The use of CPX-351, a dual-drug liposomal encapsulation of cytarabine and daunorubicin, was tied to long-term remission and survival in older patients with newly diagnosed high-risk or secondary acute myeloid leukemia (AML), according to final results of a phase 3 study.
As part of the American Society of Clinical Oncology virtual scientific program, Jeffrey E. Lancet, MD, of the Moffitt Cancer Center in Tampa, Fla., presented the 5-year final data from a trial comparing CPX-351 vs. the conventional 7+3 regimen of cytarabine and daunorubicin in more than 300 older adult patients (age 60-75 years) with newly diagnosed high-risk or secondary AML. Early mortality rates for CPX-351 vs. 7+3 were 6% vs. 11% at Day 30 and 14% vs. 21% at day 60, respectively.
The final 5-year follow-up results had a median follow-up of just greater than 60 months, and maintained the improved median overall survival previously observed in the trial with CPX-351 (153 patients), compared with 7+3 (155 patients), Dr. Lancet reported.
Allogeneic hematopoietic stem cell transplant was received by 35% of the patients in the CPX-351 arm and 25% of patients in the 7+3 arm. The median overall survival after transplant was not reached for the CPX-351 arm, compared with 10.3 months with the 7+3 treated patients.
Remission, either complete remission or complete remission with incomplete neutrophil or platelet recovery, was achieved by 48% of patients in the CPX-351 arm and 33% of patients in the 7+3 arm, according to the results of the 5-year follow-up. In addition, among all patients who achieved remission, median overall survival was longer with CPX-351 than with 7+3, and the Kaplan-Meier estimated survival rate was higher for CPX-351 at both 3 years and 5 years.
At 5 years of follow-up, 81% of patients in the CPX-351 arm and 93% of patients in the 7+3 arm had died, with similar causes cited in each arm. Progressive leukemia was the most common primary cause of death in both treatment arms, according to Dr. Lancet.
“The final 5-year follow-up results from this phase 3 study support the prior evidence that CPX-351 has the ability to produce or contribute to long-term remission and survival in older patients with newly diagnosed high-risk or secondary AML,” Dr. Lancet concluded.
CPX-351 (Vyxeos) has been approved by the Food and Drug Administration and the European Medicines Agency for the treatment of adults with newly diagnosed therapy-related AML or AML with myelodysplastic syndrome–related changes.
The study was funded by Jazz Pharmaceuticals. Dr. Lancet disclosed that he has a consulting or advisory role for Agios, Daiichi Sankyo, Jazz Pharmaceuticals, and Pfizer.
SOURCE: Lancet JE et al. ASCO 2020, Abstract 7510.