Cytarabine-daunorubicin liposome for injection: a potential new standard of care for elderly patients

The Phase III trial of a novel formulation of cytarabine-daunorubicin encapsulated in a liposome for injection, also referred to as CPX-351, reported positive results in elderly patients with acute myeloid leukemia (AML).^[1]

Prior to this Phase III trial, in vitro studies have shown that the efficacy of cytarabine and daunorubicin is dependent on the molar ratio of the two drugs, with an ideal molar ratio of 5:1. In CPX-351, the two drugs have been combined at this molar ratio and encapsulated in a nano-scale liposome. The idea behind the encapsulation is to keep the drug ratio constant after dosing in order to enhance the treatment efficacy. Without the encapsulation, the ratio of the two drugs would constantly change.^[2]

The new formulation of cytarabine-daunorubicin liposome for injection was used for the treatment of elderly patients between the ages of 60–75 with high-risk (secondary) AML, and compared to the standard of care regimen “7+3”, which consists of 7 days of standard-dose cytarabine followed by 3 days of standard-dose daunorubicin.^[1]

“The overall survival advantage seen with CPX-351 compared to 7+3, along with a superior response rate and no increase in serious toxicity indicates that we’ll likely have a new standard of care for treating older patients with secondary AML,” according to the principal investigator of the study, Dr Jeffrey E. Lancet from the Moffitt Cancer Center. He further added that “this represents a major step forward for a very difficult-to-treat patient population.”

The randomized, controlled, Phase III trial enrolled 309 patients at 39 sites across the United States of America (USA) and Canada. The primary endpoint of the trial, which was to demonstrate a statistically significant improvement in overall survival (OS), was met. Data will be submitted for presentation at the American Society of Clinical Oncology (ASCO) 2016 Annual Meeting.

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