Allogeneic stem cells early after MI cuts HF risk

JULY 4, 2012 Steve Stiles Columbia, MD - A stem-cell treatment already available in some countries for another indication appears to lower the risk of ventricular hypertrophy and arrhythmias, as well as progression to heart failure, in patients with a first MI, according to the product's developer [1]. Based on those one-year interim results from a 220-patient phase-2 trial of Prochymal (remestemcel-L), the originally planned two-year follow-up will be extended out to at least five years, announced Osiris Therapeutics this week. As previously reported by heartwire, the product's dose-finding phase-1 study in first MI [2] suggested that the treatment, which contains mesenchymal stem cells cultured from bone marrow of healthy adult donors, might improve ventricular function. It had also suggested a more pronounced benefit in patients with anterior MIs. In the randomized, double-blind phase-2 study, which was conducted at 33 centers in North America, patients received Prochymal or placebo within seven days of an acute MI. Patients were required to have a baseline LVEF of 20% to 45%. Osiris calls Prochymal "truly an off-the-shelf stem-cell product that is stored frozen at the point-of-care and infused through a simple intravenous line without the need to type or immunosuppress the recipient." At six months, actively treated patients showed less: Stress-induced ventricular arrhythmia (p<0.05). Cardiac hypertrophy by magnetic resonance imaging (p<0.05). Progression to diuretic-requiring heart failure (p=0.01). No infusion toxicities were observed in patients who received Prochymal, and the rate of serious adverse events was about 32% in both groups, according to the company. Prochymal has regulatory approval as treatment for graft-vs-host disease in children in both New Zealand and Canada, and is in phase-3 trials for MI as well as type 1 diabetes and refractory Crohn's disease.