Search

The optimal myeloablative conditioning regimen for ALL patients undergoing hematopoietic cell transplant (HCT) with an alternative donor is unknown. We analyzed HCT outcomes ALL patients (n= 269) who underwent HCT at our center from 2010 to 2020 in complete remission (CR) after FTBI-etoposide and CNI-based GvHD prophylaxis for matched donor HCT (ETOP-package; n= 196) or FTBI-Fludarabine and post-transplant cyclophosphamide (PTCy)-based prophylaxis for HLA- mismatched (related or unrelated) donors (FLU-package; n= 64). Patients in FLU-package showed a significant delay in engraftment (p< 0.001) and lower cumulative incidence (CI) of any and extensive chronic GVHD (p= 0.009 and 0.001, respectively). At the median follow up of 4.6 years (range 1–12 years); non-relapse mortality, overall or leukemia-free survival and GVHD-free/relapse-free survival were not significantly impacted by the choice of conditioning. However, in patients at CR2 or with measurable residual disease (MRD+), there was a trend towards higher relapse after FLU-package (p= 0.08 and p= 0.07, respectively), while patients at CR1 regardless of MRD status had similar outcomes despite the package/donor type (p= 0.9 and 0.7, respectively). Our data suggests that FLU-package for alternative donors offers comparable outcomes to ETOP-package for matched donor HCT to treat ALL. Disease status and depth of remission at HCT were independent predictors for better outcomes.

Allogenic hematopoietic cell transplantation (alloHCT) is a well-established curative modality for acute lymphoblastic leukemia (ALL), yet large amounts of data describing alloHCT outcomes in Philadelphia (Ph)-like ALL are lacking. We retrospectively analyzed archived DNA samples from consecutive adults with B-cell Ph-negative ALL who underwent alloHCT in complete remission (CR) (n = 127) at our center between 2006 and 2020. Identification of fusions associated with Ph-like ALL was performed using cumulative results from RNA-seq, conventional cytogenetics, fluorescence in situ hybridization, and whole genome array studies. Fusions associated with Ph-like ALL were detected in 56 (44%) patients, of whom 38 were carrying CRLF2r. Compared with other non–Ph-like ALL (n = 71), patients with fusions associated with Ph-like ALL were more frequently Hispanic (P= .008), were less likely to carry high-risk cytogenetics (P< .001), and were more likely to receive blinatumomab prior to HCT (P= .019). With the median followup of 3.5 years, patients with Ph-like ALL fusions had comparable posttransplant outcomes compared with other B-cell ALL: 3-year relapse-free survival (RFS) (41% vs 44%; P= .36), overall survival (OS) (51% vs 50%; P= .59), and relapse (37% vs 31%; P= .47). In multivariable analysis, age (P= .023), disease status at the time of transplant (P< .001), and donor type (P= .015) influenced OS. RFS (primary endpoint) was significantly influenced by disease status (P< .001) and conditioning regimen intensity (P= .014). In conclusion, our data suggest that alloHCT consolidation results in similarly favorable survival outcomes in adult patients with Ph-like fusions and other high-risk B-cell ALL.

Allogenic hematopoietic cell transplantation (alloHCT) is a well-established curative modality for acute lymphoblastic leukemia (ALL), yet large amounts of data describing alloHCT outcomes in Philadelphia (Ph)-like ALL are lacking. We retrospectively analyzed archived DNA samples from consecutive adults with B-cell Ph-negative ALL who underwent alloHCT in complete remission (CR) (n = 127) at our center between 2006 and 2020. Identification of fusions associated with Ph-like ALL was performed using cumulative results from RNA-seq, conventional cytogenetics, fluorescence in situ hybridization, and whole genome array studies. Fusions associated with Ph-like ALL were detected in 56 (44%) patients, of whom 38 were carrying CRLF2r. Compared with other non–Ph-like ALL (n = 71), patients with fusions associated with Ph-like ALL were more frequently Hispanic (P = .008), were less likely to carry high-risk cytogenetics (P < .001), and were more likely to receive blinatumomab prior to HCT (P = .019). With the median followup of 3.5 years, patients with Ph-like ALL fusions had comparable posttransplant outcomes compared with other B-cell ALL: 3-year relapse-free survival (RFS) (41% vs 44%; P = .36), overall survival (OS) (51% vs 50%; P = .59), and relapse (37% vs 31%; P = .47). In multivariable analysis, age (P = .023), disease status at the time of transplant (P < .001), and donor type (P = .015) influenced OS. RFS (primary endpoint) was significantly influenced by disease status (P < .001) and conditioning regimen intensity (P = .014). In conclusion, our data suggest that alloHCT consolidation results in similarly favorable survival outcomes in adult patients with Ph-like fusions and other high-risk B-cell ALL.

