The Simplified Comorbidity Index predicts non-relapse mortality in reduced-intensity conditioning allogeneic haematopoietic cell transplantation.

Comorbidity assessment before allogeneic haematopoietic cell transplantation (allo-HCT) is essential for estimating non-relapse mortality (NRM) risk. We previously developed the Simplified Comorbidity Index (SCI), which captures a small number of 'high-yield' comorbidities and older age. The SCI was predictive of NRM in myeloablative CD34-selected allo-HCT. Here, we evaluated the SCI in a single-centre cohort of 327 patients receiving reduced-intensity conditioning followed by unmanipulated allografts from HLA-matched donors. Among the SCI factors, age above 60, mild renal impairment, moderate pulmonary disease and cardiac disease were most frequent. SCI scores ranged from 0 to 8, with 39%, 20%, 20% and 21% having scores of 0-1, 2, 3 and ≥4 respectively. Corresponding cumulative incidences of 3-year NRM were 11%, 16%, 22% and 27%; p = 0.03. In multivariable models, higher SCI scores were associated with incremental risks of all-cause mortality and NRM. The SCI had an area under the receiver operating characteristic curve of 65.9%, 64.1% and 62.9% for predicting 1-, 2- and 3-year NRM versus 58.4%, 60.4% and 59.3% with the haematopoietic cell transplantation comorbidity index. These results demonstrate for the first time that the SCI is predictive of NRM in patients receiving allo-HCT from HLA-matched donors after reduced-intensity conditioning.

Molecular predictors of immunophenotypic measurable residual disease clearance in acute myeloid leukemia.

Measurable residual disease (MRD) is a powerful prognostic factor in acute myeloid leukemia (AML). However, pre-treatment molecular predictors of immunophenotypic MRD clearance remain unclear. We analyzed a dataset of 211 patients with pre-treatment next-generation sequencing who received induction chemotherapy and had MRD assessed by serial immunophenotypic monitoring after induction, subsequent therapy, and allogeneic stem cell transplant (allo-SCT). Induction chemotherapy led to MRD- remission, MRD+ remission, and persistent disease in 35%, 27%, and 38% of patients, respectively. With subsequent therapy, 34% of patients with MRD+ and 26% of patients with persistent disease converted to MRD-. Mutations in CEBPA, NRAS, KRAS, and NPM1 predicted high rates of MRD- remission, while mutations in TP53, SF3B1, ASXL1, and RUNX1 and karyotypic abnormalities including inv (3), monosomy 5 or 7 predicted low rates of MRD- remission. Patients with fewer individual clones were more likely to achieve MRD- remission. Among 132 patients who underwent allo-SCT, outcomes were favorable whether patients achieved early MRD- after induction or later MRD- after subsequent therapy prior to allo-SCT. As MRD conversion with chemotherapy prior to allo-SCT is rarely achieved in patients with specific baseline mutational patterns and high clone numbers, upfront inclusion of these patients into clinical trials should be considered.

Adenovirus Viral Kinetics and Mortality in Ex Vivo T Cell-Depleted Hematopoietic Cell Transplant Recipients With Adenovirus Infection From a Single Center.

BACKGROUND: We report on predictors of adenovirus (ADV) viremia and correlation of ADV viral kinetics with mortality in ex vivo T-cell depleted (TCD) hematopoietic cell transplant (HCT). METHODS: T cell-depleted HCT recipients from January 1, 2012 through September 30, 2018 were prospectively monitored for ADV in the plasma through Day (D) +100 posttransplant or for 16 weeks after the onset of ADV viremia. Adenovirus viremia was defined as ≥2 consecutive viral loads (VLs) ≥1000 copies/mL through D +100. Time-averaged area under the curve (AAUC) or peak ADV VL through 16 weeks after onset of ADV viremia were explored as predictors of mortality in Cox models. RESULTS: Of 586 patients (adult 81.7%), 51 (8.7%) developed ADV viremia by D +100. Age <18 years, recipient cytomegalovirus seropositivity, absolute lymphocyte count <300 cells/µL at D +30, and acute graft-versus-host disease were predictors of ADV viremia in multivariate models. Fifteen (29%) patients with ADV viremia died by D +180; 8 of 15 (53%) died from ADV. Peak ADV VL (hazard ratio [HR], 2.25; 95% confidence interval [CI], 1.52-3.33) and increasing AAUC (HR, 2.95; 95% CI, 1.83-4.75) correlated with mortality at D +180. CONCLUSIONS: In TCD HCT, peak ADV VL and ADV AAUC correlated with mortality at D +180. Our data support the potential utility of ADV viral kinetics as endpoints in clinical trials of ADV therapies.

