Blocker could halt advance of leukaemia

Therapy raises hopes of stopping disease without affecting normal blood cells

A PROMISING new drug therapy for an aggressive form of leukaemia has raised hopes of a “new era” for the treatment of blood cancer.

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 five years or more. There are few treatment options for acute myeloid leukaemia, which causes the bone marrow to produce a large number of abnormal blood cells. Most patients receive chemotherapy and bone marrow transplants, but these are rarely effective and have toxic side effects.

Researchers discovered that blocking an enzyme in the body’s cells which senses changes in oxygen levels could stop the disease from progressing.

In the presence of oxygen, these enzymes — known as hypoxia-inducible factor prolyl hydroxylases (PHDs) — become active to target and destroy proteins called hypoxia-inducible factor (HIF). The study, co-led by the Institute of Cancer Research, London, and the University of Oxford, explored if boosting HIF levels could prevent the progression of AML.

They genetically modified mice and de-activated PHD enzymes, which increased HIF levels and stopped disease progression without having an impact on the production of normal blood cells. Kamil Kranc, professor of Haemato-Oncology at the Institute of Cancer Research, said: “We’ve shown for the first time that targeting the pathways our cells use to respond to oxygen levels could provide a way to treat leukaemia, without impacting normal production of blood cells.”

Researchers also created a new drug called IOX5, which inhibits PHDs without impacting other enzymes.