A pilot study of cytoreductive chemotherapy combined with infusion of additional peripheral blood stem cells reserved at time of harvest for transplantation in case of relapsed hematologic malignancies after allogeneic peripheral blood stem cell transplant

Can GCSF-stimulated donor lymphocyte infusions improve outcomes for relapsed disease following allogeneic hematopoietic cell transplantation? A systematic review and meta-analysis

Donor lymphocyte infusions (DLI) can produce graft-versus tumor effects to treat relapse after allogeneic hematopoietic cell transplantation, however, durable responses remain uncommon. A systematic review and meta-analysis are needed to clarify whether DLI collected after stimulation with granulocyte colony-stimulating factor (GCSF; G-DLI) can improve clinical outcomes. Sixteen studies (4 controlled) involving 585 patients were identified in a systematic search up to 17 September 2020. A meta-analysis demonstrated no significant difference in the risk of all-cause mortality (RR: 0.94, 95% CI 0.52-1.68, p = 0.82; n = 3 studies) or relapse-related mortality (RR: 0.72, 0.44-1.18, p = 0.19; n = 3 studies) between G-DLI and conventional DLI (C-DLI) groups. G-DLI products had similar mean CD3+ cells compared to C-DLI products, but median CD34+ cells/kg were increased. No improvement in disease progression, complete response rates, or risk of developing GVHD was observed with G-DLI, however, greater non-relapse mortality was observed compared to C-DLI. Alternative approaches to enhancing graft-versus-tumor effects are needed.

High alloreactivity of low-dose prophylactic donor lymphocyte infusion in patients with acute leukemia undergoing allogeneic hematopoietic cell transplantation with an alemtuzumab-containing conditioning regimen

The value of prophylactic donor lymphocyte infusion (pDLI) is unclear and differs among diseases and transplantation protocols. Experience with this approach in patients with acute leukemia undergoing hematopoietic cell transplantation (HCT) with an alemtuzumab-incorporating conditioning protocol is lacking. We conducted a single-center prospective study to investigate the applicability and efficacy of prophylactic donor lymphocyte infusion (pDLI) in patients with leukemia undergoing HCT with a low-dose alemtuzumab-containing conditioning regimen. Inclusion criteria were high-risk acute myelogenous leukemia, acute lymphoblastic leukemia, or increasing mixed chimerism. All patients included were tapered off of immunotherapy. Exclusion criteria were a history of ≥ grade II or active graft-versus-host disease (GVHD). Of the 56 consecutive patients who underwent HCT with an alemtuzumab-containing regimen, 15 patients (8 with acute myelogenous leukemia and 7 with acute lymphoblastic leukemia) met the study inclusion criteria and received prophylactic DLI (total of 45 infusions) from 7 sibling donors and 8 unrelated donors. The first infusion was given at a median of 162 days posttransplantation. The median number of DLIs was 3, and the median cumulative CD3(+) cell dose was 2 × 10(6)cells/kg. Six of the 8 patients (75%) who received pDLI while in mixed chimerism converted to stable, complete donor chimerism. Some 47% of DLI recipients developed GVHD (4 acute GVHD and 3 with chronic GVHD) after a median cumulative dose of 2 × 10(6) CD3(+) cells/kg. After a median follow-up of 575 days, 11 (73%) pDLI recipients were alive. All 4 deaths were due to GVHD-related causes. None of the patients who received pDLIs relapsed. Patients with leukemia who received low-dose pDLI after conditioning with alemtuzumab are at low risk for relapse; however, this approach is associated with a relatively high incidence of severe GVHD.

Tailored strategy for AML patients receiving allogeneic peripheral blood stem cell transplantation

Considering the heterogeneity of acute myelogenous leukemia (AML), along with the pros and cons of allogeneic peripheral blood stem cell transplantation (PBSCT), a tailored strategy is needed to minimize the transplant-related mortality and maximize the transplant outcomes in AML patients exhibiting certain factors that have an impact on the post-transplant quality of life and outcomes. The factors that need to be considered when tailoring a strategy in an allogeneic PBSCT setting include the recipient's performance status and co-morbid disease include AML risk stratification, disease status, expected severity of graft-versus-host disease, and the necessity of a graft-versus-leukemia effect. Accordingly, this review article describes a possible tailoring strategy for AML patients receiving allogeneic PBSCT based on certain factors influencing the transplant outcome.

Prospective trial of high-dose chemotherapy followed by infusions of peripheral blood stem cells and dose-escalated donor lymphocytes for relapsed leukemia after allogeneic stem cell transplantation

To determine whether induction of graft-versus-host disease (GVHD) improves the outcome of acute relapsed leukemia after stem cell transplantation (SCT), we used high-dose cytarabine (ara-C) followed by infusions of donor-derived buffy coats containing peripheral blood stem cells to treat 12 patients with relapsed leukemia. Donor lymphocyte infusion (DLI) was repeated at least twice over a 5-week interval for patients in whom grade II to IV acute GVHD did not develop after the first DLI. Grade II to IV acute GVHD developed in 4 (33%) of the patients. Chronic GVHD developed in 3 patients, 2 of whom had not experienced acute GVHD. Four (67%) of the 6 patients who developed grade II to IV acute and/or chronic GVHD after DLI responded, but none of the other 6 patients responded. Four (33%) of the patients (2 with acute myelogenous leukemia [AML] and 2 with acute lymphoblastic leukemia [ALL]) achieved complete remission lasting longer than 4 months after the first DLI, but 3 of them had relapses in bone sites. Of these 4 patients, 1 patient with AML and 2 with ALL were alive 8 to 27 months after DLI. These findings indicate that high-dose ara-C combined with megadose DLI may produce durable remission of acute leukemia that has relapsed after SCT when GVHD is induced. The low induction rate of GVHD and extramedullary relapse after remission is achieved with DLI are problems yet to be solved.

