Related Experiment Video
Updated: Feb 8, 2026

Murine Model of Leukemia Relapse to Induction Chemotherapy for Acute Lymphoblastic Leukemia
Published on: October 17, 2025
The FOSSIL Study: FLAG or standard 7+3 induction therapy in secondary acute myeloid leukemia
Vera Vulaj1, Anthony J Perissinotti1, James R Uebel2
1Department of Pharmacy Services and Clinical Sciences, Michigan Medicine and University of Michigan College of Pharmacy, Ann Arbor, MI, USA.
Abstract:
Patients with secondary acute myeloid leukemia (sAML) have poor outcomes, with CR/CRi rates of 25-35% with standard 7 + 3 induction chemotherapy, while single center non-comparative analyses suggest promising outcomes with FLAG. We conducted a single-center, retrospective cohort study assessing outcomes in treatment-naïve patients with sAML treated with fludarabine, high-dose cytarabine, and granulocyte colony-stimulating factor (FLAG, n = 40) compared with 7 + 3 (n = 66). Median patient age was 63 years (range: 27-82) in the FLAG group and 60 years (range: 21-76) in the 7 + 3 group (P = 0.968). Patients treated with FLAG achieved higher overall response rates (CR + CRi + MLFS) compared to 7 + 3 (70% vs. 48%, P = 0.043). FLAG was well tolerated, with only one induction death (30-day mortality rate, 3% vs. 8%, P = 0.405) and no cases of cerebellar toxicity. Duration of neutropenia was significantly shorter with FLAG (median 16 vs. 23 days, P < 0.001). Half of the FLAG-treated patients proceeded to consolidative therapy compared with only 27% of those who received 7 + 3 (P = 0.022). Overall survival was comparable between groups (8.5 mos, FLAG vs. 9.1 mos, 7 + 3; P = 0.798). Thus, FLAG may represent a low-cost treatment strategy in sAML that produces higher response rates and promising survival outcomes with minimal treatment-related toxicity. Further studies are required to prospectively compare FLAG to the newly FDA-approved CPX-351 in sAML.
More Related Videos
Related Concept Videos
The Fossil Record
Secondary Active Transport
Secondary Healthcare System
Measurement: Standard Units
Acute Pyelonephritis II: Diagnostic Studies and Management
Primary and Secondary Growth in Roots and Shoots

