Safety, efficacy and biological predictors of response to sequential azacitidine and lenalidomide for elderly patients with acute myeloid leukemia

A randomised evaluation of low-dose cytosine arabinoside plus lenalidomide versus single-agent low-dose cytosine arabinoside in older patients with acute myeloid leukaemia: Results from the LI-1 trial

Improving outcomes for older patients with acute myeloid leukaemia remains an unmet need. As part of the LI-1 trial, we evaluated lenalidomide (LEN) in combination with low-dose cytosine arabinoside (LDAC) in patients aged >60 years unfit for intensive therapy and compared this to LDAC alone. Two hundred and two patients, randomised 1:1, were evaluable. Overall response rate (CR + CRi) was higher for LDAC + LEN versus LDAC (26% and 13.7% respectively p = 0.031). However, there was no difference in overall survival between the arms (14% and 11.5% at 2 years for LDAC + LEN and LDAC respectively). The addition of LEN was associated with increased toxicity and supportive care requirements.

Clinical Utility of Azacitidine in the Management of Acute Myeloid Leukemia: Update on Patient Selection and Reported Outcomes

Acute myeloid leukemia (AML) is predominantly a disease of the elderly, and a significant proportion of these patients are not candidates for intensive, curative-intent therapies. Epigenetic dysregulation resulting in abnormal DNA hypermethylation is one of the hallmarks of AML pathogenesis. For the past two decades, hypomethylating agents including azacitidine (AZA) have been the mainstay of treatment for AML patients who are ineligible to receive intensive chemotherapies. As our understanding of AML disease biology has improved, several novel treatment combinations have been developed to improve the outcome of AML patients, with remarkable success. A considerable proportion of these novel combinations have utilized AZA as the backbone of their treatment scheme. In this review, we have highlighted the evolution of AML treatment, focusing on novel AZA-based treatment combinations and their clinical efficacy.

Reshaping the tumor microenvironment: The versatility of immunomodulatory drugs in B-cell neoplasms

Immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide and pomalidomide are antitumor compounds that have direct tumoricidal activity and indirect effects mediated by multiple types of immune cells in the tumor microenvironment (TME). IMiDs have shown remarkable therapeutic efficacy in a set of B-cell neoplasms including multiple myeloma, B-cell lymphomas and chronic lymphocytic leukemia. More recently, the advent of immunotherapy has revolutionized the treatment of these B-cell neoplasms. However, the success of immunotherapy is restrained by immunosuppressive signals and dysfunctional immune cells in the TME. Due to the pleiotropic immunobiological properties, IMiDs have shown to generate synergetic effects in preclinical models when combined with monoclonal antibodies, immune checkpoint inhibitors or CAR-T cell therapy, some of which were successfully translated to the clinic and lead to improved responses for both first-line and relapsed/refractory settings. Mechanistically, despite cereblon (CRBN), an E3 ubiquitin ligase, is considered as considered as the major molecular target responsible for the antineoplastic activities of IMiDs, the exact mechanisms of action for IMiDs-based TME re-education remain largely unknown. This review presents an overview of IMiDs in regulation of immune cell function and their utilization in potentiating efficacy of immunotherapies across multiple types of B-cell neoplasms.

Solute Carrier Nucleoside Transporters in Hematopoiesis and Hematological Drug Toxicities: A Perspective

Simple Summary

Anticancer nucleoside analogs are promising treatments that often result in damaging toxicities and therefore ineffective treatment. Mechanisms of this are not well-researched, but cellular nucleoside transport research in mice might provide additional insight given transport’s role in mammalian hematopoiesis. Cellular nucleoside transport is a notable component of mammalian hematopoiesis due to how mutations within it relate to hematological abnormities. This review encompasses nucleoside transporters, focusing on their inherent properties, hematopoietic role, and their interplay in nucleoside drug treatment side effects. We then propose potential mechanisms to explain nucleoside transport involvement in blood disorders. Finally, we point out and advocate for future research areas that would improve therapeutic outcomes for patients taking nucleoside analog therapies.

Abstract

Anticancer nucleoside analogs produce adverse, and at times, dose-limiting hematological toxicities that can compromise treatment efficacy, yet the mechanisms of such toxicities are poorly understood. Recently, cellular nucleoside transport has been implicated in normal blood cell formation with studies from nucleoside transporter-deficient mice providing additional insights into the regulation of mammalian hematopoiesis. Furthermore, several idiopathic human genetic disorders have revealed nucleoside transport as an important component of mammalian hematopoiesis because mutations in individual nucleoside transporter genes are linked to various hematological abnormalities, including anemia. Here, we review recent developments in nucleoside transporters, including their transport characteristics, their role in the regulation of hematopoiesis, and their potential involvement in the occurrence of adverse hematological side effects due to nucleoside drug treatment. Furthermore, we discuss the putative mechanisms by which aberrant nucleoside transport may contribute to hematological abnormalities and identify the knowledge gaps where future research may positively impact treatment outcomes for patients undergoing various nucleoside analog therapies.

Is more better? An analysis of toxicity and response outcomes from dose-finding clinical trials in cancer

BACKGROUND

The overwhelming majority of dose-escalation clinical trials use methods that seek a maximum tolerable dose, including rule-based methods like the 3+3, and model-based methods like CRM and EWOC. These methods assume that the incidences of efficacy and toxicity always increase as dose is increased. This assumption is widely accepted with cytotoxic therapies. In recent decades, however, the search for novel cancer treatments has broadened, increasingly focusing on inhibitors and antibodies. The rationale that higher doses are always associated with superior efficacy is less clear for these types of therapies.

METHODS

We extracted dose-level efficacy and toxicity outcomes from 115 manuscripts reporting dose-finding clinical trials in cancer between 2008 and 2014. We analysed the outcomes from each manuscript using flexible non-linear regression models to investigate the evidence supporting the monotonic efficacy and toxicity assumptions.

RESULTS

We found that the monotonic toxicity assumption was well-supported across most treatment classes and disease areas. In contrast, we found very little evidence supporting the monotonic efficacy assumption.

CONCLUSIONS

Our conclusion is that dose-escalation trials routinely use methods whose assumptions are violated by the outcomes observed. As a consequence, dose-finding trials risk recommending unjustifiably high doses that may be harmful to patients. We recommend that trialists consider experimental designs that allow toxicity and efficacy outcomes to jointly determine the doses given to patients and recommended for further study.

