Open AccessPS955 FEASIBLE OUTCOME OF BLINATUMOMAB FOLLOWED BY ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION FOR ADULTS WITH RELAPSED OR REFRACTORY PHILADELPHIA‐NEGATIVE ACUTE LYMPHOBLASTIC LEUKEMIA
Author(s) -
Yoon J.H.,
Yoon S.Y.,
Lee J.,
Kim C.,
Eom K.S.,
Kim H.J.,
Lee J.W.,
Lee S.
Publication year - 2019
Publication title -
hemasphere
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 11
ISSN - 2572-9241
DOI - 10.1097/01.hs9.0000562092.00325.67
Subject(s) - medicine , salvage therapy , hazard ratio , blinatumomab , discontinuation , refractory (planetary science) , transplantation , gastroenterology , surgery , lymphoblastic leukemia , chemotherapy , leukemia , confidence interval , physics , astrobiology
Background: In adult patients with relapsed or refractory (R/R) Philadelphia chromosome‐negative (Ph‐negative) acute lymphoblastic leukemia (ALL), CR rates are much lower and survival outcomes are very poor. For safe salvage and bridge to allogeneic hematopoietic cell transplantation (allo‐HCT), several immune‐based treatments have been tried. We analyzed the treatment outcomes and prognostic factors of blinatumomab. Aims: In this study, we analyzed the treatment outcome of blinatumomab and prognostic factors in adult patients with R/R Ph‐negative BCP‐ALL. Methods: From 2016 to 2018, 32 adult patients with R/R Ph‐negative ALL were treated with blinatumomab. All received uniform prephase dexamethasone 20 mg/day for 4 days. Urgent allo‐HCT was planned in patients with complete remission (CR). At the time of blinatumomab treatment, 9 patients (28.1%) were primary refractory, 10 (31.2%) had relapsed during/after consolidation chemotherapy, and 13 (40.6%) had relapsed after first (n = 11) or second (n = 2) allo‐HCT. Results: Overall, 23 patients (71.9%; 100% for primary refractory, 70% for relapsed patients during/after consolidation chemotherapy, 53.8% for relapsed patients after allo‐HCT) achieved CR but 3 of them relapsed – thus, 20 (62.5%) finally underwent allo‐HCT in CR following blinatumomab. CR rate was lower in poor‐risk karyotype (33.3% vs. 87.0% ; p = 0.005). After median follow‐up of 11.9 months (range 6.7 to 23.6), 1‐year OS of all patients was 55.4% with a median survival of 14.5 months. The 1‐year OS and relapse rate of 20 patients who underwent allo‐HCT was 77.8% and 5.6%, repectively, while 1‐year OS for patients who failed to blinatumomab was 12.0% ( p < 0.001). In addition, extramedullary relapse (EMR, 14.3% vs. 68.4%, p = 0.007) and high peripheral blood blast count (26.7% vs. 59.8%; p = 0.026) were related with poorer 1‐year OS. Summary/Conclusion: Blinatumomab is a feasible choice for salvage chemotherapy for adult patients with R/R Ph‐negative ALL which showed a good CR rate at any time of salvage and showed a good bridge to allo‐HCT. However, the role in patients with poor‐risk karyotype, EMR, or high tumor burden should be evaluated in future trials.