AL-08. Extramedullary acute myeloid leukemia: could the new targets and allogeneic stem cell transplantation improve outcomes?
Aleksina A. Shatilova, Irina G. Budaeva, Yuliya D. Matvienko, Yuliya V. Mirolyubova, Darya V. Ryzhkova, Roman V. Grozov, Konstantin V. Bogdanov, Tatiana S. Nikulina, Ksenia A. Levchuk, Renat S. Badaev, Yuliya A. Alekseeva, Elza G. Lomaia, Larisa L. Girshova
V. A. Almazov National Medical Research Centre, St. Petersburg, Russia
Contact: Dr. Aleksina A. Shatilova, phone: +7 (911) 476-35-58, e-mail: alexina-96@list.ru
Summary
Extramedullary acute myeloid leukemia (eAML) is a rare manifestation of de novo or relapsed AML. The optimal management strategy for patients with eAML is not clearly understood, especially in terms of new targets efficacy and best time for allogeneic stem cell transplantation (allo-SCT) performing. Our objective was to determine the role of intensive treatment, targeted therapy, and alloSCT in the management of patients with eAML.
Patients and methods
We retrospectively analyzed a cohort of 37 patients with eAML (24 were males, 13 were females with median age of 40 years), among them 16.2% (6/37) had isolated myeloid sarcoma. eAML in relapse was verified in 10.8% (4/37) cases. The most common lesions were found in soft tissues (18.8%) and bones (10.1%). All patients received standard (“7+3”), high (“HiDAC”, “FLAG+/-Ida”), or low-intensity chemotherapy regimens. Targeted therapy, i.e., gemtuzumab ozogamicin, (GO), venetoclax or gilteritinib, was administrated to 16 patients (43.2%). Allo-SCT was performed in 22 patients (59.5%) with positron emission tomography (PET)-negative complete remission (CR).
Results
Patients with favorable genetic alterations (according to ELN-2022) had advantage in complete bone marrow response (88.9% vs 45.5%, P=0.027), but not in complete extramedullary response (EMR) (50% vs 78.3%, P>0.05). The second induction treatment with high-intensity regimens significantly increased the rate of complete EMR (85.2% vs 0%, P=0.004), and decreased the incidence of early (during the first 12 months) relapse (26.7% vs 88.9%, P=0.014), and improved overall survival (OS) (median was not reached at 6 months, P<0.001) compared with standard-intensity regimens (Fig. 1). Venetoclax therapy was effective in 61.5% (8/13) patients, among them 3 patients achieved PET-negative EMR after the cytostatic therapy failure. Overall CR rate after adding GO to chemotherapy was 63.6% (7/11). Gilteritinib was effective in a patient with a persistent extramedullary lesion after ‘7+3+midostaurin’ (Fig. 2). The patients had a lower risk of early relapse (10% vs 86%, P=0.002), better median OS (38.85 vs 7.57 months, P=0.013), and relapse-free survival (38.85 vs 3.78 months, P=0.0021) when allo-SCT was performed in first PET-negative CR (Fig. 3).
Conclusion
The ELN-2022 risk categories do not correlate with frequency of EMR. Intensive treatment is effective in case of persistence of extramedullary disease after standard induction therapy. Use of target agents enables an increase in the rate of responses among patients with eAML. Patients have a better prognosis when allo-SCT is performed in the first PET-negative CR.
Keywords
Acute myeloid leukemia, myeloid sarcoma, extramedullary lesions, allogeneic hematopoietic stem cell transplantation.