Addition of lenalidomide to intensive treatment in younger and middle-aged adults with newly diagnosed AML: the HOVON-SAKK-132 trial

Lenalidomide, an antineoplastic and immunomodulatory drug, has therapeutic activity in acute myeloid leukemia (AML), but definitive studies about its therapeutic utility have been lacking. In a phase 3 study, we compared 2 induction regimens in newly diagnosed patients age 18 to 65 years with AML: idarubicine-cytarabine (cycle 1) and daunorubicin and intermediate-dose cytarabine (cycle 2) without or with lenalidomide (15 mg orally on days 1-21). One final consolidation cycle of chemotherapy or autologous stem cell transplantation (auto-SCT) or allogeneic SCT (allo-SCT) was provided according to a prognostic risk and minimal residual disease (MRD)-adapted approach. Event-free survival (EFS; primary end point) and other clinical end points were assessed. A second random assignment in patients in complete response or in complete response with incomplete hematologic recovery after cycle 3 or auto-SCT involved 6 cycles of maintenance with lenalidomide (10 mg on days 1-21) or observation. In all, 392 patients were randomly assigned to the control group, and 388 patients were randomly assigned to lenalidomide induction. At a median follow-up of 41 months, the study revealed no differences in outcome between the treatments (EFS, 44% ± 2% standard error and overall survival, 54% ± 2% at 4 years for both arms) although in an exploratory post hoc analysis, a lenalidomide benefit was suggested in SRSF2-mutant AML. In relation to the previous Dutch-Belgian Hemato-Oncology Cooperative Group and Swiss Group for Clinical Cancer Research (HOVON-SAKK) studies that used a similar 3-cycle regimen but did not pursue an MRD-guided approach, these survival estimates compare markedly more favorably. MRD status after cycle 2 lost prognostic value in intermediate-risk AML in the risk-adjusted treatment context. Maintenance with lenalidomide showed no apparent effect on relapse probability in 88 patients randomly assigned for this part of the study.

A phase I study of lenalidomide plus chemotherapy with idarubicin and cytarabine in patients with relapsed or refractory acute myeloid leukemia and high-risk myelodysplastic syndrome

Patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) have poor outcomes and hematopoietic cell transplantation (HCT) is the only curative treatment. New targeted therapies improved survival in select patients with specific mutations, however management of patients without these molecular alterations is an unmet need. We conducted a phase one study of lenalidomide in combination with cytarabine/idarubicin salvage chemotherapy in patients with R/R AML and high‐risk myelodysplastic syndromes. A total of 33 patients were enrolled in the study (30 AML, 3 MDS), and treated at three dose levels with 3 + 3 design. Dose‐limiting toxicity (DLT) was seen in eight patients, including four hematologic DLTs. The most commonly observed non‐hematologic serious adverse events were febrile neutropenia, rash, sepsis and renal injury. Dose level −1, consisting of 25 mg/d lenalidomide D1‐21, 1 g/m² cytarabine D5‐8, and 8 mg/m² idarubicin D5‐7 was determined to be the maximum tolerated dose. Note, 15/33 (45%) of patients were able to receive pre‐planned 21 days of lenalidomide. Overall, 18 patients achieved complete remission (CR) (n = 14) or CR with incomplete count recovery (CRi) (n = 4) with total CR/CRi rate of 56%. The 1‐year and 2‐year overall survival (OS) were 24% and 10%, respectively. Among responders, 10/18 underwent allogeneic HCT and had a 1‐year OS of 40%. There was no molecular pattern associated with response. These data demonstrate that the combination had clinical activity in R/R AML. This regimen should be further investigated for patients who relapsed after HCT, and as a bridge therapy to HCT. (ClinicalTrials.gov identifier: NCT01132586).

Lenalidomide Plus Hypomethylating Agent as a Treatment Option in Acute Myeloid Leukemia With Recurrent Genetic Abnormalities-AML With inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2); GATA2, MECOM

INTRODUCTION

Acute myeloid leukemia (AML) is a heterogeneous clonal hematopoietic neoplasm. The cytogenetic changes associated with AML affect the response rate and survival and are one of the most important independent prognostic factors. AML with inv(3)(q21.3q26.2) or t(3;3)(q21.3;q26.2); GATA2, MECOM accounts for 1% to 2% of all forms of AML and has been associated with a younger age at diagnosis, a poor response to standard induction chemotherapy, and very poor long-term prognosis.

PATIENTS AND METHODS

We performed a single-center, retrospective cohort study comparing the outcomes with hypomethylating agent (HMA) plus lenalidomide to those with standard intensive induction therapies for newly diagnosed and relapsed/refractory AML with inv(3).

RESULTS

Of the 15 patients, 4 (26.7%) had received lenalidomide and HMA as primary therapy. The overall response rate (ORR) was 100% for the 4 patients who had received lenalidomide with HMA as first-line induction therapy. The ORR was 27.3% (3 of 11) for the patients who had received other induction regimens (P = .0256). The duration of response for first induction therapy was an average of 7.4 months after lenalidomide plus an HMA and a mean of 1.5 months after induction with other chemotherapy regimen (P = .057). The ORR for induction and reinduction therapy was also assessed, with an ORR of 21.4% (6 of 28) for alternative chemotherapy regimens and an ORR of 75% (6 of 8) for induction and reinduction with lenalidomide plus HMA (P = .0046).

CONCLUSIONS

The high ORR and reasonable duration of response could allow for potentially curative allogeneic hematopoietic cell transplantation for these patients with high-risk AML. Our initial data suggest that lenalidomide plus HMA is a promising approach for patients with AML with inv(3).

Maintenance therapy in AML: The past, the present and the future

Curative treatment in acute myeloid leukemia (AML) depends on successful induction therapy to achieve a complete remission (CR), and subsequent post-remission therapy to prevent relapse. High relapse rates after consolidation therapy and after allogeneic stem cell transplant contribute to suboptimal outcomes in AML patients, and continue to represent a difficult challenge. Effective maintenance therapy could play an important role in prolonging the remission interval in the post-consolidation setting, especially in high risk AML patients. Maintenance treatment approaches based on conventional chemotherapy, immunotherapy, hypomethylating agents, and targeted small molecules have been explored in this setting, but no data so far have been convincing enough to establish this approach as the standard of care. However, ongoing and future studies including novel targeted therapies may demonstrate promising efficacy that could facilitate incorporation of maintenance therapy into clinical practice. In this review we summarize previous and ongoing approaches of maintenance therapy in AML and discuss the most promising strategies.

