Long-term survival of older patients with MDS treated with HMA therapy without subsequent stem cell transplantation

Treatment of Myelodysplastic Syndromes for Older Patients: Current State of Science, Challenges, and Opportunities

PURPOSE OF REVIEW

Myelodysplastic syndromes/neoplasms (MDS) represent a diverse group of pathologically distinct diseases with varying prognoses and risks of leukemia progression. This review aims to discuss current treatment options for elderly patients with MDS, focusing on patients ineligible for intensive chemotherapy or allogenic hematopoietic stem cell transplantation (HSCT). The challenges associated with treatment in this population and emerging therapeutic prospects are also explored.

RECENT FINDINGS

Recent advancements in molecular diagnostics have enhanced risk stratification by incorporating genetic mutations, notably through the molecular International Prognostic Scoring System (IPSS-M). Lower-risk MDS (LR-MDS) treatment ranges from observation to supportive measures and erythropoiesis-stimulating agents (ESAs), with emerging therapies like luspatercept showing promise. High-risk MDS (HR-MDS) is treated with hypomethylating agents (HMAs) or allogenic HSCT, but outcomes remain poor. Elderly MDS patients, often diagnosed after 70, pose challenges in treatment decision-making. The IPSS-M aids risk stratification, guiding therapeutic choices. For LR-MDS, supportive care, ESAs, and novel agents like luspatercept are considered. Treatment of HR-MDS involves HMAs or allogenic HSCT. Emerging treatments, including oral HMAs and novel agents targeting FLT3, and IDH 1/2 mutations, show promise. Future research should refine treatment strategies for this elderly population focusing on quality-of-life improvement.

Measurable (Minimal) Residual Disease in Myelodysplastic Neoplasms (MDS): Current State and Perspectives

Myelodysplastic Neoplasms (MDS) have been traditionally studied through the assessment of blood counts, cytogenetics, and morphology. In recent years, the introduction of molecular assays has improved our ability to diagnose MDS. The role of Measurable (minimal) Residual Disease (MRD) in MDS is evolving, and molecular and flow cytometry techniques have been used in several studies. In this review, we will highlight the evolving concept of MRD in MDS, outline the various techniques utilized, and provide an overview of the studies reporting MRD and the correlation with outcomes.

A multicenter phase Ib trial of the histone deacetylase inhibitor entinostat in combination with pembrolizumab in patients with myelodysplastic syndromes/neoplasms or acute myeloid leukemia refractory to hypomethylating agents

Patients with myelodysplastic syndromes/neoplasms (MDS) or acute myeloid leukemia (AML) with hypomethylating agent failure have a poor prognosis. Myeloid-derived suppressor cells (MDSCs) can contribute to MDS progression and mediate resistance to anti-PD1 therapy. As histone deacetylase inhibitors (HDACi) decrease MDSCs in preclinical models, we conducted an investigator-initiated, NCI-Cancer Therapy Evaluation Program-sponsored, multicenter, dose escalation, and expansion phase Ib trial (NCT02936752) of the HDACi entinostat and the anti-PD1 antibody pembrolizumab. Twenty-eight patients (25 MDS and 3 AML) were enrolled. During dose escalation (n=13 patients), there was one dose-limiting toxicity (DLT) on dose level (DL) 1 (G5 pneumonia/bronchoalveolar hemorrhage) and two DLTs at DL 2 (G3 pharyngeal mucositis and G3 anorexia). Per the 3 + 3 dose escalation design, DL 1 (entinostat 8 mg PO days 1 and 15 + pembrolizumab 200 mg IV day 1 every 21 days) was expanded and another 15 patients were enrolled. Hematologic adverse events (AEs) were common. The most common non-hematologic ≥G3 AEs were infection (32%), hypoxia/respiratory failure (11%), and dyspnea (11%). There were no protocol-defined responses among the 28 patients enrolled. Two patients achieved a marrow complete remission (mCR). Using a systems immunology approach with mass cytometry and machine learning analysis, mCR patients had increased classical monocytes and macrophages but there was no significant change of MDSCs. In conclusion, combining entinostat with pembrolizumab in patients with advanced MDS and AML was associated with limited clinical efficacy and substantial toxicity. Absence of an effect on MDSCs could be a potential explanation for the limited efficacy of this combination. ClinicalTrial.gov Identifier: NCT02936752.

Are We Ready For "Triplet" Therapy in Higher-Risk MDS?

Higher-risk Myelodysplastic Syndromes/Neoplasms (MDS) represent an ongoing therapeutic challenge, with few effective therapies, many of which may have limited use in this older patient population often with considerations around comorbidities. Outside of transplant, azacitidine and decitabine remain the only disease-modifying therapies, and are palliative in nature. Recent interest has grown in extending combination chemotherapies used to treat acute myeloid leukemia (AML) to patients with MDS, including novel combination chemotherapy "doublets" and "triplets." In this review, we discuss considerations around combination chemotherapy in MDS, specifically as relates to study design, appropriate endpoints, supportive considerations, and how to integrate these into the current treatment paradigm. New therapies in MDS are desperately needed but also require considerations particular to this unique patient population.

A Personalized Risk Model for Azacitidine Outcome in Myelodysplastic Syndrome and Other Myeloid Neoplasms Identified by Machine Learning Model Utilizing Real-World Data

Azacitidine is an approved therapy for higher-risk myelodysplastic syndrome (MDS). However, only 30-40% patients respond to azacitidine, and the responses may take up to six cycles to become evident. Delayed responses and the myelosuppressive effects of azacitidine make it challenging to predict which patients will benefit. This is further compounded by a lack of uniform prognostic tools to identify patients at risk of early treatment failure. Hence, we performed a retrospective analysis of 273 consecutive azacytidine-treated patients. The median overall survival was 16.25 months with only 9% alive at 5 years. By using pre-treatment variables incorporated into a random forest machine learning model, we successfully identified those patients unlikely to benefit from azacytidine upfront (7.99 vs. 22.8 months, p < 0.0001). This model also identified those who required significantly more hospitalizations and transfusion support. Notably, it accurately predicted survival outcomes, outperforming the existing prognostic scoring system. By integrating somatic mutations, we further refined the model and identified three distinct risk groups with significant differences in survival (5.6 vs. 10.5 vs. 43.5 months, p < 0.0001). These real-world findings emphasize the urgent need for personalized prediction tools tailored to hypomethylating agents, reducing unnecessary complications and resource utilization in MDS treatment.

