Myelodysplastic Syndrome (MDS): Treatments and Prognosis

Research-informed explainer — last updated April 12, 2026

Myelodysplastic syndrome (MDS) is a group of bone marrow disorders in which the marrow does not produce enough healthy blood cells. Treatment ranges from supportive care with blood transfusions for low-risk disease to aggressive chemotherapy and stem cell transplantation for high-risk disease — and the right choice depends heavily on your MDS subtype, risk category, age, and overall health. Some patients live for many years with MDS; others progress to leukemia and require urgent intervention.

This explainer draws on research from three hematologists in the Convene directory: Jaroslaw Maciejewski at Cleveland Clinic, one of the world's leading researchers on MDS pathogenesis, bone marrow failure, and clonal hematopoiesis; Daniel DeAngelo at Dana-Farber Cancer Institute and Harvard Medical School, who has published extensively on targeted therapies for leukemia arising from or related to MDS; and Morie Gertz at Mayo Clinic, an expert in hematologic malignancy staging and supportive care.

What is myelodysplastic syndrome?

MDS is a clonal disorder of the bone marrow — a family of conditions in which stem cells that should produce red blood cells, white blood cells, and platelets instead develop abnormally and either die prematurely (a process called ineffective hematopoiesis) or accumulate and crowd out healthy production.

The result is low blood counts (cytopenias), which cause the symptoms most patients first notice:

• Fatigue and shortness of breath from low red blood cell counts (anemia)
• Increased infection risk from low or poorly functioning white blood cells (neutropenia)
• Easy bruising or bleeding from low platelet counts (thrombocytopenia)

MDS most often affects older adults — the median age at diagnosis is around 70 — but it can occur at any age. In some patients, MDS is detected incidentally on routine blood work before significant symptoms develop.

MDS is classified by the World Health Organization based on the number of cell lines affected (single vs multi-lineage dysplasia), blast percentage in the bone marrow, and specific chromosomal abnormalities. This classification shapes both prognosis and treatment decisions.

How MDS is diagnosed

No single test diagnoses MDS. Diagnosis requires a combination of:

Complete blood count (CBC). Low hemoglobin (anemia), white blood cell count, or platelet count prompts further workup. The abnormality may affect one, two, or all three cell lines.

Peripheral blood smear. A trained hematologist examines the blood under a microscope looking for abnormally shaped or immature cells (dysplastic changes). In MDS, cells often look abnormal — hypersegmented neutrophils, oval macrocytes, hypolobated neutrophils (pseudo-Pelger-Huet cells).

Bone marrow biopsy. The definitive test. A needle is inserted into the back of the pelvis (posterior iliac crest) under local anesthesia and a small core of marrow is removed. The pathologist assesses the percentage of immature cells (blasts), the degree of dysplasia, and the marrow's overall cellularity.

Cytogenetics and molecular testing. Chromosomal abnormalities (detected by conventional karyotyping or FISH) are present in about 50% of MDS patients and are critical for prognosis. Mutations in specific genes — SF3B1, SRSF2, TET2, DNMT3A, TP53, and others — are identified by next-generation sequencing (NGS). These mutations influence treatment response and help distinguish MDS from other conditions. Work from Maciejewski's group and collaborators established that MDS often overlaps biologically with other marrow failure states including paroxysmal nocturnal hemoglobinuria (PNH) [1] and large granular lymphocytic leukemia [2], pointing to shared immune-mediated mechanisms of marrow suppression that can influence treatment selection.

Risk stratification scoring. Once diagnosis is confirmed, risk scores guide treatment intensity. The most widely used is the Revised International Prognostic Scoring System (IPSS-R), which incorporates hemoglobin, platelet count, absolute neutrophil count, marrow blast percentage, and cytogenetic risk group into a score that predicts survival and leukemia transformation risk. Scores range from very low to very high risk.

Treatment options

Supportive care (all risk categories)

Supportive care manages symptoms without treating the underlying disease. It is the primary strategy for low-risk MDS and a component of care at all risk levels.

