Blood Allogeneic Hematopoietic Cell Transplantation Research Articles

Itacitinib for Prevention of Graft-Versus-Host Disease and Cytokine Release Syndrome with T-Cell Replete Peripheral Blood Haploidentical Transplantation

Introduction: Haploidentical peripheral blood allogeneic hematopoietic cell transplantation (PB haplo-HCT) can be complicated by graft-versus-host disease (GVHD) and cytokine release syndrome (CRS). Acute GVHD rates are higher with PB grafts compared with bone marrow, affecting 35-45% of patients and outcomes are poor in steroid refractory cases. Severe CRS occurs in 10-15% of patients receiving PB haplo-HCT and is associated with high non-relapse mortality and one-year overall survival between 25-30%. As interferon-γ and IL-6 are important mediators in both acute GVHD and CRS, we hypothesized that JAK1 inhibition with itacitinib could prevent these toxicities without impairing engraftment. Here we report outcomes from our study of itacitinib with haplo-HCT (NCT03755414). Methods: Patients with AML, MDS, ALL, or NHL in remission undergoing PB haplo-HCT were treated with itacitinib 200 mg/day on days -3 through +100 (first 20 patients) or 180 (second 22 patients), followed by a taper. Myeloablative and reduced intensity conditioning were allowed. GVHD prophylaxis was tacrolimus, mycophenolate mofetil, and post-transplant cyclophosphamide. Primary outcomes were incidence of primary graft failure and incidence of grade III-IV acute GVHD. Secondary outcomes included incidence and severity of CRS, relapse, GRFS, and overall survival. Results: Forty-two patients were enrolled and underwent transplantation on study between November 2019 and December 2022, median days of follow up was 453 days (range 142-1259). The patient population had a median age of 60 years (20 - 73 years) with the majority of patients having AML (AML 60%, ALL 21%), MDS 10%, MF 5%, NHL 4%). All patients with AML, MDS, or ALL were in a complete morphologic remission, although 45% had disease by either cytogenetics, next generation sequencing, or measurable residual disease assay (flow cytometry for AML/MDS, NGS for ALL). There were no cases of grade III-IV acute GVHD. The cumulative incidence of grade II acute GVHD on day 100 was 17.3% (95% CI, 7% - 31%), day 180 was 20.5% and day 365 was 20.5%. There were no cases of severe CRS with 90% of patients having grade 1 CRS and 10% having no CRS. No anti-IL6R or steroid therapy was used. There were no cases of primary graft failure. The cumulative incidence of relapse at 1 year was 10% (95% CI, 3% to 22%) and at 2 years was 14% (95% CI, 5% to 29%). In patients who survived without relapse to day 100, the 1-year cumulative incidence of moderate or severe chronic GVHD was 5% (95% CI 1% - 17%). The refined GRFS at day +180 was 85% (95% CI 69% - 93%) and at day +365 was 79% (95% CI 62% - 89%). Overall survival at 180 days 87% (95% CI 72% - 94%) and at 1 year was 80% (95% CI 63% - 90%). Analysis of peripheral blood mononuclear cells at day +28, +60, and +100, revealed that patients on itacitinib, compared with control haplo-HCT patients, had lower numbers of CD4 and CD8 central memory T cells, lower numbers of CD4 and CD8 naïve T cells, and higher numbers of classical monocytes, nonclassical monocytes, and both myeloid and plasmacytoid dendritic cells. In itacitinib treated patients, T-cell subsets expressed lower LAG3 and PD-1 and higher TIGIT, while monocytes expressed higher HLA-DR, CD80, and CD86. Conclusions: Itacitinib with PB haplo-HCT was safe with low rates of acute and chronic GVHD, without increased risk of relapse or transplant related mortality. Severe CRS was not seen in this trial, and no anti-IL6 or steroid therapy was used. The addition of Jak inhibition to standard PtCy based GVHD prophylaxis was associated with encouraging rates of GRFS and OS on this pilot and expansion study. Patients on itacitinib have unique immune reconstitution characteristics both in terms of PBMC counts and signaling markers within subsets.

