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
'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
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.