The Yin and Yang of the Bone Marrow Microenvironment: Pros and Cons of Mesenchymal Stromal Cells in Acute Myeloid Leukemia

Mesenchymal stromal cells (MSCs) have, for a long time, been recognized as pivotal contributors in the set up and maintenance of the hematopoietic stem cell (HSC) niche, as well as in the development and differentiation of the lympho-hematopoietic system. MSCs also have a unique immunomodulatory capacity, which makes them able to affect, both in vitro and in vivo, the function of immune cells. These features, namely the facilitation of stem cell engraftment and the inhibition of lymphocyte responses, have both proven essential for successful allogeneic stem cell transplantation (allo-SCT), which remains the only curative option for several hematologic malignancies. For example, in steroid-refractory acute graft-vs. host disease developing after allo-SCT, MSCs have produced significant results and are now considered a treatment option. However, more recently, the other side of the MSC coin has been unveiled, because of their emerging role in creating a protective and immune-tolerant microenvironment able to support the survival of leukemic cells and affect the response to therapies. In this light, it has been proposed that the failure of current treatments to efficiently override the stroma-mediated protection of leukemic cells accounts for the high rate of relapse in acute myeloid leukemia, at least in part. In this review, we will focus on emerging microenvironment-driven mechanisms conferring a survival advantage to leukemic cells overt physiological HSCs. This body of evidence increasingly highlights the opportunity to consider tumor-microenvironment interactions when designing new therapeutic strategies.

Treatment of Lymphoid and Myeloid Malignancies by Immunomodulatory Drugs

Thalidomide and its derivatives (lenalidomide, pomalidomide, avadomide, iberdomide hydrochoride, CC-885 and CC-90009) form the family of immunomodulatory drugs (IMiDs). Lenalidomide (CC5013, Revlimid®) was approved by the US FDA and the EMA for the treatment of multiple myeloma (MM) patients, low or intermediate-1 risk transfusion-dependent myelodysplastic syndrome (MDS) with chromosome 5q deletion [del(5q)] and relapsed and/or refractory mantle cell lymphoma following bortezomib. Lenalidomide has also been studied in clinical trials and has shown promising activity in chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL). Lenalidomide has anti-inflammatory effects and inhibits angiogenesis. Pomalidomide (CC4047, Imnovid® [EU], Pomalyst® [USA]) was approved for advanced MM insensitive to bortezomib and lenalidomide. Other IMiDs are in phases 1 and 2 of clinical trials. Cereblon (CRBN) seems to have an important role in IMiDs action in both lymphoid and myeloid hematological malignancies. Cereblon acts as the substrate receptor of a cullin-4 really interesting new gene (RING) E3 ubiquitin ligase CRL4CRBN. This E3 ubiquitin ligase in the absence of lenalidomide ubiquitinates CRBN itself and the other components of CRL4CRBN complex. Presence of lenalidomide changes specificity of CRL4CRBN which ubiquitinates two transcription factors, IKZF1 (Ikaros) and IKZF3 (Aiolos), and casein kinase 1α (CK1α) and marks them for degradation in proteasomes. Both these transcription factors (IKZF1 and IKZF3) stimulate proliferation of MM cells and inhibit T cells. Low CRBN level was connected with insensitivity of MM cells to lenalidomide. Lenalidomide decreases expression of protein argonaute-2, which binds to cereblon. Argonaute-2 seems to be an important drug target against IMiDs resistance in MM cells. Lenalidomide decreases also basigin and monocarboxylate transporter 1 in MM cells. MM cells with low expression of Ikaros, Aiolos and basigin are more sensitive to lenalidomide treatment. The CK1α gene (CSNK1A1) is located on 5q32 in commonly deleted region (CDR) in del(5q) MDS. Inhibition of CK1α sensitizes del(5q) MDS cells to lenalidomide. CK1α mediates also survival of malignant plasma cells in MM. Though, inhibition of CK1α is a potential novel therapy not only in del(5q) MDS but also in MM. High level of full length CRBN mRNA in mononuclear cells of bone marrow and of peripheral blood seems to be necessary for successful therapy of del(5q) MDS with lenalidomide. While transfusion independence (TI) after lenalidomide treatment is more than 60% in MDS patients with del(5q), only 25% TI and substantially shorter duration of response with occurrence of neutropenia and thrombocytopenia were achieved in lower risk MDS patients with normal karyotype treated with lenalidomide. Shortage of the biomarkers for lenalidomide response in these MDS patients is the main problem up to now.

Efficacy and safety of lenalidomide for the treatment of acute myeloid leukemia: a systematic review and meta-analysis

Background

Lenalidomide is effective for the treatment of low-risk myelodysplastic syndromes with deletion 5q abnormalities. However, whether lenalidomide leads to a significant improvement in treatment response and overall survival (OS) in cases of acute myeloid leukemia (AML) remains controversial. A systematic review and a meta-analysis were performed to evaluate the efficacy and safety of lenalidomide in the treatment of AML.

Methods

Clinical studies were identified from the Cochrane Central Register of Controlled Trials, PubMed, Embase, and ClinicalTrials.gov. Efficacy outcomes included overall response rate (ORR), complete remission (CR), and OS. Safety was evaluated based on the incidence of grade 3 and 4 treatment-related adverse events (AEs).

Results

Eleven studies were included in our meta-analysis; collectively these studies featured 407 AML patients. Pooled estimates for overall ORR and CR were 31% (95% CI: 26%–36%) and 21% (95% CI: 16%–27%), respectively. Thrombocytopenia, anemia, neutropenia, and infection were the most common grade 3 and 4 AEs.

Conclusion

Lenalidomide may have some clinical activity in AML, but the population that would benefit from lenalidomide and incorporating lenalidomide into combination drug strategies need to be better defined.

IMiDs mobilize acute myeloid leukemia blasts to peripheral blood through downregulation of CXCR4 but fail to potentiate AraC/Idarubicin activity in preclinical models of non del5q/5q- AML

Treatment for acute myeloid leukemia (AML) remains suboptimal and many patients remain refractory or relapse upon standard chemotherapy based on nucleoside analogs plus anthracyclines. The crosstalk between AML cells and the BM stroma is a major mechanism underlying therapy resistance in AML. Lenalidomide and pomalidomide, a new generation immunomodulatory drugs (IMiDs), possess pleiotropic anti-leukemic properties including potent immune-modulating effects and are commonly used in hematological malignances associated with intrinsic dysfunctional BM such as myelodysplastic syndromes and multiple myeloma. Whether IMiDs may improve the efficacy of current standard treatment in AML remains understudied. Here, we have exploited in vitro and in vivo preclinical AML models to analyze whether IMiDs potentiate the efficacy of AraC/Idarubicin-based standard AML chemotherapy by interfering with the BM stroma-mediated chemoresistance. We report that IMiDs do not exert cytotoxic effects on either non-del5q/5q- AML cells nor BM-MSCs, but they enhance the immunomodulatory properties of BM-MSCs. When combined with AraC/Idarubicin, IMiDs fail to circumvent BM stroma-mediated resistance of non-del5q/5q- AML cells in vitro and in vivo but induce robust extramedullary mobilization of AML cells. When administered as a single agent, lenalidomide specifically mobilizes non-del5q/5q- AML cells, but not healthy CD34⁺ cells, to peripheral blood (PB) through specific downregulation of CXCR4 in AML blasts. Global gene expression profiling supports a migratory/mobilization gene signature in lenalidomide-treated non-del5q/5q- AML blasts but not in CD34⁺ cells. Collectively, IMiDs mobilize non-del5q/5q- AML blasts to PB through CXCR4 downregulation, but fail to potentiate AraC/Idarubicin activity in preclinical models of non-del5q/5q- AML.