Association of CD34 Cell Dose with 5-Year Overall Survival after Peripheral Blood Allogeneic Hematopoietic Cell Transplantation in Adults with Hematologic Malignancies

Higher CD34 cell dose is associated with improved engraftment after peripheral blood allogeneic hematopoietic stem cell transplantation (alloHCT) but also may increase the risk of long-term complications, such as graft-versus-host disease (GVHD). Prior studies examining the relationship between CD34 cell dose and long-term survival outcomes have yielded conflicting results. In this study, we sought to clarify the prognostic impact of CD34 cell dose by examining a large contemporary cohort of patients undergoing alloHCT with a matched sibling peripheral blood stem cell (PBSC) donor. We retrospectively examined the impact of CD34 cell dose on overall survival (OS), neutrophil engraftment, platelet engraftment, treatment-related mortality, relapse, acute GVHD grade II-IV and III-IV, and chronic GVHD in 377 consecutive patients undergoing alloHCT with a PBSC graft source from a matched sibling donor at the University of Minnesota between 2002 and 2015. The patients were classified into 3 groups based on the tertile (T) of CD34 cell dose received: T1, <5×106 cells/kg; T2, 5 to 7.5×106 cells/kg; and T3, ≥7.5×106 cells/kg. Multivariable analysis demonstrated that high CD34 cell dose was associated with superior 5-year OS (hazard ratio [HR], 0.57; P=.01) and more rapid platelet engraftment (HR, 1.70; P < .01). Higher CD34 cell dose also was associated with improved absolute neutrophil count engraftment (T2: HR, 1.54; T3: HR, 1.52; P < .01). There was no association between CD34 cell dose and TRM or relapse at 5 years. Although higher CD34 cell dose was not associated with acute GVHD grade II-IV, it was associated with chronic GVHD (T2: HR, 1.68; T3: HR, 1.50; P=.04). Our data indicate that higher CD34 cell dose (>7.5×106/kg) is associated with superior OS at 5 years and improved engraftment but carries an increased risk of chronic GVHD. These data support a target CD34 cell dose goal of 7.5×106/kg for sibling PBSC graft donors.

A Single-Arm, Open-Label, Pilot Study of the JAK1 Selective Inhibitor Itacitinib for the Prophylaxis of Graft-Versus-Host Disease and Cytokine Release Syndrome in T-Cell Replete Haploidentical Peripheral Blood Hematopoietic Cell Transplantation

