In April of this year, Celladon, a biotech company based in San Diego, California, received permission from the Federal Drug Administration (FDA) to apply its MYDICAR gene therapy treatment for heart failure patients in a clinical trial. The FDA has designated this as a type of therapy that is an advanced development therapy, or breakthrough gene remedy. It is a sort of last treatment offer for patients with a type of condition, like heart failure, where other methods have been tried without success.
The new method is designated MYDICAR, by Celladon. It is a type of gene therapy that transfers an enzyme, SERCA2a into cardiac muscles directly. It is supposed to improve the ability of the heart to pump blood. The transfer to heart muscle cells is carried by a benign virus with the delivery system similar to an outpatient angiogram procedure, usually done in a catheterization department, or lab.
Celladon requested the FDA classification according to a previous long-term research project named Cupid-1, which was an objective study with 39 patients who had severe heart failure issues. Some patients received a placebo while other patients were given high, mid or low doses of Mydicar with through-the-heart catheterization. Confirmed results displayed an 88 percent reduction in heart failure-connected hospital visits for those patients who received the highest doses of Mydicar treatments.
The enzyme SERCA2a has a pivotal role of recycling calcium within the cells of the heart muscle. Cells in the heart muscle need to relax and contract, and calcium fuels that role. A variety of heart failure conditions, such as diabetes, coronary artery disease, drug abuse and alcoholism, may contribute to heart failure. These conditions play a part in the loss of enzyme function in the heart muscle cells. Gene therapy may not be a treat for those with heart failure, but conceivably it will assist patients to enjoy a better lifestyle.
The success rate of the Cupid-1 research opened the door for the current acceptance by the FDA for Celladon to continue with a second study, designated Cupid-2. This study has a larger number of patients, 250, in Europe and the U.S., 14 of whom are in Britain. Results from Cupid-2 may be available in April of 2015.
A major reason for the development of Mydicar gene therapy and the FDA acceptance of this type of procedure is the current expense of surgical implants known as left ventricle assist devices (LVAD), heart transplants and the cost of re-admissions to hospitals by heart failure patients. Re-admissions may take place three or four times before a heart failure patient succumbs to the loss of heart function altogether. The cost for these hospital stays are an estimated $37 billion.
Along with the Cupid-2 study, another smaller trial is being conducted by Celladon and the Imperial College London with additional funding by the British Heart Foundation. There are 24 patients currently in the study on LVAD’s – 16 of whom will be given Mydicar, and eight who will receive a placebo. The purpose of this study is to evaluate the success of the gene therapy. There is a potential for those patients currently on LVAD therapy to have only the gene therapy as their main source of treatment.
Within six months, the patients within the study will have a heart muscle biopsy performed (tissue sample) and laboratories will examine the tissues for success or failure of the SERCA2a enzyme. Some patients, who are on a heart transplant waiting list and who receive new hearts, will have their original heart muscle tissues examined closely for enzyme analysis. During the trial, patients will be tested at regular intervals to check for improvements in the function of their hearts. At long last, a heart failure treatment using gene therapy may soon triumph as a successful alternative to conventional treatments.
By Andy Towle