Ex Vivo T Cell-Depleted Hematopoietic Stem Cell Transplantation for Adult Patients with Acute Myelogenous Leukemia in First and Second Remission: Long-Term Disease-Free Survival with a Significantly Reduced Risk of Graft-versus-Host Disease.

Large series of patients with acute myelogenous leukemia (AML) after ex vivo T cell-depleted (TCD) allogeneic hematopoietic stem cell transplantation (allo-HSCT) have not been reported previously. We retrospectively analyzed the outcomes of 266 patients (median age, 54 years) with AML who received CD34-selected TCD allo-HSCTs while in first (75%) or second (25%) complete remission (CR1/CR2) at a single institution. The conditioning regimens were all myeloablative, and no additional graft-versus-host disease (GVHD) prophylaxis was given. The cumulative incidences of grade II-IV and grade III-IV acute GVHD at 180 days were 14% (95% confidence interval [CI], 10% to 18%) and 3% (95% CI, 1% to 5%), respectively. The cumulative incidence of chronic GVHD at 3 years was 3% (95% CI, 1% to 6%). The 3-year cumulative incidence of nonrelapse mortality was 21% (95% CI, 16% to 26%) and that of relapse was 21% (95% CI, 17% to 27%). Overall survival (OS) and disease-free survival (DFS) at 1, 3, and 5 years were 75%, 61%, and 56% and 68%, 57%, and 53%, respectively. There were no significant differences in OS, DFS, and relapse rates for patients who underwent transplantation in CR1 and those who did so in CR2. However, patients with high-risk cytogenetics at diagnosis had significantly poorer outcomes. The OS and DFS rates compare favorably with those for unmodified allo-HSCT, but with considerably lower rates of GVHD.

Standard Antithymocyte Globulin Dosing Results in Poorer Outcomes in Overexposed Patients after Ex Vivo CD34+ Selected Allogeneic Hematopoietic Cell Transplantation.

Antithymocyte globulin (ATG) use mitigates the risk of graft rejection and graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (allo-HCT), but ATG overexposure in the setting of lymphopenia negatively affects immune recovery. We hypothesized that standard empiric weight-based dosing of ATG, used to prevent graft rejection in ex vivo CD34-selected allo-HCT, may lead to serious adverse consequences on outcomes in certain patients. We evaluated 304 patients undergoing myeloablative-conditioned ex vivo CD34-selected allo-HCT with HLA-matched donors for the treatment of hematologic malignancies. Patients received rabbit ATG at a dose of 2.5 mg/kg/day i.v. on days -3 and/or -2. An ATG dosing cutoff of 450 mg was used for statistical analyses to assess the relationship between ATG and overall survival (OS). Among all patients, median total ATG dose was 360 mg (range, 130 to 510 mg); 279 (92%) received a total dose of ATG ≤450 mg, and 25 (8%) received a total dose >450 mg. On the first day of ATG administration (day -3), the median absolute lymphocyte count was .0 K/µL. For patients who received a total dose of ATG >450 mg or ≤450 mg, the incidences of acute and late-acute GVHD grade II-IV were statistically similar. At 3 years post-HCT, for patients who received a total dose of ATG >450 mg or ≤450 mg, nonrelapse mortality (NRM) rates were 35% and 18%, respectively (P = .029), disease-free survival (DFS) rates were 37% and 61%, respectively (P = .003), and OS rates were 40% and 67%, respectively (P = .001). Among all patient and HCT characteristics in multivariable analyses, receipt of a total dose of ATG >450 mg was associated with an increased risk of NRM (hazard ratio [HR], 2.9; P = .01), shorter DFS (HR, 2.0; P = .03), and inferior OS (HR, 2.1; P = .01). In summary, the use of weight-based ATG at a time of relative lymphopenia before ex vivo CD34-selected allo-HCT results in overdosing in heavier patients, leading to higher NRM and lower DFS and OS. Further pharmacokinetic investigation in this setting is critical to determining the optimal dosing strategy for ATG.

Immune Cytopenias after Ex Vivo CD34+-Selected Allogeneic Hematopoietic Cell Transplantation.