Red blood cell (RBC) transfusions correct anemia and relieve fatigue. Many low-risk MDS patients receive transfusions every 4 to 12 weeks indefinitely. Frequent transfusions, however, carry a risk: iron overload. Each unit of blood contains about 250 mg of iron, which the body cannot excrete on its own. Over time, iron accumulates in the heart, liver, and other organs. Iron chelation therapy (deferasirox, deferoxamine) reduces this buildup in patients who have received many transfusions and have adequate organ function.

Growth factor support. Erythropoiesis-stimulating agents (ESAs) like erythropoietin or darbepoetin can reduce transfusion dependence in select low-risk patients, particularly those with low baseline erythropoietin levels and no del(5q) chromosome deletion. Response rates are approximately 40–60% in appropriately selected patients, and response typically lasts 1 to 2 years before the disease becomes refractory.

Platelet transfusions and growth factors. For patients with severe thrombocytopenia, platelet transfusions prevent bleeding. Thrombopoietin receptor agonists (romiplostim, eltrombopag) can increase platelet counts in some MDS patients, though they are not universally used.

Lenalidomide for del(5q) MDS

Patients with MDS associated with a deletion in chromosome 5q (del(5q)) represent a distinct and fortunate subgroup. Lenalidomide (Revlimid) produces transfusion independence in approximately 67% of del(5q) MDS patients — a rate far higher than in non-del(5q) disease. Response is durable in many patients. Lenalidomide is oral and generally well-tolerated, with neutropenia and thrombocytopenia as the main side effects. It is considered first-line treatment for transfusion-dependent, low-risk MDS with del(5q).

Hypomethylating agents (HMA) for higher-risk MDS

For patients with intermediate-2 or high-risk MDS by IPSS (or intermediate, high, or very high by IPSS-R), hypomethylating agents — azacitidine (Vidaza) and decitabine — are the standard of care when allogeneic stem cell transplant is not feasible or not immediately planned.

These drugs work by reversing abnormal silencing of tumor-suppressor genes in MDS cells. They are given in repeated cycles (typically monthly) as outpatient intravenous or subcutaneous injections. Response rates are approximately 40–60% for overall response (including stabilization of counts, reduction in transfusion dependence, partial response, and complete remission). Median overall survival with azacitidine in high-risk MDS is approximately 24 months compared to about 15 months with conventional care.

HMAs do not cure MDS. Most patients eventually develop resistance, at which point disease progression is rapid. Clinical trials testing HMAs combined with targeted agents — venetoclax, magrolimab, IDH inhibitors — are ongoing. The work of DeAngelo and colleagues on IDH2 inhibition (enasidenib) in AML [6] established a proof of concept that targeting specific molecular mutations in myeloid disease can produce meaningful responses, including in patients whose disease evolved from MDS.

Allogeneic stem cell transplant: the only curative option

Allogeneic hematopoietic stem cell transplantation (allo-SCT) — also called a bone marrow or stem cell transplant — is the only treatment with the potential to cure MDS. The procedure replaces your bone marrow with healthy donor marrow, and the donor immune system attacks and eliminates any remaining MDS cells (the graft-versus-leukemia effect).

The decision to transplant is driven by risk, age, and fitness:

• High-risk MDS (IPSS-R high or very high): transplant is generally recommended in eligible patients because the disease is likely to progress to AML within months to a few years
• Intermediate-risk MDS: transplant decisions are individualized — the risks of the procedure must be weighed against the risk of disease progression
• Low-risk MDS: transplant is generally deferred because the long-term risks of the procedure exceed the disease's natural history for most patients

Age is a major factor. Myeloablative conditioning (high-dose chemotherapy before transplant) carries higher mortality risk in patients over 60 to 65. Reduced-intensity conditioning (RIC) regimens, which use lower chemotherapy doses, have extended transplant eligibility to patients into their 70s at centers with experience. Treatment-related mortality at experienced centers ranges from about 10–20% at 1 year depending on patient fitness and conditioning regimen.

MDS genetics influence transplant outcomes. Mutations in TP53, for example, confer a poor prognosis even after transplant. Work from DeAngelo's group established that specific somatic mutations distinguish secondary AML (often arising from MDS) from de novo AML, and that these mutations persist in clonal remissions, helping explain why some post-transplant remissions are not durable [9]. Understanding your mutational profile helps predict transplant outcomes.

