The American Heart Association estimates 80 million American adults (approximately 1 in 3) have one or more forms of cardiovascular diseases. It cost the United States alone approximately $500 billion a year, with the burden growing as the population ages.
The principal aims of cardiovascular therapies are to reduce morbidity and mortality from congestive heart failure, heart attacks, strokes and other blood vessel related diseases. The consequences of heart attacks and the progression of congestive heart failure are currently poorly serviced.
The delivery of stem cells to a patient for therapeutic purposes is a new approach to therapeutic intervention and to date there are no products approved for sale.
An effective cell therapy that could help repair the heart would be a blockbuster therapeutic.
Mesoblast’s cardiovascular product development programs are aimed at several conditions including congestive heart failure (CHF) and Acute Myocardial Infarct (AMI) or heart attacks, strokes and peripheral arterial disease.
Congestive Heart Failure
More than 6 million people in the United States suffer from heart failure with an additional 670,000 new cases diagnosed each year. This is the number one cause of mortality and hospitalization in the Western world.
CHF is a chronic condition characterized by an enlarged heart and insufficient blood flow to the extremities of the body. The condition develops over time and can be caused by many factors that put an excess demand on the heart muscle, including high blood pressure, incompetent valves, infections of the heart muscle or valves, or congenital
heart problems.
Although patients are initially treated with drug therapy, the only method of treating end-stage disease currently is a heart transplant or mechanical assist device. Only around 3,000 heart transplants are performed annually in the United States.
Mesoblast’s target market is CHF patients in NYHA class II to IV with an ejection fraction of less than 35%. The estimated market size in the United States alone is currently 2.5 million patients (41% of 6.2 million pre-existing sufferers) and 201,000 newly diagnosed (30% of 670,000) each year.
Mesoblast has developed the adult stem cell-based heart product Revascor® to treat moderate to severe congestive heart failure. In a Phase 2 trial using Revascor®, interim results showed sustained improvement in heart muscle function at six months following implantation with the proprietary stem cells compared with progressive loss in heart function seen in controls. Improvements in these endpoints are used as surrogates to predict reduced mortality and hospitalization due to heart failure.
Heart attacks
At the other end of the disease spectrum, Mesoblast is evaluating the MPC technology for the treatment of acute coronary artery disease and heart attacks. Heart attacks are the single biggest killer of Americans.
Easy physician access to the proprietary “off-the-shelf” stem cell product Revascor® means it can be used in conjunction with all the standard life-saving procedures, such as clot-busting and stent technologies, at the earliest and most effective time. Unfortunately, even after receiving a stent or clot-buster post-heart attacks there remains a subset of patients who continue to have deteriorated cardiac function and are at high risk for death and or degenerating into heart failure within a year. The MPC therapy aims to prevent this continued cardiac decline through the regeneration and repair of the heart that could not otherwise be addressed by the stent or clot-buster technology.
About 80% now survive the initial heart attack, mostly by undergoing an early angioplasty procedure of the blocked artery accompanied by implantation of a metal stent to keep the artery patent long-term. However, despite this success with early survival, nearly half of the surviving patients become disabled with heart failure over the ensuing six years.
The aim of Mesoblast’s stem cell treatment is to prevent the onset of heart failure after heart attack. The initial target for Revascor® is the approximately 50% of the annually 880,000 surviving heart attack patients with the poorest prognosis.
Treatments for heart attack are relatively ineffective in preventing heart failure and none of them is capable of increasing the formation of blood vessels or inducing cardiac repair.
Mesoblast’s studies have shown that methods which increase the amount of blood vessels present in healthy heart muscle adjacent to the heart attack area can induce cardiac regeneration and effectively prevent heart failure after a heart attack. The larger the blood vessels can be created, the greater the preventative effect on post-infarct heart failure.
Mesoblast’s cardiovascular product Revascor® has been shown to induce sustainable large blood vessel formation and protect heart muscle against progression to heart failure. Mesoblast has developed a successful protocol to infuse Revascor® directly into the affected coronary artery after removing an initial obstruction.
Mesoblast envisages that coronary artery infusion of Revascor® by a standard catheter immediately after angioplasty and stent implantation could become a routine procedure to improve cardiac function, enhance quality of life, and reduce the likelihood of heart failure following a heart attack.