Why do we not have more drugs approved for MDS? A critical viewpoint on novel drug development in MDS

Approval of new agents to treat higher risk (HR) myelodysplastic syndrome (MDS) has stalled since the approval of DNA methyltransferase inhibitors (DNMTi). In addition, the options for patients with lower risk (LR) MDS who have high transfusion needs and do not harbor ring sideroblasts or 5q- syndrome are limited. Here, we review the current treatment landscape in MDS and identify areas of unmet need, such as treatment after failure of erythropoiesis-stimulating agents or DNMTis, TP53-mutated disease, and MDS with potentially targetable mutations. We discuss how our understanding of MDS pathogenesis can inform therapy development, including treating HR-MDS similarly to AML and pursuing therapies to address splicing factor mutations and dysregulated inflammation. We then bring a critical lens to current methodology of MDS studies and propose solutions to improve the efficiency and yield of these clinical trials, including using the most meaningful response metrics and expanding enrollment.

What's Next after Hypomethylating Agents Failure in Myeloid Neoplasms? A Rational Approach

Hypomethylating agents (HMA) such as azacitidine and decitabine are a mainstay in the current management of patients with myelodysplastic syndromes/neoplasms (MDS) and acute myeloid leukemia (AML) as either single agents or in multidrug combinations. Resistance to HMA is not uncommon, and it can result due to several tumor cellular adaptations. Several clinical and genomic factors have been identified as predictors of HMA resistance. However, the management of MDS/AML patients after the failure of HMA remains challenging in the absence of standardized guidelines. Indeed, this is an area of active research with several potential therapeutic agents currently under development, some of which have demonstrated therapeutic potential in early clinical trials, especially in cases with particular mutational characteristics. Here, we review the latest findings and give a rational approach for such a challenging scenario.

Therapeutic approaches for the management of higher risk myelodysplastic syndromes

The heterogeneous nature of myelodysplastic syndromes (MDS) demands a risk-adapted therapeutic approach, and higher risk MDS, characterized by an increased risk of transformation into acute myeloid leukemia and inferior survival, is typically defined based on an integrated assessment of cytopenias, bone marrow blast percentage, and cytogenetic findings using the revised International Prognostic Scoring System. Incorporating mutational data could further refine the risk assessment and identify those with higher-than-expected disease risk. The principal therapeutic goal in this disease subset is to modify the natural history and prolong survival. Allogeneic stem cell transplant, the only potentially curative treatment, should be offered to eligible patients. Hypomethylating agents are the only approved treatment with unsatisfactory response rates and duration, and patients who failed prior hypomethylating agents unfortunately have dismal outcomes with urgent need of novel therapeutic agents. In this review, we provide the therapeutic landscape in higher risk MDS based on the current evidence and discuss the investigational treatment options under development.

Novel immune directed therapies in myelodysplastic syndromes and acute myeloid leukemia

PURPOSE OF REVIEW

Therapies that target the immune system are increasingly used across oncology, including in hematologic malignancies such as myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). While allogeneic transplant has been a key therapy in these cancers, new approaches that target the immune system are being explored including immune checkpoint therapies, antibody-drug conjugates, and cellular therapies.

RECENT FINDINGS

This review outlines updates in the preclinical rationale for immune directed therapies in MDS and AML, as well as recent clinical trials exploring these therapies. This manuscript summarizes the development of therapies targeting T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) and CD47, which are being evaluated in late phase studies in MDS and AML. It also reviews the landscape of other immune based therapies including antibody-drug conjugates, chimeric antigen receptor-T cells, bispecific antibodies, and tumor vaccines.

SUMMARY

The treatment landscape in MDS and AML is rapidly changing; with a goal of improving the quality and duration of responses, a number of immune based therapies are under investigation. This review outlines recent advances with these therapies as well as some of the challenges that remain to incorporate them into leukemia care.

Cost-effectiveness of azacitidine and ivosidenib in newly diagnosed older, intensive chemotherapy-ineligible patients with IDH1-mutant acute myeloid leukemia

Ivosidenib + azacitidine (IVO/AZA) is approved in the United States for newly diagnosed, older or intensive chemotherapy-ineligible patients with IDH1-mutated acute myeloid leukemia. We created a partitioned survival analysis model to evaluate the health economic implications of this approval. Model outputs were used to calculate the incremental cost-effectiveness ratio (ICER) of IVO/AZA versus AZA. One-way and probabilistic sensitivity analyses were conducted. In the base case scenario, IVO/AZA and AZA resulted in life-time costs of $403,062 and $161,887, respectively. With an incremental gain of 0.95 QALYs, the ICER of IVO/AZA was $252,782/QALY. In sensitivity analyses, only a reduction in the price of IVO by 59.3% lowered the ICER to below $150,000/QALY and 99.95% of model calculations yielded ICERs of >$150,000/QALY. In a model in which all patients received IVO monotherapy after progression on AZA monotherapy, the ICER was $155,453/QALY and various model inputs that would make IVO/AZA cost-effective were identified.

How I Manage Transplant Ineligible Patients with Myelodysplastic Neoplasms

Myelodysplastic neoplasms, formerly known as myelodysplastic syndromes (MDS), represent a group of clonal disorders characterized by a high degree of clinical and molecular heterogeneity, and an invariable tendency to progress to acute myeloid leukemia. MDS typically present in the elderly with cytopenias of different degrees and bone marrow dysplasia, the hallmarks of the disease. Allogeneic hematopoietic stem cell transplant is the sole curative approach to date. Nonetheless, given the disease’s demographics, only a minority of patients can benefit from this procedure. Currently used prognostic schemes such as the Revised International Prognostic Scoring System (R-IPSS), and most recently the molecular IPSS (IPSS-M), guide clinical management by dividing MDS into two big categories: lower- and higher-risk cases, based on a cut-off score of 3.5. The main clinical problem of the lower-risk group is represented by the management of cytopenias, whereas the prevention of secondary leukemia progression is the goal for the latter. Herein, we discuss the non-transplant treatment of MDS, focusing on current practice and available therapeutic options, while also presenting new investigational agents potentially entering the MDS therapeutic arsenal in the near future.

