Failed fusion and failure to relieve back pain following spinal fusion are still frequent, irrespective of the type of procedures or grafts used by the surgeon. Moreover, revision surgeries are unfortunately associated with higher procedure-related complication rates, technical difficulties, longer operative time, and quite disappointing and unreliable success rates for both fusion and clinical results.

The present Phase 2a study aims at demonstrating the safety and efficacy of ALLOB®, a proprietary population of allogeneic osteoblastic cells, in rescue interbody fusion.

Inclusion Criteria:

• Ability to provide a written, dated, and signed informed consent prior to any study related procedure, and to understand and comply with study requirements
• Failed lumbar fusion of 15 months minimum requiring a revision surgery at one or two levels between L1 and S1

Exclusion Criteria:

• More than two failed interbody fusions at the involved lumbar level(s)
• Instrumentation failure requiring revision surgery
• Local active or latent infection at the involved lumbar level(s)
• Positive serology for hepatitis B, hepatitis C, HIV
• Current or past medical disease that could interfere with the evaluation of the safety and efficacy, as judged by the investigator