Parameters for predicting allogeneic PBSCT outcome of acute myeloid leukemia: cytogenetics at presentation versus disease status at transplantation

In addition to the clinical disease status at transplantation, the cytogenetic risk at presentation also provides critical information for predicting the prognosis or deciding the future therapeutic strategy. As such, the current study examined various parameters, including the cytogenetics at presentation and clinical disease status at transplantation, regarding their effect on the transplant outcomes of acute myeloid leukemia (AML) patients in an allogeneic peripheral blood stem cell transplantation (PBSCT) setting. A total of 36 patients receiving an allogeneic PBSCT from matched sibling donors were included in a state of first complete remission (CR) (n=22, 61%) or beyond the first CR (n=14, 39%). The cytogenetic risk was classified according to Medical Research Council (MRC) 10 criteria: favorable, 7 patients (20%); intermediate, 21 patients (58%); unfavorable eight patients (22%). The 3-year overall survival rates were 80% for the favorable, 63% for the intermediate, and 0% for the unfavorable cytogenetic risk groups (p=0.0002), and 62% for the patients in a state of first CR and 35% for those beyond the first CR (p=0.0524). Multivariate analysis revealed that higher CD34+ cell doses, favorable cytogenetics at presentation, and a lower marrow blast percentage at transplantation were all strongly associated with favorable transplant outcomes, including overall survival (OS), progression-free survival (PFS), and the probability of progression. The cytogenetic risk at presentation was found to be a useful parameter in predicting the transplant outcomes for patients with AML, regardless of the clinical disease status. However, an additive innovative therapeutic strategy is still needed to overcome an unfavorable cytogenetic risk with refractory AML after allogeneic PBSCT.

Diverse clinical applications using advantages of allogeneic peripheral blood stem cell transplantation

The diverse clinical applications of allogeneic peripheral blood stem cells based on use of their advantages are summarized. It is apparent that more stem cells and T-lymphocytes can be harvested by mobilization treatment with cytokines from healthy donors in allogeneic peripheral blood stem cell transplantation (PBSCT) than in bone marrow transplantation. It is also clear that a stronger graft-versus-tumor effect can be induced with allogeneic PBSCT than with bone marrow transplantation. One merit of allogeneic PBSCT is that it allows clinicians to design diverse clinical applications. It would appear that allogeneic PBSCT may be preferable in special clinical settings, such as advanced hematological malignancies, situations requiring a strong graft-versus-tumor effect, nonmyeloablative stem cell transplantation, and situations requiring a megadose of stem cells. Cytokine-primed peripheral blood stem cells can also be used for adoptive immunotherapy, such as a nonprimed donor lymphocyte infusion.

Different efficacy of mycophenolate mofetil as salvage treatment for acute and chronic GVHD after allogeneic stem cell transplant

OBJECTIVE

The therapeutic options currently available for treating refractory graft-vs.-host disease (GVHD) are limited. Therefore, the present study evaluated the efficacy of mycophenolate mofetil (MMF) as a salvage treatment for acute and chronic GVHD in allograft patients.

METHODS

Twenty-six consecutive patients with refractory acute (13 patients) or chronic (13 patients) GVHD were enrolled. The first-line treatment for all patients with acute GVHD consisted of a combination of cyclosporine A (CyA) and steroids, while the first-line treatment for chronic GVHD was steroids with or without CyA according to the risk group. MMF was added at a dose of 1.5 or 2 g daily and the steroids were tapered in the refractory cases.

RESULTS

Four (30.8%) of 13 patients with refractory acute GVHD responded to MMF. When analyzing the overall results according to the type of acute GVHD, improvement was observed in four (30.8%) of 13 skin cases, four (44.4%) of nine liver cases, and two (22.9%) of nine gut cases. Ten (76.9%) of 13 patients with refractory chronic GVHD responded to MMF. The common side effects were gastrointestinal disturbance (26.9%) or infectious complications (23.1%). The estimated 2-yr survival rate for patients with acute GVHD and chronic GVHD was 33.3% and 53.9%, respectively.

CONCLUSIONS

MMF would appear to be effective and safe for treating refractory chronic GVHD, yet not as effective for treating refractory acute gut GVHD. Accordingly, a prospective randomized clinical trial is warranted to assess the impact of MMF in the treatment of refractory GVHD.

Risk factors for late cytomegalovirus infection after allogeneic stem cell transplantation using HLA-matched sibling donor: donor lymphocyte infusion and previous history of early CMV infection

An increased incidence of late cytomegalovirus (CMV) infection has been reported during the last decade since the introduction of ganciclovir (GCV) prophylaxis or GCV pre-emptive therapy. Given that a donor lymphocyte infusion (DLI) can induce more severe GVHD, this may predispose a patient to late CMV infection. In all, 64 patients (median age 36, M/F 38/26) underwent allogeneic stem cell transplantation (SCT) using a matched sibling donor with bone marrow (n=9) or peripheral blood stem cells (n=55). The overall incidence of CMV infection, early and late CMV infection was 46.9 (30/64), 42.2 (27/64), and 16.4% (9/55), respectively. Early CMV infection was treated with GCV pre-emptive therapy that produced a 92.6% success rate. Among the 20 patients who received 35 DLIs, late CMV infection developed in eight (42.1%) of 19 evaluable cases with a median onset at 127 days post transplant. Risk factors for late CMV infection in a logistic regression analysis included DLIs (P=0.001) and a previous history of CMV infection (P=0.006). In conclusion, late CMV infection was strongly associated with DLIs and a previous history of early CMV infection. Accordingly, extended surveillance of CMV antigenemia is recommended for patients receiving DLIs or who have a previous history of CMV infection.