Conference Coverage

For lower-risk MDS, treat ‘what bugs patients most’


 

FROM ASH HEMATOLOGIC MALIGNANCIES 2020

Clinicians who treat patients with lower-risk myelodysplastic syndrome should focus on “what bugs patients most,” with therapeutic goals reflecting and respecting the patients’ goals, a specialist in MDS recommended.

“There’s an uncomfortable truth in treating lower-risk MDS: No treatment that we have has ever been demonstrated in a prospective trial to prolong survival in lower-risk MDS, so in the end, what we’re doing is trying to improve transfusion needs and to improve quality of life,” said Michael A. Sekeres, MD, MS, from the Cleveland Clinic.

Dr. Sekeres described optimal therapy for patients with lower-risk MDS in an online presentation during the virtual American Society of Hematology Meeting on Hematologic Malignancies.

He acknowledged that the definition of MDS as “a heterogeneous clonal hematopoietic disorder derived from an abnormal multipotent progenitor cell, characterized by a hyperproliferative bone marrow, dysplasia of the cellular elements, and ineffective hematopoiesis” can be confusing even for hematologists well versed in the disorder.

An easier-to-grasp explanation, he said, is that “MDS is considered a cancer, and like other cancers it has a clonal origin, involves the abnormal growth of cells that exceeds the growth of other cells around them and don’t know when to stop growing, and it takes over normal tissue, so that the normal tissues – in this case the hematopoietic precursors in the bone marrow – don’t function normally, resulting in cytopenias.”

‘Mild displeasure syndrome’

Approximately 95% of patients with MDS have a discrete genetic abnormality, but only one driver mutation, in the gene SF3B1, is considered to be a lower-risk abnormality, with a more favorable prognosis.

Treatment options for patients with lower-risk MDS, defined as an International Prognostic Scoring System score of 1 or less, or a Revised IPSS score of 3.5 or less, will depend on the patients’ transfusion needs and quality of life.

Patients with no transfusion requirements and a generally good quality of life may be followed by observation alone, with blood counts every 1 to 6 months depending on clinical presentation.

“We have some folks coming in who really don’t have very bad blood counts and have a good quality of life,” Dr. Sekeres said. “Those folks we would consider to have a very good risk type of MDS, which one of my patients referred to once as ‘mild displeasure syndrome.’ It was a displeasure to him to have to fight the traffic to come into Cleveland to see me every month, or 2 months, or 6 months, but beyond that we didn’t have to treat his MDS.”

Isolated cytopenias

Patients with isolated anemia, with hemoglobin less than 10 g/dL and/or transfusion dependence, and who are symptomatic should be started on an erythopoiesis-stimulating agent (ESA), either recombinant humanized erythropoietin or darbepoetin, or the erythroid-maturing agent luspatercept (Reblozyl).

The probability of a response to ESAs in this populations ranges from about 15% to 35%, with patients who have low baseline serum erythropoietin and no or few transfusions most likely to respond.

“On the other hand, patients who come into our clinic who are already dependent on red blood cell transfusions and have a sky-high [erythropoietin] level in the hundreds or even thousands have a very low likelihood of responding to exogenously administered ESAs,” he said.

Patients with no response to ESAs or luspatercept or a loss of response suggestive of disease progression should undergo repeat bone marrow biopsy. Patients who develop deletion 5q should be started on lenalidomide (Revlimid). In these patients, next-generation sequencing may also reveal targetable abnormalities.

For patients with isolated thrombocytopenia, thrombopoietin agonists such as romiplostim or eltrombopag may help to reduce platelet transfusion requirements and clinically significant bleeding events, but these agents come with a very important caveat: in addition to promoting platelet production, thrombopoietin receptor agonists can promote the growth of blasts, which could in turn promote the transformation of MDS to acute myeloid leukemia.

“This is an off-label use of romiplostim for the treatment of MDS with thrombocytopenia, and this drug should never, never, never be given to a patient who has excess blasts at baseline MDS; the same is true of its cousin eltrombopag.” Dr. Sekeres said.

Multlineage dysplasia

Patients with multilineage dysplasia can have good responses to hypomethylating agents, either azacitidine 75 mg/m2 IV or subcutaneously for 3 days every 4 weeks, or decitabine 20 mg/m2 IV for 3 days every 4 weeks.

“Another approach to treating patients with multilineage dysplasia is to consider the use of antithymocyte globulin; in other words, treat these patients as if they have aplastic anemia, because there are some types of MDS in which immune-mediated destruction of bone marrow plays a role,” Dr. Sekeres said.

“This is particularly appealing in patients who have a hyperplastic marrow, or those who have other autoimmune conditions that are going on that may indicate a broader autoimmune process that’s involved in the bone marrow,” he added.

Patients treated with antithymocyte globulin require hospitalization with discharge on steroids for 1 month to prevent serum sickness in response to the treatment, and maintenance on low-dose cyclosporine.

“In MDS, unfortunately, our understanding of the biology of the disease far exceeds what we can do about it, but we’re starting to catch up,” Dr. Sekeres said.

No funding source for the presentation was disclosed. Dr. Sekeres disclosed serving on advisory boards for Celegene/Bristol-Myers Squibb, Takeda/Millenium, and Pfizer.

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