Immune-mediated cytopenias (ICs), such as immune thrombocytopenia and immune hemolytic anemia, are among the adverse events after allogeneic hematopoietic cell transplantation (allo-HCT). Previous reports suggest that in vivo T cell depletion may increase the incidence of IC after allo-HCT. We evaluated whether a strategy that reduces functional donor T cells via ex vivo CD34+-selection associates with the development of IC in a cohort of 408 patients who underwent allo-HCT for hematologic malignancy. The cumulative incidence of IC at 6, 12, and 36 months after the 30-day landmark post-HCT was 3.4%, 4.9%, and 5.8%, respectively. Among 23 patients who developed IC, 7 died of relapse-related mortality and 4 of nonrelapse mortality. A median 2 types of treatment (range, 1 to 5) was required to resolve IC, and there was considerable heterogeneity in the therapies used. In univariable analyses, a hematologic malignancy Disease Risk Index (DRI) score of 3 was significantly associated with an increased risk of IC compared with a DRI of 1 or 2 (hazard ratio [HR], 4.12; P = .003), and IC (HR, 2.4; P = .03) was associated with increased risk of relapse. In a multivariable analysis that included DRI, IC remained significantly associated with increased risk of relapse (HR, 2.4; P = .03). Our findings show that IC events occur with relatively similar frequency in patients after ex vivo CD34+-selected allo-HCT compared with unmodified allo-HCT, suggesting that reduced donor T cell immunity is not causative of IC. Moreover, we noted a possible link between its development and/or treatment and increased risk of relapse.

Allogeneic haematopoietic cell transplantation impacts on outcomes of mantle cell lymphoma with TP53 alterations.

TP53 alterations portend extremely poor prognosis in patients with mantle cell lymphoma treated with standard treatment modalities. We reviewed outcomes of 42 patients with available TP53 status who had received a reduced-intensity or non-myeloablative allogeneic haematopoietic cell transplant at our institution. We demonstrated a 2-year overall survival and progression-free survival of 78% [95% confidence interval (CI) 60-88] and 61% (95% CI 43-75), respectively. The 2-year cumulative incidences of relapse and non-relapse mortality were 19% and 20%, respectively. Importantly, there is no significant difference among patients with and without TP53 alterations, suggesting for the first time a beneficial treatment modality for these high-risk patients.

Letermovir for primary and secondary cytomegalovirus prevention in allogeneic hematopoietic cell transplant recipients: Real-world experience.

Cytomegalovirus (CMV) is associated with significant morbidity and mortality in allogeneic hematopoietic cell transplantation (HCT) patients. We evaluated the efficacy of letermovir as primary and secondary prophylaxis in 53 CMV-seropositive hematopoietic stem cell transplant recipients. 70% of patients were at high risk for CMV reactivation and disease (primarily ex vivo T-cell-depleted HCT [n = 18; 34%] or haploidentical T-replete HCT [n = 12; 23%]). This was a retrospective, single-center study which identified patients transplanted between January 2018 and June 2018. Patients were followed through September 2018. The primary outcome was the incidence of clinically significant CMV infection (CMV viremia requiring preemptive treatment or CMV disease). Primary letermovir prophylaxis started at a median of 7 days (range, 7-40) after allo-HCT. The median duration of primary letermovir prophylaxis was 116 days (range, 12-221). With primary prophylaxis in 39 patients, the observed CMV reactivation rate was 5.1%. Twenty-nine patients continued primary prophylaxis beyond 14 weeks with a reactivation rate of 3.4%. No recurrent reactivation was seen with secondary prophylaxis of an additional 14 patients. Our experience demonstrates the efficacy of letermovir in a real-world setting for CMV prevention for the first 14 weeks and continued efficacy when given longer than 14 weeks after allogeneic stem cell transplantation or as secondary prophylaxis.

Early Fluid Overload Is Associated with an Increased Risk of Nonrelapse Mortality after Ex Vivo CD34-Selected Allogeneic Hematopoietic Cell Transplantation.

In a recently published and validated definition of fluid overload (FO), grade ≥ 2 FO was significantly associated with an increased risk of nonrelapse mortality (NRM) after unmodified and haploidentical allogeneic hematopoietic cell transplantation (allo-HCT) using calcineurin inhibitor (CNI)-based graft-versus-host disease (GVHD) prophylaxis. We evaluated the effect of FO on outcomes in 169 patients undergoing myeloablative-conditioned ex vivo CD34+ selected allo-HCT using the same grading scale. Thirty patients (17.8%) had grade ≥ 2 FO within the 30 days after ex vivo CD34+ selected allo-HCT with a median onset at day 11 (range, -8 to 28). Age ≥ 55 years (odds ratio, 3.43; P = .005) and chemotherapy-based conditioning (odds ratio, 3.89; P = .007) were associated with an increased risk of grade ≥ 2 FO. Patients with early grade ≥ 2 FO had a significantly higher NRM when compared with patients with grade < 2 FO (24.1% versus 3.6% at day 100, P = .01). The HCT-specific comorbidity index (HCT-CI) ≥ 3, FEV1 < 80, adjusted DLco < 80, and HLA mismatch were associated with an increased risk of NRM, whereas total body irradiation-based conditioning was associated with a reduced risk of NRM. In a multivariate analysis grade ≥ 2 FO was associated with increased NRM after adjusting for HCT-CI and HLA match (hazard ratio, 2.3; P = .014). There was a trend toward inferior relapse-free survival in patients with grade ≥ 2 FO compared with patients with grade < 2 FO, 62% versus 72% at 1 year (P = .07), and a trend toward inferior overall survival, 69% versus 79% at 1 year (P = 0.06), respectively. Our findings show that FO should be routinely assessed to identify patients at risk for NRM. Despite a CNI-free allo-HCT platform, regimen-related tissue and endothelial injury leads to FO in susceptible patients. FO is a highly relevant post-HCT toxicity that requires further inquiry.