SOHO State of the Art and Next Questions: Treatment of Higher-Risk Myelodysplastic Syndromes

Higher-risk myelodysplastic syndromes (MDS) carry a dismal prognosis with rapid disease progression, disease-related complications that impact quality of life, high risk of transformation to acute myeloid leukemia (AML), and poor long-term survival. Higher-risk disease is determined by a number of factors including the depth and type of cytopenias, percentage of myeloblasts occupying the bone marrow, cytogenetic abnormalities, and increasingly also by the presence of higher-risk molecular alterations. In addition to disease characteristics, a patient's performance status and degree of co-morbidity strongly influence treatment decisions and clinical outcomes. A critical first step in the management of patients with higher-risk MDS is evaluating eligibility for allogeneic hematopoietic stem cell transplant (HCT), which currently remains the only curative therapy, and is available to an ever-increasing number of patients. Outside of stem cell transplant, treatment with hypomethylating agent chemotherapy, azacitidine or decitabine, remains the cornerstone of therapy with improvements in overall survival and reduced transformation to AML; however, these approaches are palliative in nature and outcomes remain very poor overall. With a deepening understanding of disease pathophysiology has come a burgeoning array of novel targeted therapies that are currently in pre-clinical and early phase clinical trials offering hope for new treatment options for this malignancy.

Evaluating complete remission with partial hematologic recovery (CRh) as a response criterion in myelodysplastic syndromes (MDS)

Myelodysplastic syndromes (MDS) treated with DNMTI therapy have responses according to the 2006 IWG response criteria. CR responses have had the strongest association with OS. Recently, CR with partial hematologic recovery (CRh; i.e. blasts &lt;5%, ANC &gt; 500, platelets &gt; 50) has been evaluated in AML, but its relevance is unknown in MDS. We identified adult patients with MDS treated with DNMTIs. We assessed best overall response to therapy according to IWG 2006 criteria, and subsequently identified patients meeting CRh criteria from the subgroup with SD or mCR. We evaluated duration of therapy and overall survival according to response. We identified 311 patients with MDS who received treatment between 2007 and 2018. The median age at the time of therapy was 69 years (range 23-91). Median follow up was 60 months. According to IWG 2006, responses included CR (n = 43, 14%), PR (n = 2, 1%), mCR (n = 57, 18%), SD (n = 149, 48%) and PD (n = 60, 19%). 79 patients (25%) achieved HI. A total of 62 patients (20%) met CRh criteria leading to reclassification of mCR (now n = 26, 8%) or SD (now n = 118, 38%). Patients achieving CR had similar time on therapy (median 8.1mo) compared to CRh (median 6mo, HR 1.4, 95% CI 0.9-2.0), and longer than other responses (p &lt; 0.001). OS varied according to response; median OS was similar between CR (23.3mo) and CRh (25mo, HR 1.28 [0.79-2.08]), which was longer than those with mCR (17.2mo, HR 1.71 [0.96-3.05]), SD (16.3mo, HR 1.61 [1.04-2.48]), and PD (8.7mo, HR 3.04 [1.91-4.83]) (p &lt; 0.001). OS associations with CR/CRh were confirmed in multivariable analysis accounting for allogeneic transplant. MDS patients who achieve a CRh response had similar survival and duration on therapy as patients who achieve CR response and superior to other IWG responses. These data support further evaluation of CRh into future response criteria and clinical trials.

Clinical impact of transformation to acute myeloid leukemia in patients with higher-risk myelodysplastic syndromes

Aim: Forty percent of patients with higher-risk myelodysplastic syndromes (HR-MDS) transform to acute myeloid leukemia (AML). Materials & methods: This retrospective study assessed the impact of HR-MDS transformation to AML on OS in a 6-month landmark analysis and the results were validated using a time-varying analysis. Results: The rate of AML transformation was 26.9% at 1 year. Patients who transformed to AML had a higher risk of death than patients who did not in the 6-month landmark analysis (HR: 1.82; p: 0.0072) and time-varying analysis at 1 year (HR: 2.85; p < 0.0001). Patients treated with azacitidine and decitabine in first-line therapy had similar results. Conclusion: HR-MDS transformation to AML is associated with inferior OS in patients with HR-MDS initiating first-line therapy.

Impact of Hypomethylating Agent Use on Hospital and Emergency Room Visits, and Predictors of Early Discontinuation in Patients With Higher-Risk Myelodysplastic Syndromes

BACKGROUND

Previous analyses using the SEER-Medicare database have reported substantial underutilization of hypomethylating agents (HMAs) among patients with higher-risk myelodysplastic syndromes (MDS), and an association between poor HMA persistence and high economic burden. We aimed to compare rates of hospitalizations and emergency room (ER) visits among patients with higher-risk MDS according to use or non-use of HMA therapy, and to explore factors associated with early discontinuation of HMA therapy.

PATIENTS AND METHODS

We used the 2010-2016 SEER-Medicare database to identify patients aged ≥66 years with a new diagnosis of refractory anemia with excess blasts (RAEB; a surrogate for higher-risk MDS) between 2011 and 2015. New hospitalizations and ER visits during the 12 months following MDS diagnosis were determined. Treatment discontinuation was defined as stopping HMA therapy before 4 cycles.

RESULTS

Overall, 664 (55.8%) patients were HMA users and 526 (44.2%) non-users. Non-users had more hospitalizations (mean 0.47 vs. 0.30, P < .001) and ER visits (mean 0.69 vs. 0.41, P = .005) per month than HMA users. Among HMA users, 193 (29.1%) discontinued HMA therapy before 4 cycles, and 91 (47.2%) of these after 1 cycle. Older age and poor performance status were associated with higher risk of HMA discontinuation.

CONCLUSION

An increased rate of hospitalizations and ER visits occurred in HMA non-users vs. HMA users. Approximately one-third of patients discontinued HMA therapy early. Predictors of discontinuation included older age and poor performance status. Novel approaches are needed to improve utilization and persistence with HMA therapy and associated outcomes, particularly among these higher-risk groups.

Treatment of myelodysplastic syndromes in the era of precision medicine and immunomodulatory drugs: a focus on higher-risk disease

Myelodysplastic syndromes (MDS) are a heterogeneous clonal disease of myeloid neoplasms characterized by ineffective hematopoiesis, variable degree of cytopenias, and an increased risk of progression to acute myeloid leukemia (AML). Molecular and genetic characterization of MDS has led to a better understanding of the disease pathophysiology and is leading to the development of novel therapies. Targeted and immune therapies have shown promising results in different hematologic malignancies. However, their potential use in MDS is yet to be fully defined. Here, we review the most recent advances in therapeutic approaches in MDS, focusing on higher-risk disease. Allogeneic hematopoietic cell transplantation is beyond the scope of this article.

