A study of high-dose lenalidomide induction and low-dose lenalidomide maintenance therapy for patients with hypomethylating agent refractory myelodysplastic syndrome

Phase Ib trial of lenalidomide as post-remission therapy for older adults with acute myeloid leukemia: Safety and longitudinal assessment of geriatric functional domains

BACKGROUND AND OBJECTIVES

Novel, non-cytotoxic agents are driving a paradigm shift for treatment of older adults with acute myeloid leukemia (AML). Older patients who initially receive intensive cytotoxic induction may choose to not proceed with cytotoxic consolidation therapy. Lenalidomide is an orally-administered immunomodulatory small molecule with activity in AML and a favorable safety profile in older adults with active leukemia. We conducted a phase Ib study of lenalidomide as post-remission therapy in older adults and assessed its impact on geriatric functional domains.

MATERIALS AND METHODS

Participants were patients with AML over age 60 years who had undergone induction therapy and were poor candidates for cytotoxic consolidation. Lenalidomide was administered for 28 days in three dose cohorts. A Bayesian dose-escalation method determined cohort assignment and maximum tolerated dose (MTD). Geriatric assessment (GA) was performed before and after the cycle of lenalidomide.

RESULTS

Nineteen patients with median age 68 were treated with at least one 28-day course of lenalidomide. Dose-limiting toxicities were observed in three participants at 25 mg, zero participants at 35 mg, and one participant at 50 mg. MTD was 35 mg. Median relapse-free survival was 4.3 months. GA was completed before and after treatment in fifteen patients, demonstrating improved cognitive function and no changes in physical, psychological, or social function after lenalidomide.

CONCLUSION

Lenalidomide can be safely administered to older adults with AML with preservation of functional domains important to older patients. Serial GA can be performed in a novel drug study as a tool to characterize treatment tolerability.

Molecular Targeted Therapy in Myelodysplastic Syndromes: New Options for Tailored Treatments

Simple Summary

Myelodysplastic syndromes (MDS) are a group of diseases in which bone marrow stem cells acquire genetic alterations and can initiate leukemia, blocking the production of mature blood cells. It is of crucial importance to identify those genetic abnormalities because some of them can be the targeted. To date only very few drugs are approved for patients manifesting this group of disorders and there is an urgent need to develop new effective therapies. This review gives an overview of the genetic of MDS and the therapeutic options available and in clinical experimentation.

Abstract

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematopoietic disorders characterized by ineffective hematopoiesis, progressive cytopenias and increased risk of transformation to acute myeloid leukemia. The improved understanding of the underlying biology and genetics of MDS has led to better disease and risk classification, paving the way for novel therapeutic opportunities. Indeed, we now have a vast pipeline of targeted agents under pre-clinical and clinical development, potentially able to modify the natural history of the diverse disease spectrum of MDS. Here, we review the latest therapeutic approaches (investigational and approved agents) for MDS treatment. A deep insight will be given to molecularly targeted therapies by reviewing new agents for individualized precision medicine.

Emerging treatment options for patients with high-risk myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis with peripheral blood cytopenias, dysplastic cell morphology, and a variable risk of progression to acute myeloid leukemia (AML). The hypomethylating agents (HMA) azacitidine and decitabine have been used for over a decade in MDS treatment and lead to a modest survival benefit. However, response rates are only around 40% and responses are mostly transient. For HMA-refractory patients the prognosis is poor and there are no therapies approved by the United States Food and Drug Administration.

Combinations of HMAs, especially along with immune checkpoint inhibitors, have shown promising signals in both the frontline and HMA-refractory setting. Several other novel agents including orally available and longer acting HMAs, the BCL-2 inhibitor venetoclax, oral agents targeting driver mutations (IDH1/2, FLT3), immunotherapies, and new options for intensive chemotherapy have been studied with variable success and will be reviewed herein. Except for the minority of patients with targetable driver mutations, HMAs – likely as part of combination therapies – will remain the backbone of frontline MDS treatment. However, the wider use of genetic testing may enable a more targeted and individualized therapy of MDS patients.

How I treat MDS after hypomethylating agent failure

Hypomethylating agents (HMA) azacitidine and decitabine are standard of care for myelodysplastic syndrome (MDS). Response to these agents occurs in ∼50% of treated patients, and duration of response, although variable, is transient. Prediction of response to HMAs is possible with clinical and molecular parameters, but alternative approved treatments are not available, and in the case of HMA failure, there are no standard therapeutic opportunities. It is important to develop a reasoned choice of therapy after HMA failure. This choice should be based on evaluation of type of resistance (primary vs secondary, progression of disease [acute leukemia or higher risk MDS] vs absence of hematological improvement) as well as on molecular and cytogenetic characteristics reassessed at the moment of HMA failure. Rescue strategies may include stem-cell transplantation, which remains the only curative option, and chemotherapy, both of which are feasible in only a minority of cases, and experimental agents. Patients experiencing HMA failure should be recruited to clinical experimental trials as often as possible. Several novel agents with different mechanisms of action are currently being tested in this setting. Drugs targeting molecular alterations (IDH2 mutations, spliceosome gene mutations) or altered signaling pathways (BCL2 inhibitors) seem to be the most promising.

