When added to chemotherapy, a targeted combination therapy of venetoclax and azacitidine resulted in a 66% complete remission rate among patients with acute myeloid leukemia (AML), according to new research from the University of Texas MD Anderson Cancer Center.

Although there is currently no reliable treatment regimen for AML, researchers noted that many patients receive 1 or both of a chemotherapy and a stem cell transplant, although not all patients are eligible for these therapies.

“A large portion of patients with AML, including those older than 75 or those who have medical comorbidities, cannot tolerate existing treatment strategies, and the patients with AML who are ineligible for intensive chemotherapy often experience poor prognoses,” said lead investigator Courtney D. DiNardo, MD, in a press release. “We launched the VIALE-A trial to evaluate whether we could safely use a combination therapy to treat this critical patient population.”

The multi-institution trial randomized 431 patients with AML to receive either the combination of venetoclax and azacitidine or azacitidine plus a placebo, with the goal of evaluating whether the combination improved overall survival (OS).

According to results presented at the virtual 25th European Hematology Association Annual Congress and published in the New England Journal of Medicine, the combination therapy resulted in a median OS of 14.7 months compared with 9.6 months among patients who received azacitidine alone. Furthermore, 66.4% of patients receiving the combination therapy achieved complete remission, compared with 28.3% of patients receiving only azacitidine.

The researchers also found that these treatment responses were both rapid and durable, with 43% of patients in the combination group exhibiting a response during the first cycle, and with a median duration of remission of 17.5 months.

In addition to their efficacy findings, the investigators found that the combination of venetoclax and azacitidine has a safety profile similar to that of both drugs separately. The most common adverse events (AEs) in both treatment groups included hematologic and gastrointestinal events, and rates of AEs were generally consistent between the 2 treatment groups. The investigators did note a higher frequency of neutropenia (42% vs 29%) and febrile neutropenia (42% vs 19%) among those with the combination therapy compared with those receiving azacitidine and a placebo.

“The primary adverse events seen with azacitidine and venetoclax are related to increased cytopenias, including neutropenia and neutropenia-related infections,” DiNardo said in the release. “Key management guidelines include dosing interruptions between cycles to allow for count recovery in the setting of a leukemia-free marrow, and the use of granulocyte colony-stimulating factor as an adjunct to improve neutrophil count once a patient is in remission.”

The authors said this research is likely to be practice-changing for the treatment of some patients with AML, although additional research is needed to evaluate how new therapies can improve outcomes for all patients with AML.

“While this combination represents a key advance in AML therapy, improving both remission and survival rates in newly diagnosed patients with AML, many unfortunately will still relapse,” DiNardo said in the release. “Our next steps include an evaluation of azacitidine and venetoclax as a backbone to which additional novel therapeutics are being evaluated in particularly high-risk populations.”

REFERENCE
Combination therapy significantly improves survival outcomes for patients with acute myeloid leukemia [news release]. University of Texas MD Anderson Cancer Center; August 12, 2020. https://www.mdanderson.org/newsroom/combination-therapy-significantly-improves-survival-outcomes-for.h00-159384312.html. Accessed August 25, 2020.