogel (HYADD4-G) in degenerative disc disease patients: a multicentric open label study.

In this premarket clinical study, we evaluated the efficacy and safety of a novel Hydrogel (HYADD4-G) for reducing low back pain (LBP) in patients with degenerative disc disease (DDD). Twenty-three patients with chronic LBP were enrolled. All patients presented with up to three lumbar black discs (Pfirrmann grade III or IV), LBP of at least 40 mm on the Visual Analogue Scale (VAS), and a Roland-Morris Disability Questionnaire (RMDQ) score of at least 9. Patients received a single 1.5 ml intradiscal injection of HYADD4-G (8 mg/ml), guided by X-ray. Our primary endpoint was the change in VAS score from baseline (day 0) to 4, 12, and 24 weeks. Our secondary endpoints were black disc hydration by Magnetic Resonance Imaging (MRI); the patient's therapeutic response according to the RMDQ; the quality of life, as determined by the EuroQol-5 Dimension (EQ-5D) Index; and a global assessment of patient health status, safety, and local tolerability. Compared with baseline values, VAS score showed a significant reduction at each time point, and across the overall 24-week follow-up period (p < 0.0001). MRI scanning observed a significant reduction in Pfirrmann grade from baseline, by at least one grade, at both week 4 (p = 0.0039) and week 24 (p = 0.0010). Furthermore, compared with baseline values, there was a significant reduction in RMDQ score at each timepoint, and across the entire study period (p < 0.0001). The EQ-5D index increased significantly from baseline to week 24 (p = 0.0001). Finally, mean VAS scores for Patient Global Assessment (PTGA), and Clinical Observer Global Assessment (COGA), decreased significantly at each time point (p < 0.0001), except for week 4. HYADD4-G proved to be an efficient reliever of low back pain due to DDD.