The majority of patients with chronic myeloid leukaemia (CML) are willing to attempt treatment free remission – taking a 50:50 chance on a life free of the side effects associated with tyrosine kinase inhibitors.
The Australian research found 81% of CML patients who have achieved a stable, deep molecular response with drugs such as imatinib were willing to have a drug free trial.
The catch-all was evidence that patients who were closely monitored and who fail treatment free remission can have their therapy safely re-established.
Dr David Ross, a consultant haematologist at the Royal Adelaide Hospital and Flinders Medical Centre, said the approach was making the transition to routine care.
“It has until recently been considered experimental but just this year the US National Comprehensive Cancer Network has included the option of treatment-free remission in their guidelines.”
He said while the drugs were subsidised by the PBS in Australia, there was still the potential for considerable savings to the public purse.
“The cost to the public is in the order of $30,000-40,000 per patient per year. If we save someone 10 years of treatment, that’s a major cost saving.”
The study found most patients would attempt treatment free remission in order to eliminate actual or potential toxicity associated with TK inhibitors.
Dr Ross said most side effects were niggling, low grade problems such as muscle cramps, tiredness, fluid retention, skin irritation or stomach upsets.
“However, many patients feel their quality of life is better if they are no longer taking these medications.”
Additionally, patients were keen to be relieved of the inconvenience of treatment.
“Depending on the inhibitor, some patients need to be fasting or planning their meals around taking their tablets.”
Dr Ross said patients who have been on treatment for at least three years and have achieved at least MR4.0 for two years were eligible for a trial off treatment.
About 80% of patients who relapse will do so in the first six months, he said.
The study found patients understandably had information needs and needed the strong support of their physician.
Dr Ross said good tests results were obvious triggers to initiate discussions with patients about the possibility of a treatment free remission in the future. Patients certainly benefited from a number of discussions over time, he said.
Research is ongoing to identify which patients are more or less likely to be successful in achieving treatment free remission. Duration of treatment with tyrosine kinase inhibitors and immunological status were possible predictors.