Sirolimus Is an Acceptable Alternative to Tacrolimus for Graft-versus-Host Disease Prophylaxis after Haploidentical Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide.

Graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide (PTCy), tacrolimus (Tac), and mycophenolate mofetil (MMF) for allogeneic haploidentical donor (haplo) hematopoietic cell transplantation (HCT) results in comparable outcomes to matched unrelated donor HCT. A phase II study from the Moffitt Cancer Center substituting sirolimus (Siro) for Tac in this prophylactic regimen reported comparable rates of grade II-IV acute GVHD (aGVHD). Many centers have substituted Siro for Tac in this setting based on a preferable side effect profile, although comparative data are limited. In this study, we retrospectively compared outcomes in haplo-HCT with PTCy/Siro/MMF versus haplo-HCT with PTCy/Tac/MMF. The study cohort included all consecutive patients receiving haploidentical donor T cell-replete peripheral blood stem cell (PBSC) HCT for hematologic malignancies at Moffitt Cancer Center or the City of Hope National Medical Center between 2014 and 2019. A total of 423 patients were included, of whom 84 (20%) received PTCy/Siro/MMF and 339 (80%) received PTCy/Tac/MMF. The median age for the entire cohort was 54 years (range, 18 to 78 years), and the median follow-up was 30 months. The Siro group had a higher proportion of patients age ≥60 years (58% versus 34%; P < .01), and the groups also differed in diagnosis type, conditioning regimen, and cytomegalovirus serostatus. There were no significant differences in the rates of grade II-IV aGVHD (45% versus 47%; P = .6) at day +100 or chronic GVHD (cGVHD) (47% versus 54%; P = .79) at 2 years post-HCT. In multivariate analysis, neutrophil engraftment at day +30 was significantly better in the Tac group (odds ratio, .30; 95% confidence interval, .1 to .83; P = .02), with a median time to engraftment of 17 days versus 18 days in the Siro group, but platelet engraftment was similar in the 2 groups. Otherwise, in multivariate analysis, GVHD prophylaxis type had no significant influence on aGVHD or cGVHD, nonrelapse mortality, relapse, GVHD-free relapse-free survival, disease-free survival, or overall survival after PBSC haplo-HCT. These findings suggest that Siro is a comparable alternative to Tac in combination with PTCy/MMF for GVHD prophylaxis, with overall similar clinical outcomes despite delayed engraftment after peripheral blood stem cell haplo-HCT. Although Tac remains the standard of care, Siro may be substituted based on the side effect profile of these medications, with consideration of patient medical comorbidities at HCT.

WT1-mutated acute myeloid leukemia is sensitive to fludarabine-based chemotherapy and conditioning regimens.

We conducted a retrospective analysis of WT1-mutated acute myeloid leukemia (AML) patients who underwent allogeneic stem cell transplant. Thirty-seven patients with WT1-mutated AML were identified. Primary induction failure (40%) and early relapse rate (18%) after idarubicin/cytarabine (7 + 3) chemotherapy were observed. All patients with induction failure subsequently achieved CR with additional chemotherapy. There was no significant difference between outcomes after myeloablative vs. reduced intensity (Fludarabine/Melphalan [Flu/Mel]) conditioning regimens. RFS but not OS was significantly better in patients who received FLAG-IDA prior to transplant and/or a fludarabine-containing conditioning. In an independent ex vivo study, WT1-mutated AML samples exhibited greater sensitivity to fludarabine (p = 0.026) and melphalan (p = 0.0005) than non-WT1-mutated AML samples while there was no difference between sensitivity to cytarabine. Our data favor using a fludarabine-based induction for AML with WT1 mutation instead of 7 + 3. Fludarabine conditioning regimens for alloHCT showed better RFS but not OS.

Tocilizumab for Cytokine Release Syndrome Management After Haploidentical Hematopoietic Cell Transplantation With Post-Transplantation Cyclophosphamide-Based Graft-Versus-Host Disease Prophylaxis.

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.

Use of monoclonal antibody therapy in hematologic patients with mild-to-moderate COVID-19: A retrospective single-center experience.

