Methods to prevent and treat relapse after hematopoietic stem cell transplantation with tyrosine kinase inhibitors, immunomodulating drugs, deacetylase inhibitors, and hypomethylating agents

Outcomes of patients undergoing third hematopoietic cell transplantation for hematologic malignancies

With advancements in novel therapeutics, it is unclear whether third hematopoietic cell transplantation (HCT3) has a place in the treatment of recurrent hematopoietic malignancies. We evaluated patients with hematologic malignancies who underwent HCT3 between 2000-2020. Nine patients, with a median age of 18 (9-68) years at HCT3 with acute myelogenous leukemia (n = 5), acute lymphoblastic leukemia (n = 2), myelodysplastic syndrome (n = 1), or undifferentiated acute leukemia (n = 1), were identified. The median time between first HCT and HCT3 was 3.9 (0.7-13.6) years. Indication for HCT3 was relapse (n = 8) or graft failure (n = 1) after second HCT. At HCT3, seven of nine patients were in complete remission by flow cytometry. All experienced robust donor engraftment by one month after HCT3 (≥ 90% CD3) while one died at day + 24 of multi-organ failure and was not evaluable for chimerism. In total, eight patients died from relapse (n = 4), non-relapse, (n = 3) or unknown (n = 1) causes at a median of 0.6 (range, 0.1 - 9.9) years after HCT3. After HCT3, estimated overall survival at 6 months, 1 year, and 5 years was 88%, 63%, and 22%, respectively. In this highly selected group, HCT3 provided a treatment option although long-term survival was still dismal.

Role of Endoscopic Techniques in the Diagnosis of Complications of Allogeneic Hematopoietic Stem Cell Transplantation: A Review of the Literature

Allogeneic stem cell transplantation (Allo-SCT) implies that a donor and a recipient are not genetically identical. Allo-SCT is used to cure a variety of conditions, including hematologic malignancies using the graft versus tumor effect, nonmalignant hematologic, immune deficiencies, and, more recently, genetic disorders and inborn errors of metabolism. Given the immunosuppressive and myeloablative nature of some of the conditioning chemotherapy regimens used during the Allo-SCT, patients are often at high risk of infection, including viral infections affecting the gastrointestinal tract, following the transplant. Furthermore, other complications such as hepatic sinusoidal obstruction syndrome (SOS) or graft-versus-host disease may occur post-transplant and may require endoscopy to assist in the diagnosis. This review will provide newer insights into the importance of endoscopic techniques in the diagnosis of post-Allo-SCT complications with a focus on safety and timing.

MicroRNA-125b as a valuable predictive marker for outcome after autologous hematopoietic stem cell transplantation

BACKGROUND

Relapse is a frequent occurrence in autologous hematopoietic stem cell transplantation (AHSCT), and early relapse after AHSCT results in poor survival and low quality of life. Predictive marker determination for AHSCT outcomes could be helpful in the prevention of relapse through personalized medicine. Here the predictive value of circulatory microRNAs (miRs) expression for AHSCT outcomes was studied.

METHODS

50 MM and lymphoma candidates for AHSCT participated in this study. Two plasma samples were obtained before AHSCT from each candidate; one before mobilization and the other after conditioning. Extracellular vesicles (EVs) were isolated by ultracentrifugation. miR-125b, miR-126, miR-150, and miR-155 expression were analyzed in both plasma and EVs using real time polymerase chain reaction analysis. Other data related to AHSCT and its outcomes were also collected. The predictive value of miRs and other factors for outcomes was assessed by multi-variant analysis.

RESULTS

By 90 weeks follow up after AHSCT, multi-variant and ROC analysis showed miR-125b as a predictive marker for relapse, high lactate dehydrogenase (LDH), and high erythrocyte sedimentation rate (ESR). The cumulative incidence of relapse, high LDH, and high ESR increased with an increase in circulatory miR-125b expression.

CONCLUSION

miR-125b could be applicable in prognosis evaluation and also create a possible new targeted therapy opportunity for enhanced outcomes and survival after AHSCT.

TRIAL REGISTRATION

The study was retrospectively registered. Ethic code No: IR.UMSHA.REC.1400.541.

Single-agent 5-azacytidine as post-transplant maintenance in high-risk myeloid malignancies undergoing allogeneic hematopoietic cell transplantation

