Monzr M. Al Malki

Mobilized Peripheral Blood Stem Cells Versus Unstimulated Bone Marrow As a Graft Source for T-Cell–Replete Haploidentical Donor Transplantation Using Post-Transplant Cyclophosphamide

Purpose T-cell-replete HLA-haploidentical donor hematopoietic transplantation using post-transplant cyclophosphamide was originally described using bone marrow (BM). With increasing use of mobilized peripheral blood (PB), we compared transplant outcomes after PB and BM transplants. Patients and Methods A total of 681 patients with hematologic malignancy who underwent transplantation in the United States between 2009 and 2014 received BM (n = 481) or PB (n = 190) grafts. Cox regression models were built to examine differences in transplant outcomes by graft type, adjusting for patient, disease, and transplant characteristics. Results Hematopoietic recovery was similar after transplantation of BM and PB (28-day neutrophil recovery, 88% v 93%, P = .07; 100-day platelet recovery, 88% v 85%, P = .33). Risks of grade 2 to 4 acute (hazard ratio [HR], 0.45; P < .001) and chronic (HR, 0.35; P < .001) graft-versus-host disease were lower with transplantation of BM compared with PB. There were no significant differences in overall survival by graft type (HR, 0.99; P = .98), with rates of 54% and 57% at 2 years after transplantation of BM and PB, respectively. There were no differences in nonrelapse mortality risks (HR, 0.92; P = .74) but relapse risks were higher after transplantation of BM (HR, 1.49; P = .009). Additional exploration confirmed that the higher relapse risks after transplantation of BM were limited to patients with leukemia (HR, 1.73; P = .002) and not lymphoma (HR, 0.87; P = .64). Conclusion PB and BM grafts are suitable for haploidentical transplantation with the post-transplant cyclophosphamide approach but with differing patterns of treatment failure. Although, to our knowledge, this is the most comprehensive comparison, these findings must be validated in a randomized prospective comparison with adequate follow-up.

Phase I Trial of Total Marrow and Lymphoid Irradiation Transplantation Conditioning in Patients with Relapsed/Refractory Acute Leukemia

Current conditioning regimens provide insufficient disease control in relapsed/refractory acute leukemia patients undergoing hematopoietic stem cell transplantation (HSCT) with active disease. Intensification of chemotherapy and/or total body irradiation (TBI) is not feasible because of excessive toxicity. Total marrow and lymphoid irradiation (TMLI) allows for precise delivery and increased intensity treatment via sculpting radiation to sites with high disease burden or high risk for disease involvement, while sparing normal tissue. We conducted a phase I trial in 51 patients (age range, 16 to 57 years) with relapsed/refractory acute leukemia undergoing HSCT (matched related, matched unrelated, or 1-allele mismatched unrelated) with active disease, combining escalating doses of TMLI (range, 1200 to 2000 cGy) with cyclophosphamide (CY) and etoposide (VP16). The maximum tolerated dose was declared at 2000 cGy, as TMLI simulation studies indicated that >2000 cGy might deliver doses toxic for normal organs at or exceeding those delivered by standard TBI. The post-transplantation nonrelapse mortality (NRM) rate was only 3.9% (95% confidence interval [CI], .7 to 12.0) at day +100 and 8.1% (95% CI, 2.5 to 18.0) at 1 year. The cumulative incidence of grades II to IV acute graft-versus-host disease (GVHD) was 43.1% (95% CI, 29.2 to 56.3) and for grade III and IV, it was 13.7% (95% CI, 6.9 to 27.3). The day +30 complete remission rate for all patients was 88% and was 100% for those treated at 2000 cGy. The overall 1-year survival was 55.5% (95% CI, 40.7 to 68.1). The TMLI/CY/VP16 conditioning regimen is well tolerated at TMLI doses up to 2000 cGy with a low 100-day and 1-year NRM rate and no increased risk of GVHD with higher doses of radiation.

Haploidentical Transplantation with Post-Transplantation Cyclophosphamide for High-Risk Acute Lymphoblastic Leukemia

Haploidentical transplantation performed with post-transplantation cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis has been associated with favorable outcomes for patients with acute myeloid leukemia and lymphomas. However, it remains unclear if such approach is effective for patients with acute lymphoblastic leukemia (ALL). We analyzed outcomes of 109 consecutively treated ALL patients 18 years of age and older at 5 institutions. The median age was 32 years and the median follow-up for survivors was 13 months. Thirty-two patients were in first complete remission (CR1), while the rest were beyond CR1. Neutrophil engraftment occurred in 95% of the patients. The cumulative incidences of grades II to IV and III and IV acute GVHD at day 100 after transplantation were 32% and 11%, respectively, whereas chronic GVHD, nonrelapse mortality, relapse rate, and disease-free survival (DFS) at 1 year after transplantation were 32%, 21%, 27%, and 51%, respectively. Patients in CR1 had 52% DFS at 3 years. These results suggest that haploidentical transplants performed with PTCy-based GVHD prophylaxis provide a very suitable alternative to HLA-matched transplantations for patients with ALL.

