Session: 723. Allogeneic Transplantation: Long-term Follow-up and Disease Recurrence: Poster II
Hematology Disease Topics & Pathways:
Biological therapies, Therapies, Transplantation
We retrospectively analyzed a cohort of 553 AML and MDS adult patients consecutively allotransplanted between January 1, 2015, and December 31, 2021, at Saint-Antoine University Hospital, Paris (France) (n=420) and Spedali Civili di Brescia, Brescia (Italy) (n=133). 134/553 (24%) patients relapsed and were included in this study. 103/134 (77%) were subsequently treated. Among patients who received treatment, 40/103 (39%) were treated with a DLI-based regimen. In this group, 9 received DLIs alone, while the others also received HMAs (4 cases), HMAs+ venetoclax (12 cases), FLT3-inhibitors (3 cases), intensive chemotherapy (5 cases), a second allo-SCT (5 cases), or other therapies (2 cases). The remaining 63/103 (61%) patients were treated with regimens that did not include DLIs. Of these, 10 received HMAs, 27 HMAs+ venetoclax, 4 FLT3-inhibitors, 6 intensive chemotherapy, 9 a second allo-SCT, and 7 other therapies.
With a median follow up of 1.6 years, the estimated 1-, 2- and 5-year OS rate of the 134 patients who relapsed after allo-SCT was 32%, 18 %, and 11 %, respectively. The OS of patients treated after allo-SCT relapse was 40 %, 20%, and 15% at 1, 2 and 5 years compared with 6 %, 3%, and 0 % for patients who did not receive therapy, respectively (p<0.01). Moreover, the OS was significantly better in patients treated in a pre-emptive setting than in those treated for a morphological relapse (OS at 1, 2 and 5 years was 60%, 36% and 30%, respectively, for patients treated in a pre-emptive setting versus 26%, 12%, and 6%, respectively, for patients treated in hematological relapse (p<0.01) (Figure 1A). Focusing on post-relapse treatment, patients who received DLI-based regimens had a 1-, 2- and 5-year OS of 55%, 32% and 32%, respectively, compared to 27%, 16% and 7% for patients treated with other therapies (p<0.01). Among patients who received DLIs, 50% of patients were treated in the pre-emptive setting. Conversely, in the group of patients treated without DLI, only 22% were treated in the pre-emptive setting, reflecting the more advanced phase of relapse in this group. Finally, when patients were analyzed by the treatment strategy (pre-emptive therapy vs therapy in hematological relapse) and DLI administration (yes vs no), the best outcome was achieved when the relapse was promptly detected and pre-emptive therapy was started, particularly if a DLI was administered. Indeed, the 1-year OS of patients treated in the pre-emptive setting was 67% for those receiving a DLI and 54% for those treated without DLI, while for patients with hematologic relapse, the 1-year OS was 43% for those treated with the DLI-based regimen and 17% for those treated without DLI (p<0.01) (Figure 1B). On multivariate analysis, treatment with DLI after relapse, and pre-emptive setting were independent factors associated with better OS (p=0.03 and p<0.01), respectively.
Our data showed that relapse treatment with pre-emptive therapies is associated with improved outcomes and this effect is more evident when combined with a DLI . These results confirm the primary role of the graft-versus leukemia effect in the treatment of relapse and underscore the importance of its early identification through MRD monitoring.
Disclosures: Malagola: Biotest, MSD: Consultancy, Honoraria. Mohty: JAZZ PHARMACEUTICALS: Honoraria, Research Funding. Polverelli: BMS: Honoraria; GSK: Honoraria; Abbvie: Honoraria; Novartis: Honoraria. Russo: Medac, Abbvie, MSD, Jazz Pharma, Gilead, Novartis: Membership on an entity's Board of Directors or advisory committees; MSD, Novartis, Gilead, BMS, Medac: Honoraria.