The next horizon now that everyone has a donor: Precision allogeneic transplantation

Post-transplant cyclophosphamide (PTCy) allows safe and effective partially matched donor allogeneic blood or marrow transplantation (alloBMT), so that almost everyone in need of the procedure now has a donor. Moreover, PTCy and other recent advances have lowered alloBMT mortality rates to less than half of that seen before the turn of the century, at costs that are substantially less than most newly approved anticancer agents. These advances also make tailoring BMT based on patients' unique diseases and characteristics now feasible for further improving outcomes. Personalizing every aspect of alloBMT, including conditioning, donor, graft type, and post-transplant maintenance is now possible. For example, alloBMT's antitumor activity historically was restricted to the allogeneic graft-versus-tumor effect directed against histocompatibility antigens. However, replacing exhausted immune systems with healthy non-exhausted, non-tolerant ones likely can enhance the activity of novel targeted therapies. The impressive results seen with tyrosine kinase inhibitors after alloBMT for patients with both Ph+ acute lymphoblastic leukemia and FLT/ITD+ acute myeloid leukemia herald the potential of precision BMT.

Ixazomib With or Without Rituximab Following Maintenance Autologous Stem Cell Transplant in Mantle Cell Lymphoma: A Single-Center Phase I Trial

BACKGROUND

Induction chemotherapy followed by autologous stem cell transplantation (ASCT) is a standard first-line treatment for fit patients with mantle cell lymphoma (MCL). We conducted a single-center phase I trial investigating post-transplant maintenance with ixazomib, an oral proteasome inhibitor.

METHODS

Patients enrolled between days +70 and +180 post ASCT. Patients received ixazomib per dose cohort on days 1, 8, and 15 of each 28-day cycle for up to 10 cycles. During recruitment, published phase III data reported a survival benefit with rituximab maintenance, so all subsequent patients received ixazomib 4 mg at the same schedule along with rituximab 375 mg/m² on day 1 of cycles 1, 3, 5, 7, and 9. All patients were in complete remission at enrollment.

RESULTS

Seven patients received ixazomib monotherapy; 1 dose limiting toxicity (grade 3 neutropenia) occurred at dose level 2 (4 mg). Five patients received combination Ixazomib plus rituximab, with 2 experiencing DLTs (both Grade 4 neutropenia). Grade 3-4 neutropenia, lymphopenia, and thrombocytopenia occurred in 57%, 8%, and 8% of patients, respectively. Non-hematologic adverse events (AE) included nausea (42%), peripheral neuropathy (42%), and abdominal discomfort (33%), all of which were grade 1 or 2 in severity. There were no infectious AEs. With a median follow up of 46 months, all patients are alive and in complete remission.

CONCLUSION

The trial was closed to further accrual due to high rates of treatment-related myelosuppression. The current dose and schedule of ixazomib, especially when combined with rituximab, results in unacceptable hematologic toxicity when administered as post-transplant maintenance in MCL. Ixazomib maintenance micro abstract: The authors conducted a phase I study investigating the use of ixazomib, an oral proteasome inhibitor, with or without rituximab in patients with mantle cell lymphoma in first remission following chemoimmunotherapy and autologous stem cell transplantation. All patients treated on study remain in complete remission with a median follow-up of 46 months, but the study was closed early due to a high rate of hematologic adverse events.

Dose-finding trial of azacitidine as post-transplant maintenance for high-risk MDS: a KSGCT prospective study

This 3+3 dose-escalation phase I multicenter study investigated the optimal dose of azacitidine (AZA) for post-hematopoietic stem cell transplantation (HSCT) maintenance, which remains unknown in Japan. Recipients of a first HSCT for high-risk myelodysplastic syndromes (MDS, n = 12) or acute myeloid leukemia (AML) with antecedent MDS (n = 3) received post-HSCT AZA maintenance in 2015-2019. The optimal AZA dose was defined as the dose at which 50-70% of patients can complete four cycles without dose-limiting toxicity (DLT). The initial dose level 1 was set as 30 mg/m² for 5 days per 28-day cycle, and dose levels 0, 2, and 3 were set as 20, 40, and 50 mg/m². DLT was defined as any grade 3 non-hematological or grade 4 hematological toxicity. The 15 evaluable patients were 55 (37-64) years old. The median observation of the post-HSCT survivors was 935 (493-1915) days. The median number of days post-HSCT to the start of AZA was 101 (59-176). In the first, second, and third cohorts, five of nine patients completed four cycles at dose level 1. In the final cohort, five of six additional patients completed at the same dose. In total, 10 (67%) patients tolerated AZA 30 mg/m², which was determined as optimal. DLT occurred in five cases: grade 3 hepatotoxicity, pneumonia, enterocolitis, and grade 4 thrombocytopenia and neutropenia. The 2-year overall survival and disease-free survival rates post-HSCT were 77.0% and 73.3%. Post-HSCT AZA maintenance was well-tolerated and merits further evaluation for patients with MDS or AML with antecedent MDS. Trial registration: UMIN000018791.