Dynamics of PD-1 expression are associated with treatment efficacy and prognosis in patients with intermediate/high-risk myelodysplastic syndromes under hypomethylating treatment

Hypomethylating agents (HMAs) are widely used in patients with higher-risk MDS not eligible for stem cell transplantation. However, the general response rate by HMAs is lesser than 50% in MDS patients, while the relapse rate is high. Emerging evidence indicates that demethylating effects committed by HMAs may facilitate the up-regulation of a range of immune checkpoints or cancer suppressor genes in patients with MDS, among which the programmed death protein 1 (PD-1) and its ligands are demonstrated to be prominent and may contribute to treatment failure and early relapse. Although results from preliminary studies with a limited number of enrolled patients indicate that combined administration of PD-1 inhibitor may yield extra therapeutic benefit in some MDS patients, identifications of this subgroup of patients and optimal timing for the anti-PD-1 intervention remain significant challenges. Dynamics of immune checkpoints and associated predictive values during HMA-treatment cycles remained poorly investigated. In this present study, expression levels of immune checkpoints PD-1 and its ligands PD-L1 and PD-L2 were retrospectively analyzed by quantitative PCR (Q-PCR) in a total of 135 myelodysplastic syndromes (MDS) cohort with higher-risk stratification. The prognostic value of dynamics of these immune checkpoints during HMA cycles was validated in two independent prospective cohorts in our center (NCT01599325 and NCT01751867). Our data revealed that PD-1 expression was significantly higher than that in younger MDS patients (age ≤ 60) and MDS with lower IPSS risk stratification (intermediate risk-1). A significantly up-regulated expression of PD-1 was seen during the first four HMA treatment cycles in MDS patients, while similar observation was not seen concerning the expression of PD-L1 or PD-L2. By utilizing binary logistic regression and receiver operating characteristic (ROC) models, we further identified that higher or equal to 75.9 PD-1 expressions after 2 cycles of HMA treatment is an independent negative prognostic factor in predicting acute myeloid leukemia (AML) transformation and survival. Collectively, our data provide rationales for monitoring the expression of PD-1 during HMA treatment cycles, a higher than 75.9 PD-1 expression may identify patients who will potentially benefit from the combined therapy of HMA and PD-1 inhibitors.

Historical expectations with DNA methyltransferase inhibitor monotherapy in MDS: when is combination therapy truly "promising"?

DNA methyltransferase inhibitors (DNMTIs) for patients with higher risk myelodysplastic syndromes (HR-MDS) have low complete remission rates and are not curative. Early DNMTI combination clinical trials in HR-MDS are often termed "promising," but many randomized trials subsequently failed to show benefit. Clearer understanding of when a combination is likely to improve upon DNMTI monotherapy would inform randomized studies. We reviewed MDS azacitidine or decitabine monotherapy studies. We collected baseline demographics including International Prognostic Scoring System (IPSS) risk, DNMTI, disease characteristics; and response variables including survival and marrow and hematologic responses. Aggregate estimates across studies were calculated using meta-analyses techniques. Using a binomial design, we estimated the necessary operating characteristics to design a phase 2 study showing improved efficacy of a combination over monotherapy. Among 1908 patients, the overall response rate (ORR) was 24% (n = 464; 95% confidence interval [CI], 0.22-0.26): 267 complete response (CR, 14%), 68 partial response (4%), and 129 marrow complete remission (7%). Among 1604 patients for whom a hematologic response was reported, 476 (30%; 95% CI, 0.27-0.32) reported hematologic improvement (HI). More patients treated with azacitidine achieved HI (38%; 95% CI, 0.35-0.41) compared with decitabine (15%; 95% CI, 0.13-0.19), whereas the marrow ORR rate was higher with decitabine (29%; 95% CI, 0.26-0.33) compared with azacitidine (21%; 95% CI, 0.19-0.23). CR rates were similar between DNMTIs: 13% with azacitidine and 16% with decitabine. Variables that influence MDS response include the specific DNMTI backbone and the distribution of IPSS risk of patients enrolled on a trial. Considering these factors can help identify which early combination approaches are worth assessing in larger randomized trials.

The impact of race and ethnicity on outcomes of patients with myelodysplastic syndromes: a population-based analysis

Race and ethnic backgrounds affect the disease characteristics and clinical outcomes in many cancers, including acute myeloid leukemia; however, the association of race/ethnicity on myelodysplastic syndrome (MDS) is still controversial. Therefore, we aimed to study the impact of race/ethnicity on the disease characteristics and survival outcomes in patients with MDS. Adult patients with MDS diagnosed in 2004-2016 were selected using the SEER database. Race/ethnicity was categorized as non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic. Hispanic and NHB patients had significantly lower incidence rate ratio (IRR) in age group ≥01 years (p < .001) compared to NHW; however, in the age group <50 years, NHB patients had significantly higher IRR with an increased incidence rate of 49%. NHB patients had better overall survival than Hispanic and NHW patients (p < .001), even after adjusting for confounding variables. MDS have significant differences in age at diagnosis, disease risk, and survival outcomes based on racial/ethnic backgrounds.

Oral hypomethylating agents: beyond convenience in MDS

Oral hypomethylating agents (HMAs) represent a substantial potential boon for patients with myelodysplastic syndrome (MDS) who have previously required between 5 and 7 visits per month to an infusion clinic to receive therapy. For patients who respond to treatment, ongoing monthly maintenance visits represent a considerable burden to quality of life, and for those who are early in therapy, these sequential visits may tax transportation and financial resources that would be optimally distributed over the treatment cycle to facilitate transfusion support. The availability of oral HMAs may support the optimal application of these agents by contributing to adherence and lessening the burden of therapy, potentially encouraging patients to stay on longer-term treatment. Distinct pharmacokinetic profiles for the recently approved oral HMAs (oral azacitidine and decitabine-cedazuridine) result in differential toxicity profiles and have prompted their clinical trial development in lower- and higher-risk MDS, respectively.

It is time to shift the treatment paradigm in myelodysplastic syndromes: A focus on novel developments and current investigational approaches exploring combinatorial therapy in high-risk MDS

Higher risk myelodysplastic syndromes are defined as a subset of disease with higher risk of AML transformation and poor overall survival. For decades, therapeutic options for high-risk MDS have been limited to allogeneic stem cell transplant (the only option for cure but limited to only a handful of patients) or hypomethylating agents, with the goal to alter the natural history of disease, delay progression and improve survival, while addressing cytopenias, transfusion requirements and improving quality of life. Recent developments in DNA sequencing and other technologies have shed significant light into the pathogenesis of MDS and led to rational and targeted drug development across a variety of therapeutic vulnerabilities, including disruption of protein ubiquitination through NAE inhibition, selective modulation of macrophage activity and immune checkpoint inhibition through blockade of TIM-3. This review highlights some of the most promising agents in recent drug development and their therapeutic efficacy in the management of high-risk MDS, and further explores the rationale behind potential combinatorial approaches using an HMA backbone to synergistically improve treatment outcomes.

