What salvage therapy is most effective in acute myeloid leukemia?

This study examined treatment options for patients who did not respond to induction therapy (treatment to induce complete remission). This study concluded that stem cell transplantation (SCT) or a combination of chemotherapy and other therapies are effective options.

Induction therapy in acute myeloid leukemia (AML) is hoped to lead to a complete remission (CR, no sign of disease). However, roughly 20-25% of patients fail to respond. Certain genetic changes (such as mutations) have been associated with an increased risk of induction failure.

Intensifying (increasing) treatment doses has been one option in these patients. Combinations of treatments have also been tried, with varying success rates. These include high-dose cytarabine and high-dose cytarabine combined with all-trans retinoic acid (ATRA) and mitoxantrone (A-HAM). Another possibility is A-HAM combined with the targeted therapy (treatment that targets proteins involved with cancer growth) gemtuzumab ozogamacin (GO-A-HAM). Stem cell transplantation (transplant of immature blood cells from a donor) is also used in these patients. The optimal treatment for patients who have failed induction therapy (known as salvage therapy) is not clear.

This study reviewed the records of 875 patients who failed induction therapy. These patients were treated with various intensive salvage therapies, including A-HAM, GO-A-HAM, and SCT. 472 patients underwent SCT after chemotherapy. 87 patients underwent SCT without prior chemotherapy (dSCT). Patients were followed for an average of 2 years.

Overall, 36% of patients saw a CR to salvage therapy. CR rates were highest in patients who underwent dSCT (64%) and those treated with GO-A-HAM (50%).

48% of patients who were in CR at the time of SCT were alive after 5 years. 36% of patients who underwent dSCT were alive at 5 years.

Patients who responded to salvage therapy and who could undergo SCT had better odds of survival.

This study concluded that dSCT and GO-A-HAM were associated with increased odds of response to salvage therapy.