Hypomethylating Agents as a Therapy for AML

Acute myeloid leukemia (AML) is predominantly a disease of older adults associated with poor long-term outcomes with available therapies. Used as single agents, hypomethylating agents (HMAs) induce only 15 to 25% complete remissions, but current data suggest that median OS observed after HMAs is comparable to that observed after more intensive therapies. Whether long-term cure may be obtained in some patients treated with HMAs is unknown. Combinations of HMAs to novel agents are now extensively investigated and attractive response rates have been reported when combining HMAs to different drug classes. The absence of reliable predictive biomarkers of efficacy of HMAs in AML and the uncertainties regarding their most relevant mechanisms of action hinder the rational design of the combinations to be tested in priority, usually in untreated older AML patients.

Low-dose lenalidomide plus cytarabine in very elderly, unfit acute myeloid leukemia patients: Final result of a phase II study

Outcome for elderly patients with acute myeloid leukemia (AML) is extremely poor. Intensive induction chemotherapy is often unsuitable. Sixty-six newly diagnosed AML patients (median age: 76years), ineligible for standard therapy, were consecutively treated with low-dose lenalidomide (10mg/day orally, days 1-21) plus 10mg/m² low-dose cytarabine, subcutaneously, twice a day (days 1-15) every six weeks, up to 6 cycles. Complete remission (CR) rate was 36.3% according to intention-to-treat. Responding patients had a longer median overall survival than non-responders (517 vs. 70days, P<0.001). The achievement of CR was not predicted by bone marrow blast count, cytogenetics, molecular markers, prior MDS, white blood cell count. Conversely, by studying the global gene expression profile, we identified a molecular signature, including 309 genes associated with clinical response (CR versus no CR). Based on the expression of a minimal set of 16 genes, we developed an algorithm to predict treatment response, that was successfully validated by showing an overall accuracy of 88%. We met the primary endpoint of the study, by beating the estimated successful CR rate (P1) fixed at 30%. Moreover, CR induced by this 2-drug combo was efficiently predicted by genetic profiling, identifying a biomarker that warrants validation in independent series.

Azacitidine in adult patients with acute myeloid leukemia

Azacitidine is recommended front-line treatment for older patients with acute myeloid leukemia (AML) who are not candidates for intensive treatment regimens, and was recently granted approval in the European Union for treatment of adult AML. Reviewed here is azacitidine experience in AML, including: mechanistic and pharmacokinetic data; safety and efficacy in controlled trials; treatment effects in AML subpopulations defined by disease characteristics; experience in unselected patients treated in the community setting; clinical outcomes relative to other approved AML therapies; and experience with azacitidine-based combination treatment regimens. Collectively, these data suggest that (a) azacitidine may prolong overall survival to a similar or greater extent than do other approved AML treatments, but with less toxicity, (b) azacitidine may be the preferred treatment option for older patients with unfavorable cytogenetics, and (c) experience and outcomes with azacitidine in the clinic are similar to those seen in clinical trials. Continued investigation of combination regimens on an azacitidine backbone is warranted.

Role of Epigenetic Modification and Immunomodulation in a Murine Prostate Cancer Model

INTRODUCTION

Decreased expression of highly immunogenic cancer-testis antigens (CTA) might help tumor to achieve low immunogenicity, escape immune surveillance and grow unimpeded. Our aim was to evaluate CTA expression in tumor and normal tissues and to investigate possible means of improving the immune response in a murine prostate cancer (CaP) model by using the combination of epigenetic modifier 5-azacitidine (5-AzaC) and immunomodulator lenalidomide. No study to date has examined the effect of this combination on the prostate cancer or its impact on antigen-presenting cells (APC).

MATERIALS AND METHODS

Gene microarrays were performed to compare expression of several CTA in murine prostate cancer (RM-1 cells) and normal prostate. RM-1 cells were treated with 5-AzaC and real-time PCR was performed to investigate the expression of several CTA. Western blotting was used to determine whether expression of CTA-specific mRNA induced by 5-AzaC resulted in increase in the corresponding protein. Effect of the epigenetic agents and immunomodulators was assessed on dendritic cells (DC) using flow cytometry, ELISA and T-cell proliferation assay.

RESULTS

Gene arrays demonstrated decreased expression of 35 CTA in CaP tissue compared to normal prostate. 5-AzaC treatment of RM-1 prostate cancer cells upregulated the expression of all 13 CTA tested in a dose-dependent fashion. DC were treated with 5-AzaC and lenalidomide and the expression of surface markers MHC Class I, MHC Class II, CD80, CD86, CD 205, and CD40 was increased. Combination of 5-AzaC and lenalidomide enhances the ability of DC to stimulate T-cell proliferation in mixed leukocyte reaction. Secretion of IL-12 and IL-15 by DC increased significantly with addition of 5-AzaC or 5-AzaC and lenalidomide.

CONCLUSIONS

Decreased expression of CTA by prostate cancer may be a means of escaping immune monitoring. Combination of epigenetic modifications and immunomodulation by 5-AzaC and lenalidomide increased tumor immunogenicity and enhanced DC function and may be used in the treatment of advanced prostate cancer. Prostate 77: 361-373, 2017. © 2016 Wiley Periodicals, Inc.

DNA methyltransferase inhibitors: an updated patent review (2012-2015)

INTRODUCTION

DNA methyltransferases (DNMTs), important enzymes involved in epigenetic regulation of gene expression, represent promising targets in cancer therapy. DNMT inhibitors (DNMTi), which can modulate the aberrant DNA methylation pattern in a reversible way via inhibiting DNMT activity, have attracted significant attention in recent years.

