Treatment for relapsed acute promyelocytic leukemia

The advent of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has significantly improved the outcomes of acute promyelocytic leukemia (APL); nevertheless, a small fraction of patients still experience relapse. Due to the infrequency of APL relapse coupled with the rapid change in the therapeutic landscape, there are limited available data regarding the treatment of relapsed APL. In this situation, however, ATO-based therapy has been shown to result in high rates of hematological and molecular complete remission (CR). Autologous hematopoietic cell transplantation (HCT) is considered the postremission therapy of choice when patients achieve molecular CR, whereas recent studies have suggested that molecular CR is not prerequisite for the success of autologous HCT. Allogeneic HCT can be reserved for selected patients, i.e., those who cannot achieve CR and those who relapse after autologous HCT, because of high toxicities and the expectation of highly favorable outcomes with autologous HCT during CR. For patients who are ineligible for HCT, prolonged administration of ATRA + ATO would be a viable option. To further refine the therapy for patients with relapsed APL, it is imperative to aggregate clinical data of patients who relapse after the ATRA + ATO frontline therapy within the framework of national and international collaboration.

Automated summary

The introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has greatly improved the outcomes of acute promyelocytic leukemia (APL). ATO-based therapy has shown high rates of hematological and molecular complete remission (CR) in relapsed APL. Autologous hematopoietic cell transplantation (HCT) is the preferred post-remission therapy for patients who achieve molecular CR, while allogeneic HCT is reserved for selected patients who cannot achieve CR or relapse after autologous HCT. Prolonged administration of ATRA + ATO is an option for patients ineligible for HCT.