Posttransplant cyclophosphamide (PTCy) platform has shown low rates of graft-versus-host disease (GVHD) and nonrelapse mortality (NRM) after haploidentical hematopoietic cell transplantation (HaploHCT). However, because of the limited disease control, relapse rate remains a major cause of treatment failure in high-risk patients. Total marrow and lymphoid irradiation (TMLI) allows for delivery of high radiation to bone marrow and other targeted structures, without increasing off-target radiation exposure and toxicity to end organs. In this phase 1 trial, 31 patients with high-risk and/or active primary refractory leukemias or myelodysplastic syndrome underwent peripheral blood stem cell HaploHCT with TMLI, fludarabine, and cyclophosphamide as the conditioning regimen. Radiation dose was escalated in increments of 200 cGy (1200-2000 cGy). GVHD prophylaxis was PTCy with tacrolimus/mycophenolate mofetil. Grade 2 toxicities by the Bearman scale were mucositis (n = 1), hepatic (n = 3), gastrointestinal (n = 5), and cardiac (n = 2). One patient (1800 cGy) experienced grade 3 pulmonary toxicity (dose-limiting toxicity). At a follow-up duration of 23.9 months for the whole cohort; 2-year NRM was 13%. Cumulative incidence of day 100 grade 2 to 4 and 3 to 4 acute GVHD was 52% and 6%, respectively. Chronic GVHD at 2 years was 35%. For patients treated with 2000 cGy, with a median follow-up duration of 12.3 months, 1-year relapse/progression, progression-free survival, and overall survival rates were 17%, 74%, and 83%, respectively. In conclusion, HaploHCT-TMLI with PTCy was safe and feasible in our high-risk patient population with promising outcomes.

Current FDA approved agents for cGVHD are associated with low complete response rates and high cost. Leflunomide is an FDA-approved drug for treatment of rheumatoid arthritis (RA) and is in clinical trial development to treat multiple myeloma, solid tumors, acute GVHD, and COVID19. Based on its role in promoting lymphocyte apoptosis and its anti-inflammatory properties, we conducted a phase 1 trial (NCT04212416) to study leflunomide's safety in patients with cGVHD (primary objective). The 6-month anti-cGVHD activity, defined by overall response rate (ORR per NIH consensus criteria), was the secondary objective.

TA-TMA is an increasingly recognized post-HCT complication with no standard diagnosis or treatment criteria, a suspected incidence of 10-40%, and poor prognosis. Currently, there are no FDA-approved therapies for TA-TMA, but with identifying the role of complement as a terminal event in TA-TMA pathophysiology, complement blockade drugs like eculizumab have been used to treat this complication. Outcomes of the largest prospective study of eculizumab to treat TA-TMA in pediatric patients showed a complete response rate of 88% and a 1-year post-HCT survival rate of 66% (Jodele et al.). Limited data is available to guide therapy for adult patients.

We report results of our prospective pilot trial evaluating safety/feasibility of peritransplantation ruxolitinib for myelofibrosis treatment. Primary objectives were to determine safety and maximum tolerated dose (MTD) of ruxolitinib. Ruxolitinib was administered at 2 dose levels (DLs) of 5 and 10 mg twice daily, with fludarabine/melphalan conditioning regimen and tacrolimus/sirolimus graft-versus-host disease (GVHD) prophylaxis. We enrolled 6 and 12 patients at DL1 and DL2, respectively. Median age at transplantation was 65 years (range, 25-73). Per Dynamic International Prognostic Scoring System, 4 patients were high and 14 intermediate risk. Peripheral blood stem cells were graft source from matched sibling (n = 5) or unrelated (n = 13) donor. At each DL, 1 patient developed dose-limiting toxicities (DLTs): grade 3 cardiac and gastrointestinal with grade 4 pulmonary DLTs in DL1, and grade 3 kidney injury in DL2. All patients achieved engraftment. Grade 2 to 4 and 3 to 4 acute GVHD cumulative incidence was 17% (95% confidence interval [CI], 6-47) and 11% (95% CI, 3-41), respectively. Cumulative incidence of 1-year chronic GVHD was 42% (95% CI, 24-74). With 22.6-month (range, 6.2-25.8) median follow-up in surviving patients, 1-year overall and progression-free survival were 77% (95% CI, 50-91) and 71% (95% CI, 44-87), respectively. Causes of death (n = 4) were cardiac arrest, GVHD, respiratory failure, and refractory GVHD of liver. Our results show peritransplantation ruxolitinib is safe and well tolerated at MTD of 10 mg twice daily and associated with dose-dependent pharmacokinetic and cytokine profile. Early efficacy data are highly promising in high-risk older patients with myelofibrosis. This trial was registered at www.clinicaltrials.gov as #NCT02917096.

We report results of our prospective pilot trial evaluating safety/feasibility of peritransplantation ruxolitinib for myelofibrosis treatment. Primary objectives were to determine safety and maximum tolerated dose (MTD) of ruxolitinib. Ruxolitinib was administered at 2 dose levels (DLs) of 5 and 10 mg twice daily, with fludarabine/melphalan conditioning regimen and tacrolimus/sirolimus graft-versus-host disease (GVHD) prophylaxis. We enrolled 6 and 12 patients at DL1 and DL2, respectively. Median age at transplantation was 65 years (range, 25-73). Per Dynamic International Prognostic Scoring System, 4 patients were high and 14 intermediate risk. Peripheral blood stem cells were graft source from matched sibling (n = 5) or unrelated (n = 13) donor. At each DL, 1 patient developed dose-limiting toxicities (DLTs): grade 3 cardiac and gastrointestinal with grade 4 pulmonary DLTs in DL1, and grade 3 kidney injury in DL2. All patients achieved engraftment. Grade 2 to 4 and 3 to 4 acute GVHD cumulative incidence was 17% (95% confidence interval [CI], 6-47) and 11% (95% CI, 3-41), respectively. Cumulative incidence of 1-year chronic GVHD was 42% (95% CI, 24-74). With 22.6-month (range, 6.2-25.8) median follow-up in surviving patients, 1-year overall and progression-free survival were 77% (95% CI, 50-91) and 71% (95% CI, 44-87), respectively. Causes of death (n = 4) were cardiac arrest, GVHD, respiratory failure, and refractory GVHD of liver. Our results show peritransplantation ruxolitinib is safe and well tolerated at MTD of 10 mg twice daily and associated with dose-dependent pharmacokinetic and cytokine profile. Early efficacy data are highly promising in high-risk older patients with myelofibrosis. This trial was registered at www.clinicaltrials.govas #NCT02917096.