INTRODUCTION: In November 2020, the FDA issued an emergency use authorization (EUA) for monoclonal antibody (mAb) therapy in patients with mild-to-moderate COVID-19 at high risk for disease progression. METHODS: We retrospectively reviewed 38 adult hematology patients who received mAbs from 11/2020 to 2/2021. RESULTS: Thirty (79%) patients received bamlanivimab and 8 (21%) casirivimab-imdevimab. Four (11%) patients were hospitalized due to COVID-19, two (5%) progressed to severe disease and one patient (3%) died within 30 days from COVID-19 disease. Most patients (n = 34, 89%) ultimately tested negative for SARS-CoV-2, with 34% (n = 13) clearing the virus within 14 days after mAb infusion. The median time to clearance of viral shedding was 25.5 days (range: 7-138). After mAb infusion, most patients with hematological malignancies (HM) (n = 10/15; 67%) resumed therapy for underlying disease with a median delay of 21.5 days (range: 12-42). We observed a significant difference in hospitalization among patients who received a HCT versus non-HCT (0% n = 0/26 and 36% n = 4/11, respectively; p < 0.01). CONCLUSIONS: This study demonstrates that SARS-CoV-2 specific mAb was safe and may reduce hospitalization compared to what is reported in malignant hematology patients at high risk for disease progression. Our HCT cohort patients had less hospitalization rate compared with HM cohort patients.

The impact of SARS-CoV2 vaccines on the incidence of graft versus host disease in allogeneic hematopoietic stem cell transplant recipients: a single-center retrospective study.

This study reports the incidence of chronic graft versus host disease (GvHD) in allogeneic hematopoietic stem cell transplant (alloHCT) recipients who received SARS-CoV2 vaccination. The overall rates of new and worsening chronic GvHD combined were 14%, with median time from vaccination to GVHD being approximately three to four weeks. A majority of the cases were of mild to moderate severity and primarily localized to either the skin, mouth, or joints. Prior chronic GVHD and recent transplant were associated with higher GVHD rates following COVID-19 vaccination. More prospective studies are needed to provide a definitive mechanism for the impact of SARS-CoV2 vaccination on alloHCT patients.

High response rates and transition to transplant after novel targeted and cellular therapies in adults with relapsed/refractory acute lymphoblastic leukemia with Philadelphia-like fusions.

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is associated with a poor response to standard chemotherapy. However, outcomes with novel antibody and cellular therapies in relapsed/refractory (r/r) Ph-like ALL are largely unknown. We conducted a single-center retrospective analysis of adult patients (n = 96) with r/r B-ALL and fusions associated with Ph-like who received novel salvage therapies. Patients were treated with 149 individual novel regimens (blinatumomab = 83, inotuzumab ozogamicin [InO] = 36, and CD19CAR T cells = 30). The median age at first novel salvage therapy was 36 years (range; 18-71). Ph-like fusions were IGH::CRLF2 (n = 48), P2RY8::CRLF2 (n = 26), JAK2 (n = 9), ABL-class (n = 8), EPOR::IGH (n = 4) and ETV6::NTRK2 (n = 1). CD19CAR T cells were administered later in the course of therapy compared to blinatumomab and InO (p < .001) and more frequently in recipients who relapsed after allogeneic hematopoietic cell transplantation (alloHCT) (p = .002). Blinatumomab was administered at an older age compared to InO and CAR T-cells (p = .004). The complete remission (CR)/CR with incomplete hematologic recovery (CRi) rates were 63%, 72%, and 90% following blinatumomab, InO and CD19CAR, respectively, among which 50%, 50%, and 44% of responders underwent consolidation with alloHCT, respectively. In multivariable analysis, the type of novel therapy (p = .044) and pretreatment marrow blasts (p = .006) predicted the CR/CRi rate, while the Ph-like fusion subtype (p = .016), pretreatment marrow blasts (p = .022) and post-response consolidation with alloHCT (p < .001) influenced event-free survival. In conclusion, novel therapies are effective in inducing high remission rates in patients with r/r Ph-like ALL and successfully transitioning the responders to alloHCT.

Hematopoietic stem cell donor vaccination with cytomegalovirus triplex augments frequencies of functional and durable cytomegalovirus-specific T cells in the recipient: A novel strategy to limit antiviral prophylaxis.