Relapse is a major cause of treatment failure after allogeneic hematopoietic cell transplantation (allo-HCT) in myeloid malignancies. Additional strategies have been devised to further maximize the immunologic effect of allo-HCT, notably through maintenance therapy with hypomethylating agents such as 5-azacytidine (AZA). We conducted a single-center retrospective study to investigate the efficacy of AZA after allo-HCT for high-risk myeloid malignancies. All patients transplanted between Jan 2014 and Sept 2019 for high-risk acute myeloid leukemia (n = 123), myelodysplastic syndrome (n = 51), or chronic myelomonocytic leukemia (n = 11) were included. Patients who died, relapsed, or developed grade ≥ 2 acute graft-versus-host disease before day + 60 were excluded, as well as those who were eligible for anti-FMS-like tyrosine kinase 3 maintenance. Of the 185 included patients, 65 received AZA while 120 did not. Median age at transplant was 59 years; 51.9% of patients were males. The median follow-up was 24 months for both groups. Regarding main patient characteristics and transplantation modalities, the two groups were comparable. In multivariate analyses, there were no significant differences between the two groups in terms of 2-year cumulative incidence of relapse (HR = 1.19; 95% confidence interval (CI) 0.67-2.12; p = 0.55), overall survival (HR = 0.62; 95%CI 0.35-1.12; p = 0.12) and event-free survival (HR = 0.97; 95%CI 0.60-1.58; p = 0.91) rates. In conclusion, single-agent AZA does not appear to be an optimal drug for preventing post-transplant relapse in patients with high-risk myeloid malignancies. This study highlights the need for prospective studies of alternative therapies or combination approaches in the post-transplant setting.

Maintenance With Hypomethylating Agents After Allogeneic Stem Cell Transplantation in Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Systematic Review and Meta-Analysis

Introduction

Hypomethylating agents (HMAs) seem to have a range of properties favorable to post-allogeneic hematopoietic stem cell transplantation (allo-SCT) maintenance in acute myeloid leukemia (AML) patients.

Materials and Methods

The Embase, MEDLINE, and Cochrane Central Register of Controlled Trials databases were independently searched by two investigators to identify relevant studies published inception to 18 November 2021. These trials compared HMA maintenance to observation following allo-SCT for AML or myelodysplastic syndrome.

Results

The meta-analysis eligibility criteria were fulfilled by 14 studies. The overall survival and relapse-free survival of the HMA maintenance group were superior to the observation group, with a pooled risk ratio (RR) of 1.38 and 1.46, respectively. Moreover, the cumulative incidence of relapse was significantly lower in those who received HMAs. The HMA group also had lower non-relapse mortality compared with the observation group. Overall, the incidences of grades III–IV acute graft-vs.-host disease (GVHD) and chronic GVHD did not differ in both groups. However, when looking specifically at those receiving decitabine maintenance, the rate of chronic GVHD seemed to be lower compared with observation alone.

Conclusions

The current systematic review and meta-analysis illustrated that AML and MDS patients receiving HMA maintenance after allo-SCT had better outcomes in regards to OS, RFS, NRM, CIR as well as a reduced incidence of chronic GVHD.

Second allogeneic transplants for multiple myeloma: a report from the EBMT Chronic Malignancies Working Party

The EBMT Chronic Malignancies Working Party performed a retrospective analysis of 215 patients who underwent a second allo-HCT for myeloma between 1994 and 2017, 159 for relapse and 56 for graft failure. In the relapse group, overall survival (OS) was 38% (30–46%) at 2 years and 25% (17–32%) at 5 years. Patients who had a HLA-identical sibling (HLAid-Sib) donor for their first and second transplants had superior OS (5 year OS: HLAid-Sib/HLAid-Sib: 35% (24–46%); Others 9% (0–17%), p < 0.001). There was a significantly higher incidence of acute grade II-IV GvHD in those patients who had also developed GvHD following their initial HLA-identical sibling allo-HCT (HLAid-Sib/HLAid-Sib: 50% (33–67%); Other 22% (8–36%), p = 0.03). More as opposed to fewer than 2 years between transplants was associated with superior 5-yr OS (31% (21–40%) vs. 10% (1–20%), P = 0.005). On multivariate analysis, consecutive HLA-identical sibling donor transplants conferred a significant OS advantage (0.4 (0.24–0.67), p < 0.001). In the graft failure group, OS was 41% at 2 years. In summary, a second allo-HCT using a HLA-identical sibling donor, if available, provides the best transplant outcomes for relapsed myeloma in this setting.

Hypomethylating agents as maintenance therapy following allogeneic hematopoietic cell transplantation for myeloid malignancies

With improved safety of the procedure, disease recurrence is now the leading cause of treatment failure when allogeneic hematopoietic cell transplantation is used to treat acute myeloid leukemia (AML). Recent studies suggest that maintenance therapy with hypomethylating agents after standard induction and consolidation chemotherapy prolongs disease-free and possibly overall survival in older patients with AML. While these results argue that hypomethylating agents should likewise prolong remission duration if used as maintenance after allogeneic transplantation for AML, trials to date have failed to show a benefit. This failure may be due, in part, to difficulties in administering the drugs in this setting, and in part, because of an inability to identify those patients most likely to benefit. Realizing the full potential of hypomethylating agents in the management of patients with AML will likely require both improved drug formulations as well as an increased understanding of their mechanism of action in the complex post-allogeneic transplant environment.