CC-486 Maintenance after Stem Cell Transplantation in Patients with Acute Myeloid Leukemia or Myelodysplastic Syndromes.

Relapse is the main cause of treatment failure after allogeneic stem cell transplant (alloSCT) in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Injectable azacitidine can improve post-transplant outcomes but presents challenges with exposure and compliance. Oral CC-486 allows extended dosing to prolong azacitidine activity. We investigated use of CC-486 maintenance therapy after alloSCT. Adults with MDS or AML in morphologic complete remission at CC-486 initiation (42 to 84 days after alloSCT) were included. Patients received 1 of 4 CC-486 dosing schedules per 28-day cycle for up to 12 cycles. Endpoints included safety, pharmacokinetics, graft-versus-host disease (GVHD) incidence, relapse/progression rate, and survival. Of 30 patients, 7 received CC-486 once daily for 7 days per cycle (200 mg, n = 3; 300 mg, n = 4) and 23 for 14 days per cycle (150 mg, n = 4; 200 mg, n = 19 [expansion cohort]). Grades 3 to 4 adverse events were infrequent and occurred with similar frequency across regimens. Standard concomitant medications did not alter CC-486 pharmacokinetic parameters. Three patients (10%) experienced grade III acute GVHD and 9 experienced chronic GVHD. Of 28 evaluable patients, 6 (21%) relapsed or had progressive disease: 3 of 7 patients (43%) who had received 7-day dosing and 3 of 23 (13%) who had received 14-day dosing. Transplant-related mortality was 3%. At 19 months of follow-up, median overall survival was not reached. Estimated 1-year survival rates were 86% and 81% in the 7-day and 14-day dosing cohorts, respectively. CC-486 maintenance was generally well tolerated, with low rates of relapse, disease progression, and GVHD. CC-486 maintenance may permit epigenetic manipulation of the alloreactive response postallograft. Findings require confirmation in randomized trials. (ClinicalTrials.gov NCT01835587.).

Impact of Toxicity on Survival for Older Adult Patients after CD34+ Selected Allogeneic Hematopoietic Stem Cell Transplantation.

Ex vivo CD34+ selection before allogeneic hematopoietic stem cell transplantation (allo-HCT) reduces graft-versus-host disease without increasing relapse but usually requires myeloablative conditioning. We aimed to identify toxicity patterns in older patients and the association with overall survival (OS) and nonrelapse mortality (NRM). We conducted a retrospective analysis of 200 patients who underwent CD34+ selection allo-HCT using the ClinicMACS® system between 2006 and 2012. All grade 3 to 5 toxicities by CTCAE v4.0 were collected. Eighty patients aged ≥ 60 years with a median age of 64 (range, 60 to 73) were compared with 120 patients aged < 60 years. Median follow-up in survivors was 48.2 months. OS and NRM were similar between ages ≥ 60 and <60, with 1-year OS 70% versus 78% (P = .07) and 1-year NRM 23% versus 13% (P = .38), respectively. In patients aged ≥ 60 the most common toxicities by day 100 were metabolic, with a cumulative incidence of 88% (95% CI, 78% to 93%), infectious 84% (95% CI, 73% to 90%), hematologic 80% (95% CI, 69% to 87%), oral/gastrointestinal (GI) 48% (95% CI, 36% to 58%), cardiovascular (CV) 35% (95% CI, 25% to 46%), and hepatic 25% (95% CI, 16% to 35%). Patients aged ≥ 60 had a higher risk of neurologic (HR, 2.63 [95% CI, 1.45 to 4.78]; P = .001) and CV (HR, 1.65 [95% CI, 1.04 to 2.63]; P = .03) toxicities but a lower risk of oral/GI (HR, .58 [95% CI, .41 to .83]; P = .003) compared with those aged < 60. CV, hepatic, neurologic, pulmonary, and renal toxicities remained independent risk factors for the risk of death and NRM in separate multivariate models adjusting for age and hematopoietic cell transplantation-specific comorbidity index. Overall, the toxicity of a more intense regimen is potentially balanced by the absence of toxicity related to methotrexate and calcineurin inhibitors in older patients. Prospective study of toxicities after allo-HCT in older patients is essential.