Inhibition of CBP synergizes with the RNA-dependent mechanisms of Azacitidine by limiting protein synthesis

The nucleotide analogue azacitidine (AZA) is currently the best treatment option for patients with high-risk myelodysplastic syndromes (MDS). However, only half of treated patients respond and of these almost all eventually relapse. New treatment options are urgently needed to improve the clinical management of these patients. Here, we perform a loss-of-function shRNA screen and identify the histone acetyl transferase and transcriptional co-activator, CREB binding protein (CBP), as a major regulator of AZA sensitivity. Compounds inhibiting the activity of CBP and the closely related p300 synergistically reduce viability of MDS-derived AML cell lines when combined with AZA. Importantly, this effect is specific for the RNA-dependent functions of AZA and not observed with the related compound decitabine that is only incorporated into DNA. The identification of immediate target genes leads us to the unexpected finding that the effect of CBP/p300 inhibition is mediated by globally down regulating protein synthesis.

Dynamics of epigenetic regulator gene BCOR mutation and response predictive value for hypomethylating agents in patients with myelodysplastic syndrome

Background

BCOR (BCL6 corepressor) is an epigenetic regulator gene involved in the specification of cell differentiation and body structure development. Recurrent somatic BCOR mutations have been identified in myelodysplastic syndrome (MDS). However, the clinical impact of BCOR mutations on MDS prognosis is controversial and the response of hypomethylating agents in MDS with BCOR mutations (BCOR^MUT) remains unknown.

Results

Among 676 MDS patients, 43 patients (6.4%) harbored BCOR mutations. A higher frequency of BCOR mutations (8.7%) was investigated in patients with normal chromosome, compared to 4.2% in patients with abnormal karyotype (p = 0.040). Compared to the BCOR^WT patients, the BCOR^MUT patients showed a higher ratio of refractory anemia with excess blasts subset (p = 0.008). The most common comutations with BCOR genes were ASXL1 (p = 0.002), DNMT3A (p = 0.114) and TET2 (p = 0.148). When the hierarchy of somatic mutations was analyzed, BCOR mutations were below the known initial mutations (ASXL1 or TET2) but were above U2AF1 mutations. Transformation-free survival was significantly shorter in BCOR^MUT patients than that in BCOR^WT patients (16 vs. 35 months; p = 0.035). RNA-sequencing was performed in bone marrow mononuclear cells from BCOR^MUT and BCOR^WT patients and revealed 2030 upregulated and 772 downregulated genes. Importantly, HOXA6, HOXB7, and HOXB9 were significantly over-expressed in BCOR^MUT patients, compared to BCOR^WT patients. Eight of 14 BCOR^MUT patients (57.1%) achieved complete remission (CR) with decitabine treatment, which was much higher than that in BCOR^WT patients (28.7%, p = 0.036). Paired sequencing results (before and after decitabine) showed three of 6 CR patients lost the mutated BCOR. The median survival of CR patients with a BCOR^MUT was 40 months, which was significantly longer than that in patients with BCOR^WT (20 months, p = 0.036). Notably, prolonged survival was observed in three BCOR^MUT CR patients even without any subsequent therapies.

Conclusions

BCOR mutations occur more frequently in CN MDS patients, predicting higher risk of leukemia transformation. BCOR^MUT patients showed a better response to decitabine and achieved longer post-CR survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01157-8.

Management of the Older Patient with Myelodysplastic Syndrome

No two diagnoses of myelodysplastic syndrome are genuinely alike, owing to differing and dynamic mutational topography and epigenetic aberrancy. Consequently, no two patients with myelodysplastic syndrome are identical and disease-specific and patient-specific factors are considered in formulating the optimal treatment, which includes few that are disease modifying. Age itself should not be an absolute contraindication to therapy, including intensive therapy such as allogeneic hematopoietic stem cell transplantation, which is the only curative therapy. However, age associates with an increased prevalence of frailty and comorbidities that must be considered and may preclude a path to cure. Palliative therapies are the mainstay for many patients with myelodysplastic syndrome, which is a disease of older adults with the majority of patients diagnosed at age ≥ 75 years. The older patient requires heightened attention to end organ function/reserve and drug-drug interactions as well as insurance, income, cost, and socioeconomic and psychosocial issues that influence management. Many prior studies have included relatively younger populations or have not specifically performed high-quality subgroup analyses of older patients. In this review, we discuss the available standard-of-care therapies for myelodysplastic syndrome as they specifically relate to the older population and assess the emerging therapeutics that may further the pursuit for personalized treatment and improve both the outcomes and quality of life of the older patient with myelodysplastic syndrome.

Phase II study of azacitidine with pembrolizumab in patients with intermediate-1 or higher-risk myelodysplastic syndrome

Programmed cell death protein 1 (PD-1) and PD-ligand 1 (PD-L1) expression is upregulated in cluster of differentiation 34 (CD34)⁺ bone marrow cells from patients with myelodysplastic syndromes (MDS). Hypomethylating agent (HMA) treatment results in further increased expression of these immune checkpoints. We hypothesised that combining an anti-PD-1 antibody with HMAs may have efficacy in patients with MDS. To test this concept, we designed a phase II trial of the combination of azacitidine and pembrolizumab with two cohorts. In the 17 previously untreated patients, the overall response rate (ORR) was 76%, with a complete response (CR) rate of 18% and median overall survival (mOS) not reached after a median follow-up of 12·8 months. For the HMA-failure cohort (n = 20), the ORR was 25% and CR rate was 5%; with a median follow-up of 6·0 months, the mOS was 5·8 months. The most observed toxicities were pneumonia (32%), arthralgias (24%) and constipation (24%). Immune-related adverse events requiring corticosteroids were required in 43%. Overall, this phase II trial suggests that azacitidine and pembrolizumab is safe with manageable toxicities in patients with higher-risk MDS. This combined therapy may have anti-tumour activity in a subset of patients and merits further studies in the front-line setting.