AREAS COVERED

This review outlines the newly patented inhibitors targeting DNMTs, mainly incorporating small molecular inhibitors and oligonucleotide derivatives. The chemical structures, biological activity, and the encouraging clinical research in progress are delineated in detail.

EXPERT OPINION

Two drugs, azacitidine and decitabine, have evidently shown efficacy in hematologic malignancies, yet do not work well on solid tumors, have low specificity, substantial toxicity, and poor bioavailability. With the rapid advancement in systems biology, drug combinations, such as DNMTi, in conjugation with histone deacetylase inhibitors (HDACi) or immunotherapy, probably serve as an efficient way of implementing epigenetic therapy. Meanwhile, the resolved autoinhibitory structures of DNMTs afford a novel strategy for targeting the protein-protein interface involved in the autoinhi-bitory interactions. The molecular mechanism underlying the conformational transitions would also shed new light on the design of allosteric inhibitors. Both strategies would produce inhibitors with more selectivity compared to nucleotide derivatives.

The combination of FLT3 and DNA methyltransferase inhibition is synergistically cytotoxic to FLT3/ITD acute myeloid leukemia cells

Effective treatment regimens for elderly acute myeloid leukemia (AML) patients harboring internal tandem duplication mutations in the FMS-like tyrosine kinase-3 (FLT3) gene (FLT3/ITD) are lacking and represent a significant unmet need. Recent data on the effects of FLT3 tyrosine kinase inhibitors on FLT3/ITD(+) AML showed promising clinical activity, including in elderly patients. DNA methyltransferase (DNMT) inhibitors such as decitabine (5-aza-2-deoxycytidine, DEC) and 5-azacitidine (AZA) demonstrated clinical benefit in AML, are well tolerated and are associated with minimal increases in FLT3 ligand, which can represent a potential resistance mechanism to FLT3 inhibitors. In addition, both FLT3 and DNMT inhibition are associated with the induction of terminal differentiation of myeloid blasts. Consequently, there is a strong theoretical rationale for combining FLT3 and DNMT inhibition for FLT3/ITD(+) AML. We therefore sought to study the anti-leukemic effects of DEC, AZA and FLT3 inhibitors, either as single agents or in combination, on AML cell lines and primary cells derived from newly diagnosed and relapsed AML patients. Our studies indicate that combined treatment using FLT3 inhibition and hypomethylation confers synergistic anti-leukemic effects, including apoptosis, growth inhibition and differentiation. The simultaneous administration of AZA and FLT3 inhibition appears to be the most efficacious combination in this regard. These drugs may provide a novel therapeutic approach for FLT3/ITD(+) AML, in particular for older patients.

Sequential azacitidine plus lenalidomide in previously treated elderly patients with acute myeloid leukemia and higher risk myelodysplastic syndrome

The outcome of sequential azacitidine with lenalidomide has not been reported in previously treated patients with acute myeloid leukemia (AML) and higher risk myelodysplastic syndrome (MDS). This study describes a phase 2 study evaluating the safety and efficacy of this combination in elderly patients with AML and MDS with prior hypomethylating agent (HMA) and/or immunomodulatory agent exposure. Patients were treated on a 42-day cycle with azacitidine at 75 mg/m2 SQ/IV daily on days 1-7, followed by lenalidomide 50 mg orally daily on days 8-28. The median number of treatment cycles on study was two (range = 1-11). Of 32 evaluable patients, the overall response rate was 25%. Neutropenic fever was the most common serious adverse event, but overall the combination was well-tolerated. The median overall survival (OS) for responders vs non-responders was 9.8 vs 4.0 months, respectively (HR = 0.36, p = 0.016). In conclusion, this combination demonstrated modest clinical activity in this poor risk population.

How Center Volumes Affect Early Outcomes in Acute Myeloid Leukemia

Early mortality (EM) is all too frequent during induction chemotherapy for acute myeloid leukemia. Older patients shoulder an undue amount of this burden as a result of the inherent biology of their disease and increased comorbidities. EM rates in academic centers have seen a sharp decline over the past 20 years; however, data from population-based registries show that EM rates for the general population have significantly lagged behind. In this review, we analyze the data available on EM in academic centers and the general population, explore recent improvements in supportive care and the use of predictive models, and finally investigate the relationship between case volume and complications during chemotherapy.

Ruxolitinib in combination with lenalidomide as therapy for patients with myelofibrosis

Ruxolitinib and lenalidomide may target distinct clinical and pathological manifestations of myelofibrosis and prevent therapy-related worsening of blood cell counts. To determine the efficacy and safety of the combination in patients with myelofibrosis, patients were given 15 mg ruxolitinib orally twice daily in continuous 28-day cycles, plus 5 mg lenalidomide orally once daily on days 1-21. Thirty-one patients were treated, with a median followup of 28 months (range, 12 - 35+). Due to failure to meet the predetermined efficacy rules for treatment success the study was terminated early. Simultaneous administration of ruxolitinib and lenalidomide was difficult: 20 of the 23 dose interruptions occurred within the first 3 months of therapy. Lenalidomide was interrupted in all 20 cases. Fourteen patients (45%) were completely off lenalidomide within 3 months of initiation. Responses were noted in 17 patients (55%). The median time to response was 1.8 months (range, 0.4 - 31). All responses were International Working Group for Myelofibrosis Research and Treatment-defined clinical improvement in palpable spleen size. One spleen responder also met the criteria for clinical improvement in hemoglobin. The response rate was higher (73%) among patients who did not require early dose interruption than among those who required early interruption (45%). Improvements in bone marrow fibrosis and serial reductions in lactate dehydrogenase >50% were noted in 17% and 50% of evaluable responders, respectively. Alternate approaches such as sequential dosing need to be evaluated when considering novel combination strategies for myelofibrosis. This trial was registered with clinicaltrials.gov identifier: NCT01375140.