[Hematopoietic cell transplantation for FLT3-mutated acute myeloid leukemia]

FMS-like tyrosine kinase 3 (FLT3) mutations are observed in 25-30% of patients with acute myeloid leukemia (AML). Due to poor prognosis associated with FLT3-mutated AML, allogeneic hematopoietic transplantation is commonly performed to induce remission. With the availability of active FLT3 inhibitors and improvement in transplants techniques, the outcomes of AML have improved drastically. The results of many clinical trials have shown that FLT3 inhibitors in combination with chemotherapy and post-transplant maintenance therapy are most effective for AML. Furthermore, these developments have opened up the possibility of transplantation for elderly patients in whom transplantation is difficult. Here, we discuss the optimal approach for treating FLT3-mutated AML using FLT3 inhibitors, allogenic transplantation, and post-transplant maintenance therapy.

A phase II study of azacitidine in combination with granulocyte-macrophage colony-stimulating factor as maintenance treatment, after allogeneic blood or marrow transplantation in patients with poor-risk acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS)

Relapse is the most common cause of treatment failure following allogeneic blood or marrow transplantation (alloBMT) for AML or MDS. Post-transplant maintenance therapies may prevent relapse. We conducted a phase II trial combining azacitidine (AZA) with GM-CSF in non-relapsed, post-transplant patients with AML or MDS. Patients received escalating doses of AZA to a maximum of 75 mg/m² for 5 days per cycle for up to 12 cycles. GM-CSF was given on days 1-10 of each cycle. Eighteen patients were treated following non-myeloablative (17) and myeloablative (1) alloBMT for AML (61.1%), MDS (27.7%), or therapy-related myeloid neoplasm (11.1%). The majority of patients (72%) received their graft from an HLA-haploidentical donor. The treatment was well-tolerated with rare grade 3-4 hematologic toxicities. One patient suffered an exacerbation of GVHD. The 24-month relapse-free and overall survivals were 47 and 57%, respectively, with a median of 18.6 and 29 months.

Risk adapted therapeutic strategy in newly diagnosed acute myeloid leukemia: Refining the outcomes of ELN 2017 intermediate-risk patients

INTRODUCTION

Despite advances in the treatment of acute myeloid leukemia (AML), cytotoxic chemotherapy remains the standard induction regimen.

PATIENTS AND METHODS

In this single center retrospective study, we assessed outcomes of 99 consecutive adult AML patients treated with a risk-adapted strategy with a median follow-up of 35.5 months.

RESULTS

We identified 24 (24 %), 55 (56 %) and 20 (20 %) patients classified as favorable-, intermediate-, and adverse- risk group respectively, according to the European LeukemiaNet (ELN) 2017 classification. Patients either received idarubicin and cytarabine induction chemotherapy with or without FLT3 inhibitors or hypomethylating agents based on age and comorbidity. The complete response (CR) rate was 76 % (82 % and 61 % in patients aged < 60 and ≥ 60, respectively). For the whole cohort, the 3-year overall survival (OS) was 53 %, being 62 % and 30 % in patients aged < 60 and ≥ 60, respectively. The 3-year leukemia-free survival (LFS) was 54 %, with 56 % and 45 % in patients aged < 60 and ≥ 60, respectively. The 3-year LFS were 58 %, 62 % and 25 % for patients within ELN favorable-, intermediate-, and adverse-risk groups respectively. Twenty-seven (36 %) out of 75 patients with intermediate- and adverse-risk disease underwent allogeneic hematopoietic cell transplantation (allo-HCT) in first CR with 92 % of them receiving post-transplant maintenance consisting of azacitidine in 19 (76 %) patients or sorafenib in 6 (24 %) patients. Of these patients younger than 60 years, the 3-year OS and LFS were 85 % and 69 %, respectively.

CONCLUSION

These results indicate an improved OS for AML patients especially in intermediate-risk category who were treated with a total therapy consisting of induction chemotherapy followed by allo-HCT and post-transplant maintenance.