Erythroid nuclear dysplasia is associated with inferior outcomes for patients with myelodysplastic syndrome undergoing allogeneic hematopoietic cell transplantation

Disease burden prior to hematopoietic cell transplantation (HCT) is difficult to assess in myelodysplastic syndrome (MDS), particularly in patients without excess blasts. We assessed whether morphologic dysplasia at the time of transplant can be a metric of disease burden that is associated with post-transplant outcomes in MDS patients. We identified 84 MDS patients undergoing allogeneic HCT at our institution between 2010 and 2017 who received a bone marrow evaluation immediately prior to HCT. Dysplasia was independently determined by two hematopathologists blinded to existing pathology reports. Erythroid nuclear dysplasia, but not megakaryocytic or myeloid, was associated with post-HCT outcomes. Presence compared to absence of erythroid nuclear dysplasia was associated with lower 2-year progression-free survival (PFS; 34 % vs 62 %, p = 0.0495) and 2-year overall survival (OS; 34 % vs 62 %, p = 0.042). In a multivariate analysis including age, IPSS-R at the time of transplant, pre-HCT therapy, and donor type as covariates, erythroid nuclear dysplasia remained associated with lower PFS (HR 2.6, p = 0.036) and OS (HR 2.7, p = 0.028). Dysplasia assessment prior to transplant may serve as an estimate of disease burden in MDS and identify high-risk patients who merit additional therapies pre- or post-transplant.

Cedazuridine/decitabine: from preclinical to clinical development in myeloid malignancies

Since the US Food and Drug Administration (FDA) approvals of parenteral decitabine and azacitidine, DNA methyltransferase inhibitors, otherwise referred to as DNA hypomethylating agents (HMAs), have been a mainstay in the treatment of higher-risk myelodysplastic syndromes. The development of oral HMAs has been an area of active interest; however, oral bioavailability has been quite poor due to rapid metabolism by cytidine deaminase (CDA). This led to the development of the novel CDA inhibitor cedazuridine, which was combined with an oral formulation of decitabine. Preclinical work demonstrated a pharmacokinetic and pharmacodynamic profile approximate to parenteral decitabine, leading to early-phase clinical trials of oral cedazuridine-decitabine (C-DEC) in myelodysplastic syndromes and chronic myelomonocytic leukemia (CMML). A combination of oral decitabine 35 mg with oral cedazuridine 100 mg was established as the recommended phase 2 dose. Phase 2 data confirmed bioequivalence of C-DEC when compared with parenteral decitabine, and a larger phase 3 trial has demonstrated similar results, leading to the FDA approval of C-DEC for use in intermediate/high-risk myelodysplastic syndrome (MDS) and CMML. This review will focus upon the current role of HMA therapy in MDS/CMML, preclinical and clinical development of C-DEC, and potential roles of oral HMA therapy in myeloid malignancies moving forward.

Epigenetics in a Spectrum of Myeloid Diseases and Its Exploitation for Therapy

Simple Summary

The genome is stored in the limited space of the nucleus in a highly condensed form. The regulation of this packaging contributes to determining the accessibility of genes and is important for cell function. Genes affecting the genome’s packaging are frequently mutated in bone marrow cells that give rise to the different types of blood cells. Here, we first discuss the molecular functions of these genes and their role in blood generation under healthy conditions. Then, we describe how their mutations relate to a subset of diseases including blood cancers. Finally, we provide an overview of the current efforts of using and developing drugs targeting these and related genes.

Abstract

Mutations in genes encoding chromatin regulators are early events contributing to developing asymptomatic clonal hematopoiesis of indeterminate potential and its frequent progression to myeloid diseases with increasing severity. We focus on the subset of myeloid diseases encompassing myelodysplastic syndromes and their transformation to secondary acute myeloid leukemia. We introduce the major concepts of chromatin regulation that provide the basis of epigenetic regulation. In greater detail, we discuss those chromatin regulators that are frequently mutated in myelodysplastic syndromes. We discuss their role in the epigenetic regulation of normal hematopoiesis and the consequence of their mutation. Finally, we provide an update on the drugs interfering with chromatin regulation approved or in development for myelodysplastic syndromes and acute myeloid leukemia.

Factors affecting response to 5-azacytidine and prognosis of myelodysplastic syndrome. Is long-term survival a realistic goal?

The introduction of hypomethylating agents (HMAs) 5-azacytidine and decitabine has altered the prognosis of patients with myelodysplastic syndrome (MDS). Over the past few years, the International Prognostic Scoring System (IPSS) and the revised IPSS (IPSS-R) have been used both to define the prognosis of patients with MDS and to select patients to be treated with HMAs. Nevertheless, the prognosis of individual patients with MDS can differ considerably from the one calculated with the use of the above-mentioned prognostic systems. Thus, some patients may achieve long-term survival irrespective of their initial prognostic score. Several factors besides those used to define the IPSS/IPSS-R are analyzed in this review article; these include age and gender, the baseline hematologic characteristics, the comorbidities, the cytogenetic and molecular profile of the patients, as well as their response to treatment with 5-azacytidine. Thus, insight into a more personalized way of managing patients with MDS is given and long-term survival is set as a more realistic goal of treatment with 5-azacytidine.

Distinctive phenotypes in two children with novel germline RUNX1 mutations - one with myeloid malignancy and increased fetal hemoglobin

RUNX1 associated familial platelet disorder (FPD) is a rare autosomal dominant hematologic disorder characterized by thrombocytopenia and/or altered platelet function. There is an increased propensity to develop myeloid malignancy (MM) - acute myeloid leukemia, myeloproliferative neoplasms or myelodysplastic syndrome often in association with secondary somatic variants in other genes. To date, 23 FPD-MM pediatric cases have been reported worldwide. Here, we present two new kindreds with novel RUNX1 pathogenic variants in which children are probands. The first family is a daughter/mother diad, sharing a heterozygous frameshift variant in RUNX1 gene (c.501delT p.Ser167Argfs*9). The daughter, age 13 years, presented with features resembling juvenile myelomonocytic leukemia - severe anemia, thrombocytopenia, high white cell count with blast cells, monocytosis, increased nucleated red cells and had somatic mutations with high allele burden in CUX1, PHF6, and SH2B3 genes. She also had increased fetal hemoglobin and increased LIN28B expression. The mother, who had a long history of hypoplastic anemia, had different somatic mutations- a non-coding mutation in CUX1 but none in PHF6 or SH2B3. Her fetal hemoglobin and LIN28B expression were normal. In the second kindred, the proband, now 4 years old with thrombocytopenia alone, was investigated at 3 months of age for persistent neonatal thrombocytopenia with large platelets. Molecular testing identified a heterozygous intragenic deletion in RUNX1 encompassing exon 5. His father is known to have increased bruising for several years but is unavailable for testing. These two cases illustrate the significance of secondary mutations in the development and progression of RUNX1-FPD to MM.