Effect of donor characteristics on haploidentical transplantation with posttransplantation cyclophosphamide

We studied the association between non-HLA donor characteristics (age, sex, donor-recipient relationship, blood group [ABO] match, and cytomegalovirus [CMV] serostatus) and transplant outcomes after T-cell-replete HLA-haploidentical transplantation using posttransplantation cyclophosphamide (PT-Cy) in 928 adults with hematologic malignancy transplanted between 2008 and 2015. Siblings (n = 358) and offspring (n = 450) were the predominant donors, with only 120 patients having received grafts from parents. Although mortality risks were higher with donors aged 30 years or older (hazard ratio, 1.39; P < .0001), the introduction of patient age to the Cox regression model negated the effect of donor age. Two-year survival adjusted for CMV seropositivity, disease, and disease risk index was lower in patients aged 55 to 78 years after transplantation of grafts from donors younger than 30 years (53%) or aged at least 30 years (46%) compared with younger patients who received grafts from donors younger than 30 years (61%) and at least 30 years (60%; P < .0001). Similarly, 2-year survival in patients aged 55 to 78 years was lower after transplantation of grafts from siblings (45%) or offspring (48%) compared with patients aged 18 to 54 years after transplantation of grafts from siblings (62%), offspring (58%), and parents (61%; P < .0001). Graft failure was higher after transplantation of grafts from parents (14%) compared with siblings (6%) or offspring (7%; P = .02). Other non-HLA donor characteristics were not associated with survival or graft failure. The current analyses suggest patient and disease, rather than non-HLA donor characteristics, predominantly influence survival in adults.

Allogeneic haematopoietic cell transplantation for extranodal natural killer/T‐cell lymphoma, nasal type: a CIBMTR analysis

Author(s): Kanate, Abraham S; DiGilio, Alyssa; Ahn, Kwang W; Al Malki, Monzr; Jacobsen, Eric; Steinberg, Amir; Hamerschlak, Nelson; Kharfan-Dabaja, Mohamed; Salit, Rachel; Ball, Edward; Bashir, Qaiser; Cashen, Amanda; Couriel, Daniel; Diez-Martin, Jose; Katsanis, Emmanuel; Linhares, Yulia; Mori, Shahram; Nash, Richard; Pawarode, Attaphol; Perales, Miguel-Angel; Phipps, Colin D; Richman, Carol; Savani, Bipin N; Shapira, Michael Y; Stiff, Patrick; Strair, Roger; Fenske, Timothy S; Smith, Sonali M; Sureda, Anna; Olteanu, Horatiu; Hamadani, Mehdi

Long-Term Results of High-Dose Therapy and Autologous Stem Cell Transplantation for Mantle Cell Lymphoma: Effectiveness of Maintenance Rituximab

High-dose therapy followed by autologous stem cell transplantation (ASCT) can improve outcomes for mantle cell lymphoma (MCL) but is associated with a high incidence of relapse. A retrospective study of 191 MCL patients who underwent ASCT at City of Hope was performed to examine prognostic factors for outcomes after ASCT. For all patients the 5-year overall survival (OS) was 71% (95% confidence interval [CI], 63% to 77%) and progression-free survival (PFS) was 53% (95% CI, 45% to 60%). The 5-year cumulative incidence of relapse was 41% (95% CI, 34% to 48%) with a continuous pattern of relapse events occurring at a median of 2.1 years (range, .2 to 13.4) after ASCT. In multivariate analysis, post-transplant maintenance rituximab was the factor most significantly associated with both OS (relative risk [RR], .17; 95% CI, .07 to .38) and PFS (RR, .25; 95% CI, .14 to .44). For the subset of patients who had positron emission tomography (PET) data available and were in a PET-negative first complete remission at ASCT (n = 105), maintenance rituximab was significantly associated with superior OS (RR, .17; 95% CI, .05 to .59) and PFS (RR, .20; 95% CI, .09 to .43). These results support a benefit with maintenance rituximab for all MCL patients treated with ASCT.

The European Society for Blood and Marrow Transplantation (EBMT) Consensus Guidelines for the Detection and Treatment of Donor-specific Anti-HLA Antibodies (DSA) in Haploidentical Hematopoietic Cell Transplantation

Haploidentical donors are now increasingly considered for transplantation in the absence of HLA-matched donors or when an urgent transplant is needed. Donor-specific anti-HLA antibodies (DSA) have been recently recognized as an important barrier against successful engraftment of donor cells, which can affect transplant survival. DSA appear more prevalent in this type of transplant due to higher likelihood of alloimmunization of multiparous females against offspring’s HLA antigens, and the degree of mismatch. Here we summarize the evidence for the role of DSA in the development of primary graft failure in haploidentical transplantation and provide consensus recommendations from the European Society for Blood and Marrow Transplant Group on testing, monitoring, and treatment of patients with DSA receiving haploidentical hematopoietic progenitor cell transplantation.

