Can oral azacitidine maintenance promote longer survival in older patients with acute myeloid leukemia in first remission following chemotherapy?

This study evaluated the effectiveness of oral azacitidine (Onureg; Oral-AZA) maintenance treatment in older patients with acute myeloid leukemia (AML) in remission. The data showed that Oral-AZA maintenance therapy can be considered in older patients with AML for which hematopoietic stem cell transplantation (HSCT) is not an option.

Acute myeloid leukemia (AML) is a cancer that affects the blood-forming cells of the bone marrow (spongy tissues centrally located in certain bones). Advanced treatment options for AML are limited for older patients. Survival outcomes for these patients remain poor despite achieving complete remission (disappearance of cancer cells). Moreover, HSCT (replacement of unhealthy bone marrow and cells of the immune system with healthy ones after chemotherapy) is not an option for many older patients in remission.

Oral-AZA is a chemotherapy drug that modifies DNA (deoxyribonucleic acid; genetic information) and blocks the expression of cancer genes. There is a need to investigate the long-term survival of older patients with AML in remission after chemotherapy treated with Oral-AZA as maintenance treatment.

This study included 472 patients with AML who were in complete remission after previous chemotherapy. Patients were randomly assigned to receive either Oral-AZA (238 patients) or a placebo (234). Patients were treated for 14 days in repeated 28-day cycles. After 28 cycles, patients in the Oral-AZA group were given the option to continue treatment. Patients were followed on average for 41.2 months.

The average overall survival for patients treated with Oral-AZA was 24.7 months compared to 14.8 months with placebo. It was estimated that after 2 years 50.6% of patients in the Oral-AZA group and 37.1% of the placebo group would be alive. 

16% of patients continued to take Oral-AZA after 28 cycles. Overall, these patients were followed up for an average of 55.5 months. After 3 years, 37.4% of patients in the Oral-AZA group were alive compared to 27.9% in the placebo group. After 5 years, 26.5% of the Oral-AZA group were alive compared to 20.1% of the placebo. group. 

The study concluded that Oral-AZA maintenance treatment showed sustained and improved survival in older patients with AML in remission after chemotherapy.

The study evaluated data from a small number of patients who opted to continue treatment with Oral-AZA after disclosure of treatment allocation to investigators and patients. This may have influenced data interpretation. This study was funded by Bristol Myers Squibb, the manufacturer of Oral-AZA.