MDS Treatment

For around 80% of aplastic anemia patients, the underlying cause of the disease is immunologic – it’s an autoimmune disease. As with other autoimmune diseases like multiple sclerosis, lupus, or even rheumatoid arthritis, the body has misdirected its immune response. In the case of aplastic anemia, the immune system targets the bone marrow stem cells, which causes bone marrow failure. So an immunologically-based therapy has the potential to alleviate this immunologic defect. 

With patients for whom stem cell transplantation is not feasible – and there are different reasons for this -- immunosuppressive therapy is used, most often anti-thymocyte globulin (ATG), cyclosporine, or tacrolimus, and sometimes high dose cyclophosphamide.  These aren’t cures, and we don’t anticipate in an autoimmune disease that that immunosuppressive therapy will be curative. But it palliates the disease, and most patients still require long-term treatment with these immunosuppressive agents as the disease can easily recur, especially with events like pregnancy.

In 20 to 40% of aplastic anemia patients, there is significant stem cell loss, and immunosuppression does not offer much in the way of potential improvement.  In this situation, we will try to use stem cell transplantation if we have the option, as it is curative. Here, the treatment is giving a higher dose of immunosuppressive therapy, and then supply stem cells from a donor. Graft rejection can occur but it is uncommon with the intensive immunosuppression provided by the transplant conditioning regimen as well as the post-transplant immunosuppression.

A relatively new option for patients who have failed immunosuppressive therapy and are not eligible for a stem cell transplant is eltrombopag (Promacta®). Thus far, it has been shown to work in about 40% of this group. This is a marrow stimulant, that at least in the small number patients who have been studied, has been useful in stimulating blood cell production. Eltrombopag is a growth factor, which was originally developed to treat immune thrombocytopenic purpura (ITP). It mimics the effects of thrombpoeitin, which is a natural hormone that stimulates platelet production. There are some concerns about its use of because some patients develop mutated blood cells. But again, there are also concerns with ongoing immunosuppressive therapy -- patients developing PNH or MDS. So because of these scenarios, we prefer to do stem cell transplantation if possible.

For MDS, we typically try and do stem cell transplantation instead of immunosuppression. This is because MDS can sometimes progress to acute myeloid leukemia (AML) or on to progressive bone marrow failure. There’s really only one subset of MDS that responds well to immunosuppressive therapy – hypoplastic MDS – where’s there’s a nearly empty marrow, but the cells that remain are dysplastic cells.  So immunosuppressive therapy in this case does ameliorate cytopenias (low blood cell counts) and is not curative, but can be useful for older patients or those for whom transplantation is not an option.

PNH is more complicated because there are several manifestations of it – hemolysis, thrombosis, and bone marrow failure. Bone marrow failure in PNH is less responsive to immunosuppression. Here we use eculizumab (Soliris®) to reduce the risk of thrombosis (blood clots) and reduce hemolysis. This treatment is not curative and is often given for an extended term. Marrow transplantation is typically used in the setting of bone marrow failure, and there are scenarios where aplastic anemia enters the picture and complicates matters.  So immunosuppressive therapy is really only used in PNH when aplastic anemia also develops.

These are complex diseases with complex therapies which can have substantial risks. Stem cell transplantation can be curative, and the other therapies are not. But stem cell transplantation can’t and should not be used in every patient even though it is a potential cure. The other approaches can provide long term control of the disease, lessened the need for transfusion or even complete transfusion independent, and lessen the risk of complications from bone marrow failure.

There is some evolution in the classification systems used for MDS. For years, we have used the International Prognostic Scoring System (IPSS) as the standard system for prognostication.  IPSS risk classifications help predict survival and determine what kinds of treatments will be used. The IPSS was recently revised – and there is a new system called the IPSS-R, signifying this revision. There were a number of abstracts presented that validated the IPSS-R, applying it to MDS patients in international medical centers to see if it could accurately predict survival in those patient groups. In fact, it worked in a variety of patient groups around the world!

