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New hope for MDS, with AML treatments


 

Until just over a year ago, Pat Trueman, an 82-year-old in New Hampshire, had always been a “go-go-go” kind of person. Then she started feeling tired easily, even while doing basic housework.

“I had no stamina,” Ms. Trueman said. “I didn’t feel that bad, but I just couldn’t do anything.” She had also begun noticing black and blue bruises appearing on her body, so she met with her cardiologist. But when switching medications and getting a pacemaker didn’t rid Ms. Trueman of the symptoms, her doctor referred her to a hematologist oncologist.

A bone marrow biopsy eventually revealed that Ms. Trueman had myelodysplastic neoplasms, or MDS, a blood cancer affecting an estimated 60,000-170,000 people in the United States, mostly over age 60. MDS includes several bone marrow disorders in which the bone marrow does not produce enough healthy, normal blood cells. Cytopenias are therefore a key feature of MDS, whether it’s anemia (in Ms. Trueman’s case), neutropenia, or thrombocytopenia.

Jamie Koprivnikar, MD, a hematologist oncologist at Hackensack (N.J) University Medical Center, describes the condition to her patients using a factory metaphor: “Our bone marrow is the factory where the red blood cells, white blood cells, and platelets are made, and MDS is where the machinery of the factory is broken, so the factory is making defective parts and not enough parts.”

Dr. Azra Raza, MD, director MDS Center, Columbia University Medical Center, New York courtesy Chad Hunt

Dr. Azra Raza

The paradox of MDS is that too many cells are in the bone marrow while too few are in the blood, since most in the marrow die before reaching the blood, explained Azra Raza, MD, a professor of medicine and director of the MDS Center at Columbia University Medical Center, New York, and author of The First Cell (New York: Basic Books, 2019).

Although MDS is not rare, the condition has seen remarkably few new therapies in recent years. Most are either improvements on an existing treatment – such as an oral formulation of an infused drug – or a drug borrowed from therapies for other blood cancers, particularly acute myeloid leukemia (AML).

“We’re looking at taking a lot of the therapies that we’ve used to treat AML and then trying to apply them to MDS,” Dr. Koprivnikar said. “With all the improvement that we’re seeing there with leukemia, we’re definitely expecting this trickle-down effect to also help our high-risk MDS patients.”

Workup begins with risk stratification

While different types of MDS exist, based on morphology of the blood cells, after diagnosis the most important determination to make is of the patient’s risk level, based on the International Prognostic Scoring System–Revised (IPSS-R), updated in 2022.

While there are six MDS risk levels, patients generally fall into the high-risk and low-risk categories. The risk-level workup includes “a bone marrow biopsy with morphology, looking at how many blasts they have, looking for dysplasia, cytogenetics, and a full spectrum myeloid mutation testing, or molecular testing,” according to Anna Halpern, MD, an assistant professor of hematology in the clinical research division at Fred Hutchinson Cancer Center, Seattle. ”I use that information and along with their age, in some cases to calculate an IPSS-M or IPPS-R score, and what goes into that risk stratification includes how low their blood counts are as well as any adverse risks features we might see in their marrow, like adverse risk genetics, adverse risk mutations or increased blasts.”

Treatment decisions then turn on whether a patient is high risk – about a third of MDS patients – or low risk, because those treatment goals differ.

“With low-risk, the goal is to improve quality of life,” Dr. Raza said. “For higher-risk MDS, the goal is to prolong survival and delay progression to acute leukemia” since nearly a third of MDS patients will eventually develop AML.

More specifically, the aim with low-risk MDS is “to foster transfusion independence, either to prevent transfusions or to decrease the need for transfusions in people already receiving them,” explained Ellen Ritchie, MD, an assistant professor of medicine and hematologist-oncologist at Weill Cornell Medicine, New York. “We’re not hoping so much to cure the myelofibrosis at that point, but rather to improve blood counts.”

Sometimes, Dr. Halpern said, such treatment means active surveillance monitoring of blood counts, and at other times, it means treating cytopenia – most often anemia. The erythropoiesis-stimulating agents used to treat anemia are epoetin alfa (Epogen/Procrit) or darbepoetin alfa (Aranesp).

Ms. Trueman, whose MDS is low risk, started taking Aranesp, but she didn’t feel well on the drug and didn’t think it was helping much. She was taken off that drug and now relies only on transfusions for treatment, when her blood counts fall too low.

A newer anemia medication, luspatercept (Reblozyl), was approved in 2020 but is reserved primarily for those who fail one of the other erythropoiesis-stimulating agents and have a subtype of MDS with ring sideroblasts. Although white blood cell and platelet growth factors exist for other cytopenias, they’re rarely used because they offer little survival benefit and carry risks, Dr. Halpern said. The only other medication typically used for low-risk MDS is lenalidomide (Revlimid), which is reserved only for those with 5q-deletion syndrome.

The goal of treating high-risk MDS, on the other hand, is to cure it – when possible.

“The only curative approach for MDS is an allogeneic stem cell transplant or bone marrow transplant,” Dr. Halpern said, but transplants carry high rates of morbidity and mortality and therefore require a base level of physical fitness for a patient to consider it.

Dr. Koprivnikar observed that “MDS is certainly a disease of the elderly, and with each increasing decade of life, incidence increases. So there are a lot of patients who do not qualify for transplant.”

Age is not the sole determining factor, however. Dr. Ritchie noted that transplants can be offered to patients up to age 75 and sometimes older, depending on their physical condition. “It all depends upon the patient, their fitness, how much caretaker support they have, and what their comorbid illnesses are.”

If a transplant isn’t an option, Dr. Halpern and Dr. Raza said, they steer patients toward clinical trial participation. Otherwise, the first-line treatment is chemotherapy with hypomethylating agents to hopefully put patients in remission, Dr. Ritchie said.

The main chemo agents for high-risk patients ineligible for transplant are azacitidine (Vidaza) or decitabine (Dacogen), offered indefinitely until patients stop responding or experience progression or intolerance, Dr. Koprivnikar said. The only recently approved drug in this space is Inqovi, which is not a new agent, but it provides decitabine and cedazuridine in an oral pill form, so that patients can avoid infusions.

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