Cardiovascular risk assessment and management of patients undergoing hematopoietic cell transplantation

The purpose of this review is to provide a framework for the cardiovascular evaluation and management of patients undergoing hematopoietic cell transplantation (HCT). To accomplish this, we have performed an extensive literature review, critically analyzed the available evidence, and developed a set of recommendations to guide best practice. Herein, we discuss the cardiovascular risk profile of patients undergoing HCT along with putative mechanisms of HCT-induced cardiovascular injury. We then present an algorithm for cardiovascular testing and risk mitigation of potential recipients. Last, we address the management of the most prevalent cardiovascular conditions associated with HCT recipients.

Prophylactic donor lymphocyte infusion for relapse prevention: a meta-analysis

OBJECTIVE

Primary disease relapse (PDR) of malignant hematologic conditions after standard hematopoietic stem cell transplant (HSCT) is one of the most challenging diseases; therefore ongoing researches are aiming at relapse prevention and minimizing the transplant-related side effects. Prophylactic donor lymphocytes (pDLI) had been proposed as a valuable strategy for PDR prevention, but early studies had been discouraging due to the limited benefit and possible association with acute graft-versus-host disease (aGVHD). Therefore, we conducted a meta-analysis to evaluate the association between pDLI use, PDR, aGVHD and OS.

METHOD

We performed a comprehensive literature search in MEDLINE, Cochrane library and Embase database from inception to May 2019 for studies that evaluated the association between pDLI and PDR. We conducted a random effect meta-analysis of 9 studies involving a total of 748 participants (pDLI = 398, non-pDLI = 350) and reported the pooled odd ratio (OR) for association of pDLI use, PDR, aGVHD and OS.

RESULT

We found a significant decreased odd of PDR in the pDLI group (pooled OR = 0.42, 95% CI 0.30-0.58, I2 = 0%), but there was no significant increased odd of aGVHD (pooled OR of 0.98, 95% CI 0.56-1.72, I2 = 0.8%). We also found that there was an increased odd of overall survival (OS) (pooled OR 3.17, 95% CI 1.85-5.45, I2 = 50.2%).

CONCLUSION

There are significantly decreased odd of PDR and increased odd of OS in the pDLI group compared to the control group, but there is no statistically significant increased odd of aGVHD as suggested by previous studies. We concluded that pDLI is a potentially valuable method for post-transplant PDR prevention.

Single-center experience suggests donor lymphocyte infusion may promote long-term survival in children with high-risk acute lymphoblastic leukemia

BACKGROUND

Donor lymphocyte infusion (DLI) is often used to treat leukemic relapse after hematopoietic cell transplantation (HCT). However, the relationship between outcomes and distinct DLI cellular composition has not been previously reported. Additionally, there are limited published data on efficacy in pediatrics. We evaluated whether DLI cellular content and development of graft-versus-host disease (GVHD) impacted disease and influenced overall survival (OS) in children receiving DLI for recurrent leukemia.

METHODS

We performed an Institutional Review Board-approved, retrospective study investigating all consecutive DLIs given to patients at the Children's Hospital of Wisconsin between 1980 and 2018. Analyses were conducted using Mann-Whitney, Fisher exact, and chi-square tests.

RESULTS

Thirty patients ≤20 years old with hematologic malignancies (myeloid [AML/MDS/CML/JMML], n = 23; lymphoid [ALL], n = 7) received DLI to treat post-transplant relapse. We found no significant difference in OS or development of GVHD based on CD3, CD4, CD8, CD56, or CD19 DLI cellular composition. With a median follow-up of 0.69 (range, 0.04-16.61) years, OS at five years was 32% ± 9%.  The lymphoid group had a five-year survival rate at 71% ± 17% compared with the myeloid group at 22% ± 9%, although not statistically significant (P = 0.11).  The development of GVHD did not affect OS (P = 0.62).

CONCLUSION

Here, we report a single-center, long-term experience of pediatric DLIs. Surprisingly, many children with ALL were able to achieve durable remissions. Although cellular composition did not have a significant effect on GVHD or OS in our small study, engineering DLI products to maximize specific effector cell populations could be one strategy to improve efficacy.

Immunomodulatory Effects of Drugs for Effective Cancer Immunotherapy

Recent advances in cancer immunotherapy, including immune checkpoint inhibitors or adoptive T cell therapies, have contributed to better outcomes in cancer patients. However, there are still many cancers with no cure. Therefore, combinations of several treatment strategies are being explored, and enhancing anticancer immunity will play an important role to combat the disease. There have been several reports on the immune-modulatory effects of commonly used drugs, namely, statin, metformin, and angiotensin receptor blockers (ARBs), which suggest that these drugs could enhance immunity against cancer cells. Other anticancer drugs, such as anthracyclines, thalidomides, lenalidomides, and hypomethylating drugs, could also strengthen the immune system to attack cancer cells at a relatively low dose. Hence, these drugs might contribute to better outcomes in cancer patients.