One abstract that interested me was from a French group that took the IPSS-R and applied it specifically to patients who were on azacitidine (Vidaza®). This is important because both the IPSS and IPSS-R were developed around patients who did not receive any therapy for their MDS. So the goal was to find out if either of these systems could be used in patients who are receiving active treatment for their MDS. This French group showed that IPSS-R can be used to predict survival in patients who are treated with azacitidine, thus it is valid for a patient who is about to start azacitidine to use IPSS-R to predict how long that person will live.

However, keep in mind that IPSS-R is a new system, and doctors have to get used to using it just as much as patients need to get used to using it. In time, it may come to replace the IPSS,  but that would be a least a couple of years away, and quite possibly longer, before it is widely used.

One interesting report was an update about the drug romiplostin (Nplate®) which has been FDA-approved for patients with idiopathic thrombocytopenic purpura (ITP). Patients with ITP have a low platelet count, not because of a bone marrow problem, but due to an autoimmune problem in which the immune system is attacking the platelets.

This drug had been earlier studied in patients with MDS who also have a low platelet count and in the largest study, it was found that romiplostin did improve platelet counts in about 40 to 50% of MDS patients with low platelet counts.  This is good news, since we now have a drug that works for platelets in the way that growth factors like erythropoietin (Procrit®) or darbepoetin (Aranesp®) work for low red blood cell counts. Romiplostin can be considered a platelet growth factor, also called a thrombopoietic growth factor (TPO).

The problem was that while the randomized Phase 2 study was in progress, the data safety and monitoring board noticed that the patients receiving romiplostin seemed to have an increased blast percentage, and some of these patients progressed to leukemia. So the study was closed earlier than would have normally happened, and the last patients admitted to the study could not be fully evaluated as to whether they responded to romiplostin.

What I found significant was that the follow-up presented this year of patients from the original study who did or did not receive romiplostim reported that the percentage of patients progressing to leukemia was no different in the romiplostin group and the group treated with a placebo. In other words, with additional follow-up, there actually did not appear to be a higher risk of leukemia among MDS patients treated with romiplostim, compared to MDS patients not treated with the drug.

In a companion study from our group, we developed and validated a model to predict response in patients treated with romiplostin, based on prior platelet transfusion needs and blood levels of the hormone TPO. So just as there is a model to predict patient response for red blood cell growth factors such as erythropoietin, we now have a model to predict patient response with rominplostin. 

One of the more common drugs used to treat MDS is azacitidine, or Vidaza®. This is given as a shot under the skin or into the vein through an IV line. More recently, a pill form of azacitidine has been developed and studied in patients with lower-risk MDS. A clinical trial update on oral azacitidine in lower-risk MDS patients showed that approximately 40-50% of patients had improvements in their blood counts and/or in their requirements for red blood cell transfusions. This is an important preliminary study that has set the stage for the study that will determine whether oral administration of azacitidine will be FDA approved for treatment of lower-risk MDS.

As we get better at discovering and defining the genetic underpinnings of MDS, the next step will be to see if patients with certain genetic abnormalities are more likely to respond to some drugs than other ones.  We are becoming more sophisticated at selecting patients who are more likely to respond to a certain drug.

There were presentations on new genetic abnormalities found in MDS, some validating findings previously reported and some identifying new findings. One of the major ones was an international collaboration reporting on over 700 patients with MDS, MDS/MPN overlap, or AML that had evolved from MDS. This study found that 20% of the patients had a genetic abnormality (called SETBP1) that happens to be the same found in a rare congenital syndrome of infants born with retardation and skeletal abnormalities. This was typical of discoveries in MDS presented at ASH 2012.

I think it is important to point out that the quality and number of presentations on MDS were higher at this meeting than any ASH meeting I have attended over the past 20 years. Patients should fi nd it encouraging that there is so much good work going on in this fi eld. Although it will take time for these new discoveries to be translated into improvements in diagnosis and treatment for MDS, there is good reason to be optimistic that outcomes for our patients will improve in the coming years.