Effects of Late Toxicities on Outcomes in Long-Term Survivors of Ex-Vivo CD34+-Selected Allogeneic Hematopoietic Cell Transplantation.

The late adverse events in long-term survivors after myeloablative-conditioned allogeneic hematopoietic cell transplantation (HCT) with ex vivo CD34+ cell selection are not well characterized. Using the National Cancer Institute's Common Terminology Criteria for Adverse Events, version 4.0, we assessed all grade ≥3 toxicities from the start of conditioning to the date of death, relapse, or last contact in 131 patients who survived >1 year post-HCT, identifying 285 individual toxicities among 17 organ-based toxicity groups. Pretransplantation absolute lymphocyte count >.5 K/µL and serum albumin >4.0 g/dL were associated with a reduced risk of toxicities, death, and nonrelapse mortality (NRM), whereas serum ferritin >1000 ng/mL was associated with an increased risk of toxicities and NRM after 1 year. An HCT Comorbidity Index (HCT-CI) score ≥3 was associated with an increased risk of all-cause death and NRM, but was not associated with a specific increased toxicity risk after 1 year. Patients who incurred more than the median number of toxicities (n = 7) among all patients within the first year subsequently had an increased risk of hematologic, infectious, and metabolic toxicities, as well as an increased risk of NRM and inferior 4-year overall survival (OS) (67% versus 86%; P = .003) after the 1-year landmark. The development of grade II-IV acute graft-versus-host disease (GVHD) within the first year was associated with incurring >7 toxicities within the first year (P = .016), and also with an increased risk of all-cause death and NRM after 1 year. In multivariate models, cardiovascular, hematologic, hepatic, infectious, metabolic, neurologic, and pulmonary toxicities incurred after 1 year were independently associated with increased risk of death and NRM when adjusting for both HCT-CI and grade II-IV acute GVHD within the first year. One-year survivors of ex vivo CD34+ selection had a favorable 4-year OS of 77%, although the development of grade ≥3 toxicities after the first year was associated with poorer outcomes, emphasizing the fundamental importance of improving survivorship efforts that may improve long-term toxicity burden and outcome.

Allogeneic Stem Cell Transplantation for Advanced Myelodysplastic Syndrome: Comparison of Outcomes between CD34+ Selected and Unmodified Hematopoietic Stem Cell Transplantation.

In this study, we compared transplantation outcomes of allogeneic hematopoietic stem cell transplantation (HSCT) in patients with advanced myelodysplastic syndrome (MDS) who received a CD34+ cell-selected and those who received an unmodified allograft. This analysis initially included 181 patients, 60 who received a CD34+ cell-selected transplant and 121 who received an unmodified transplant. Owing to significant differences in disease characteristics, the analysis was limited to patients with <10% blasts before HSCT (n = 145). Two groups were defined: low risk, with low- and intermediate-risk cytogenetics (CD34+, n = 39; unmodified, n = 46), and high risk: poor and very poor risk cytogenetics (CD34+, n = 19; unmodified, n = 41). In the low-risk group, the incidence of grade II-IV acute graft-versus-host disease (aGVHD) at 1 year post-transplantation was 18% in the CD34+ subgroup versus 41.3% in the unmodified subgroup (P = .015). There were no differences between the subgroups in the incidence of grade III-IV aGVHD. The incidence of chronic graft-versus-host disease (cGVHD) at 3 years in the 2 subgroups was 5.3% and 56%, respectively (P < .001). At 3 years post-transplantation, relapse, overall survival (OS), and relapse-free survival (RFS) were similar in the CD34+ and unmodified subgroups: 8.1% versus 19.4% (P = .187), 58.5% versus 53.7% (P = .51), and 59.5% versus 52.4% (P = .448). However, the composite outcome combining extensive cGVHD-free status and relapse-free status (CRFS) at 3 years was 59.5% in the CD34+ group versus 19.2% in the unmodified group (P < .001). In the high-risk group, grade II-IV aGVHD at 1 year was 31.6% in the CD34+ subgroup versus 24.4% in the unmodified subgroup (P = .752). There were no differences between the subgroups in the incidence of grade III-IV aGVHD. The incidence of cGVHD at 3 years in the 2 subgroups was 0% versus 27.6% (P = .013). At 3 years post-transplantation, relapse, OS, RFS, and CRFS in the 2 subgroups were 31.6% versus 69.3% (P = .007), 35.5% versus 14.5% (P = .068), 31.6% versus 10.7% (P = .045), and 31.6% versus 6.1% (P = .001), respectively. Cytogenetic abnormalities at diagnosis and transplant type had significant univariate associations with RFS in the high-risk cohort. Only cytogenetics (P = .03) remained associated with this outcome in a multivariate model. OS was similar in the 2 transplant groups; however, CRFS was superior in the CD34+ cell-selected transplant group.

