What is the prognosis of allogeneic hematopoietic stem cell transplantation in 2022 EBMT patients with primary myelofibrosis?

Primary myelofibrosis (PMF) and secondary myelofibrosis (SMF) secondary to essential thrombocythemia (ET)/polycythemia vera (PV) are one of the Ph-myeloproliferative neoplasms, The prognosis is poor, with a survival of about 6 years
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Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has great therapeutic potential and can cure a large number of PMF and SMF patients, but due to its toxicity and resulting treatment-related morbidity and mortality, allo-HSCT is still not universally applicable to all PMF and SMF patients
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Spanish and Algerian scholars conducted separate studies to explore the prognosis of PMF undergoing allo-HSCT
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Both studies were selected for the poster presentation of the 48th European Society of Blood and Marrow Transplantation (EBMT) Annual Meeting in 2022.
The editor will organize the main contents as follows for the reference of readers
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Abstract number: P572 Title: Allogeneic hematopoietic stem cell transplantation in myelofibrosis: a single-center retrospective study in Spain Methods The investigators conducted a retrospective study and analyzed the correlation between overall survival of patients after allo-HSCT ( OS) related variables
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The study collected 16 patients who were diagnosed with myelofibrosis between January 2005 and December 2020 and were admitted to the Central University Hospital of Asturias in Orvieto, Spain for allo-HSCT, of whom 9 Patients (56.
3%) were male, and the median age was 51 years (range: 32-66 years)
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Seven patients (43.
75%) underwent hematopoietic stem cell transplantation from matched siblings, 7 patients underwent hematopoietic stem cell transplantation from unrelated donors, and 2 patients underwent haploidentical hematopoietic stem cell transplantation
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Stem cell sources: peripheral blood (n=14) and bone marrow (n=2)
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Results Seven patients (43.
71%) had PMF; 6 patients (37.
5%) progressed from ET to SMF with a median time of 12.
6 years; 3 patients progressed from PV to SMF with a median time of 13.
6 years 
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The median time from PMF diagnosis to receiving allo-HSCT was 12.
5 months
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All patients had a driver gene mutation, including 13 cases (81.
25%) of JAK2 gene mutation, 3 cases of CALR gene mutation, and no MPL gene mutation or triple negative result
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Before Allo-HSCT, 14 patients (87.
5%) had systemic symptoms and all had splenomegaly, with an average spleen size of 19.
3 cm
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Thirteen patients (81.
25%) developed anemia (hemoglobin <10 g/dL), of which 3 patients (23%) were transfusion dependent
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10 patients (62.
5%) had peripheral blood blasts ≥1%, 2 patients (12.
5%) had white blood cell counts >25×109/L, and 2 patients (12.
5%) had platelet counts <100×109/L
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Eleven patients (68.
75%) received ruxolitinib prior to Allo-HSCT
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Graft dysfunction or graft dysfunction occurred in 6 patients (37.
5%)
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The median time to 500 neutrophils/µL was 19 days, and the median time to 1000/µL was 21 days; the median time to 20,000 platelets/µL was 24 days, and the median time to 50,000/µL was 24 days.
The median was 48 days
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Thirteen patients achieved complete chimerism with a median time of 7.
3 months
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Bone marrow biopsy was performed on day 100 in 13 patients, of which 5 patients (38.
46%) had grade 0 or 1 myelofibrosis
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Acute plant-versus-host disease (aGVHD) (≥ grade II) occurred in 62.
5% of patients, and chronic plant-versus-host disease (cGVHD) occurred in 18.
75% of patients
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Six patients (37.
5%) died, three from aGVHD, and the remainder from disease progression, second tumor, and sepsis
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The median follow-up time was 51 months, the longest follow-up time was 131 months, and the 5-year overall survival rate was 54%
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The distribution of risk subgroups assessed according to different prognostic scoring systems is shown in Figure 1.
According to the International Prognostic Scoring System (IPSS): the 1-year survival rate of the intermediate-1 group was 100%, the intermediate-2 group was 79%, and the high-risk group was 79%.
group was 25%, but the difference was not significant due to the small number of cases
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Table 1 Prognostic Scores Study Conclusions In this retrospective study, only 7 patients had PMF, and the remaining patients developed myelofibrosis more than 10 years after PV/ET
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Most patients had systemic symptoms and splenomegaly before transplantation, and 68.
75% were treated with ruxolitinib
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The most common complication of transplantation was GVHD, which accounted for 66.
7% of deaths
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Abstract No.
: P574 Title: Prognosis Analysis of Allogeneic Hematopoietic Stem Cell Transplantation in 6 Cases of Primary Myelofibrosis Research Methods From May 2002 to July 2019, allo-HSCT was performed on 6 PMF patients
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The median age was 37 years (range: 5-48 years), and one patient was 5 years old
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Sex ratio (male/female): 1
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The mean time from PMF diagnosis to receiving allo-HSCT was 29 months (range: 12-89 months)
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Four patients (66.
6%) had a history of red blood cell transfusion, of which one (16.
6%) received more than 20 units of red blood cell transfusion
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Before transplantation, 2 patients underwent splenectomy and 2 patients received hydroxyurea-based therapy
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According to the dynamic international prognostic scoring system (DIPSS) score: intermediate risk -2 (5 cases), high risk (1 case)
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All patients received a busulfan-based conditioning regimen
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GVHD preventive measures include cyclosporine-methotrexate
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The grafts were peripheral blood stem cells, and the average ratio of CD34+ cells was 8.
89 x 106 cells/kg (range: 6.
11-12.
9 x 106 cells/kg)
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As of July 2021, the shortest follow-up period was 24 months and the longest follow-up period was 206 months 
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All patients developed hypoplasia, and the median time to neutrophil engraftment was 12 days (range: 8-15 days)
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Early rejection occurred in 1 patient
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1 patient (25%) developed aGVHD (grade IV)
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CMV reactivation occurred in 3 patients (60%)
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After a median follow-up of 30 months (range: 24-36 months), 2 patients were alive with normal blood counts, and 3 of the 4 patients (66.
6%) who died (50%) died of transplant-related deaths ( TRM) (2 serious infections, 1 GVHD), and 1 patient died of early rejection
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Conclusion Allo-HSCT is still the only way to cure PMF, which can restore hematopoietic function on the one hand and prevent the progression to acute leukemia on the other hand
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Fludarabine-busulfan was selected as a conditioning regimen before Allo-HSCT, which was not only well tolerated by patients, but also appeared to be more effective (50%) in allo-HSCT 
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References: 1.
J.
Zanabili Al-Sibai, LR Morais Bras, MdP Palomo Moraleda, et al.
ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION IN MYELOFIBROSIS: OUR 15-YEARS EXPERIENCE.
The 48th Annual Meeting of the EBMT.
Abstract P572.
2.
F.
Mehdid, M.
Benakli, M.
Baazizi, et al.
ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION IN PRIMARY MYELOFIBROSIS: ABOUT 6 CASES.
The 48th Annual Meeting of the EBMT.
Abstract P574.
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