Pediatric MDS, like adult MDS, is a clonal myeloid malignancy that is typically fi rst spotted as cytopenias (low blood counts). It’s a stem cell disorder in the bone marrow that results in disturbances  in blood cell differentiation and apoptosis (cell death). It is distinguished from acute myeloid leukemias (AML) by having a relatively low percentage of blasts (immature blood cells in the bone marrow). There’s really no difference in the definition of MDS as it applies to children or adults – the only thing that makes it a different category is the age of the patient. The reason it’s seldom mentioned in overall discussions of MDS is because of a far lower incidence than the adult age group and particularly, the older adult age group. The other interesting point is that within pediatric myeloid malignancies, pediatric MDS is a much smaller proportion than it is for adult myeloid malignances. Less than 5% of pediatric myeloid malignancies are MDS, whereas it’s much higher in for adult myeloid malignancies.

That’s a good question. They can apply and we do our best to apply those classification systems. We have attempted to fit pediatric MDS into the World Health Organization (WHO) classification system, but it’s not optimal for this. This is because there are certain subtypes of MDS, for example, refractory anemia with ringed sideroblasts (RARS), that don’t occur in children. Another interesting point is that one-third to one-half of children with MDS has an associated constitutional abnormality that can play a large part in the child developing MDS. The most common ones are Down Syndrome and inherited bone marrow failure diseases such as Fanconi Anemia. Those are difficult to classify in the adult systems because they generally don’t take inherited abnormalities into account.

Another issue is that familial MDS is not uncommon in children with MDS. Many young MDS patients will have siblings who also have MDS. We have had a few families we have treated with familial monosomy 7-related MDS, and that doesn’t occur on the adult side. Finally, some of the subsets of cytogenetic abnormalities that occur in MDS are very different in children. A larger proportion of children have monosomy 7 compared to adults, and a much small proportion of children have the 5q-minus variant – this one is almost never seen in children.

They typically don’t apply. Our approach on the pediatric side is to take the patient to an allogeneic bone marrow transplant as soon as possible because it’s a much different set of circumstances. For younger children, a bone marrow transplant, like adults, is the only potential curative therapy for MDS. Because children are often in a better position to handle the intensity of bone marrow transplant therapy, and because the potential upside of number of years of life that can be extended is much higher, we usually try right away to find a bone marrow transplantation option for a pediatric MDS patient.

Because pediatric MDS is so heterogeneous, most of the research occurring is more in the conditions that can predispose to MDS, or make it more likely for pediatric MDS to occur. For example, with Down syndrome-related MDS, there have been striking advances in the understanding of what causes it and the development of different treatments that can help. There have also been advances in understanding the genetic causes of various bone marrow failure syndromes. But those haven’t yet translated into better therapies for pediatric MDS once it develops - bone marrow transplant remains the treatment of choice.

There are two points here. We consider pediatric MDS to be a curable condition as long as a patient can have an allogeneic bone marrow transplant. Just like with recurrent MDS, bone marrow transplantation doesn’t guarantee a cure. However, the proportion of pediatric patients for which we can find a suitable donor and who can tolerate a transplant is so high that we can reasonably be very optimistic about pediatric patients diagnosed with MDS.

It’s also important to say that any parent of a child diagnosed with a rare blood or bone marrow malignancy like pediatric MDS should be treated at a specialized pediatric oncology center. It should one that has a lot of experience with these conditions and that also has a collaborative relationship with their adult oncology colleagues, who see many more cases of MDS and can be a great source of expertise and advice.

The idea of the recurrent MDS is exactly that. If a patient’s MDS has been treated into remission or even controlled and stabilized from an earlier state and then starts to progress with symptoms,
worsening blood counts, and worsening bone marrow studies, that is recurrent MDS. Recurrent MDS can happen after supportive approaches, after medical treatments, and even after an allogeneic stem cell transplant. So, I think of recurrent MDS to mean progression or re-emergence of MDS after a period of remission or managed stability.

To date, this has not been well studied, but what we do understand is that the large majority of  patients with MDS who have periods of disease stability or respond to treatments will eventually recur. Most supportive care or active medical treatments are more temporary treatments and are not permanent or curative.

