Why a Breakthrough Blood Cancer Drug Could be Better for Patients

A more effective and better-tolerated treatment for chronic myeloid leukaemia (CML) could improve quality of life for people living with the disease.

A new study led by Adelaide University and the South Australian Health and Medical Research Institute (SAHMRI) has provided the first direct evidence that a breakthrough targeted therapy can rapidly and consistently suppress the molecular signals that drive CML.

The researchers compared the blocking ability of a new therapy called asciminib with commonly used tyrosine kinase inhibitor (TKI) medications, imatinib and nilotinib. These existing medications have helped many CML patients manage their disease for the past two decades.

We found asciminib was much more powerful at suppressing the cancer-driving protein that causes the leukaemia cells to spread. This is a huge step forward in the search for better, frontline treatment options for patients who don’t respond to current medications. Currently, 25% of patients will develop a resistance or intolerance to existing treatments.”

Chung Hoow Kok, Associate Professor, Centre for Cancer Biology and SA Pathology, Adelaide University

To test the potency of the drug, researchers developed a new way to measure how effectively the treatment switches off the cancer-driving protein inside patients' blood cells.

“Within just one week, asciminib achieved substantially stronger suppression of the cancer-driving protein than the currently available treatments,” said Adelaide University Professor Tim Hughes, who is the leader of SAHMRI’s Chronic Myeloid Leukaemia Group.

“Importantly, none of the patients experienced the poorer responses sometimes seen with the existing drugs.

“This new biological evidence from our research supports the excellent clinical outcomes from recent trials of asciminib.”

Researchers also investigated if asciminib worked in patients who had a specific genetic mutation, which is known to increase the risk of treatment failure. They found the medication was still able to block the main driver of abnormal cell growth, but noted other factors may still affect patient outcomes.

There are more than 7,000 people living with CML in Australia. A type of blood cancer, it is caused by a genetic abnormality which fuels the growth of abnormal blood cells. Medical advances mean that many patients can now manage the potentially life-threatening condition through medication, but only 25% ever reach treatment-free remission.

The findings have been published in the international journal Leukemia and could help doctors identify much earlier whether a patient is responding well to treatment, allowing therapy to be tailored sooner and moving CML care closer to truly personalized medicine.

“This is an important step towards precision medicine, where treatment decisions are guided by the biology of each patient's cancer rather than a one-size-fits-all approach,” said Associate Professor Kok.

“Our findings reinforce the importance of combining genomic testing with treatment monitoring to work out which patients may benefit from additional therapies or more frequent reviews.

“Our goal is to move beyond treating all patients in the same way. By understanding the biology of each person’s CML, we can work towards selecting the right treatment, for the right patient, at the right time.”