International phase 3 study of azacitidine vs conventional care regimens in older patients with newly diagnosed AML with >30% blasts

This multicenter, randomized, open-label, phase 3 trial evaluated azacitidine efficacy and safety vs conventional care regimens (CCRs) in 488 patients age ≥65 years with newly diagnosed acute myeloid leukemia (AML) with >30% bone marrow blasts. Before randomization, a CCR (standard induction chemotherapy, low-dose ara-c, or supportive care only) was preselected for each patient. Patients then were assigned 1:1 to azacitidine (n = 241) or CCR (n = 247). Patients assigned to CCR received their preselected treatment. Median overall survival (OS) was increased with azacitidine vs CCR: 10.4 months (95% confidence interval [CI], 8.0-12.7 months) vs 6.5 months (95% CI, 5.0-8.6 months), respectively (hazard ratio [HR] was 0.85; 95% CI, 0.69-1.03; stratified log-rank P = .1009). One-year survival rates with azacitidine and CCR were 46.5% and 34.2%, respectively (difference, 12.3%; 95% CI, 3.5%-21.0%). A prespecified analysis censoring patients who received AML treatment after discontinuing study drug showed median OS with azacitidine vs CCR was 12.1 months (95% CI, 9.2-14.2 months) vs 6.9 months (95% CI, 5.1-9.6 months; HR, 0.76; 95% CI, 0.60-0.96; stratified log-rank P = .0190). Univariate analysis showed favorable trends for azacitidine compared with CCR across all subgroups defined by baseline demographic and disease features. Adverse events were consistent with the well-established safety profile of azacitidine. Azacitidine may be an important treatment option for this difficult-to-treat AML population. This trial was registered at www.clinicaltrials.gov as #NCT01074047.

Expanding role of lenalidomide in hematologic malignancies

Lenalidomide is an immunomodulatory agent that has been approved by the US Food and Drug Administration for treatment of multiple myeloma, deletion 5q myelodysplastic syndrome, and mantle cell lymphoma. In addition, it has clinical activity in lymphoproliferative disorders and acute myeloid leukemia. The mode of action includes immunomodulatory, anti-inflammatory, antiangiogenic, and antiproliferative mechanisms. The antitumor effect is a result of direct interference of key pathways in tumor cells and indirect modulation of the tumor microenvironment. There has been no recent collective review on lenalidomide in multiple myeloma, myelodysplastic syndrome/acute myeloid leukemia, and lymphoma. This review summarizes the results of current clinical studies of lenalidomide, alone and in combination with other agents, as a therapeutic option for various hematologic malignancies.

Azacitidine and lenalidomide as an alternative treatment for refractory acute myeloid leukemia: a case report

CONTEXT

Refractory acute myeloid leukemia (AML) is a difficult disease to control with second or third-line chemotherapy regimens. In this report, we describe using azacitidine in combination with lenalidomide as salvage therapy.

CASE REPORT

52-year-old female was diagnosed with refractory AML and high-risk cytogenetics: complex monosomal karyotype consisting of t (3, 3) in association with monosomy 7 and del 5q. Morphological remission associated with maintenance of the cytogenetic abnormality of chromosome 3 and disappearance of the abnormalities relating to chromosomes 5 and 7 was achieved after three cycles of combination therapy with azacitidine and lenalidomide.

CONCLUSION

Azacitidine plus lenalidomide can be a therapeutic option for patients with refractory AML, as illustrated in this case.

Rational Combinations of Targeted Agents in AML

Despite modest improvements in survival over the last several decades, the treatment of AML continues to present a formidable challenge. Most patients are elderly, and these individuals, as well as those with secondary, therapy-related, or relapsed/refractory AML, are particularly difficult to treat, owing to both aggressive disease biology and the high toxicity of current chemotherapeutic regimens. It has become increasingly apparent in recent years that coordinated interruption of cooperative survival signaling pathways in malignant cells is necessary for optimal therapeutic results. The modest efficacy of monotherapy with both cytotoxic and targeted agents in AML testifies to this. As the complex biology of AML continues to be elucidated, many “synthetic lethal” strategies involving rational combinations of targeted agents have been developed. Unfortunately, relatively few of these have been tested clinically, although there is growing interest in this area. In this article, the preclinical and, where available, clinical data on some of the most promising rational combinations of targeted agents in AML are summarized. While new molecules should continue to be combined with conventional genotoxic drugs of proven efficacy, there is perhaps a need to rethink traditional philosophies of clinical trial development and regulatory approval with a focus on mechanism-based, synergistic strategies.

Real-time assessment of relapse risk based on the WT1 marker in acute leukemia and myelodysplastic syndrome patients after hematopoietic cell transplantation

Relapse is the major cause of treatment failure after allogeneic hematopoietic cell transplantation (alloHCT) for acute leukemia and myelodysplastic syndrome (MDS). Wilms' tumor Ag (WT1) is overexpressed in the majority of acute leukemia and MDS patients and has been proposed as a universal diagnostic marker for detection of impending relapse. Comprehensive studies have shown that WT1 transcript levels have predictive value in acute leukemia patients in CR after chemotherapy. However, the focus of this study is the period after alloHCT for predicting relapse onset. We analyzed the accumulation of WT1 mRNA transcripts in PB of 82 leukemia and MDS patients and defined specific molecular ratios for relapse prediction. The extensively validated WT1/c-ABL ratio was used to normalize increases in WT1 transcript levels. The observed lead time of crossing or exceeding set WT1 levels is presented along with linear interpolation to estimate the calculated day the WT1 thresholds were crossed. The WT1/c-ABL transcript ratio of 50 or above yielded 100% specificity and 75% sensitivity reliably predicting future relapse with an observed average of 29.4 days (s.d.=19.8) and a calculated average of 63 days (s.d.=29.3) lead time before morphologic confirmation. A lower ratio of 20 or above gave lower specificity, but higher sensitivity (84.8% and 87.5%, respectively) identified more patients who relapsed, at earlier times, providing an earlier warning with actual average lead time of 49.1 days (s.d.=30.8) and calculated average of 78 days (s.d.=28.8). WT1 transcript levels serve as a diagnostic relapse test with greater sensitivity than the morphologic approach used in the clinic as a readout.

The role of the immunosuppressive microenvironment in acute myeloid leukemia development and treatment

Functional interplay between acute myeloid leukemia (AML) cells and the bone marrow microenvironment is a distinctive characteristic of this hematological cancer. Indeed, a large body of evidence suggests that proliferation, survival and drug resistance of AML are sustained and modulated by the bone marrow immunosuppressive microenvironment, where both innate and adaptive immune responses are profoundly deregulated. Furthermore, the presence of a number of different immunosuppressive mechanisms results in massive immune deregulation, which causes the eventual escape from natural immune control. Modulating the immune system, as documented by 40 years of stem cell transplantation, may improve survival of AML patients, as the immune system is clearly able to recognize and attack leukemic cells. The understanding of the factors responsible for the escape from immune destruction in AML, which becomes more prominent with disease progression, is necessary for the development of innovative immunotherapeutic treatment modalities in AML.

CNS Involvement in AML Patient Treated with 5-Azacytidine

Central nervous system (CNS) involvement in acute myeloid leukemia (AML) is a rare complication of the disease and is associated with poor prognosis. Sometimes the clinical presentation can be unspecific and the diagnosis can be very challenging. Here we report a case of CNS infiltration in a patient suffering from AML who presented with normal complete blood count and altered mental status.

