The two trials will involve injecting copies of a healthy gene into the heart via a cardiac catheter and will be run by a team from Imperial College London. The first patients will start treatment in the next month at the Royal Brompton Hospital and over 200 people will receive the therapy worldwide.
The researchers will deliver a gene known as SERCA2a into heart cells using a virus known as an adenoassociated virus, which has been genetically altered so it is not harmful. The gene will cause the expression of a protein involved in calcium signalling that will allow the heart to pump more effectively, the researchers hope.
Heart failure is the term used to describe a variety of problems that can damage the heart, and affects more than 750,000 people in the UK. Those with heart failure often rely on medicines, but as their condition worsens they may have to use mechanical aids, such as a pacemaker, or wait for a transplant.
'Once heart failure starts, it progresses into a vicious cycle where the pumping becomes weaker and weaker, as each heart cell simply cannot respond to the increased demand', said Dr Alexander Lyon, a consultant cardiologist at the Royal Brompton. 'Our goal is to fight back against heart failure by targeting and reversing some of the critical molecular changes arising in the heart when it fails'.
The same team will also be testing the gene therapy in people who are using a type of mechanical heart pump called a Left Ventricular Assist Device.
Previous trials of SERCA2a gene therapy have shown that it is safe in humans and reduces the symptoms of heart failure. The researchers claim that the symptoms of those tested have been reduced, such as breathlessness and fatigue, and the treatment has resulted in fewer emergency admissions to hospital and fewer deaths.
The researchers are optimistic that the gene technique will improve the quality of life in some of the patients. 'It's been a painstaking, 20-year process to find the right gene and make a treatment that works, but we're thrilled to be working with cardiologists to set up human trials that could help people living with heart failure', said Professor Sian Harding from Imperial College London.
However, Dr Lyon estimated that it will be at least eight years until the treatment becomes more widely available, as a longer-term study involving many patients will need to take place to confirm that the therapy is safe and effective. The treatment will not be suitable for everyone, as some people produce antibodies to the virus carrying the gene, which would be neutralised so that the therapy would have no effect.