Mesoblast Tees Up Phase 3 Stem Cell Spine Test

Mesoblast Limited’s NeoFuse stem cell product showed positive results in the firm’s Phase 2 lumbar spinal fusion trial, according Mesoblast Chief Executive Silviu Itescu speaking at the annual JP Morgan Healthcare Conference in San Francisco. The results suggest that Mesoblast’s NeoFuse product comprising allogeneic mesenchymal precursor cells (MPCs) is as effective for interbody lumbar fusion as the gold standard, bone autograft, without the need for a second surgical procedure and its attendant morbidity risks. These results, Itescu said, support the progression of NeoFuse to a Phase 3 trial in interbody lumbar fusion.

Researchers enrolled 24 patients in five sites in the United States with 8 patients in each treatment arm—one was bone autograft standard of care, which was the control group, with the second group receiving 25 million MPCs and the third 75 million MPCs . Patients underwent the surgical procedure, one or two level fusions using a posterior approach to the spine, and were evaluated for safety and efficacy. The median follow-up times for the three treatment groups were 23.9, 20.7, and 22.9 months for the bone autograft and the two stem cell groups, respectively.

MPCs were well tolerated with no cell-related serious adverse events and no ectopic bone formation at all. The MPC treated groups had a 30% to 43% lower mean estimated blood loss during surgery compared to the autograft treatment group. At 12 months, fusion was achieved in 85.7% of the patients in the 25 million treatment group compared to 62.5% in the 75 million and 75% in the control patient groups.

Overall, patients from all three treatment groups had a clinically significant and comparable decrease in low back and leg pain, assessed on the Visual Analogue Scale and functional improvement, assessed by the Oswestry Disability Index questionnaire.

Randall Dryer, M.D., an orthopedic surgeon with the Central Texas Spine Institute and an investigator in Mesoblast’s study, said: “For patients whose spinal discs have degenerated too extensively for repair, bony fusion of adjacent vertebra is the primary option to eliminate chronic and debilitating pain. Other than autograft, there is no approved product for posterior spinal fusion, a surgical approach which accounts for 62% of all lumbar fusion procedures. There is a critical unmet need for new technologies to achieve fusion that are safe, effective, and that eliminate the need for bone autograft.” Dryer added, “Based upon my experience in the Phase 2 study, Mesoblast’s cells may provide a significant and valuable option to achieve fusion in patients with severe spinal disc degeneration and these results warrant progressing to a Phase 3 study.”