Mesoblast Limited Scales Down Phase 3 Trial


Mesoblast Limited announced that the number of subjects treated in their ongoing Phase 3 clinical trial in chronic heart failure (CHF) that is testing their proprietary cell-based medicine MPC-150-IM will be substantially reduced.

CHF is characterized by an enlarged heart, coupled with insufficient blood supply to the organs and extremities of the body. Unfortunately, this is a progressing condition that tends to get worse with time. CHF is caused by many different factors such as chronic high blood pressure, faulty heart valves, infections, or congenital heart problems.

Mesoblast centers their company around the isolation and expansion of so-called mesenchymal precursor cells (MPCs) from bone marrow.  Mesenchymal stem cells are found in many different tissues and organs throughout our bodies.  They play vital roles in maintaining tissue health.  However, relatively speaking, mesenchymal stem cells are rare cells.  They are found around blood vessels and respond to signals associated with tissue damage.  They secrete mediators and growth factors that promote tissue repair and control the immune response to prevent it from going out of control.

Mesoblast uses an array of monoclonal antibodies to isolate primitive mesenchymal stem cells that are actually precursors to mesenchymal stem cells or mesenchymal precursor cells (MPCs).  These cells are then expanded in culture without being differentiated into any other cell type.

Mesoblasts, MPC-150-IM product consists of 150 million MPCs that are injected straight into the heart muscle (hence the moniker, “IM” for intramuscular).  Once in the heart muscle, the MPCs induce the formation of new blood vessels to feed the heart muscle, stimulate resident stem cell populations in the heart to repair the heart muscle, and quell inflammation that can cause scarring and decrease heart function (see Yanping Cheng, et al., Cell Transplantation 22(12): 2299-2309; Jaco H. Houtgraaf, Circulation Research. 2013; 113: 153-166). 

Initially, Mesoblast planned to test their product on 1,165 subjects, but have scaled that number back to approximately 600 patients.

Mesoblast’s development and commercial partner, Teva Pharmacueticals has communicated this reduction in the number of subjects to the US Food and Drug Administration (USFDA). “The reduction in the size of the Phase 3 trial may significantly shorten the time to trial completion,” said Mesoblast CEO Silviu Itescu.

The reduction in the number of patients was due to a proposed change in the primary endpoint of the trial. The revised primary endpoint is now a comparison of recurrent heart failure-related major adverse cardiovascular events (HF-MACE) between patients treated with Mesoblast’s MPC-150-IM cells and the control patients who were not treated with these cells.

Why the change in the primary endpoint? The reason lies in the success that MPC-150-IM cells had their Phase 2 clinical trial. In this trial, a single injection of MPC-150-IM cells successfully prevented HF-MACE over three years. This second, confirmatory study will be conducted in parallel with a patient population that has an identical clinical profile; approximately 600 of them using the same primary endpoint.

In the completed Phase 2 trial, patients treated with MPC-150-IM had no HF-MACE over 36 months of follow-up, compared with 11 HF-MACE in the control group. From this same clinical trial, of those patients who suffered from advanced heart failure (defined by baseline Left Ventricular Systolic Volume being greater than 100 milliliters), 71 percent of the controls (who received no cells) had at least on HF-MACE versus none of those who received a single injection of MPC-150-IM cells. As it turns out, this Phase 2 patient population closely resemble the patients being recruited in the Phase 3 trial.

“Patients with advanced heart failure continue to represent among the largest unmet medical needs, where existing therapies are inadequate and the economic burden is the greatest. The current Phase 3 trial targets this patient population, continues to recruit well across North America, and is now expanding to Europe,” said Itescu.

Mesoblast Phase Degenerative Disc Disease Treatment Receives Positive Feedback from European Regulatory Agencies


Mesoblast Limited announced that European Medicines Agency has approved expansion of their Phase 3 clinical program of its product candidate MPC-06-1D for degenerative disc disease.

Mesoblast’s Phase 3 program for this product candidate is currently in the process of enrolling patients in the United States under an Investigational New Drug (IND) application filed with the US Food and Drug Administration (FDA).  Having received general agreement from EMA on the target patient population, trial size, primary composite endpoint, and comparators in the control population, Mesoblast now intends to additionally enroll patients across multiple European sites.

The discussions with EMA occurred as part of combined scientific and reimbursement advice under an EU pilot program known as Shaping European Early Dialogues (SEED). The SEED pilot program was established to facilitate early dialogue between EMA, European Health Technology Assessment reimbursement bodies, and selected companies with late-stage clinical development programs. Mesoblast’s product candidate MPC-06-ID is one of only seven medicines accepted for the SEED program.

Mesoblast and SEED representatives discussed key clinical trial aspects of the development of MPC-06-ID including the safety database, mechanisms of action, patient population and trial size, composite endpoints, and comparators. The discussions also focused on access to EU markets and pharmacoeconomic endpoints that may lead to reimbursement.

The guidance from the meeting with SEED representatives may result in a final comprehensive EU development and commercialization program that has an increased likelihood of producing data that will be acceptable for both registration and reimbursement review in multiple European countries.

Adult Stem Cells Used for Spinal Disc Repair


The Australian regenerative medicine company Mesoblast Limited announced the results of their 12-month clinical trial that examined the use of their “off-the-shelf” product to treat patients with disc-related low back pain.

This phase 2 clinical trial enrolled 100 patients with chronic moderate to severe “discogenic low back pain” and tested the ability of “mesenchymal precursor cells” to shore up degenerating intervertebral discs.

Intervertebral discs

Intervertebral discs sit between each vertebra and act as shock absorbers. Each disc consist of an outer layer called the “annulus fibrosus.” The annulus fibrosus consists of several layers of fibrocartilage. The annulus fibrosus surrounds an inner layer called the nucleus pulposus, which contains loose fibers suspended in a mucoprotein gel with the consistency of jelly. This jelly-like center distributes pressure evenly across the disc. These discs absorb the impact of the body’s daily activities and keep the two vertebrae separated. The development of a prolapsed disc results when the jelly in the nucleus pulposus is forced out of the doughnut/disc, which may put pressure on the nerve located near the disc.

Intervertebral structure

More than six million people in the United States alone deal with chronic back pain that has persisted for at least three months, and 3.5 million people are affected by moderate or severe degenerative intervertebral disc disease.

In this clinical trial, Mesoblast Limited injected their mesenchymal precursor cells (MPCs) into the degenerating intervertebral discs of patients suffering from moderate to severe back pain. When compared with a control group, patients who received the MPC injections used less pain killers, went through fewer surgeries and non-surgical interventions, and had greater disc stability as ascertained by X-rays. MPC injections also were well tolerated and produced few side effects.

This phase 2 clinical trial extends earlier observations by Mesoblast Limited on laboratory animals. In preclinical trials, purified MPCs increased the quality of the jelly content of the nucleus pulposus and improved disc structure in sheep.

This present study enrolled 100 patients at 13 different sites across Australia and the United States with early disc degeneration and randomly assigned the subjects to one of four groups: 1) those who received saline injections; 2) those who received hyaluronic acid injections; 3) those who received low-dose MPCs in hyaluronic acid; and 4) those who received high-dose injections of MPCs in hyaluronic acid.

All patients received their injections in an outpatient procedure, and are being evaluated for safety and efficacy to evaluate long-term treatment effects.

At 12 months, the key findings were improvement in chronic low back pain, function, and disc stability. Also, no safety concerns emerged as a result of the treatment.

As this trial proceeds, more data should be forthcoming.