Acute myeloid leukemia (AML) continues to carry a dismal prognosis in older adults and those with secondary or high-risk disease, where conventional 7 + 3 chemotherapy has long delivered complete remission rates below 40% and median overall survival often under 6 months. CPX-351 (Vyxeos), a liposomal co-encapsulation of cytarabine and daunorubicin at a fixed synergistic 5:1 molar ratio, was designed to overcome the pharmacokinetic mismatch that undermines the traditional regimen. This review critically examines the preclinical rationale and clinical evidence for CPX-351, with particular attention to whether its nanoparticle platform truly represents a breakthrough or merely an incremental refinement of decades-old cytotoxics. Across phase I–III trials and real-world cohorts, CPX-351 consistently outperformed standard 7 + 3 in its approved populations of newly diagnosed therapy-related AML (t-AML) and AML with myelodysplasia-related changes (AML-MRC) in patients aged 60–75 years. In the pivotal phase III study (n = 309), CPX-351 improved median overall survival from 5.95 to 9.56 months (HR 0.69, 95% CI 0.52–0.90; p = 0.005) and raised the complete remission rate from 33.3% to 47.7%, while facilitating allogeneic transplantation in 34% as opposed to 25% of patients. A five-year follow-up sustained the separation in survival curves, and post-hoc analyses of responders showed median overall survival exceeding 25 months with CPX-351 versus approximately 10 months with 7 + 3 (HR 0.49). Real-world series have reported composite remission rates of 53–60%, measurable residual disease negativity in up to 65% of responders, and median overall survival of 12–20 months, depending on transplant utilization. Despite these gains, the absolute survival benefit remains modest, prolonged cytopenias are universal, and outcomes in TP53-mutated or younger adverse-risk patients are still poor, raising legitimate questions about cost-effectiveness and generalizability. Nonetheless, CPX-351 stands as the first clinically validated example of ratiometric nanomedicine in oncology, proving that reformulating established drugs can yield meaningful progress where novel agents have often failed.
Konstantinidis et al. (2025) studied this question.