CXXC5 (retinoid-inducible nuclear factor, RINF) is a potential therapeutic target in high-risk human acute myeloid leukemia

The retinoid-responsive gene CXXC5 localizes to the 5q31.2 chromosomal region and encodes a retinoid-inducible nuclear factor (RINF) that seems important during normal myelopoiesis. We investigated CXXC5/RINF expression in primary human acute myeloid leukemia (AML) cells derived from 594 patients, and a wide variation in CXXC5/RINF mRNA levels was observed both in the immature leukemic myeloblasts and in immature acute lymphoblastic leukemia cells. Furthermore, patients with low-risk cytogenetic abnormalities showed significantly lower levels compared to patients with high-risk abnormalities, and high RINF/CXXC5/ mRNA levels were associated with decreased overall survival for patients receiving intensive chemotherapy for newly diagnosed AML. This association with prognosis was seen both when investigating (i) an unselected patient population as well as for patients with (ii) normal cytogenetic and (iii) core-binding factor AML. CXXC5/RINF knockdown in AML cell lines caused increased susceptibility to chemotherapy-induced apoptosis, and regulation of apoptosis also seemed to differ between primary human AML cells with high and low RINF expression. The association with adverse prognosis together with the antiapoptotic effect of CXXC5/RINF suggests that targeting of CXXC5/RINF should be considered as a possible therapeutic strategy, especially in high-risk patients who show increased expression in AML cells compared with normal hematopoietic cells.

Azacitidine in untreated acute myeloid leukemia: a report on 149 patients

Limited data are available on azacitidine (AZA) treatment and its prognostic factors in acute myeloid leukemia (AML). One hundred and forty-nine previously untreated AML patients considered ineligible for intensive chemotherapy received AZA in a compassionate patient-named program. AML diagnosis was de novo, post-myelodysplastic syndromes (MDS), post-MPN, and therapy-related AML in 51, 55, 13, and 30 patients, respectively. Median age was 74 years, median white blood cell count (WBC) was 3.2 × 10⁹ /L and 58% of the patients had ≥ 30% marrow blasts. Cytogenetics was adverse in 60 patients. Patients received AZA for a median of five cycles (range 1-31). Response rate (including complete remission/CR with incomplete recovery/partial remission) was 27.5% after a median of three cycles (initial response), and 33% at any time (best response). Only adverse cytogenetics predicted poorer response. Median overall survival (OS) was 9.4 months. Two-year OS was 51% in responders and 10% in non-responders (P<0.0001). Adverse cytogenetics, WBC >15 × 10⁹ /L and ECOG-PS ≥ 2 predicted poorer OS, while age and marrow blast percentage had no impact. Using MDS IWG 2006 response criteria, among patients with stable disease, those with hematological improvement had no significant survival benefit in a 7 months landmark analysis. Outcomes observed in this high-risk AML population treated with AZA deserve comparison with those of patients treated intensively in prospective studies.

Prolonged administration of azacitidine with or without entinostat for myelodysplastic syndrome and acute myeloid leukemia with myelodysplasia-related changes: results of the US Leukemia Intergroup trial E1905

PURPOSE

Although azacitidine (AZA) improves survival in patients with high-risk myelodysplastic syndrome, the overall response remains approximately 50%. Entinostat is a histone deacetylase inhibitor that has been combined with AZA with significant clinical activity in a previous phase I dose finding study.

DESIGN

Open label phase II randomized trial comparing AZA 50 mg/m(2)/d given for 10 days ± entinostat 4 mg/m(2)/d day 3 and day 10. All subtypes of myelodysplasia, chronic myelomonocytic leukemia, and acute myeloid leukemia with myelodysplasia-related changes were eligible for the study. The primary objective was the rate of hematologic normalization (HN; complete remission + partial remission + trilineage hematological improvement).

RESULTS

One hundred forty-nine patients were analyzed, including 97 patients with myelodysplastic syndrome and 52 patients with acute myeloid leukemia. In the AZA group, 32% (95% CI, 22% to 44%) experienced HN and 27% (95% CI, 17% to 39%) in the AZA + entinostat group. Both arms exceeded the HN rate of historical control (Cancer and Leukemia Group B 9221 trial), but only the AZA group fulfilled the primary objective of the study. Rates of overall hematologic response were 46% and 44%, respectively. Median overall survivals were 18 months for the AZA group and 13 months for the AZA + entinostat group. The combination arm led to less demethylation compared with the monotherapy arm, suggesting pharmacodynamic antagonism.

CONCLUSION

Addition of entinostat to AZA did not increase clinical response as defined by the protocol and was associated with pharmacodynamic antagonism. However, the prolonged administration of AZA by itself seems to increase HN rate compared with standard dosing and warrants additional investigation.

Beyond hypomethylating agents failure in patients with myelodysplastic syndromes

PURPOSE OF REVIEW

Although hypomethylating agents (HMAs) significantly improve outcomes in myelodysplastic syndromes (MDS), only half the patients achieve objective responses, and most responders lose response within 1-2 years. Azacitidine prolongs survival by a median of only 9.5 months. Failure of HMA therapy is associated with a very dismal prognosis. Therefore, novel therapeutic approaches are clearly needed.

RECENT FINDINGS

The sequential use of the alternative HMA after failure of first line HMA is associated with modest efficacy. The improved understanding of the biologic underpinnings of the disease have opened the door to study investigational agents that target disrupted molecular pathways critical to the pathogenesis of MDS. Combination treatment strategies using an azacitidine backbone are demonstrating promising early results. Expanding the applicability of allogeneic stem cell transplantation (alloSCT), the only curative modality, by reducing toxicity and relapse rates is another area of active research.

SUMMARY

Sequential switching to the alternative HMA, clinical trials of novel targeted therapies, azacitidine-based combination therapeutic strategies, and improvements in the alloSCT platform are the main directions in improving outcomes of MDS post HMA failure.

5-Azacytidine/5-Azacitidine

The hypomethylating agent 5-Azacytidine epigenetically modulates various genes, including tumor suppressor genes. For many years, the "new agent", which was first discovered in the 1960s, remained fairly unobtrusive in the rank of salvage treatment options for myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). When the significance of epigenetics in tumorigenesis became clear, 5-Azacytidine attracted new attention. Finally, it was the first drug approved for the treatment of all categories of MDS, and its survival benefit over best conventional care was confirmed. Today, in many clinical situations, when aggressive therapies including allogeneic hematopoietic cell transplantation are not an option, 5-Azacytidine is the first treatment of choice. Preliminary data on combinations of the hypomethylating agent with other new drugs are promising, and innovative strategies involving immune modulation and regenerative tissue repair hold a broad potential for future developments.

