Acute myeloid leukemia (AML) is a rare cancer that begins in the white blood cells and bone marrow. It makes up about 1% of cancers. Because AML is hard to treat, the five-year survival rate is only 25%. A trial that combines two cancer drugs may change treatment for some individuals with AML. This combination was shown to be safe, and it improved overall survival.

The trial results were virtually presented by researchers at The University of Texas MD Anderson Cancer Center to the European Hematology Association Annual Congress and also published in The New England Journal of Medicine.

In the trial, 431 AML patients were randomly assigned to receive the cancer drug azacitidine and a placebo (single-drug therapy) or azacitidine and the cancer drug venetoclax (combination therapy).

Azacitidine is an injection drug used to treat AML and other bone marrow diseases. It works by killing abnormal bone marrow cells. Venetoclax is an oral drug that treats several types of white blood cell cancers. It works by blocking a type of protein that cancer cells need to survive.

Study results: During the trial, patients in the combination therapy group had a better response than patients in the single-drug group. Specifically, the combination therapy group had a rapid response, with 43% of patients responding to the first treatment cycle. Patients in the combination therapy group had an average survival of about 15 months compared with about 10 months for patients in the single-drug group. Although many patients did eventually relapse, 66% of patients in the combination therapy group had a complete remission of their cancer compared with only 28% in the single-drug group.

The combination therapy was found to be as safe as the single-drug therapy. The researchers see the combination therapy as an improvement for AML patients who are older and would not tolerate more aggressive treatments such as stem-cell transplantation.

Takeaway: AML affects about 20,000 people every year. The average age at diagnosis is 68. For many older patients, a tolerable, effective treatment has been elusive. The researchers plan to use this new therapy as a “backbone” treatment to which other new drugs may be added. This may improve survival for patients at highest risk with AML.

Source: Study titled “Azacitidine and Venetoclax in Previously Untreated Acute Myeloid Leukemia,” by researchers at The University of Texas MD Anderson Cancer Center in Houston, published in The New England Journal of Medicine.