Clinical Management of Anemia in Patients with Myelodysplastic Syndromes: An Update on Emerging Therapeutic Options

For the majority of patients with lower-risk myelodysplastic syndrome (LR-MDS), one of the primary clinical goals is to alleviate the symptoms associated with the resultant cytopenias and to minimize the transfusion burden. While supportive red blood cell (RBC) transfusions and erythropoiesis-stimulating agents (ESAs) may lead to clinical improvement, frequent transfusions are often complicated by iron overload and decreased quality of life; furthermore, most patients either do not respond to ESAs or will eventually develop resistance. As such, there is a great need for further therapeutic options in the management of anemia related to MDS. Several additional therapeutics are now available in select patients with LR-MDS and symptomatic anemia including luspatercept, lenalidomide, and immunosuppressive therapy. Furthermore, several novel agents are currently in development to address this area of clinical need such as imetelstat and roxadustat. In this article, we review the currently available therapeutic options for symptomatic anemia in LR-MDS as well as review the therapeutic agents in development.

Treatment patterns and outcomes in patients with myelodysplastic syndromes treated with hypomethylating agents: a SEER-Medicare analysis

To describe real-world treatment patterns and outcomes among adult patients with myelodysplastic syndromes (MDS) treated with hypomethylating agents (HMA), patients were identified in the SEER-Medicare database (01/2006-12/2016); 3,046 patients with MDS treated with HMA were included. An algorithm was developed to categorize patients into MDS risk groups: the majority of patients were classified as Higher-risk (70.9%), 8.0% as Intermediate-risk, and 21.1% as Unknown-risk. Overall, 77.4% of patients initiated azacitidine and 22.6% decitabine; they received an average of 5.1 index-HMA cycles, of which 90.9% were complete with a median cycle duration of 28 days. Median survival was 11.6, 18.4, and 19.1 months for the Higher-risk, Intermediate-risk, and Unknown-risk groups, respectively. Median time-to-AML transformation was 19.3 months for the Higher-risk group and 50.4 months for the Intermediate-risk group (not reached for Unknown-risk). Data highlight the unmet medical needs of patients with MDS treated with HMA, particularly for the Higher-risk MDS group.

Direct Medical Costs Associated With Treatment Nonpersistence in Patients With Higher-Risk Myelodysplastic Syndromes Receiving Hypomethylating Agents: A Large Retrospective Cohort Analysis

BACKGROUND

Suboptimal use of hypomethylating agents (HMAs) among higher-risk myelodysplastic syndrome (HR-MDS) patients can translate into worse health outcomes and economic burden. We estimated the direct medical costs associated with HMA treatment nonpersistence among HR-MDS patients.

PATIENTS AND METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare linked database, a retrospective cohort of patients diagnosed with refractory anemia with excess blasts (RAEB), a diagnosis that substantially overlaps with HR-MDS, between January 2011 and December 2015 was analyzed. Patients who had ≥ 1 year of continuous Medicare enrollment before diagnosis and who did not receive stem cell transplant or lenalidomide in the follow-up period were included. Patients receiving HMAs were stratified into HMA persistent (≥4 HMA cycles) and HMA nonpersistent (<4 cycles or a gap of ≥ 90 days between cycles) groups. Healthcare resource use and costs during the follow-up period were reported descriptively as total and per patient per month (PPPM). Weighted generalized linear models (GLM) were used to compare estimated healthcare resource use and costs between HMA groups.

RESULTS

Among the 664 patients with RAEB, 295 (44.4%) were HMA nonpersistent and 369 (55.6%) HMA persistent. On the basis of weighted GLM analysis, the HMA nonpersistent group incurred significantly (P < .05) higher total PPPM costs compared to the HMA persistent group ($18,039 vs. $13,893), particularly for hospitalization ($3,375 vs. $2,131), and emergency room ($5,517 vs. $2,867) costs.

CONCLUSION

There is a substantial economic burden associated with early discontinuation of guideline-recommended HMA therapy in RAEB patients. The study findings necessitate closer care management in this population in order to improve outcomes and reduce healthcare spending.

Under-use of Hypomethylating Agents in Patients With Higher-risk Myelodysplastic Syndrome in the United States: A Large Population-based Analysis

BACKGROUND

Recent data suggest significant underutilization of hypomethylating agents (HMAs) that are recommended treatments for patients with myelodysplastic syndromes (MDS) with refractory anemia with excess blasts (RAEB). The study objective was to assess the degree of HMA use and predictors of HMA underuse in this population.

PATIENTS AND METHODS

This was a retrospective study including patients diagnosed with the RAEB form of MDS between January 2011 and December 2015 using the Surveillance, Epidemiology, and End Results-Medicare linked database. Patients were excluded if they had < 1 year of continuous enrollment before diagnosis or received stem cell transplant or lenalidomide during the follow-up period. HMA non-peristence was defined as use of < 4 cycles (3-10 HMA days/28 days) of HMAs or a gap of ≥ 90 days between consecutive cycles. Patients were characterized as HMA never-users, HMA-persistent users, and HMA-non-persistent users. Descriptive statistics were used to summarize patient characteristics. Multivariable logistic regression was used to assess predictors of HMA underuse and persistence.

RESULTS

Of the 1190 patients, 526 (44%) were never-users, 295 (25%) were non-persistent users, and 369 (31%) were persistent users. Age at diagnosis (eg, 66-70 years vs. ≥ 80 years; odds ratio [OR], 2.36; 95% confidence interval [CI], 1.56-3.56), marital status (single vs. married; OR, 0.67; 95% CI, 0.51-0.89), National Cancer Institute comorbidity index (≥ 3 vs. 0-1; OR, 0.62; 95% CI, 0.46-0.83), and performance status (poor vs. good; OR, 0.67; 95% CI, 0.51-0.87) were significantly associated with HMA underuse.

CONCLUSION

Several demographic and clinical factors were associated with underuse of HMAs. There is need for a better understanding of suboptimal HMA use and its relationship with clinical response.

Low participation rates and disparities in participation in interventional clinical trials for myelodysplastic syndromes

BACKGROUND

The development of novel therapies for the myelodysplastic syndromes (MDS) is hampered by inadequate trial recruitment. Factors contributing to low trial accrual are incompletely understood.

METHODS

This study analyzed a pooled patient database from institutions of the US MDS Clinical Research Consortium to compare the characteristics of participants in interventional trials with those of patients who did not enroll in a trial.