To enhance protective cytomegalovirus (CMV)-specific T cells in immunosuppressed recipients of an allogeneic hematopoietic cell transplant (HCT), we evaluated post-HCT impact of vaccinating healthy HCT donors with Triplex. Triplex is a viral vectored recombinant vaccine expressing three immunodominant CMV antigens. The vector is modified vaccinia Ankara (MVA), an attenuated, non-replicating poxvirus derived from the vaccinia virus strain Ankara. It demonstrated tolerability and immunogenicity in healthy adults and HCT recipients, in whom it also reduced CMV reactivation. Here, we report feasibility, safety, and immunological outcomes of a pilot phase 1 trial (NCT03560752 at ClinicalTrials.gov) including 17 CMV-seropositive recipients who received an HCT from a matched related donor (MRD) vaccinated with 5.1 × 108 pfu/ml of Triplex before cell harvest (median 15, range 11-28 days). Donor and recipient pairs who committed to participation in the trial resulted in exceptional adherence to the protocol. Triplex was well-tolerated with limited adverse events in donors and recipients, who all engrafted with full donor chimerism. On day 28 post-HCT, levels of functional vaccinia- and CMV-specific CD137+ CD8+ T cells were significantly higher (p < .0001 and p = .0174, respectively) in recipients of Triplex vaccinated MRD than unvaccinated MRD (control cohort). Predominantly, central and effector memory CMV-specific T-cell responses continued to steadily expand through 1-year follow-up. CMV viremia requiring antivirals developed in three recipients (18%). In summary, this novel approach represents a promising strategy applicable to different HCT settings for limiting the use of antiviral prophylaxis, which can impair and delay CMV-specific immunity, leading to CMV reactivation requiring treatment.

Post-Transplantation Sinusoidal Obstruction Syndrome in Adult Patients with B Cell Acute Lymphoblastic Leukemia Treated with Pretransplantation Inotuzumab.

Sinusoidal obstruction syndrome (SOS) is a potentially life-threatening complication that can be observed after allogeneic hematopoietic cell transplantation (HCT). Inotuzumab ozogamicin is an anti-CD22 monoclonal antibody-drug conjugate that has demonstrated high efficacy in relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) but is associated with an increased risk of SOS in HCT recipients. Here we aimed to examine the incidence and outcomes of SOS in 47 adult patients with R/R ALL who received inotuzumab therapy and subsequently underwent HCT at our institution. All patients received prophylactic therapy with ursodiol, and continuous low-dose heparin also was administered to patients receiving myeloablative conditioning (MAC). SOS occurred in 12 patients (26%) post-HCT, at a median onset of 11 days (range, 3 to 41 days). SOS was graded as very severe in 50% (n = 6), severe in 25% (n = 3), and mild in 25% (n = 3). All patients diagnosed with SOS received treatment with defibrotide for a median of 21 days (range, 3 to 34 days), with resolution of SOS occurring in 8 patients (67%). Mortality from SOS was 33% (n = 4) and occurred at a median of 10 days from diagnosis (range, 3 to 31 days) in patients graded as very severe (n = 3) or severe (n = 1). There were no significant differences between patients who developed SOS and those who did not develop SOS in the median time from the last dose of inotuzumab to transplantation (46 days versus 53 days; P = .37), use of an MAC regimen (42% versus 49%; P = .75), number of lines of therapy prior to inotuzumab (P = .79), median number of administered cycles of inotuzumab (2 versus 2; P = .14), or receipt of inotuzumab as the last therapy prior to HCT (67% versus 66%; P = 1.0). Sirolimus-based graft-versus-host disease (GVHD) prophylaxis was used more frequently in the SOS group (75% versus 29%; P < .01), but there was no between-group difference in the peak sirolimus level (P = .81) or the median time to peak sirolimus level (7 days versus 3.5 days; P = .39). In univariable analysis, only the use of sirolimus-based GVHD prophylaxis was significantly associated with an increased risk of SOS (hazard ratio [HR], 7.50; 95% confidence interval [CI], 1.7 to 33.6; P < .01). In the SOS group, the 100-day mortality rate was 33% (n = 4), and median overall survival (OS) post-HCT was 4.3 months (range, 0.2 to 57.2 months). In the group without SOS, the 100-day mortality rate was 14% (n = 5) and the median OS post-HCT was 10.7 months (range, .52 to 39.6 months). In this study cohort, SOS was prevalent in HCT recipients who had been treated with inotuzumab prior to transplantation, and sirolimus-based GVHD prophylaxis was a risk factor for SOS in inotuzumab recipients.

New strategies for mismatched unrelated donor (MMUD) hematopoietic cell transplant (HCT).

With increasing numbers of patients with hematologic malignancies requiring allogeneic hematopoietic cell transplant (HCT), including minority racial and ethnic groups, the limited availability of matched related donors and matched unrelated donors remains a significant obstacle. Hence, the use of alternative donors such as haploidentical and mismatched unrelated donors (MMUDs) is on the rise. Herein, we present case studies to outline a rational and stepwise approach with a focus on the use of MMUD for HCT in patients with hematologic malignancies. We also review novel approaches used to reduce the incidence of severe graft-versus-host disease and improve HCT outcomes in patients undergoing MMUD HCT.