Introduction:Haploidentical peripheral blood allogeneic hematopoietic cell transplantation (PB haplo-HCT) can be complicated by graft-versus-host disease (GVHD) and cytokine release syndrome (CRS). Acute GVHD rates are higher with PB grafts compared with bone marrow, affecting 35-45% of patients and outcomes are poor in steroid refractory cases. Severe CRS occurs in 10-15% of patients receiving PB haplo-HCT and is associated with high non-relapse mortality and dismal one year overall survival between 25-30%. As interferon-γ and IL-6 are important mediators in both acute GVHD and CRS, we hypothesized that JAK1 inhibition with itacitinib could prevent these toxicities without impairing engraftment. Here we report the clinical outcomes from our pilot study of itacitinib with haplo-HCT (NCT03755414).Methods:Patients with AML, ALL, or NHL in remission undergoing PB haplo-HCT were treated with itacitinib 200 mg/day on days -3 through +100, followed by a taper. Myeloablative and reduced intensity conditioning were allowed. GVHD prophylaxis was tacrolimus, mycophenolate mofetil, and post-transplant cyclophosphamide. Primary outcomes were incidence of primary graft failure and incidence of grade III-IV acute GVHD. Secondary outcomes included incidence and severity of CRS (graded by Lee criteria). Peripheral blood and serum samples were banked prior to conditioning and on days -1, 1, 3, 7, 14, 28, 60, 100, end of treatment, and time of diagnosis of acute GVHD. Matched control samples were collected from patients undergoing haplo-HCT off clinical trials. Correlative studies include flow cytometry (FACS) with five 28-color panels for cellular subsets, mass cytometry (CyTOF) with 40-colors for intracellular signaling events, single cell RNA sequencing, and serum cytokine and chemokine measurements.Results:Twenty of a planned 20 patients completed enrollment and underwent haplo-HCT between 11/2019 and 3/2021. Median age at transplant was 49 (21-74). Diagnoses were AML (13), ALL (5) and NHL (2). Median follow up is 319 days, with 18/20 beyond 180 days. There were no cases of engraftment failure with short median times to neutrophil (14 days, range 12-20) and platelet (14 days, range 7-54) engraftment (historical 16 and 25 days, respectively). There were no cases of grade III-IV acute GVHD. The incidence of grade II acute GVHD on day 100 was 15%. Two patients developed grade I-II skin acute GVHD during itacitinib taper and responded to resumption of a higher dose. There were no cases of extensive chronic GVHD. There were no cases of severe CRS (historical rate 17%), with 90% of patients having grade 1 CRS and 10% having no CRS. Furthermore, no anti-IL6R or steroid therapy was used. Overall survival at day 180 was 90% (95% CI 75-100%) by Kaplan-Meier estimate. Incidence of relapse at 180 days was 5.5% (95% CI 0-15.6%). Refined GVHD and relapse-free survival at 180 days was 83% (95% CI 68-100%). All patients had full donor engraftment and >95% chimerism at day 100.FACS and CyTOF have been performed and analyzed for the day 28 time point from 14 patients and four controls. Flow cytometry revealed no difference in cell subset numbers between controls and patient samples. CyTOF revealed differences in intracellular signaling molecules between itacitinib and control patients - including higher Ki-67, pNF-κB, and Caspase3 in controls. Phospho-Stat1 and pStat3 were lower CD4 T subsets. FACS and CyTOF at remaining time points, single cell RNA sequencing, and serum cytokine and chemokine measurements are underway and will be presented at the ASH 2021 meeting.Conclusions:Itacitinib with PB haplo-HCT was safe with no engraftment failure and prompt engraftment. Rates of acute and chronic GVHD were low, without increased risk of relapse or transplant related mortality. Severe CRS was not seen in this trial, and no anti-IL6 or steroid therapy was used. Flow cytometry demonstrated comparable immune reconstitution in terms of cell lineage and number between treated patients and controls. Mass cytometry revealed lower Ki-67, pNF-κB, and caspase3 levels, among other markers, which suggest lower immune cell activity, proliferation, and apoptosis. An extension cohort of 20 additional patients is enrolling. Multi-platform correlative studies are underway, comparing samples from haplo-HCT patients treated with and without itacitinib. [Display omitted] DisclosuresUy: Astellas: Honoraria, Speakers Bureau; Novartis: Consultancy; Agios: Consultancy; Jazz: Consultancy; Genentech: Consultancy; AbbVie: Consultancy; GlaxoSmithKline: Consultancy; Macrogenics: Research Funding. Ghobadi: Atara: Consultancy; Amgen: Consultancy, Research Funding; Wugen: Consultancy; Celgene: Consultancy; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding. Jacoby: Abbvie: Research Funding; Jazz: Research Funding. Pusic: Syndax: Other: Advisory Board. Schroeder: Equillium Inc: Honoraria; Janssen: Honoraria; Sanofi Genzyme: Honoraria.

Higher CD34 Cell Dose Is Associated with Improved 5-Year Survival after Peripheral Blood Allogeneic Hematopoietic Cell Transplantation in Adults with Hematologic Malignancies

