In a world-first trial, Australians are among the patients whose cancer has all but disappeared and now doctors are hopeful they can treat other cancers as effectively.
Leukaemia patient Catherine Ringwood, 63, was one of 67 who took part in the international trial.
She said her future had been turned around.
"This is a second chance at life for me, absolutely," she said.
Ms Ringwood is one of the successful participants in a trial for ABT-199, pioneered by Australian researchers and developed by US drug companies.
"Doctors are telling me that instead of having 85 per cent disease in my bone marrow, I've got only five per cent disease," she said.
The treatment applies only to patients whose illness cannot be treated by any other medication, including chemotherapy.
The drug works by targeting the cancer cell producing protein "BCL2".
It melts the protein away, and the cancer cells begin to die.
So far the only side-effect detected has been a drop in the white blood cell count for some patients.
Successful trial participants will now be monitored and need to take the pills for the rest of their lives.
Doctors are hopeful the pills will also be available to other patients within three to five years.
