Major Study Update: Stem Cells Ease Back Pain

Mesoblast, the highest value stem company in the world, released the latest in string of studies examining the ability of a certain type of stem cell to treat back pain.

In its earliest test of its stem cells (known as mesenchymal precursor cells – MPCs) the company injected its MPCs into three adjacent lumbar discs in 24 adult male sheep. The MPCs were injected intradiscally. The particular sheep model that was used (Journal of Neurosurgery: Spine May 2012; Vol. 16; No. 5; Pages 479-488) was one where some discs were injected with chrondroitinase in order to mimic disc degeneration and other discs were left alone to represent normal discs as a control arm in the study.

In the sheep test, the degenerated discs had 45-50% less height before treatment with Mesoblast’s MPCs. After MPC treatment the discs rehydrated and increased in height at rates that were statistically significant as compared to the controls. It was, in fact, a significant and highly important animal study and set up Mesoblast’s human study.

This past week, Mesoblast released its second round of preliminary results from this Phase 2 human study of MPCs as an intradiscal injection treatment for back pain.

In the study, researchers injected allogeneic mesenchymal precursor cells (MPCs) into damaged intervertebral discs in what is, essentially, a one hour outpatient procedure.

This is the six-month follow-up data. All 100 patients have been enrolled.

Researchers Kasra Amirdelfan, M.D. (IPM Medical Group, Walnut Creek, California), Hyun Bae, M.D. (The Spine Institute, Santa Monica, California, Domagoj Coric, M.D. (Carolina Neurosurgery & Spine, Charlotte, North Carolina), Tory McJunkin, M.D. (Arizona Pain Specialists, Phoenix, Arizona), Michael DePalma, M.D. (Virginia I-Spine Physicians, Richmond, Virginia) and William Beckworth, M.D. (Emory Orthopaedics & Spine Center, Atlanta, Georgia) report that a single low-dose injection of MPC significantly reduced low back pain in the treated patients and did so at a statistically significant way as compared to the control group.

The control group, by the way, received hyaluronic acid injections. In terms of safety, the researchers found no cell-related safety issues.

The study has enrolled 100 patients across 13 sites in the United States and Australia. Researchers are randomizing patients to receive direct intra-disc injection of saline (n= 20), hyaluronic acid (HA, n=20), 6 million MPCs in hyaluronic acid carrier (n=30) or 18 million MPCs in hyaluronic acid carrier (n=30).

The study participants received their injection in an outpatient setting and only patients with single level degeneration were admitted into the study. The investigators are evaluating the patients for safety and efficacy at 30 days, 3 months and 6 months.

Company officials say that researchers will continue to follow the patients for a total of 36 months to evaluate long-term treatment effects.

At six months, 71% of those patients who received a low dose of MPCs met the pre-specified treatment success criteria. By contrast, only 20% and 30% of the patients in the two control arms who received hyaluronic acid and saline met the pre-specified success criteria.

Mesoblast officials expect to have full trial results by the third quarter this year. Company officials report that confirmation of the interim results supports progression of the study to Phase 3 for MPC treatment of chronic discogenic low back pain.

Over 6 million patients in the United States alone are currently dealing with chronic back pain that has persisted for at least three month, according to Mesoblast’s accounting. The CDC's National Center for Health Statistics reported in 2010 that low back pain was the leading cause of pain, affecting 28% of American adults. The United States lifetime prevalence of low back pain is estimated to be at least 60-84%.

Total costs of low back pain are estimated to be between $100 billion and $200 billion annually, two-thirds of which are due to decreased wages and productivity.