Outcomes of allogeneic hematopoietic cell transplantation in adults with fusions associated with Ph-like 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.

Extramedullary disease relapse and progression after blinatumomab therapy for treatment of acute lymphoblastic leukemia.

BACKGROUND: Blinatumomab has demonstrated encouraging activity in relapsed/refractory (r/r) and minimal residual disease-positive (MRD+) acute lymphoblastic leukemia (ALL). Extramedullary disease (EMD) relapse or relapse with CD19- disease has been observed after blinatumomab therapy in patients with r/r or MRD+ ALL. However, the pathophysiology and risk factors of treatment failure are not fully understood. METHODS: This study retrospectively reviewed the outcomes of adult patients with B-cell ALL treated with blinatumomab (n = 132) for either r/r (n = 103) or MRD+ disease (n = 29) at the authors' center (2013-2021) and analyzed factors associated with treatment response and EMD failure. RESULTS: The overall response rate was 64%. A lower marrow blast burden before blinatumomab (P = .049) and no history of previous EMD (P = .019) were significantly associated with a higher response. Among the patients who responded to blinatumomab, 56% underwent consolidation with allogeneic transplantation. Blinatumomab failure was observed in 89 patients; 43% of these patients (n = 38) either progressed or relapsed at extramedullary sites. A history of extramedullary involvement (53% vs 24%; P = .005) and retention of CD19 expression at the time of relapse/progression (97% vs 74%; P = .012) were associated with a higher risk for extramedullary failure. Central nervous system (CNS) failure after blinatumomab was encountered in 39% of the patients with EMD. CONCLUSIONS: A history of EMD predicted an inferior response to blinatumomab therapy with a higher risk for relapse/progression at extramedullary sites (particularly CNS). Consolidation with allogenic transplantation in patients who primarily responded to blinatumomab did not abrogate the risk of extramedullary relapse. The incorporation of extramedullary assessment and the intensification of CNS prophylaxis may help in addressing extramedullary failure. LAY SUMMARY: Extramedullary failure is common during blinatumomab therapy for relapsed/refractory acute lymphoblastic leukemia. A history of extramedullary disease predicts an inferior response to blinatumomab therapy and a higher risk for relapse/progression at extramedullary sites. Most extramedullary failure cases retain CD19 expression.

Cytokine Release Syndrome Following Peripheral Blood Stem Cell Haploidentical Hematopoietic Cell Transplantation with Post-Transplantation Cyclophosphamide.

Post-transplantation cyclophosphamide (PTCy) is a safe and efficacious graft-versus-host-disease (GVHD) prophylaxis following hematopoietic cell transplantation (HCT) from a haploidentical (haplo) donor. Cytokine release syndrome (CRS) is a common complication of this platform. Early fever post-haplo-HCT using bone marrow grafts is associated with higher CD3+ cell dose and CRS. However, the impact of CD3+ and CD34+ cell dose on CRS post-haplo-HCT using peripheral blood stem cell (PBSC) grafts is unknown. Our goals were to evaluate the incidence of CRS following PBSC transplantation (PBSCT) and to identify factors that can be modified to prevent the development of severe CRS in this setting. In 271 patients, we investigated factors associated with the development of CRS following haplo-PBSCT and examined the impact of CRS on clinical outcomes. Ninety-three percent of the patients developed CRS of any grade post-haplo-PBSCT. In multivariate analysis, severe CRS (grade 3-4 versus grade 0-1) was associated with higher nonrelapse mortality (hazard ratio [HR], 6.42; 95% confidence interval [CI], 2.68 to 15.39; P < .001), worse 1-year overall survival (HR, 3.40; 95% CI, 1.63 to 7.08; P = .005), and worse disease-free survival (HR, 4.02; 95% CI, 1.99 to 8.08; P < .001). Moderate to severe CRS (grade 2-4) did not impact 1-year relapse or acute GVHD (grade II-IV and III-IV) at 100 days (P = .71 and .19, respectively). Importantly, higher CD3+ cell dose, but not CD34+ cell dose, predicted a higher incidence of grade 2-4 CRS (HR, 1.20; 95% CI,1.07 to 1.36; P = .003) and grade 3-4 CRS (HR, 1.40; 95% CI, 1.05 to 1.86; P = .022). Both older age (HR, 8.57; 95% CI, 1.73 to 42.36; P < .001) and non-total body irradiation-based reduced-intensity conditioning with fludarabine/melphalan (HR, 15.38; 955 CI, 2.06 to 114.67; P < .001) were predictive of grade 3-4 CRS. Overall, we observed that severe CRS (grade 3-4) negatively affected transplantation outcome, and that higher CD3 cell dose was associated with the development of any grade CRS and severe CRS.

