Homoharringtonine Combined with Pegylated Liposomal Doxorubicin Bridging to Haploidentical Hematopoietic Stem Cell Transplantation for Rare Acute Promyelocytic Leukemia with CPSF6-RARG Variants: A Case Report

Acute promyelocytic leukemia (APL) with CPSF6-RARG fusion gene is a rare leukemia. Patients with this fusion are resistant to all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), as well as conventional chemotherapy with anthracycline plus cytosine arabinoside. Therefore, it is necessary to explore new protocols for these patients to improve remission and survival. In this case, a 21-year-old female with APL of CPSF6-RARG fusion gene was resistant to daunorubicin combined with cytarabine, ATRA, and ATO. Then the patient underwent a combination of homoharringtonine and pegylated liposomal doxorubicin chemotherapy (homoharringtonine 2 mg/day from day 1–7, Ara-C 15 mg/m² every 12 hours from day 1–7, Peg-Dox 40 mg/m² divided over 3 days from day 1–3 and rhG-CSF 300 μg/day from day 0–8). Following one month of treatment, the patient reached CR. And after another two cycles of the HADG protocol with medium-dose Ara-C treatment, the CPSF6-RARG turned negative. Then the patient successfully received stem cell transplantation. Currently, the patient has survived disease-free for more than 2 years. This study indicates that a combination of homoharringtonine and pegylated liposomal doxorubicin chemotherapy is a successful treatment plan for AML resembling APL with the CPSF6-RARG fusion gene. However, further validation in larger sample sizes is required.