Higher-risk myelodysplastic syndromes with del(5q): is sequential azacitidine-lenalidomide combination the way to go?

High-risk myelodysplastic syndromes (HR-MDS) and acute myeloid leukemia (AML) with deletions of long arm of chromosome 5 (del[5q]) are characterized by rapid progression and poor survival. The majority of these patients are elderly with comorbidities, therefore limiting the use of intensive therapies which, even if used, unfortunately yield low responses. While azacitidine prolongs survival in patients with HR-MDS by a median of 9.5 months, responses only occur in less than half of the patients, and azacitidine therapy is not curative, with most patients relapsing within 2 years. Therefore, strategies to improve outcomes in these patients are needed. Azacitidine and lenalidomide both have meaningful single-agent clinical activity in HR-MDS and AML with del(5q). Early-phase trials in HR-MDS without del(5q) suggest increased activity with a concurrent azacitidine-lenalidomide combination. In this article, we review the results of a Phase I trial of a sequential azacitidine-lenalidomide combination approach in patients with HR-MDS and AML with del(5q) abnormality.

Trial Watch: Lenalidomide-based immunochemotherapy

Lenalidomide is a synthetic derivative of thalidomide currently approved by the US Food and Drug Administration for use in patients affected by multiple myeloma (in combination with dexamethasone) and low or intermediate-1 risk myelodysplastic syndromes that harbor 5q cytogenetic abnormalities. For illustrative purposes, the mechanism of action of lenalidomide can be subdivided into a cancer cell-intrinsic, a stromal, and an immunological component. Indeed, lenalidomide not only exerts direct cell cycle-arresting and pro-apoptotic effects on malignant cells, but also interferes with their physical and functional interaction with the tumor microenvironment and mediates a robust, pleiotropic immunostimulatory activity. In particular, lenalidomide has been shown to stimulate the cytotoxic functions of T lymphocytes and natural killer cells, to limit the immunosuppressive impact of regulatory T cells, and to modulate the secretion of a wide range of cytokines, including tumor necrosis factor α, interferon γ as well as interleukin (IL)-6, IL-10, and IL-12. Throughout the last decade, the antineoplastic and immunostimulatory potential of lenalidomide has been investigated in patients affected by a wide variety of hematological and solid malignancies. Here, we discuss the results of these studies and review the status of clinical trials currently assessing the safety and efficacy of this potent immunomodulatory drug in oncological indications.

Novel therapies for children with acute myeloid leukaemia

Significant improvements in survival for children with acute myeloid leukaemia (AML) have been made over the past three decades, with overall survival rates now approximately 60-70%. However, these gains can be largely attributed to more intensive use of conventional cytotoxics made possible by advances in supportive care, and although over 90% of children achieve remission with frontline therapy, approximately one third in current protocols relapse. Furthermore, late effects of therapy cause significant morbidity for many survivors. Novel therapies are therefore desperately needed. Early-phase paediatric trials of several new agents such as clofarabine, sorafenib and gemtuzumab ozogamicin have shown encouraging results in recent years. Due to the relatively low incidence of AML in childhood, the success of paediatric early-phase clinical trials is largely dependent upon collaborative clinical trial design by international cooperative study groups. Successfully incorporating novel therapies into frontline therapy remains a challenge, but the potential for significant improvement in the duration and quality of survival for children with AML is high.

Declining rates of treatment-related mortality in patients with newly diagnosed AML given 'intense' induction regimens: a report from SWOG and MD Anderson

Less-intense remission induction regimens for adults with newly diagnosed acute myeloid leukemia (AML) aim to reduce treatment-related mortality (TRM), here defined as death within 4 weeks after starting induction therapy. This assumes that TRM rates are similar to the 15-20% observed 20 years ago. Herein we test this assumption. We examined TRM rates in 1409 patients treated on SWOG (Southwest Oncology Group) trials and 1942 patients treated at MD Anderson (MDA) from 1991 to 2009. Eighty-eight percent of SWOG patients received '3+7' or regimens of similar intensity while 92% of the MDA patients received ara-C at 1.5-2.0 g/m(2) daily × 3-5 days+other cytotoxic agents. We examined the relationship between time and TRM rates after accounting for other covariates. TRM rates between 1991 and 2009 decreased from 18-3% in SWOG and 16-4% at MDA. Multivariate analyses showed a significant decrease in TRM over time (P=0.001). The decrease in TRM was not limited to younger patients, those with a better performance status or a lower white blood cell count. Though our observations are limited to patients treated with intensive therapy at SWOG institutions and MDA, the decrease in TRM with time emphasizes the problem with historical controls and could be considered when selecting AML induction therapy.

Trial Watch: Immunostimulatory cytokines

During the past two decades, the notion that cancer would merely constitute a cell-intrinsic disease has gradually been complemented by a model postulating that the immune system plays a relevant role during all stages of oncogenesis and tumor progression. Along with this conceptual shift, several strategies have been devised to stimulate tumor-specific immune responses, including relatively unselective approaches such as the systemic administration of adjuvants or immunomodulatory cytokines. One year ago, in the July issue of OncoImmunology, we described the main biological features of this large group of proteins and discussed the progress of ongoing clinical studies evaluating their safety and therapeutic potential in cancer patients. Here, we summarize the latest developments in this area of clinical research, focusing on high impact studies that have been published during the last 13 mo and clinical trials launched in the same period to investigate which cytokines can be employed as safe and efficient immunostimulatory interventions against cancer.

Combination of azacitidine and lenalidomide in myelodysplastic syndromes or acute myeloid leukemia-a wise liaison?

Treatment options for older patients with advanced myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) are limited and the prognosis remains poor, thereby warranting development of novel therapies. Aberrant epigenetic modifications, including altered DNA methylation, seem to contribute to the pathogenesis of these patients. In fact, hypomethylating agents (HMA) like azacitidine have been successfully used in clinical trials and achieved approval from health authorities. There is now growing evidence suggesting that the combination of drugs with different mechanisms of action might offer a potential benefit to these patients. This is especially done with the intention to synergize the positive effects of each drug on the defective hematopoiesis while sparing potential side effects and toxicities. Combination of HMA with histone deacetylase inhibitors, although mechanistically very tempting, have not yielded convincing improvement of the results in the majority of trials compared to single agent HMA treatment. Currently, combination therapies of azacitidine with lenalidomide appear to be promising thus making them an appealing option for treatment in these patients.