CD34+ Cell Selection versus Reduced-Intensity Conditioning and Unmodified Grafts for Allogeneic Hematopoietic Cell Transplantation in Patients Age >50 Years with Acute Myelogenous Leukemia and Myelodysplastic Syndrome .

Reduced-intensity conditioning (RIC) and T cell depletion (TCD) through CD34+ cell selection without the use of post-transplantation immunosuppression are 2 strategies used to reduce nonrelapse mortality (NRM) in older patients after allogeneic hematopoietic cell transplantation (allo-HCT). To compare the efficacy of the RIC and TCD approaches, we evaluated the outcomes of patients age >50 years with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) who underwent allo-HCT from an HLA-matched donor with one of these strategies. Baseline characteristics were comparable in the patients receiving TCD (n = 204) and those receiving RIC (n = 151), except for a higher proportion of unrelated donors (68% versus 40%; P < .001) and a higher comorbidity burden (Hematopoietic Cell Transplantation Comorbidity Index [HCT-CI] ≥3: 51% versus 38%; P < .001) in the TCD cohort. Analysis of outcomes at 3 years showed a higher chronic graft-versus-host disease (GVHD)/relapse-free survival (CRFS) (51% versus 7%; P < .001), lower incidences of grade II-IV acute GVHD (18% versus 46% at day +180) and chronic GVHD (6% versus 55% at 3 years; P < .001), and a lower incidence of relapse (19% versus 33% at 3 years; P = .001) in the TCD group compared with the RIC group. Relapse-free survival (RFS), overall survival (OS), and NRM were similar in the 2 groups. Combining transplantation approach (RIC versus TCD) and comorbidity burden (HCT-CI 0-2 versus ≥3), patients with an HCT-CI score of 0-2 seemed to benefit from the TCD approach. In conclusion, in this retrospective study, the use of a CD34+ cell-selected graft and a myeloablative conditioning regimen was associated with higher CRFS and similar RFS and OS compared with unmodified allo-RIC in patients age >50 years with AML and MDS.

Efficacy of brincidofovir as prophylaxis against HSV and VZV in hematopoietic cell transplant recipients.

Allogeneic hematopoietic cell transplant (HCT) recipients are at risk for herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections. Routine prophylaxis with acyclovir is recommended during periods of immunosuppression. Brincidofovir (BCV, CMX001), a lipid conjugate of cidofovir, has shown in vitro activity against HSV/VZV, but has not been formally studied for HSV/VZV prophylaxis. We report our clinical experience of BCV for HSV/VZV prophylaxis in HCT recipients. This was a retrospective review of 30 hematopoietic cell transplant (HCT) recipients between 8/2010 and 8/2015 who received BCV doses not exceeding 200 mg/week for adults/adolescents and 4 mg/kg/week for pediatric (<12 years) patients, for ≥14 days BCV without concomitant acyclovir under clinical trials or single patient use. HSV/VZV cases during BCV treatment were confirmed by viral culture or PCR and clinical symptoms. Of 30 patients who met the inclusion criteria, 27 (90%) patients were adults and 22 (73%) patients received T-cell depleted HCT. The most common indications for BCV were cytomegalovirus in 12 patients (40%) and adenovirus in 11 patients (37%). One patient was treated for acyclovir-resistant HSV and one for disseminated VZV. There were two breakthrough cases of HSV infection during 2170 patient-days. There were no cases of breakthrough VZV infection. The overall rate of breakthrough HSV infection was 1.0 per 1000 patient-days, without any breakthrough VZV infections. Our study provides the only available-albeit limited-evidence on the potential efficacy of BCV for HSV/VZV prophylaxis in HCT patients. Additional studies are needed to further assess the efficacy and safety of BCV in the setting.

Allogeneic Hematopoietic Stem Cell Transplantation with Myeloablative Conditioning Is Associated with Favorable Outcomes in Mixed Phenotype Acute Leukemia.