Haematopoietic cell transplantation for blastic plasmacytoid dendritic cell neoplasm: a North American multicentre collaborative study

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is incurable with conventional therapies. Limited retrospective data have shown durable remissions after haematopoietic cell transplantation (HCT) [allogeneic (allo) or autologous (auto)]. We conducted a multicentre retrospective study in BPDCN patients treated with allo‐HCT and auto‐HCT at 8 centres in the United States and Canada. Primary endpoint was overall survival (OS). The population consisted of 45 consecutive patients who received an allo‐HCT (n = 37) or an auto‐HCT (n = 8) regardless of age, pre‐transplant therapies, or remission status at transplantation. Allo‐HCT recipients were younger (50 (14–74) vs. 67 (45–72) years, P = 0·01) and had 1‐year and 3‐year OS of 68% [95% confidence interval (CI) = 49–81%] and 58% (95% CI = 38–75%), respectively. Allo‐HCT in first complete remission (CR1) yielded superior 3‐year OS (versus not in CR1) [74% (95% CI = 48–89%) vs. 0, P < 0·0001]. Allo‐HCT outcomes were not impacted by regimen intensity [3‐year OS for myeloablative conditioning = 61% (95% CI = 28–83%) vs. reduced‐intensity conditioning = 55% (95% CI = 28–76%)]. One‐year OS for auto‐HCT recipients was 11% (95% CI = 8–50%). These results demonstrate efficacy of allo‐HCT in BPDCN, especially in patients in CR1. Pertaining to auto‐HCT, our results suggest lack of efficacy against BPDCN, but this observation is limited by the small sample size. Larger prospective studies are needed to better define the role of HCT in BPDCN.

Implications and Management of Central Nervous System Involvement before Allogeneic Hematopoietic Cell Transplantation in Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) with a history of central nervous system (CNS) involvement, either at diagnosis or relapse, poses challenges when the decision is made to proceed with allogeneic hematopoietic cell transplantation (alloHCT), as there is no evidence-based consensus on the best peri-transplantation approach to reduce subsequent CNS relapse risk. Here, we retrospectively analyzed outcomes of 87 patients with ALL and a history of CNS involvement who later underwent alloHCT. Patients with pretransplantation CNS involvement had higher risk of CNS relapse after transplantation (2-year CNS relapse: 9.6% versus 1.4%, P < .0001), inferior event-free survival (EFS) (hazard ratio [HR], 1.52; P = .003), and worse overall survival (OS) (HR, 1.55; P = .003) compared with patients without pretransplantation CNS involvement (n = 543). There was no difference in post-transplantation CNS relapse, EFS, or OS among patients presenting with CNS involvement at diagnosis, those with isolated CNS relapse, and those with combined bone marrow and CNS relapse before HCT. Interestingly, neither pretransplantation cranial irradiation, use of total body irradiation-based conditioning, nor post-transplantation prophylactic intrathecal chemotherapy were associated with a reduction of CNS relapse risk after transplantation. Thus, among the patients in the cohort studied, there was no clear benefit of CNS-directed therapy in the peri-transplantation period among patients who had prior CNS involvement and underwent subsequent alloHCT.

Favorable impact of allogeneic stem cell transplantation in patients with therapy-related myelodysplasia regardless of TP53 mutational status

Therapy-related myelodysplastic syndrome is a long-term complication of cancer treatment in patients receiving cytotoxic therapy, characterized by high-risk genetics and poor outcomes. Allogeneic hematopoietic cell transplantation is the only potential cure for this disease, but the prognostic impact of pre-transplant genetics and clinical features has not yet been fully characterized. We report here the genetic and clinical characteristics and outcomes of a relatively large cohort of patients with therapy-related myelodysplastic syndrome (n=67) who underwent allogeneic transplantation, comparing these patients to similarly treated patients with de novo disease (n=199). The 5-year overall survival was not different between patients with therapy-related and de novo disease (49.9% versus 53.9%; P=0.61) despite a higher proportion of individuals with an Intermediate-2/High International Prognostic Scoring System classification (59.7% versus 43.7%; P=0.003) and high-risk karyotypes (61.2% versus 30.7%; P<0.01) among the patients with therapy-related disease. In mutational analysis, TP53 alteration was the most common abnormality in patients with therapy-related disease (n=18: 30%). Interestingly, the presence of mutations in TP53 or in any other of the high-risk genes (EZH2, ETV6, RUNX1, ASXL1: n=29: 48%) did not significantly affect either overall survival or relapse-free survival. Allogeneic stem-cell transplantation is, therefore, a curative treatment for patients with therapy-related myelodysplastic syndrome, conferring a similar long-term survival to that of patients with de novo disease despite higher-risk features. While TP53 alteration was the most common mutation in therapy-related myelodysplastic syndrome, the finding was not detrimental in our case-series.