A new maintenance treatment for patients with acute myeloid leukemia (AML) has shown so much promise in extending post-chemotherapy remission it is already being implemented into standard care.
The trial, documented in the New England Journal of Medicine, showed the powerful potential of the pill form of cancer drug azacitidine to hold AML at bay. “At last, we have an effective treatment that can be given in the post-remission setting to help keep AML patients in remission and improve their survival,” said Gail Roboz, senior author of the study and a professor of medicine in the division of Hematology and Medical Oncology and director of the Clinical and Translational Leukemia Program at Weill Cornell Medicine.
“We are especially gratified that the drug is very well-tolerated, so that quality of life is not compromised.”
AML is a rare form of cancer that affects just over a thousand or so Canadians annually, according to Cancer.ca. The disease, which originates in blood cells and bone marrow, prompts the abnormal production of “blast” cells that multiply and crowd out regular cells. This results in lower levels of red blood cells, white blood cells and platelets, which impede the body’s ability to stave off infection and circulate oxygen.
Just 21 per cent of Canadians diagnosed with AML live for another five years and patients frequently relapse despite achieving full remission through chemotherapy.
Researchers, determined to improve these numbers, recruited 472 patients from medical centres around the world to probe whether oral azacitidine, also known by the trade name Onureg, could be used as a maintenance therapy to extend remission. The team found that the group of patients that received 300 mg of azacitidine for two weeks each month showed statistical and clinical improvements in both relapse-free survival (RFS) and overall survival (OS).
Without the drug, patients experienced an RFS and OS of 4.8 months and 14.8 months, respectively. The patients who took azacitidine, however, had an RFS of 10.2 months and an OS of 24.7 months, considerable improvements. Two years after the start of the trial, slightly more than 50 per cent of azacitidine patients were still alive, compared to 37.1 per cent of patients who did not receive the drug. Side effects, which can include vomiting, infections and low white blood cell counts, were described by researchers as moderate and manageable.
The team believes the drug works by removing chemical markings called methyl groups from cellular DNA. As these groups are responsible for regulating gene activity, their removal is suspected to restore the activity of tumour-suppressing genes in the vicinity, which are then able to combat the spread of cancerous cells.
The new maintenance therapy has been life-changing for some of the people who have experienced it, Roboz said. “One of my patients on the trial was so critically ill when she was initially diagnosed that she was told to get her affairs in order,” she said. “But her AML was put into remission and she has been receiving oral azacitidine maintenance therapy as part of the QUAZAR trial since 2013.”
Thanks to the study’s findings, the U.S. Food and Drug Administration approved oral azacitidine as a maintenance treatent for AML patients in September 2020, a bit before official publication of the study in the medical journal. Health Canada followed suit in January 2021.
Dave Yasvinski is a writer with Healthing.ca
If you or someone you care about is living with leukemia, connecting with a support network can help to not only learn ways to better manage their health, but also share experiences with others. Some resources include the Wellspring, Cancer Connect at the Canadian Cancer Society, and the Leukemia & Lymphoma Society of Canada.