Mixed phenotype acute leukemia (MPAL) represents a poorly characterized group of acute leukemias that lack an accepted therapeutic approach and are typically associated with poor outcomes. We present our experience of genomic profiling, pretransplantation therapy, and transplantation outcomes for 36 well-characterized pediatric and adult patients with MPAL, defined according to the 2016 World Health Organization leukemia update. A predominance of acute lymphoid leukemia (ALL)-associated mutations and cytogenetic abnormalities was noted. Remission rates after induction appeared comparable among adults (20 of 23) and children (11 of 13) and among those who received ALL (10 of 11) or acute myeloid leukemia-type (21 of 25) induction. Adults underwent transplantation in first remission while children underwent transplantation in the setting of relapse or MLL rearrangement. The median follow-up among the 25 patients who underwent transplantation was 39.6 months and median overall survival was not reached. Relapse after transplantation was associated with MLL rearrangement (P = .022), reduced-intensity conditioning (P < .001), and higher WBC at diagnosis (P = .034). These data highlight differing therapeutic approaches between adult and pediatric MPAL and demonstrate favorable survival of adult MPAL patients consolidated with allogeneic hematopoietic cell transplantation.

A Chemotherapy-Only Regimen of Busulfan, Melphalan, and Fludarabine, and Rabbit Antithymocyte Globulin Followed by Allogeneic T-Cell Depleted Hematopoietic Stem Cell Transplantations for the Treatment of Myeloid Malignancies.

We sought to develop a myeloablative chemotherapeutic regimen to secure consistent engraftment of T-cell depleted (TCD) hematopoietic stem cell transplantations (HSCT) without the need for total body irradiation, thereby reducing toxicity while maintaining low rates of graft-versus-host disease (GVHD) and without increasing relapse. We investigated the myeloablative combination of busulfan (Bu) and melphalan (Mel), with the immunosuppressive agents fludarabine (Flu) and rabbit antithymocyte globulin (r-ATG) as cytoreduction before a TCD HSCT. No post-transplantation immunosuppression was administered. Between April 2001 and May 2008, 102 patients (median age, 55 years) with a diagnosis of primary or secondary myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) underwent cytoreduction with Bu/Mel/Flu, followed by TCD grafts. TCD was accomplished by CD34+-selection followed by E-rosette depletion for peripheral blood stem cell grafts and, for bone marrow grafts, by soybean agglutination followed by E-rosette depletion. Donors included matched and mismatched, related and unrelated donors. Risk stratification was by American Society for Blood and Marrow Transplantation risk categorization for patients with primary disease. For patients with secondary/treatment-related MDS/AML, those in complete remission (CR) 1 or with refractory anemia were classified as intermediate risk, and all other patients were considered high risk. Neutrophil engraftment occurred at a median of 11 days in 100 of 101 evaluable patients. The cumulative incidences of grades II to IV acute and chronic GVHD at 1 year were 8.8% and 5.9%, respectively. Overall- and disease-free survival (DFS) rates at 5 years were 50.0% and 46.1%, respectively, and the cumulative incidences of relapse and treatment-related mortality were 23.5% and 28.4%, respectively. Stratification by risk group demonstrated superior DFS for low-risk patients (61.5% at 5 years) compared with intermediate- or high-risk (34.2% and 40.0%, respectively, P = .021). For patients with AML, those in CR1 had superior 5-year DFS compared with those in ≥CR2 (60% and 30.6%, respectively, P = .01), without a significant difference in incidence of relapse (17.1% and 30.6%, respectively, P = .209). There were no differences in DFS for other patient, donor, or disease characteristics. In summary, cytoreduction with Bu/Mel/Flu and r-ATG secured consistent engraftment of TCD transplantations. The incidences of acute/chronic GVHD and disease relapse were low, with favorable outcomes in this patient population with high-risk myeloid malignancies.

Hematopoietic Cell Transplantation Comorbidity Index Predicts Outcomes in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndromes Receiving CD34+ Selected Grafts for Allogeneic Hematopoietic Cell Transplantation.

