A team of international researchers gave the anti-diabetic drug pioglitazone to 24 volunteers who had previously been diagnosed with chronic myeloid leukaemia (CML).
According to Macmillan Cancer Support, CML is a rare type of leukaemia that can occur at any age, but is more common in middle-aged and older people.
Around 600 people in the UK are diagnosed with CML each year and the disease is rare in children.
The volunteers in the latest study also received their regular leukaemia treatment alongside the diabetes drug.
After taking the combination of treatments for a total of 12 months, more than 50% of the cancer patients were in remission.
The first three patients to be given the diabetes drug alongside cancer treatment had no reoccurrences of cancer in the five years that followed the study.
Professor Peter Johnson, Cancer Research UK's chief clinician, told the BBC: "The outlook for people with chronic myeloid leukaemia has improved dramatically since the introduction of drugs like imatinib.
"But for some patients these drugs aren't always effective. This study is an interesting example of how understanding the biology of cancer stem cells could help improve treatment for these patients.
"However, this is early stage research and only a small number of patients have been studied. It will be interesting to see if this combination is also successful in larger clinical trials."
The study was published this week in the online journal, Nature.
Pioglitazone may be useful when it comes to treating blood cancer, but previous research has suggested the drug could increase the risk of an individual developing bladder cancer.
In 2012, Canadian researchers found that patients who use pioglitazone for type 2 diabetes every day for more than two years double their chances of developing bladder cancer.
The medication, which works by controlling blood sugar, is also commonly thought to increase the risk of heart failure.