Efficacy of PTCy after mismatched unrelated donor (MMUD) HCT is unknown. In this pilot clinical trial, we enrolled 38 patients with hematologic malignancies scheduled to undergo MMUD-HCT (≥6/8 HLA-matched donors) onto 1 of 2 conditioning strata: myeloablative using fludarabine and fractionated total body irradiation (n = 19) or reduced intensity with fludarabine/melphalan (n = 19). Graft source was peripheral blood stem cells (PBSCs), and GVHD prophylaxis was PTCy, tacrolimus, and mycophenolate mofetil. Patients’ median age was 53 years (range, 21-72 years). Median number of HLA mismatches was 2 (range, 1-4) of 12 loci. Twenty-three patients (61%) were considered racial (n = 12) or ethnic (n = 11) minorities. Median time to neutrophil engraftment was 16 days (range, 13-35 days). With a median follow-up of 18.3 months (range, 4.3-25.0 months) for surviving patients, 1-year overall survival (OS) and GVHD-free/relapse-free survival (GRFS) were 87% (95% confidence interval [CI]: 71-94) and 68% (95% CI: 51-81), respectively. Cumulative incidence of nonrelapse mortality at 100 days and 1 year were 0% and 11% (95% CI: 4-27), respectively, whereas relapse/progression was 11% (95% CI: 4-27). Cumulative incidence of 100-day acute GVHD grades 2-4 and 3-4 and 1-year chronic GVHD were 50% (95% CI: 36-69), 18% (95% CI: 9-36), and 48% (95% CI: 34-68), respectively. The rate of moderate/severe chronic GVHD was 3% in the entire cohort. We showed highly promising OS/GRFS rates with an acceptable risk profile after PBSC-MMUD-HCT with PTCy. This trial was registered at www.clinicaltrials.gov as #NCT03128359.

•Highly promising OS and GRFS rates of 87% and 68%, respectively, were achieved after MMUD-HCT with PTCy.•Our data support further development of PTCy in the MMUD setting to improve outcomes in patients without a matched donor.

Somatic mutations in IDHgenes are seen in ∼20% of patients with AML, with mutations in IDH2 (R172, R140)being more common (15%) than IDH1(R132). We previously reported a higher 1-year relapse rate after HCT in patients with IDHmutations (mIDH; PMC9129101). We hypothesized that enasidenib, an IDH2 inhibitor, is well-tolerated as post-HCT maintenance, and can improve leukemia free survival (LFS) in AML patients carrying mIDH2. Here, we are reporting the final results of our completed multicenter [City of Hope (COH) and Moffitt Cancer Center] pilot trial (NCT03728335), previously reported in 2022 ASH meeting with a shorter follow-up period.

•Total body irradiation- and fludarabine-based myeloablative conditioning regimen was well tolerated in mismatched related and unrelated donor HCT recipients, with a 2-year overall survival of 80.1% and a low 2-year nonrelapse mortality of 11%.•There was no difference in acute and chronic GVHD outcomes between MMUD and haploidentical donor HCT recipients.•Donor age was associated with improved disease-free survival but did not impact overall survival.•High and very high Disease Risk Index are associated with increased risk of relapse.

Introduction of novel salvage therapies and expansion of the donor pool within the past decade have allowed more patients with relapsed/refractory (r/r) B cell acute lymphoblastic leukemia (B-ALL) to receive allogeneic hematopoietic cell transplantation (alloHCT). The impact of each salvage therapy on transplant outcomes have not been compared. Our primary objective was to determine post-HCT relapse-free survival (RFS) in adult patients with r/r Philadelphia-chromosome negative (Phneg) B-ALL. We retrospectively studied alloHCT outcomes in 108 adult patients with r/r PhnegB-ALL transplanted in morphological remission achieved by salvage therapy. Salvage therapies were chemotherapy-based combination (n = 45, 42%), blinatumomab (n=43, 40%), inotuzumab (n = 14, 13%), or CAR T cells (n = 6, 6%). The 2-year RFS and overall survival (OS) were 44% and 50%, respectively. In multivariable analysis, conditioning with reduced-intensity or non-myeloablative regimens (hazard ratio [HR] = 2.23, 95% confidence interval [CI], 1.31-3.80; P = .003), having received ≥3 lines of therapies prior to transplant (HR = 2.66, 95% CI, 1.56-4.54; P< .001), and inotuzumab (HR = 2.42, 95% CI, 1.14-5.12; Wald Pvalue = .021) were independently associated with lower RFS. Blinatumomab (HR = 1.10, 95% CI, 0.62-1.96) had comparable RFS to chemotherapy. Incidence of hepatic sinusoidal syndrome was highest with inotuzumab (P< .001); however, 30-day mortality and intensive care unit admissions were not different per salvage therapy. The alloHCT in r/r PhnegB-ALL after remission induction with blinatumomab or chemotherapy led to encouraging outcomes if morphologic CR was achieved. In contrast, pretransplantation inotuzumab therapy was associated with inferior RFS. Larger studies are warranted to confirm our observations. Early transplantation after relapse and the utilization of myeloablative conditioning, when feasible, were key factors associated with improved outcomes after alloHCT in these patients.

