Chemotherapy regimens for patients with relapsed or unresponsive acute myeloid leukemia

This study aimed to compare outcomes of fludarabine–treosulfan (FT), thiotepa–busulfan–fludarabine (TBF), and fludarabine, Ara-C, amsacrine, total body irradiation/busulfan, cyclophosphamide (FLAMSA) in the treatment of patients with relapsed or unresponsive acute myeloid leukemia (AML). The study found that all 3 chemotherapy treatments had similar outcomes in these patients.

Acute myeloid leukemia (AML) is a cancer of the bone marrow. This leads to abnormal immune cells. It is often treated with stem cell transplant (SCT). Chemotherapy is often offered before SCT to kill any remaining cancer cells. It is called a conditioning regimen. It is important to research which type of chemotherapy leads to better outcomes in patients with relapsed or unresponsive AML. 

This study included 856 patients with relapsed or unresponsive AML. 113 patients received FT, 112 received TBF and 631 received FLAMSA as conditioning regimens before SCT. They received a SCT from a matched sibling or unrelated donor.

At day 100 after treatment, 92% of patients on FT, 80% of TBF and 88% of patients on FLAMSA had a complete response to treatment. Overall survival after 2 years was 47% for FT, 24% for TBF and 34% for FLAMSA. Leukemia-free survival rate was similar between the FT (29%), TBF (22%) and FLAMSA (27%) groups.

For all patients, acute graft vs host disease (GvHD; a complication after SCT where the donated cells attack the patients) was seen in 28%. Severe to life-threatening GvHD was reported in 11% of patients. This side effects was similar between the 3 groups.

The study concluded that all 3 chemotherapy plans had similar effectiveness in the treatment of relapsed and unresponsive AML.

This study is limited by a small and unequal sample size. It also looked at older collected data. New and larger studies are required to confirm the results.