To evaluate the association between the hematopoietic cell transplantation-comorbidity index (HCT-CI) and the recently developed age-adjusted HCT-CI (HCT-CI/age) and transplant outcomes in the setting of CD34-selected allogeneic HCT, we analyzed a homogeneous population of patients undergoing allogeneic HCT with CD34-selected grafts for acute myeloid leukemia and myelodysplastic syndrome (n = 346). Median HCT-CI and HCT-CI/age scores were 2 (percentile 25 to 75, 1 to 4) and 3 (percentile 25 to 75, 1 to 5), respectively. Higher HCT-CI and HCT-CI/age scores were associated with higher nonrelapse mortality (NRM) and lower overall survival (OS). The HCT-CI distinguished 2 risk groups (0 to 2 versus ≥3), whereas, with the HCT-CI/age, there was a progressive increase in NRM and decrease in OS with increasing scores in all 4 groups (0 versus 1 to 2 versus 3 to 4 versus ≥5). Higher scores in both models were associated with lower chronic graft-versus-host disease relapse-free survival but not with higher relapse. Both models showed a promising predictive accuracy for NRM (c- = .616 for HCT-CI and c- = .647 for HCT-CI/age). In conclusion, the HCT-CI and HCT-CI/age predict transplant outcomes in CD34-selected allo-HCT, including NRM, OS, and chronic graft-versus-host disease relapse-free survival and may be used to select appropriate patients for this approach.

The Impact of Toxicities on First-Year Outcomes after Ex Vivo CD34+-Selected Allogeneic Hematopoietic Cell Transplantation in Adults with Hematologic Malignancies.

Factors that impact first-year morbidity and mortality in adults undergoing myeloablative allogeneic hematopoietic cell transplantation with ex vivo CD34+ selection have not been previously reported. We assessed all toxicities ≥ grade 3 from the start of conditioning to date of death, relapse, or last contact in 200 patients during the first year after transplantation, identifying 1885 individual toxicities among 17 organ-based toxicity groups. The most prevalent toxicities in the first year were of infectious, metabolic, hematologic, oral/gastrointestinal, hepatic, cardiac, and pulmonary etiologies. Renal complications were minimal. Grades II to IV and III and IV acute GVHD at day 100 were 11.5% and 3%, respectively. In separate multivariate models, cardiovascular, hematologic, hepatic, neurologic, pulmonary, and renal toxicities negatively impacted nonrelapse mortality (NRM) and overall survival during the first year. A higher-than-targeted busulfan level, patient cytomegalovirus seropositivity, and an Hematopoietic Cell Transplantation-Specific Comorbidity Index of ≥3 were associated with increased risk of NRM and all-cause death. Ex vivo CD34+ selection had a favorable 1-year OS of 75% and NRM of 17% and a low incidence of sinusoidal obstruction syndrome. These data establish a benchmark to focus efforts in reducing toxicity burden while improving patient outcomes.

Ex Vivo CD34+-Selected T Cell-Depleted Peripheral Blood Stem Cell Grafts for Allogeneic Hematopoietic Stem Cell Transplantation in Acute Leukemia and Myelodysplastic Syndrome Is Associated with Low Incidence of Acute and Chronic Graft-versus-Host Disease and High Treatment Response.

Ex vivo CD34+-selected T cell depletion (TCD) has been developed as a strategy to reduce the incidence of graft-versus-host disease (GVHD) after allogeneic (allo) hematopoietic stem cell transplantation (HSCT). Clinical characteristics, treatment responses, and outcomes of patients developing acute (aGVHD) and chronic GVHD (cGVHD) after TCD allo-HSCT have not been well established. We evaluated 241 consecutive patients (median age, 57 years) with acute leukemia (n = 191, 79%) or myelodysplastic syndrome (MDS) (n = 50, 21%) undergoing CD34+-selected TCD allo-HSCT without post-HCST immunosuppression in a single institution. Cumulative incidences of grades II-IV and III-IV aGVHD at 180 days were 16% (95% confidence interval [CI], 12 to 21) and 5% (95% CI, 3 to 9), respectively. The skin was the most frequent organ involved, followed by the gastrointestinal tract. Patients were treated with topical corticosteroids, poorly absorbed corticosteroids (budesonide), and/or systemic corticosteroids. The overall day 28 treatment response was high at 82%. The cumulative incidence of any cGVHD at 3 years was 5% (95% CI, 3 to 9), with a median time of onset of 256 days (range, 95 to 1645). The 3-year transplant-related mortality, relapse, overall survival, and disease-free survival were 24% (95% CI, 18 to 30), 22% (95% CI, 17 to 27), 57% (95% CI, 50 to 64), and 54% (95% CI, 47 to 61), respectively. The 1-year and 3-year probabilities of cGVHD-free/relapse-free survival were 65% (95% CI, 59 to 71) and 52% (95% CI, 45 to 59), respectively. Our findings support the use of ex vivo CD34+-selected TCD allograft as a calcineurin inhibitor-free intervention for the prevention of GVHD in patients with acute leukemia and MDS.