We compared outcomes of 1461 adult patients with acute lymphoblastic leukemia (ALL) receiving hematopoietic cell transplantation (HCT) from a haploidentical (n = 487) or matched unrelated donor (MUD; n = 974) between January 2005 and June 2018. Graft-versus-host disease (GVHD) prophylaxis was posttransplant cyclophosphamide (PTCy), calcineurin inhibitor (CNI), and mycophenolate mofetil (MMF) for haploidentical, and CNI with MMF or methotrexate with/without antithymoglobulin for MUDs. Haploidentical recipients were matched (1:2 ratio) with MUD controls for sex, conditioning intensity, disease stage, Philadelphia-chromosome status, and cytogenetic risk. In the myeloablative setting, day +28 neutrophil recovery was similar between haploidentical (87%) and MUD (88%) (P = .11). Corresponding rates after reduced-intensity conditioning (RIC) were 84% and 88% (P = .47). The 3-month incidence of grade II-IV acute GVHD (aGVHD) and 3-year chronic GVHD (cGVHD) was similar after haploidentical compared with MUD: myeloablative conditioning, 33% vs 34% (P = .46) for aGVHD and 29% vs 31% for cGVHD (P = .58); RIC, 31% vs 30% (P = .06) for aGVHD and 24% vs 29% for cGVHD (P = .86). Among patients receiving myeloablative regimens, 3-year probabilities of overall survival were 44% and 51% with haploidentical and MUD (P = .56). Corresponding rates after RIC were 43% and 42% (P = .6). In this large multicenter case-matched retrospective analysis, despite the limitations of a registry-based study (ie, unavailability of key elements such as minimal residual disease testing), our analysis indicated that outcomes of patients with ALL undergoing HCT from a haploidentical donor were comparable with 8 of 8 MUD transplantations.

We compared outcomes of 1461 adult patients with acute lymphoblastic leukemia (ALL) receiving hematopoietic cell transplantation (HCT) from a haploidentical (n = 487) or matched unrelated donor (MUD; n = 974) between January 2005 and June 2018. Graft-versus-host disease (GVHD) prophylaxis was posttransplant cyclophosphamide (PTCy), calcineurin inhibitor (CNI), and mycophenolate mofetil (MMF) for haploidentical, and CNI with MMF or methotrexate with/without antithymoglobulin for MUDs. Haploidentical recipients were matched (1:2 ratio) with MUD controls for sex, conditioning intensity, disease stage, Philadelphia-chromosome status, and cytogenetic risk. In the myeloablative setting, day +28 neutrophil recovery was similar between haploidentical (87%) and MUD (88%) (P= .11). Corresponding rates after reduced-intensity conditioning (RIC) were 84% and 88% (P= .47). The 3-month incidence of grade II-IV acute GVHD (aGVHD) and 3-year chronic GVHD (cGVHD) was similar after haploidentical compared with MUD: myeloablative conditioning, 33% vs 34% (P= .46) for aGVHD and 29% vs 31% for cGVHD (P= .58); RIC, 31% vs 30% (P= .06) for aGVHD and 24% vs 29% for cGVHD (P= .86). Among patients receiving myeloablative regimens, 3-year probabilities of overall survival were 44% and 51% with haploidentical and MUD (P= .56). Corresponding rates after RIC were 43% and 42% (P= .6). In this large multicenter case-matched retrospective analysis, despite the limitations of a registry-based study (ie, unavailability of key elements such as minimal residual disease testing), our analysis indicated that outcomes of patients with ALL undergoing HCT from a haploidentical donor were comparable with 8 of 8 MUD transplantations.

Supplemental Digital Content is available in the text.

A mismatch at HLA-DPB1 locus is associated with higher acute GVHD and lower relapse rate after myeloablative (MAC) allogeneic hematopoietic cell transplantation (alloHCT). Also, in MAC setting, mismatch permissiveness and expression level impact alloHCT outcomes. However, in reduced intensity conditioning (RIC), DP mismatch effect on transplant outcomes is unknown. We retrospectively evaluated DP mismatch influence (number, permissiveness, and expression) on HCT outcomes in 310 patients with high-resolution typing (HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1), who underwent RIC HCT. By multivariable analysis, 11/12 had better overall survival (OS) and relapse vs. 12/12 (HR = 1.61 and 2.02; p= 0.04 and 0.01, respectively) and better OS vs. 10/12 (HR = 1.68; p= 0.02). Within the 11/12, nonpermissive (NoPR) mismatch was associated with higher risk of grade II–IV acute GVHD (HR = 1.97; p= 0.005) and nonrelapse mortality (HR = 2.13; p= 0.02) vs. permissive (PR). Grouping 11/12 based on the DP expression conferred higher mortality (HR = 3.78; p= 0.003) when low expressers received a graft from high expressers (AG) vs. low expressers (AA). Better OS was achieved in PR 11/12, when expression was low in patient and donor (AA) vs. all other combinations. Therefore, in RIC HCT, a single-DP mismatch has a protective role, especially in permissive setting, when donor and recipient are low expressers.