RESULTS

Data were identified for 1919 patients with MDS, and 449 of these patients (23%) participated in an interventional clinical trial. The median age of all patients was 68 years, and 64% were male. Patients who participated in trials were significantly younger than nonparticipants (P = .014), and men were more likely to participate in a trial (71% of trial participants were male, whereas 61% of nonparticipants were; P < .001). Race and ethnicity were not associated with trial enrollment. Patients in more affluent ZIP codes had a higher participation rate (P < .001). Patients with intermediate- and high-risk disease according to the revised International Prognostic Scoring System were overrepresented (P = .004), and trial participants less frequently had treatment-related disease (P < .001). In multivariable analyses, participation in a clinical trial was associated with a reduced hazard of death (P = .004). Even at large referral centers, only a minority of patients with MDS enrolled in interventional trials.

CONCLUSIONS

Restrictive trial eligibility criteria that exclude patients with MDS on account of age, comorbidities, or a history of another cancer are limit enrollment of MDS patients to clinical trials. Gaining insight into the barriers to trial accrual may help investigators and study sponsors to design trials that will accrue more rapidly and augment treatment options for patients with MDS.

[Efficacy and safety of generic azacitidine in Chinese patients with higher-risk myelodysplastic syndromes: a multicenter, prospective, single-arm study]

Objective: To evaluate the efficacy, safety, and pharmacokinetics of the generic azacitidine in Chinese patients with higher-risk myelodysplastic syndromes(MDS). Methods: Between October 2013 and 2016, 72 patients were eligible for enrollment at 9 sites from China received generic subcutaneous azacitidine 75 mg·m(-2)·d(-1) for 7 days per 28-day cycle, for ≥6 cycles. Pharmacokinetic blood samples were collected on day 1 of a single-dose. Results: For each patient at cycle 6 or at the time of study discontinuation, whichever came first, the overall response rate, which included complete remission (CR)and partial remission(PR), was 6.9%(5/72), the rate of patients who had the best effect with CR or PR during the treatment was 12.5%(9/72). Patients who were dependent on red-blood-cell transfusions and platelet transfusions at baseline became transfusion independent were 46.3%(19/41)and 41.2% (7/17), respectively. The median time of treatment was 6 cycles, and the median OS was 16.1 months (95%CI 10.9-20.6 months). For 36 patients(50%)received treatment at ≥6 cycles, and the median OS was 22.3 months(95%CI 16.1- not evaluative). Most common grade Ⅲ-Ⅳ hematologic treatment-emergent adverse events were neutropenia(55%), leukopenia(47%), and thrombocytopenia(61%). Pharmacokinetic profiles were similar for generic and original azacitidine in Chinese patients. Conclusion: Generic azacitidine treatment was favorable and safe and can be used as a standard treatment for patients with higher-risk MDS.

Which lower risk myelodysplastic syndromes should be treated with allogeneic hematopoietic stem cell transplantation?

Indications of allogeneic hematopoietic stem cell transplantation (HSCT) remain controversial in patients with lower risk myelodysplastic syndrome. We review prognostic factors in lower risk MDS, delineating patients with relatively poor risk who may potentially benefit from HSCT during the disease course. Results of HSCT in those patients, and main efforts to decrease non-relapse mortality (NRM) are detailed. Prospective studies are needed to determine more precisely which lower risk MDS patients may benefit from transplantation.

Following in the footsteps of acute myeloid leukemia: are we witnessing the start of a therapeutic revolution for higher-risk myelodysplastic syndromes?

For most patients with higher-risk myelodysplastic syndromes (HR-MDS) the hypomethylating agents (HMA) azacitidine and decitabine remain the mainstay of therapy. However, the prognosis mostly remains poor and aside from allogeneic hematopoietic stem cell transplantation no curative treatment options exist. Unlike acute myeloid leukemia, which has seen a dramatic expansion of available therapies recently, no new agents have been approved for MDS in the United States since 2006. However, various novel HMAs, HMA in combination with venetoclax, immune checkpoint inhibitors, and targeted therapies for genetically defined patient subgroups such as APR-246 or IDH inhibitors, have shown promising results in early stages of clinical testing. Furthermore, the wider availability of genetic testing is going to allow for a more individualized treatment of MDS patients. Herein, we review the current treatment approach for HR-MDS and discuss recent therapeutic advances and the implications of genetic testing on management of HR-MDS.

Hypomethylating agent (HMA) therapy use and survival in older adults with Refractory Anemia with Excess Blasts (RAEB) in the United States (USA): a large propensity score-matched population-based study†

Hypomethylating agents (HMA) showed overall survival (OS) benefits in patients with higher-risk myelodysplastic syndromes (HR-MDS) in clinical trials. We conducted a retrospective cohort study of Surveillance, Epidemiology, and End Results (SEER)-Medicare data of patients ≥66 years diagnosed with refractory anemia with excess blasts (RAEB), a proxy for HR-MDS, in 01/2001-04/2004 (pre-period) or 01/2006-12/2011 (post-period). Association between post-period diagnosis and OS was examined using propensity scores (PS)-matched samples. Among 1876 RAEB patients, median OS was 9 months and 30.8% received HMAs (3.6% in pre-period; 43.0% in post-period) with no association between post-period diagnosis and OS. In the top PS quartile, post-period diagnosis was associated with a 74% lower risk of death (Hazard ratio [HR] = 0.26, 95%-CI: 0.10-0.69, p = 0.007), while outcomes were worse in the lowest PS quartile (HR = 2.80, 95%-CI: 1.06-7.36, p = 0.037). HMA lead to a 3-month OS benefit for patients most likely to receive HMA but not for unselected RAEB cohort.

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.

Low clinical trial accrual of patients with myelodysplastic syndromes: Causes and potential solutions

Despite few effective therapies, only a small percentage of patients diagnosed with myelodysplastic syndromes (MDS) in the United States are enrolled in prospective, interventional clinical trials. MDS-specific barriers to trial accrual include a high frequency of elderly patients with comorbid conditions, atypical disease features and uncertainty regarding the diagnosis (because other nonclonal processes also can cause dysplasia and cytopenias), a history of another nonmyeloid neoplasm resulting in therapy-related MDS, rapid disease recurrence after allogeneic stem cell transplantation, and an arbitrary division between MDS and acute myeloid leukemia. In addition, barriers to accrual that are common to other oncology populations, such as difficulty traveling to clinical trial enrollment sites and narrow trial eligibility criteria, also prevent patients with MDS from enrolling in studies. Collectively these barriers must be assessed systematically, and creative solutions are needed to improve outcomes for this needy patient population.