The simple answer is that the MDS is a progressive bone marrow failure disorder, and over time, it tends to get worse for most patients. The medical therapies we have do work for many patients, but because they are not curative, their MDS will often become resistant to the treatment. We do know a lot more about MDS than we did just 10 years ago. We understand that there is a series of genetic events (mutations) that occur in the development of MDS and their accumulation can also be associated with the progression or recurrence of the disease. So even when a treatment works
for awhile, it is possible that the responding MDS will obtain additional genetic events that render it resistant to the very same treatment. There are certainly many groups working on understanding the development of mutations in hopes of finding better treatments.

MDS, like all blood and bone marrow cancers, can go into remission and then recur. Once bone marrow and blood cancers recur, we don’t think of them as being curable by medical treatments. So when patients have recurrent or progressive MDS, we often explore the possibility of whether
an allogeneic stem cell transplant might be something appropriate for them. Not all patients are good candidates for a stem cell transplant, but many are.

It needs to be stressed that an allogeneic stem cell transplant is not a guaranteed cure. Not all transplants are successful. So, in fact, many patients will have recurrent MDS following a stem cell transplant. Efforts continue to try to lower the chance of MDS returning after a stem cell transplant, but still somewhere between one third and one half of patients will eventually have their MDS return even after a potentially curative stem cell transplantation. So stem cell transplants aren’t the answer for all patients or all types of MDS.

We don’t have really good answers here. I strongly encourage all patients and families to play active roles in monitoring their condition and frequently be seen and evaluated by their medical team. Blood cell counts have to be monitored because changes in these are often the fi rst sign of a recurring
MDS. Also, they should take the necessary steps improve and maintain their overall health. This means plenty of rest, staying physically active, and working towards a balanced and healthy diet. What we’ve found through the years is that patients who are in good overall physical health tend
to better tolerate different treatments. It is also important to maintain a very active dialog with your physician and treatment team to help manage the disease and to build a solid understanding of what is going on with your body and bone marrow so you are ready to face any changes in your bone marrow that may occur post-treatment.

De novo MDS refers to an MDS that has arisen without an obvious or specifi c cause. Secondary MDS tend to have two general categories: the first is MDS that seem to have arisen or grown out of another bone marrow failure disorder or bone marrow cancer. For example, there are aplastic anemia patients with very low blood counts, and at times, we see a population of MDS cells that can develop. This may also occur related to other bone marrow problems like having an underlying  myeloproliferative disorder with a background of MDS cells as well.

The second defi nition relates to the MDS being related to previous cancer therapies, including chemotherapy and radiation therapy. So the language we use to describe the secondary MDS types has evolved over time into the “therapy-related MDS” and “MDS arising from or associated with another primary bone marrow disorder.” People tend to hear a bit more about the therapy-related MDS.

Secondary MDS makes up a small fraction of all the cases of MDS – many studies looking at the frequency suggest 5-15% of the cases are therapy-related.

The risk factors for therapy-related MDS really relate to the previous therapies that patients have undergone. Certain chemotherapies have a high incidence that are often associated with therapy-related MDS, and of course, radiation exposure is also felt to be a risk factor for developing MDS.

There is really no formal, widely accepted defi nition or model for this term. But for most, the term “coordinated care” refers to delivering ongoing treatment near the patient’s home, by the patient’s local hematologist/oncologist. This treatment occurs under the guidance of MDS specialists at the larger, often academically based cancer research and treatment centers. There are several advantages to this arrangement.

Remember, MDS is rare disease and a community hematologist/oncologist may only see a few new cases in a year at the most, where here at Moffitt, we have an equal of amount of new cases in one week. In this scenario, patients are able to have their care planned and managed by experts who see and work with MDS on a daily basis, but are they able to maintain the relationship with their local hematologist/oncologists, superb clinicians who deliver the patient care--including the ongoing treatment of the disease, dealing with emerging side effects, and general observation. The advantage here is that patients do not have to make frequent trips to a major cancer center that could be far from their home for routine or standard treatment.