Relapse of primary hematologic malignancy remains the leading cause of treatment failure afterallogeneic Hematopoietic cell transplantation (allo-HCT). Multiple studies have shown that presence of measurable residual disease (MRD), at the time of HCT, irrespective of the detection method, is associated with lower overall survival (OS) and relapse-free survival (RFS). In a recent meta-analysis of 11,151 patients with AML, Short et al., reported 5-year disease-free survival (DFS) of 25% for patients who have detectable MRD pre -HCT, compared to 64% for those without MRD. The 5-year OS was 34% and 68% for patients with or without MRD at HCT (JAMA Oncology 2020). In AML patients with genomic evidence of MRD before allo-HCT, myeloablative conditioning (MAC) regimens result in improved survival when compared to reduced intensity conditioning (RIC); (Hourigan et al, JCO 2020). Our center has pioneered and developed Total marrow and lymphoid irradiation (TMLI) that allows for delivery of higher dose of radiation to the sites with high disease burden (bone marrow and lymphoid organs), while sparing healthy tissues. In an ongoing Phase 2 trial (NCT02094794), we delivered TMLI (20Gy) with high dose chemotherapy to patients with high-risk leukemias (ALL or AML) undergoing allo-HCT from an HLA matched or mismatched donor. Here, we report on the results of our prospective analysis on a subset of patients of NCT02094794 who underwent allo-HCT with morphologic remission but had detectable MRD status in their pre HCT bone marrow biopsy (n=30).

Background

Introduction:Fludarabine/melphalan (F/M) conditioning is associated with superior disease-free survival (DFS) compared to busulfan-based reduced-intensity conditioning (RIC) regimens in patients with AML/MDS undergoing allogeneic hematopoietic cell transplantation (alloHCT). A recent CIBMTR analysis in AML patients reported 5-year OS, cumulative incidence of Relapse (CIR) and NRM of 29%, 36% and 36% respectively after F/M conditioning when Tac/MTX was used for graft-vs-host disease (GVHD) prophylaxis (Blood Adv 2020). At City of Hope (COH), tacrolimus and sirolimus (T/S)-based GVHD prophylaxis has been used in patients undergoing HLA-matched sibling and unrelated donor alloHCT, based on the results of a phase 2 study by Rodriguez et al (Blood 2010). Here, we retrospectively reviewed clinical outcomes of 409 consecutive AML patients who underwent RIC alloHCT at COH from 2008-2019 with F/M conditioning and T/S-based GVHD prophylaxis. The primary objective was to assess long term survival outcomes and associated risk factors adjusted for secular trends in patient demographics undergoing alloHCT over time.

Allogeneic hematopoietic cell transplantation (HCT) is the only curative option for patients with myelofibrosis (MF); however, a significant obstacle to proceed to HCT is availability a matched donor, especially since MF is most often diagnosed in older adults. The effective development of haploidentical transplant (haploHCT), with post-transplant cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis, has been a major therapeutic advance for patients without an available matched donor. Based on the excellent survival rates seen in older patients with myeloid malignancies using fludarabine/Melphalan-based (Flu/Mel) regimen with PTCy GVHD prophylaxis, we designed a pilot trial (NCT03118492) to evaluate safety and tolerability of reduced intensity condition (RIC) regimen of Flu/Mel and TBI (2Gy) for peripheral blood stem cells (PBSC) HaploHCT with PTCy in patients with advanced MF (Figure 1a).

Human leukocyte antigen (HLA) well matched donor (related or unrelated) has remained the preferred donor source for patients undergoing HCT for hematological disease, but the probability of finding a suitable related or unrelated donor has varied based on ethnic groups. HLA-mismatch unrelated donor (MMUD) transplantation has improved access to HCT in underrepresented minority groups and patients of mixed race. Historically, MMUD HCT has been associated with inferior survival outcomes compared to matched unrelated donor HCT when using conventional platforms of GVHD prophylaxis. (PMID: 31449184, 20538804). Efforts to improve outcomes have investigated the addition of a third agent such as anti-thymocyte globulin (ATG), mini-methotrexate (MTX) or mycophenolate mofetil (MMF). More recently, a study by the National Marrow Donor Program (NMDP) demonstrated the feasibility of post-transplant cyclophosphamide (PTCy) based GVHD prophylaxis in MMUD HCT using bone marrow (BM) grafts (PMID: 33905264). Additionally, our group demonstrated promising overall survival (OS) and GVHD-free/relapse-free-survival (GRFS) rates in peripheral blood stem cell (PBSC) MMUD HCT using PTCy based GVHD prophylaxis (PMID: 34156440). Here, we compare outcomes of PBSC MMUD HCT among patients receiving GVHD prophylaxis with either: (1) tacrolimus plus sirolimus (T/S), (2) T/S plus mini-methotrexate (T/S/MTX), or (3) PTCy, MMF, and tacrolimus or sirolimus (PTCy).

Background:Allogeneic hematopoietic cell transplantation (alloHCT) remains the only curable treatment option for several hematological malignancies. Preparative and graft-versus-host disease (GVHD) prophylactic regimens combined with graft-versus-leukemia effect (GVL) are important in preventing graft rejection, disease relapse and GVHD; and subsequently impact the success of this life saving procedure. Choice of regimen depends on patient, donor/graft source and disease characteristics.

