Efficacy and toxicity of CLAG combined with pegylated liposomal doxorubicin in the treatment of refractory or relapsed acute myeloid leukemia

Abstract

Background: Refractory and relapsed acute myeloid leukemia (r/rAML) is associated with a difficult prognosis; clinical trials are typically suggested despite lack of a recognized standard of care. Combinatorial chemotherapy regimens utilized for r/rAML salvage play a crucial role in battling this invasive phase. Although it is characterized by a low response rate, CLAG is a traditional regimen used in r/rAML. We aimed to compare the efficacy and toxicity of CLAG+PLD to explore whether there was any improvement with the addition of pegylated liposomal doxorubicin (PLD) to CLAG METHODS: A total of 110 r/rAML patients were retrospectively analyzed from February 2017 to June 2020 at the Medical Center of Hematology, XinQiao Hospital, the 303rd Hospital of the Chinese People's Liberation Army, and Central Hospital of Chang Sha, Hunan Province. The response, overall survival (OS), disease-free survival (DFS), and side effects in 110 r/rAML patients were evaluated retrospectively. Of these, 55 patients were administered CLAG+PLD, while 55 patients received CLAG alone as salvage therapy.

Results: In the CLAG+PLD group, there were 27 (49.1%) cases of complete response (CR) with no measurable residual disease (MRD-), 12 (21.8%) cases of CR with positive MRD (MRD+), 5 (9.1%) cases of partial response (PR), 11 (20%) cases of no response (NR), and no cases of death during the cycles. The response rates in the CLAG group were lower: CR was reached in 24 (46.6%) patients with MRD-, 6 (10.9%) patients with MRD+, 10 (18.2%) patients with PR, 13 (23.6%) patients with NR, and 2 (3.6%) patients who passed away, one from infection and the other from cerebral hemorrhage. The median OS and DFS were not attained in the CLAG+PLD group during the 2-year OS and DFS follow-up, while both values were 10 months in the CLAG group (p = 0.023 and p = 0.045, respectively). The results of the Cox regression analysis for the CLAG+PLD group were strongly illustrative of the importance of hematopoietic stem cell transplantation (HSCT) following salvage therapy. No increased toxicity was observed in the CLAG+PLD group.

Conclusion: CLAG+PLD is a potential salvage regimen for r/r AML that has a similar toxicity profile to CLAG and that improves response rates, 2-year OS, and DFS relative to CLAG.

Keywords: cladribine; hematopoietic stem cell transplantation; pegylated liposomal adriamycin; refractory and relapsed AML; reinduction.