Investigational and emerging therapies

The field is moving rapidly. Several approaches are in late-stage trials or recently approved:

Imetelstat is a telomerase inhibitor that showed meaningful transfusion independence rates in lower-risk, HMA-naive patients in a phase 3 trial and received FDA approval in 2024 for transfusion-dependent lower-risk MDS patients who have not responded to ESAs.

Luspatercept (Reblozyl), an activin receptor ligand trap, was approved for transfusion-dependent anemia in low/intermediate-risk MDS — particularly in patients with ring sideroblasts (who often have SF3B1 mutations) — and outperformed epoetin alfa in a head-to-head trial.

Venetoclax plus azacitidine is a combination studied in high-risk MDS after showing strong results in AML. Early results are promising, and this combination is being evaluated in frontline and relapsed MDS.

Magrolimab, an anti-CD47 antibody, showed early promise in MDS — though subsequent clinical trial results were mixed — highlighting the complexity of targeting the tumor microenvironment in bone marrow disease.

Prognosis

MDS survival is highly variable. Very-low-risk patients (IPSS-R very low) have a median survival exceeding 8 years, while very-high-risk patients have median survival under 1 year without transplant.

Several factors independently worsen prognosis:

• High-risk cytogenetics, especially complex karyotype or monosomal karyotype
• TP53 mutations (associated with rapid progression and poor transplant outcomes)
• Higher blast percentage (5–9% blasts significantly worsens outcome compared to <5%)
• RAEB-T (refractory anemia with excess blasts in transformation): 20–30% blasts, essentially AML by current WHO criteria
• Transfusion dependence at diagnosis
• Low platelet count

The risk of progression to acute myeloid leukemia (AML) — which occurs in roughly 25–35% of MDS patients — is highest in patients with excess blasts and high-risk cytogenetics. MDS that transforms to AML (secondary AML or MDS/AML) carries a worse prognosis than de novo AML, partly because of the somatic mutations that define its biology [9].

GATA2 deficiency is a special category: a hereditary MDS/bone marrow failure syndrome in which germline mutations in the GATA2 gene cause progressive immunodeficiency and very high risk of MDS transformation, often in younger patients. Research from Maciejewski's group characterizing GATA2-related MDS in children and adolescents [5] helped establish that these patients often benefit from early transplant evaluation rather than watchful waiting.

What the research shows

Several threads of research have shaped how MDS is understood and treated today.

Maciejewski's lab established early evidence for immune-mediated destruction of blood progenitor cells in MDS — specifically that inflammatory cytokines like interferon-gamma and TNF-alpha trigger apoptosis in CD34+ marrow precursors via the Fas pathway [4]. This biological insight forms part of the rationale for immunosuppressive therapy (anti-thymocyte globulin, cyclosporine) in a subset of lower-risk MDS patients who resemble aplastic anemia in their immune profile.

The overlap between MDS and paroxysmal nocturnal hemoglobinuria (PNH) — another marrow failure disorder driven by complement-mediated cell destruction — led to the development of complement inhibitors like eculizumab, which was tested in phase 1 and phase 3 trials that Maciejewski contributed to [1][3]. PNH clones are detectable in a significant proportion of MDS patients and can contribute to the anemia burden.

In the AML space, which is closely linked to high-risk MDS management, work on IDH2 inhibition (enasidenib) demonstrated that targeting specific molecular mutations in myeloid malignancies could produce meaningful remissions in patients who had failed standard therapy [6]. Mutations in IDH1 and IDH2 are found in a subset of MDS patients and may eventually inform treatment selection in that setting as well.

Questions to ask your hematologist

• What is my MDS subtype and IPSS-R risk category, and what does that mean for how urgently I need to start treatment?
• Do I have del(5q), SF3B1, TP53, or other mutations that would affect my treatment options or prognosis?
• Am I a candidate for erythropoiesis-stimulating agents, lenalidomide, or luspatercept before moving to more intensive therapy?
• If I need a hypomethylating agent, would azacitidine or decitabine be more appropriate, and how will we know if it is working?
• At what point would you recommend an evaluation for stem cell transplant, and what would make me eligible or ineligible?
• What clinical trials are open at your center for patients with my MDS profile?
• What is the risk of iron overload with my current transfusion frequency, and do I need chelation therapy?
• If my disease transforms to AML, what would change about my treatment plan?