Although allogeneic hematopoietic cell transplantation (allo-HCT) is the only curative treatment for myelofibrosis (MF), data are limited on how molecular markers predict transplantation outcomes. We retrospectively evaluated transplantation outcomes of 110 consecutive MF patients who underwent allo-HCT with a fludarabine/melphalan (Flu/Mel) conditioning regimen at our center and assessed the impact of molecular markers on outcomes based on a 72-gene next-generation sequencing panel and Mutation-Enhanced International Prognostic Scoring System 70+ v2.0 (MIPSS70+ v2.0). With a median follow-up of 63.7 months, the 5-year overall survival (OS) rate was 65% and the nonrelapse mortality (NRM) rate was 17%. In mutational analysis, JAK2 V617F and ASXL1 mutations were the most common. By univariable analysis, higher Dynamic International Prognostic Scoring System scores, unrelated donor type, and very-high-risk cytogenetics were significantly associated with lower OS. Only CBL mutations were significantly associated with lower OS (hazard ratio [HR], 2.64; P= .032) and increased NRM (HR, 3.68; P= .004) after allo-HCT, but CALR, ASXL1, and IDH mutations did not have an impact on transplantation outcomes. Patient classification per MIPSS70 showed worse OS for high-risk (HR, 0.49; P= .039) compared with intermediate-risk patients. Classification per MIPSS70+ v2.0 demonstrated better OS when intermediate-risk patients were compared with high-risk patients (HR, 0.291) and much lower OS when very-high-risk patients were compared with high-risk patients (HR, 5.05; P≤ .001). In summary, we present one of the largest single-center experiences of Flu/Mel-based allo-HCT, demonstrating that revised cytogenetic changes and MIPSS70+ v2.0 score predict transplantation outcomes, and thus can better inform physicians and patients in making decisions about allo-HCT.

Although allogeneic hematopoietic cell transplantation (allo-HCT) is the only curative treatment for myelofibrosis (MF), data are limited on how molecular markers predict transplantation outcomes. We retrospectively evaluated transplantation outcomes of 110 consecutive MF patients who underwent allo-HCT with a fludarabine/melphalan (Flu/Mel) conditioning regimen at our center and assessed the impact of molecular markers on outcomes based on a 72-gene next-generation sequencing panel and Mutation-Enhanced International Prognostic Scoring System 70+ v2.0 (MIPSS70+ v2.0). With a median follow-up of 63.7 months, the 5-year overall survival (OS) rate was 65% and the nonrelapse mortality (NRM) rate was 17%. In mutational analysis, JAK2 V617F and ASXL1 mutations were the most common. By univariable analysis, higher Dynamic International Prognostic Scoring System scores, unrelated donor type, and very-high-risk cytogenetics were significantly associated with lower OS. Only CBL mutations were significantly associated with lower OS (hazard ratio [HR], 2.64; P = .032) and increased NRM (HR, 3.68; P = .004) after allo-HCT, but CALR, ASXL1, and IDH mutations did not have an impact on transplantation outcomes. Patient classification per MIPSS70 showed worse OS for high-risk (HR, 0.49; P = .039) compared with intermediate-risk patients. Classification per MIPSS70+ v2.0 demonstrated better OS when intermediate-risk patients were compared with high-risk patients (HR, 0.291) and much lower OS when very-high-risk patients were compared with high-risk patients (HR, 5.05; P = .001). In summary, we present one of the largest single-center experiences of Flu/Mel-based allo-HCT, demonstrating that revised cytogenetic changes and MIPSS70+ v2.0 score predict transplantation outcomes, and thus can better inform physicians and patients in making decisions about allo-HCT.

Cytokine release syndrome (CRS) is a common complication after haploidentical hematopoietic cell transplantation (HaploHCT). Severe CRS after haploHCT leads to higher risk of non-relapse mortality (NRM) and worse overall survival (OS). Tocilizumab (TOCI) is an interleukin-6 receptor inhibitor and is commonly used as first-line for CRS management after chimeric antigen receptor T cell therapy, but the impact of TOCI administration for CRS management on Haplo HCT outcomes is not known. In this single center retrospective analysis, we compared HCT outcomes in patients treated with or without TOCI for CRS management after HaploHCT with post-transplantation cyclophosphamide- (PTCy-) based graft-versus-host disease (GvHD) prophylaxis. Of the 115 patients eligible patients who underwent HaploHCT at City of Hope between 2019 to 2021 and developed CRS, we identified 11 patients who received tocilizumab for CRS management (TOCI). These patients were matched with 21 patients who developed CRS but did not receive tocilizumab (NO-TOCI) based on age at the time of HCT (≤64 years or >65 years or older), conditioning intensity (myeloablative versus reduced-intensity/nonmyeloablative), and CRS grading (1, 2, versus 3-4). Instead of 22 controls, we chose 21 patients because there was only 1 control matched with 1 TOCI treatment patient in 1 stratum. With only 11 patients in receiving tocilizumab for CRS treatment, matching with 21 patients who developed CRS but did not receive tocilizumab, we had 80% power to detect big differences (hazard ratio [HR] = 3.4 or higher) in transplantation outcomes using a 2-sided 0.05 test. The power would be reduced to about 20% to 30% if the difference was moderate (HR = 2.0) using the same test. No CRS-related deaths were recorded in either group. Median time to neutrophil engraftment was 21 days (range 16-43) in TOCI and 18 days (range 14-23) in NO-TOCI group (HR = 0.55; 95% confidence interval [CI] = 0.28-1.06, P = .08). Median time to platelet engraftment was 34 days (range 20-81) in TOCI and 28 days (range 12-94) in NO-TOCI group (HR = 0.56; 95% CI = 0.25-1.22, P = .19). Cumulative incidences of day 100 acute GvHD grades II-IV (P = .97) and grades III-IV (P = .47) were similar between the 2 groups. However, cumulative incidence of chronic GvHD at 1 year was significantly higher in patients receiving TOCI (64% versus 24%; P = .05). Rates of NRM (P = .66), relapse (P = .83), disease-free survival (P = .86), and overall survival (P = .73) were similar at 1 year after HCT between the 2 groups. Tocilizumab administration for CRS management after HaploHCT appears to be safe with no short-term adverse effect and no effect on relapse rate. However, the significantly higher cumulative incidence of chronic GvHD, negates the high efficacy of PTCy on GvHD prophylaxis in this patient population. Therefore using tocilizumab for CRS management in the HaploHCT population with PTCy maybe kept only for patients with severe CRS. The impact on such approach on long term outcome in HaploHCT with PTCy will need to be evaluated in a larger retrospective study or a prospective manner.