Immunosuppressive therapy in myelodysplastic syndromes: a borrowed therapy in search of the right place

INTRODUCTION

Myelodysplastic syndromes (MDS) encompass a heterogenous collection of clonal hematopoietic stem cell disorders defined by dysregulated hematopoiesis, peripheral cytopenias, and a risk of leukemic progression. Increasing data support the role of innate and adaptive immune pathways in the pathogenesis and disease course of MDS. The role of immunosuppressive therapy has an established role in the treatment of other hematologic diseases, such as aplastic anemia whose pathogenesis is postulated to reflect that of MDS with regards to many aspects of immune activation. Areas covered: This paper discusses the current understanding of immune dysregulation as it pertains to MDS, the clinical experience with immunosuppressive therapy in the management of MDS, as well as future prospects which will likely improve therapeutic options and outcomes for patients with MDS. Expert commentary: Though limited by paucity of high quality data, immunomodulatory and immunosuppressive therapies for the treatment of MDS have shown meaningful clinical activity in selected patients. Continued clarification of the immune pathways that are dysregulated in MDS and establishing predictors for clinical benefit of immunosuppressive therapy are vital to improve the use and outcomes with these therapies.

Hypomethylating agents (HMA) treatment for myelodysplastic syndromes: alternatives in the frontline and relapse settings

INTRODUCTION

Hypomethylating agents (HMA) have played a pivotal role for treating myelodysplastic syndromes (MDS) over the past decade, inducing sustained hematological responses and delaying progression to leukemia. However, a vast majority of patients will experience treatment failure within 2 years, with poor prognoses and limited options, and management of this growing patient population remains unclear. Areas covered: With the introduction of new agents in the MDS field, a better understanding of the biology of MDS, and updated information on standard of care options (including allogeneic transplantation), we re-evaluate the global treatment strategy in MDS via novel agents, focusing in particular on investigational approaches for patients who fail to respond to HMA when applicable. This review aims to address two questions: what are reasonable alternatives to HMA in MDS, and what strategies can be used for patients experiencing HMA failure. Expert opinion/commentary: HMA therapy remains a mainstay of treatment, even if additional research is still warranted to maximize its benefits for the different groups of patients. The outcome of patients experiencing HMA failure remains grim, without standard of care, but several new approaches seem promising, as there is an increasing focus on studying treatments for patients refractory to HMA treatment.

Lenalidomide use in myelodysplastic syndromes: Insights into the biologic mechanisms and clinical applications

Myelosysplastic syndromes (MDS) include a heterogeneous group of clonal myeloid neoplasms characterized by ineffective hematopoiesis leading to blood cytopenias and a variable risk of progression into acute myeloid leukemia (AML). Although the hypomethylating agent azacitidine prolongs survival among patients with higher risk (HR)-MDS compared with conventional care, no drug has been shown conclusively to prolong survival or delay progression to AML among patients with lower-risk MDS (LR-MDS). Lenalidomide is the drug with the most impressive clinical activity in the subset of anemic LR-MDS patients who harbor a deletion of the long arm of chromosome 5 (5q-), where it leads to high rates of transfusion independence and cytogenetic responses. Furthermore, lenalidomide delays progression to AML and prolongs survival among responders. In this article, we review the recently recognized mechanisms of action of lenalidomide and discuss the most recent clinical data regarding its use in patients with both 5q- MDS as well as non-5q- MDS. Finally, we forecast the future directions to improve the efficacy of lenalidomide in MDS with and without 5q-. Cancer 2017;123:1703-1713. © 2017 American Cancer Society.

A phase 2 trial of high dose lenalidomide in patients with relapsed/refractory higher-risk myelodysplastic syndromes and acute myeloid leukaemia with trilineage dysplasia

Limited therapies exist for patients with refractory and relapsed (RR) higher-risk myelodysplastic syndromes (HR-MDS) and acute myeloid leukaemia with trilineage dysplasia (AML-TD). High dose (HD) lenalidomide (50 mg) has activity as frontline therapy in elderly AML but there is limited data in the RR setting. This phase II trial included patients with RR HR-MDS or AML-TD at 2 doses of lenalidomide (15 or 50 mg) on days 1-28 of 42-day cycles. The primary endpoint was response rate using the 2006 International Working Group criteria. Overall survival (OS) was estimated by Kaplan-Meier methods. Of 27 patients enrolled, 59% had HR-MDS and 31% AML-TD. No patient had isolated del5q; 41% had poor-risk karyotype. Of 9 patients treated at 15 mg, 56% completed ≥2 cycles with no responses. Of 18 patients treated at 50 mg, 39% completed ≥2 cycles and 11% responded but all experienced grade 3/4 neutropenic fever/infection. The 60-day mortality rate was 30%. Median OS was 114 days with 19% surviving ≥1 year. The study was terminated due to lack of robust clinical activity. In conclusion, lenalidomide at 15 mg is ineffective in RR myeloid malignancies. Continous high dosing schedules are poorly tolerated and minimally active. Further evaluation should be considered in upfront intensive chemotherapy-ineligible patients.