Tacrolimus initial steady state level in post-transplant cyclophosphamide-based GvHD prophylaxis regimens.

Post-transplant cyclophosphamide (PTCy) combined with tacrolimus (TAC) as graft-versus-host disease (GvHD) prophylaxis post-hematopoietic cell transplantation (HCT) is safe and effective. Optimal serum levels of TAC in this combination remain undetermined. We hypothesized that TAC at initial steady state (TISS) of <10 ng/mL could promote optimal transplant outcomes and prevent TAC-associated toxicities. We retrospectively analyzed a consecutive case series of 210 patients who received PTCy/TAC-based prophylaxis post-HCT from 1/2013-6/2018. Patients received HCT from haploidentical (n = 172) or mismatched donors (n = 38), and flat dose (FD) or weight-based dose (WBD) TAC. Twenty-four-month overall survival (OS), disease free survival (DFS), and relapse rate (RR) were 61%, 56%, and 22%, respectively, in TISS < 10 ng/mL cohort (n = 176), and 50%, 43%, and 35%, respectively, in TISS ≥ 10 ng/mL cohort (n = 34) (OS, P = 0.71; DFS, P = 0.097; RR, P = 0.031). OS, DFS, RR, non-relapse mortality, acute GvHD grade II-IV, grade III-IV or chronic GvHD by TISS were similar in multivariable analysis. TISS ≥ 10 ng/mL conferred increased risk of viral infection (P = 0.003). More patients receiving FD vs. WBD had TISS < 10 ng/mL (P = 0.001). Overall, TISS < 10 ng/mL early post HCT conferred similar survival outcomes and lowered risk of viral infection and toxicities compared to TISS ≥ 10 ng/mL.

Current Management and New Developments in the Treatment of Myelodysplastic Syndrome.

Myelodysplastic syndrome (MDS) is a heterogeneous hematological neoplasm with a wide range of clinical presentations from isolated anemia to pancytopenia and propensity to transform to acute myeloid leukemia. MDS is characterized by morphologic bone marrow dysplasia and ineffective hematopoiesis resulting from a range of cytogenetic abnormalities and somatic gene mutations. Disease management varies from observation alone for low-risk disease to hypomethylating agents and hematopoietic cell transplantation (HCT) for higher risk disease. In this chapter, we review the classification, risk stratification, and optimal management of patients with MDS.

Safety and Tolerability of SARS-CoV2 Emergency-Use Authorized Vaccines for Allogeneic Hematopoietic Stem Cell Transplant Recipients.

The safety and efficacy of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) emergency-use authorized (EUA) vaccines have been confirmed in the general population. However, there are no data on its safety and tolerability or efficacy in recipients of allogeneic hematopoietic stem cell transplant (HCT). We performed this study to identify the incidence of adverse events following SARS-CoV2 EUA vaccines, the incidence of new-onset graft-versus-host disease (GVHD) or worsening of existing GVHD after EUA vaccine administration, and the incidence SARS-CoV2 positivity in vaccinated HCT patients. We retrospectively reviewed 113 HCT patients who received at least one dose of EUA vaccine to describe the safety and tolerability, any impact on GVHD, and the incidence of SARS-CoV2 PCR positivity after vaccination. Patients received either Pfizer (BNT162b2) or Moderna (mRNA-1273) vaccines. Patients were included if they were 18 years or older and had received at least one dose of vaccine in the post-HCT setting. Most patients presented with myalgias/arthralgias (first dose, 7.7%; second dose, 14.6%), fatigue (first dose, 15.4%; second dose, 29.2%), and injection site pain (first dose, 40.4%; second dose, 43.8%). Other side-effects experienced by patients included nausea, vomiting, diarrhea, headache, and injection-site rash and swelling. Liver function abnormalities occurred in 18.6% of patients. Neutropenia, thrombocytopenia, and lymphopenia occurred in 13.3%, 11.5%, and 8.8% of patients, respectively. Forty percent of patients had active chronic GVHD at the time of vaccination, and worsening chronic GVHD occurred in 3.5% of the patients. New chronic GVHD developed in 9.7% of patients after vaccination. The SARS-CoV2 EUA vaccines were well tolerated in allogeneic HCT recipients.