Post-transplant cyclophosphamide (PTCy) platform has shown low rates of graft-versus-host disease (GvHD) and non-relapse mortality (NRM) after haploidentical hematopoietic cell transplantation (HaploHCT). However, due to the limited disease control, relapse rate remains a major cause of treatment failure in high-risk patients. Total marrow and lymphoid irradiation (TMLI) allow for delivery of high radiation to bone marrow and other targeted structures, without increasing off-target radiation exposure and toxicity to end-organs. In this phase I trial (NCT02446964), 31 patients with high-risk and/or active primary refractory leukemias or MDS underwent peripheral blood stem cells (PBSC)-HaploHCT with TMLI, fludarabine and cyclophosphamide as conditioning regimen. Primary objectives were to evaluate safety and determine TMLI’s recommended phase 2 dose (RP2D). Radiation dose was escalated in increments of 200cGy (1200-2000cGy). GvHD prophylaxis was PTCy with tacrolimus/mycophenolate mofetil. Grade-2 toxicities by Bearman-scale were mucositis (n=1), hepatic (n=3), gastrointestinal (n=5), and cardiac (n=2). One patient (1800cGy) experienced grade 3 pulmonary toxicity (dose limiting toxicity). The RP2D was determined at 2000 cGy. At follow-up duration of 23.9 months for the whole cohort; 2-year NRM was 13%. Cumulative incidence of day-100 grade 2-4 and 3-4 acute GvHD were 52%, 6%, respectively. Chronic GvHD at 2 years was 35%. For patients treated at the RP2D (n=12); median follow-up duration of 12.3 months; 1-year relapse/progression, progression-free survival and overall survival rates were 17%, 74% and 83%; respectively. In conclusion, HaploHCT-TMLI with PTCy was safe and feasible in our high-risk patient population. Promising low relapse/progression rate was achieved without increasing GvHD or transplant-related mortality.

Dadwal: Shire/ Takeda: Research Funding; Karius: Research Funding; Astellas: Speakers Bureau; Janssen: Other: Advisory board meeting; Ansun Biopharma: Research Funding; Chimerix: Research Funding; Gilead: Research Funding; Merck: Consultancy, Honoraria, Other: Advisory board meeting, Research Funding, Speakers Bureau. Pullarkat:Dova: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genetech: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie, Inc.: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Stein:Stemline: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau. Taplitz:Merck: Other: Immunocompromised Advisory Group. Al Malki:Neximmune: Consultancy; Rigel Pharma: Consultancy; Jazz Pharmacuticals, Inc: Consultancy. Nakamura:NapaJen Pharma: Consultancy; Magenta Therapeutics: Other: Advisory board meeting; Alexion: Other: Support on a meeting presentation; Kyowa-Kirin: Other: Support on a meeting presentation; Celgene: Other: Support on seminar; Viracor: Consultancy; Merck: Other: advisory board meeting; Kadmon Corporation: Other: Advisory board meeting.

Cytomegalovirus reactivation commonly referred to as CMV infection (CMVi) is a frequent event after allogeneic hematopoietic cell transplantation (HCT), with studies associating CMVi within the first 100 days post-HCT with higher risk of non-relapse mortality (NRM) and decreased overall survival (OS). In addition, understanding the impact of CMVi on resource utilization during the primary HCT admission is critical. Together, this knowledge of epidemiology and resource utilization may be used to inform preventive strategies to minimize CMVi, e.g., use of antiviral agent letermovir.

Peripheral blood stem cell (PBSC) as a graft source compared to bone marrow has been reported to result in lower risk of relapse after haploidentical hematopoietic cell transplantation (haplo-HCT) with use of post-transplant cyclophosphamide (PTCy) as a graft-versus-host-disease (GvHD) prophylaxis. However, cytokine release syndrome (CRS) is a common complication of this platform that can affect the outcomes of patients after PBSC haplo-HCT. CRS occurs due to rapid activation and proliferation of alloreactive donor T cells resulting in the elevated secretion of inflammatory cytokines. In this study, we sought to examine the risk factors for CRS and the effect of CRS severity on outcomes of PBSC haplo-HCT.

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) represents 20% of newly diagnosed adults with B cell ALL (B-ALL), with increased frequency in adults with Hispanic ethnicity. Ph-like ALL harbors a diverse range of genetic alterations with CRLF2-rearrangement/overexpression (CRLF2r) being the most common one. When treated with chemotherapy, Ph-like ALL is associated with inferior response, high relapse rate, and low overall survival (OS). Allogenic hematopoietic cell transplantation (alloHCT) is a well-established curative modality for adults with high-risk ALL. Considering that Ph-like ALL is a high-risk leukemia subtype, it is appealing to recommend alloHCT consolidation routinely for this entity in adults. However, large datasets describing alloHCT outcomes in patients with Ph-like ALL is lacking.

