A stem cell injection to mend a broken heart?

An Australian company has announced it has received regulatory approval from the European Medicines Agency (EMA) to begin phase II trials for its cardiovascular stem cell treatment, Revascor.

Revascor is an allogeneic stem cell treatment being developed by regenerative medicine company Mesoblast to treat a number of cardiovascular diseases including congestive heart failure, chronic angina, and heart attacks. The treatment involves injecting stem cells into the patient's heart within 12 hours of a heart attack - they are expected to rebuild damaged tissue, reducing the risk of further attacks.

Pre-clinical trials in animals suggest the injection increased the number of blood vessels in the damaged region of the heart, preventing the formation of scar tissue and improving heart muscle function after a heart attack. The UK's lead investigator in the research, Dr Jonathan Hill, cardiologist at King's College Hospital London, said the treatment 'offers the hope of a fully functioning lifestyle' to a wide range of heart patients.

Previous trials of this sort have required stem cells to be harvested from the patient themselves after a heart attack. Revascor, however, uses stem cells which can be sourced in advance from a genetically similar donor and used 'off the shelf', avoiding delays in treatment. As allogeneic stem cell transplants usually involve taking cells from a close relative, such as the patient's brother or sister, the risk of rejection is reduced.

Heart disease remains one of the biggest causes of death in the developed world with over 1.7 million people in Europe and 1.1 million in USA affected every year. The UK charity, the British Heart Foundation, says in England around 11 percent of men and 15 percent of women who were admitted to hospital with a heart attack in 2006 had died within 30 days.

Typically, people who have suffered from a heart attack undergo a procedure to widen the obstructed blood vessels, called an angioplasty, accompanied by the implantation of a stent to keep the vessels open. However, it is not uncommon for patients undergoing this process to suffer major heart failure afterwards.

Initially, over two hundred patients from six European countries will be recruited to the placebo-controlled trial, which will assess the safety and efficacy of the drug in heart attack patients. The trial will involve using Revascor in combination with angioplasty and stent procedures, and patients will be monitored for up to 36 months.

Mesoblast chief executive Professor Silviu Itescu said the company was delighted to be progressing into a second major clinical stage for Revascor. 'If the preclinical results are reproduced in this trial, we will have a product that will make a significant impact on the lives of patients after a debilitating heart attack', Professor Itescu said.

The EMA granted its approval for the trial to go ahead on 5 September this year. Mesoblast says it now aims to expand recruitment to Australia and the United States.