Which is more effective in secondary acute myeloid leukemia, FLAG or standard 7+3 induction therapy?

This study analyzed different types of induction chemotherapy regimes in secondary acute myeloid leukemia. The authors concluded that the FLAG combination had a high response rate and a low level of treatment-related side effects.

Secondary acute myeloid leukemia is a type of leukemia arising from a pre-existing blood disorder, malignancy gene or from previous chemotherapy or radiation treatment. The standard induction chemotherapy involves 3 days of daunorubicin and 7 days of cytarabine (7+3).  However, response rates to standard chemotherapy in this type of leukemia are low (25-35%).

FLAG includes a combination of the chemotherapies fludarabine and high-dose cytarabine, and a granulocyte colony-stimulating factor (stimulates white blood cell production).  It is not clear whether FLAG is as effective as the 7+3 regimen.

This study included 106 previously untreated sAML patients. 40 patients received a single cycle of FLAG,  66 patients received standard 7+3 induction therapy.

70% of patients treated with FLAG responded to treatment, compared to 48% of the 7+3 patients. 50% of FLAG patients moved on to the next stage of treatment compared to 27% of patients receiving 7+3. Average 5-year overall survival (time from treatment until death from any cause) rates were 22% with FLAG treatment and 6% with 7+3 treatment.

80% of patients treated with FLAG and 91% of patients treated with 7+3 experienced fever associated with low white blood cell levels (neutropenia). Neutropenia lasted significantly longer in patients treated with 7+3.

This study concluded that FLAG therapy had an overall high response rate with minimal treatment related side effects. The authors suggested that FLAG may be an effective treatment option for sAML.

It should be noted that this study only included adults and also the majority of these patients had acquired sAML due to a preexisting blood disorder. Also, the average age for the groups was 63 for FLAG and 60 for 7+3, and older age can negatively impact overall survival.