Graft-versus-host disease (GVHD) remains a major cause of treatment failure after allogeneic hematopoietic cell transplantation (alloHCT). In HLA-mismatched donor setting, indirect presentation of allogeneic peptides from recipient's mismatched HLA class I or II proteins by donor or recipient antigen presenting cells can be an immunogenic driver of GVHD. However, the potential diversity of such antigens is large, and predicting them in a systematic manner has proven challenging. Using a novel, highly-multiplexed peptide-MHC binding assay (MHC-PepSeq) we sought to 1) identify allogeneic peptides derived from mismatched HLA protein that can be efficiently presented by HLA-DR, and 2) explore the possibility that the frequency of these HLA-DRB1 binding allopeptides may be predictive of clinical GVHD in HLA-DPB1 mismatched donor/recipient pairs.

CMV recipient seropositivity (R+) and CMVi are independent risk factors for increased mortality after alloHCT. Preemptive therapy (PET) was standard of care until LTV approval by the FDA in November 2017 for CMVi prevention in CMV R+ alloHCT patients (pts). In a registration trial, LTV led to a significant reduction in clinically significant CMVi (CS-CMVi) defined as CMVi requiring PET in both high-risk (HR) or low-risk (LR) recipients. In the HR-group, defined as mismatched related / unrelated donor with at least one mismatch in one of the four HLA-gene loci of HLA-A, -B, -C or -DRB1, haploidentical donor, umbilical cord source or grade ≥2 acute graft-versus-host disease (aGVHD) at randomization, the impact of LTV on CS-CMVi was more robust. Small studies have confirmed the positive impact of LTV on CS-CMVi. Here, we compared the natural history of CMVi and CS-CMVi between the pre-LTV and LTV era in the first 100 days after HR-alloHCT. We also explored the impact on non-relapse mortality (NRM), overall survival (OS), disease free survival (DFS), and incidence of aGVHD between the two eras.

The gut microbiota plays an important role in maintaining intestinal homeostasis by regulating the maturation of the mucosal immune system, which constitutes an immune barrier for the integrity of the intestinal tract. In recent years, the role of the human GI microbiota in graft-versus-host disease (GVHD) and other outcomes after allogeneic hematopoietic cell transplantation (HCT) has been increasingly evaluated in observational studies. However, there have been limited interventional trials specifically designed to alter the microbiota of HCT recipients. CBM588 (clostridium butyricum MIYAIRI 588) is a novel Live Biotherapeutic Product (LBP) that produces short chain organic acids, mainly butyric acid, which plays a key role in the maintenance of colonic homeostasis by regulating fluid and electrolyte uptake, epithelial cell growth, and inflammatory responses. In this pilot trial (NCT03922035) we sought to determine the safety, feasibility, biologic activities, and preliminary efficacy of CBM588 in HCT recipients.

Dadwal: Astellas: Speakers Bureau; Aseptiscope: Consultancy; Shire/Takeda: Research Funding; AlloVir: Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Other: Investigator; Karius: Other: Investigator. Pullarkat: AbbVie, Amgen, Genentech, Jazz Pharmaceuticals, Novartis, Pfizer, and Servier: Membership on an entity's Board of Directors or advisory committees; Amgen, Dova, and Novartis: Consultancy, Honoraria. Al Malki: CareDx: Consultancy; Neximmune: Consultancy; Hansa Biopharma: Consultancy; Rigel Pharma: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy. Ali: Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Speakers Bureau; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees. Artz: Radiology Partners: Other: Spouse has equity interest in Radiology Partners, a private radiology physician practice. Stein: Amgen: Consultancy, Speakers Bureau; Celgene: Speakers Bureau; Stemline: Speakers Bureau. Budde: Roche: Consultancy; BeiGene: Consultancy; IGM Biosciences: Research Funding; Merck, Inc: Research Funding; Gilead: Consultancy; AstraZeneca: Research Funding; Mustang Bio, Inc: Research Funding; Novartis: Consultancy; Amgen: Research Funding. Popplewell: Hoffman La Roche: Other: Food; Pfizer: Other: Travel; Novartis: Other: Travel. Marcucci: Novartis: Other: Speaker and advisory scientific board meetings; Agios: Other: Speaker and advisory scientific board meetings; Abbvie: Other: Speaker and advisory scientific board meetings. Forman: Lixte Biotechnology: Consultancy, Current holder of individual stocks in a privately-held company; Mustang Bio: Consultancy, Current holder of individual stocks in a privately-held company; Allogene: Consultancy.

Dadwal: Astellas: Speakers Bureau; Aseptiscope: Consultancy; AlloVir: Research Funding; Shire/Takeda: Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Other: Investigator; Karius: Other: Investigator. Marcucci: Novartis: Other: Speaker and advisory scientific board meetings; Agios: Other: Speaker and advisory scientific board meetings; Abbvie: Other: Speaker and advisory scientific board meetings. Taplitz: Merck: Membership on an entity's Board of Directors or advisory committees. Artz: Radiology Partners: Other: Spouse has equity interest in Radiology Partners, a private radiology physician practice. Stein: Amgen: Consultancy, Speakers Bureau; Celgene: Speakers Bureau; Stemline: Speakers Bureau. Forman: Allogene: Consultancy; Lixte Biotechnology: Consultancy, Current holder of individual stocks in a privately-held company; Mustang Bio: Consultancy, Current holder of individual stocks in a privately-held company. Al Malki: Neximmune: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy; CareDx: Consultancy; Rigel Pharma: Consultancy; Hansa Biopharma: Consultancy.