<h3>Introduction</h3> Higher CD34+ cell dose is associated with improved short-term outcomes (e.g., engraftment) but may also be associated with an increased risk of complications after allogeneic hematopoietic stem cell transplantation (alloHCT), including graft-versus-host disease (GVHD). We examined the impact of CD34+ cell dose by actual and ideal body weight (ABW, IBW) on overall survival (OS) and graft-versus-host disease-free, relapse free survival (GRFS) in patients undergoing alloHCT with peripheral blood stem cell (PBSC) graft source. <h3>Methods</h3> We identified 377 adults with hematologic malignancies who received myeloablative or reduced-intensity conditioning alloHCT with matched sibling donor PBSC at the University of Minnesota from 2002-2015. <h3>Results</h3> Patients had a median age of 52 years (range 18-74), were predominantly male (n=237, 63%) and had primarily leukemia (68%) or lymphoma (25%) with an intermediate disease risk index (n=258, 68%). Median CD34+ dose was 6.1 × 10⁶/kg by ABW (quartiles in Table 1) and 7.72 × 10⁶/kg by IBW [QT1 <5.93, QT2 5.93,7.72, QT3 7.72, 10.12, QT4 >10.12]. Patients in higher quartiles were younger at transplant (p <0.02) with younger donors (p <0.01). QT4 donors required fewer collections (median 1, range 1-5, p<0.01). Highest quartile cell dose by ABW was associated with increased OS at both 1 year [HR 0.48 (0.29-0.80), p=0.02] and 5 years [HR 0.56 (0.38-0.83), p=0.01] (Figure 1) and platelet engraftment [HR 1.58 (1.19-2.09), p<0.01] in multivariate analysis. The top 3 quartiles by ABW showed significantly increased ANC engraftment and a trend toward increased GRFS at both 1 and 5 years. There was no association between cell dose and acute or chronic GVHD. Cell dose by IBW was not associated with survival, relapse, engraftment or treatment-related mortality. <h3>Conclusion</h3> The highest quartile of CD34+ cell dose by ABW is associated with superior OS at 5 years and improved engraftment without increased risk of morbidity. These data support further development of novel stem cell mobilization techniques in donors at higher risk for low collection yield. Further studies should evaluate if cell dose has similar prognostic impact in 5-year survival in alternative donor transplant.

582 - Infused Total Nucleated Cell Dose is a Better Predictor of Transplant Outcomes Than CD34+ Cell Dose for Peripheral Blood Allogeneic Hematopoietic Cell Transplantation in Children

582 - Infused Total Nucleated Cell Dose is a Better Predictor of Transplant Outcomes Than CD34+ Cell Dose for Peripheral Blood Allogeneic Hematopoietic Cell Transplantation in Children

Infused total nucleated cell dose is a better predictor of transplant outcomes than CD34+ cell number in reduced-intensity mobilized peripheral blood allogeneic hematopoietic cell transplantation.

Mobilized peripheral blood is the most common graft source for allogeneic hematopoietic stem cell transplantation following reduced-intensity conditioning. In assessing the effect of donor cell dose and graft composition on major transplant outcomes in the reduced-intensity setting, prior studies focused primarily on CD34(+)cell dose and reported conflicting results, especially in relation to survival end-points. While the impact of total nucleated cell dose has been less frequently evaluated, available studies suggest higher total nucleated cell dose is associated with improved survival outcomes in the reduced-intensity setting. In order to further explore the relationship between CD34(+)cell dose and total nucleated cell dose on reduced-intensity transplant outcomes, we analyzed the effect of donor graft dose and composition on outcomes of 705 patients with hematologic malignancies who underwent reduced-intensity peripheral blood stem cell transplantation at the Dana Farber Cancer Institute from 2000 to 2010. By multivariable analysis we found that higher total nucleated cell dose (top quartile; ≥10.8 × 10(10)cells) was associated with improved overall survival [HR 0.69 (0.54-0.88),P=0.0028] and progression-free survival [HR 0.68 (0.54-0.85),P=0.0006]. Higher total nucleated cell dose was independently associated with decreased relapse [HR 0.66 (0.51-0.85),P=0.0012] and increased incidence of chronic graft-versus-host disease [HR 1.4 (1.12-1.77),P=0.0032]. In contrast, higher doses of CD34(+)cells (top quartile; ≥10.9 × 10(6)/kg) had no significant effect on graft-versus-host disease or survival outcomes. These data suggest total nucleated cell dose is a more relevant prognostic variable for reduced-intensity transplant outcomes than the more commonly studied CD34(+)cell dose.

