Regenerative medicine company Mesoblast Limited has reported positive 12 month outcome results from the 100-patient phase II clinical trial of its proprietary allogeneic, or "off-the-shelf", Mesenchymal Precursor Cells (MPCs) in patients with chronic moderate to severe discogenic low back pain.

The results showed that a single injection of MPCs into degenerating intervertebral discs reduced low back pain and improved function for at least 12 months. When compared with controls, MPC-treated patients used less opioids for pain relief, had greater radiographically-defined disc stability, and underwent less additional surgical and non-surgical treatment interventions. MPC treatments also appeared to be well tolerated during the study.

Mesoblast chief executive Silviu Itescu said: "We are very pleased that in a trial primarily designed to assess the safety of Mesoblast's cells for intervertebral disc repair, we have seen strong indications of sustained efficacy across a broad number of clinical and radiographic parameters after a single intra-disc injection. On the basis of these positive results, Mesoblast plans to meet shortly with regulatory authorities in major jurisdictions, including the United States Food and Drug Administration, to discuss product registration trials for the potential treatment of disc degeneration."

Dr Hyun Bae, clinical investigator and medical director, director of Education, Cedars-Sinai Spine Centre, Cedars-Sinai Medical Centre, Los Angeles, and medical director of Spine Institute, Santa Monica, USA, said: “We are very excited by these results. This is compelling evidence that Mesoblast's stem cell technology has the potential to change the treatment of spinal disease from focusing on surgical reconstruction to biologic regeneration. Physicians and patients are seekingaccess to a new modality to treat patients with this highly debilitating disease for whom there are limited options. We hope that these outcomes will be replicated in a pivotal trial."

The results of the phase II clinical trial build on and extend previously reported preclinical studies which showed that Mesoblast’s highly purified and immunoselected MPCs were able to increase proteoglycan content and improve disc structure in an experimental ovine model of disc degeneration.

Mesoblast's phase II clinical trial enrolled 100 patients with moderate to severe low back pain persisting for more than six months and caused by early disc degeneration (<30% disc height loss, 83% below Pfirrmann Grade 5 by MRI). Patients were enrolled across 13 sites in the United States and Australia and randomized to receive direct intra-disc injection of saline (n= 20), hyaluronic acid (HA, n=20), 6 million allogeneic MPCs in hyaluronic acid carrier (6M, n=30) or 18 million allogeneic MPCs in hyaluronic acid carrier (18M, n=30). Patients underwent the outpatient injection for a single painful degenerated lumbar level and are being evaluated for safety and efficacy over a total of 36 months to evaluate long-term treatment effects.

Key findings at 12 months were: improvement in chronic low back pain; reduction in mean pain scores, increased proportion of patients achieving >50% reduction in pain score; increased proportion of patients achieving minimal residual back pain; reduced opioid use for pain relief; reduced need for additional surgical and non-surgical interventions for persistent pain; improvement in function: reduction in mean disability score; increased proportion of patients achieving minimal residual functional disability and improvement in disc stability.

Mesoblast Limited is a world leader in the development of biologic products for the broad field of regenerative medicine.