Scientists have discovered a promising new drug therapy for an aggressive form of leukaemia, raising hopes of a "new era" for the treatment of blood cancer.
Researchers at The Institute of Cancer Research in London found that blocking an enzyme in the body's cells which detects changes in oxygen levels could help to treat acute myeloid leukaemia.
Around 3,100 people are diagnosed with the disease each year, according to the NHS, but only 35 per cent of those diagnosed survive for 5 years or more after diagnosis.
There are currently few treatment options for acute myeloid leukaemia. The majority of patients receive chemotherapy and bone marrow transplants to control their condition, but these treatments are rarely effective and cause toxic side effects.
For the study, scientists examined the effect of blocking enzymes in the body known as hypoxia-inducible factor prolyl hydroxylases (PHDs) in mice.
They found that, in the presence of oxygen, these enzymes become active to target and destroy proteins called hypoxia-inducible factors (HIF).
When oxygen levels are low, PHD enzymes are less active, leading to higher HIF levels.
The team genetically modified mice and de-activated PHD enzymes, which increased HIF levels and stopped disease progression without affecting the production of normal blood cells.
Researchers said that a similar enzyme-blocking process is used in drugs that treat anaemia, and showed the same effect on leukaemia in mouse cells and patient samples.
Kamil Kranc, Professor of Haemato-Oncology at The Institute of Cancer Research, said: “Therapy for acute myeloid leukaemia has barely changed in several decades. There is a huge need to discover better treatments for this aggressive disease.
"We’ve shown for the first time that targeting the pathways that our cells use to respond to oxygen levels could provide a new way to treat leukaemia, without impacting the normal production of blood cells within the bone marrow."
Researchers also created a new drug called IOX5, which inhibits PHDs without impacting other enzymes.
It is hoped that the findings of the study will now be tested in clinical trials.
Professor Kristian Helin, chief executive of The Institute of Cancer Research, London, said: “Cancer exists in a complex ecosystem within the body.
“This work provides important insights into that ecosystem, and the way in which cancer uses signals within the environment – such as those relating to oxygen levels – to grow and develop.
"This study is also an excellent example of cancer researchers and chemists working closely together to develop and test new cancer therapeutics."
The research was co-led by scientists from The Institute of Cancer Research and the University of Oxford, and partly undertaken at Queen Mary University of London.