Importance of donor ethnicity/race matching in unrelated adult and cord blood allogeneic hematopoietic cell transplant

Donor race matching (both recipient and donor belonging to the same race) might be a factor in outcomes of donor allogeneic hematopoietic cell transplant (alloHCT). A total of 858 patients who underwent umbilical cord blood (UCB) (475 patients: 202 double UCB and 273 single UCB) or unrelated donor (URD) (383 patients) alloHCT between January 1995 and December 2010 were studied. Most patients were Caucasian (87%), followed by Asians (4%), African Americans (3%), Hispanics (3%), mixed race (3%) and American Indians (< 1%). Caucasians constituted 88% of the donor grafts; Caucasians were the most common race of the donor grafts among all races except for Asians. As a result, Caucasians were much more likely to have a race-matched donor than ethnic minorities (91% vs. 33%, p < 0.01). Donor race matching did not affect non-relapse mortality, relapse, acute or chronic graft-versus-host disease or overall survival. Acknowledging the limitations of this study (mainly, self-reported race information and small number of ethnic minorities), at present there are no data supporting that donor race should be considered a factor in donor selection.

In Vivo T-Cell Depletion (TCD) Does Not Improve Rates of Graft-Versus-Host Disease (GVHD) and Transplantation Outcomes in Patients Undergoing Peripheral Blood Allogeneic Hematopoietic Cell Transplant (AHCT)

In Vivo T-Cell Depletion (TCD) Does Not Improve Rates of Graft-Versus-Host Disease (GVHD) and Transplantation Outcomes in Patients Undergoing Peripheral Blood Allogeneic Hematopoietic Cell Transplant (AHCT)

Effect of T-Cell Dose On Outcomes After Peripheral Blood Allogeneic Hematopoietic Cell Transplantation in Hematological Malignancies.

Abstract 1171Poster Board I-193 Purpose:Peripheral blood allogeneic hematopoietic cell transplant (HCT) is used to treat various types of hematological malignancies. Current knowledge supports that increased CD34 + cell dose in the infusate is associated with earlier leukocyte recovery. The dose of CD3 +, CD4 + and CD8 + cells is largely disregarded except in T-cell depleted transplant. The correlation between various cell doses and outcomes is an area of great interest in HCT. Our analysis focuses on the impact of T-cell subset dosing, on outcomes after HCT, such as acute graft versus host disease (GVHD) and mortality. Methods:Retrospective analysis was conducted on 134 consecutive patients who underwent peripheral blood allogeneic HCT for various hematological malignancies in our institution between January 2003 and December 2008. Statistical analysis was performed using SPSS 15.0. The Chi - square test was used to determine any association between cell doses and the incidence of acute GVHD and all-cause mortality at one year of follow-up after transplant. Results were also compared with the association between CD3+ and CD8+ cell doses and incidence of acute GVHD as reported in 2007 by our institution. Results:A total of 134 patients were included in our analysis, consisting of 49 females and 85 males. The median age was 49 years (range 17-69). HCT was from matched related donors in 68 and from matched unrelated donors in 66 patients. A variety of conditioning regimens were used in preparation for the HCT. Overall survival at 1 year of follow-up was 60%, the incidence of acute GVHD was 52%, and chronic GVHD was 29%. All-cause mortality at one year follow up was found to be significantly higher when the CD3+ cell dose was < 30.5 × 107/kg IBW (49% vs. 29%, P = 0.018). All-cause mortality was also significantly increased when CD8+ cell dose was < 9.2 × 107/kg IBW (50% vs. 33%, P= 0.05). A CD8+ cell dose of < 9.2 × 107/kg IBW was also associated with an increased risk of grades 2-4 acute GVHD (48% vs. 22%, P = 0.026). There was no association of statistical significance between CD3+ and CD4+ cell doses and the incidence of acute GVHD. Conclusion:The data suggests a statistically significant inverse association between mortality and CD3+ cell dose of <30.5 × 107/kg IBW. A CD8+ cell dose of <9.2 × 107/kg IBW was also associated with increased all-cause mortality and acute GVHD (grades 2-4). Our institution reported in 2007, a significant association between the incidence of acute GVHD (grades 2-4) and CD3+ cell dose < 33.5 × 107/kg IBW and CD8+ cell dose of < 6.2 × 107/kg IBW, based on series of 66 patients. As we increased the sample size to 134, the association between CD3+ cell dose and acute GVHD was no more present.We conclude that T-cell dose is an important factor in terms of outcomes after all allogeneic HCT irrespective of preparative regimen. T-cell subsets likely play a pivotal role in transplant results, though it is not well described. Analysis of larger databases is required to substantiate our results. Disclosures:No relevant conflicts of interest to declare.