It can happen both ways, and it certainly may be initiated by the patient. They can suggest to their local primary care physician or hematologist that they are interested in a second opinion from a specialist who sees many MDS cases. The local hematologist/oncologist often makes the original referral to the larger center to begin the process. This arrangement lets a patient benefit from work being done at the big cancer centers, but also keeps most of the patient’s time-consuming treatment local. Both sides should be in agreement that dividing the total care plan between the local physician’s oversight and the care of specialists is the best interests of the patient. At Moffitt, we have developed a unique relationship with our community hematologist/oncologists, where we see those patients early in the course of the disease and follow patients through the entire course, including certain milestones for major decisions on treatment, or for possible inclusion in clinical trials if standard care stops working. But the day-to-day treatments patients get occur near their homes. So this model originates both ways, but we encourage patients to suggest this if their local doctor does not.

It is an informal model and can be adjusted or modified to suit the clinical needs of the patient. But generally, the patient should visit the academic center early in the process to confirm a diagnosis, particularly for a rare disease like MDS. Original diagnosis of MDS can be very challenging. There was a recent article in Blood highlighting the MD Anderson Cancer Center experience—reviewing pathology on MDS that comes from outside of the center at the time of first referral, and in 25 to 30 percent of the time, the diagnosis was changed or revised. Our center shares similar a experience. The specialized centers offer experienced hematopathologists’ review of diagnostic materials and advanced molecular testing. A crucial initial step is risk stratifi cation or staging to understand the exact risk of the disease, prognosis, and tailor the plan of treatment accordingly. At Moffitt, we apply several tools to allow this staging which often are not utilized in busy community hematology/oncology practices. Patients may get the opportunity to receive cutting edge novel therapies in the context of clinical trials upfront or down the road in their journey fighting this disease.

Finally, patients can be part of databases that track outcomes and ones that follow them through the whole disease process. Patients may allow scientists to study leftover material of routine tests like bone marrow aspirate and biopsy or regular blood tests which allows physician-scientists to learn more about the disease, explore and assess new treatments, and potentially benefit many other patients. So, the initial referral to a large center offers a lot of advantages. It allows us to confirm a prior diagnosis, make a plan, and be sure the patient knows about clinical trials that may be of interest. If the treatment plan is a standard one such as hypomethylating agents, patients can have this treatment locally, as well as the blood tests that are also required for monitoring this treatment. Then, at three or four months, they would return to the specialized center like Moffitt for an overall evaluation and assessment of treatment progress.

The initial diagnosis, specialized testing, proper and fi ne staging/risk stratifi cation, formulation of initial treatment plan, and the additional benefits of all this occurring within a larger pool of patients is what the large center does best. The ongoing (often every day) treatment, and supportive care— including transfusions, blood tests, and therapy for any side effects—are the parts of the process that occur locally, under highly qualified hematologist/oncologists. What each setting does is very important, and in most cases, it is an effective division of tasks needed to administer total care.

These can happen if communication breaks down between the two locations involved in coordinating the care. Open communication between the community hematology/ oncologist and the referral center is essential for this arrangement to work correctly and to its best advantage. The local doctor has to receive information from the center in a timely manner. So both parties have a shared responsibility to see that information is communicated and received without delay. In almost all cases, a good working relationship develops. Sometimes, there have been confl icting recommendations between the local doctor and the experts at the large cancer center. This requires discussion between both parties so an agreement is reached. In these situations, sometimes there really is no single right answer— where there really are two options—requiring patients to decide what best serves their interests and meets their needs. I don’t believe that any problems result for fear of competition between the two locations. Both sides build a comfort level working with each other, whether over a single patient or group of patients, and this reduces any fear of competition.

This is by no means out of the patient’s hands. Patients can play a role in this by being engaged, by paying attention, and by making the decisions that they are required to make, based on the information that has been provided to them. They should be ready to bring the details of an appointment at one facility to the other, and of course, adherence to appointments is crucial so all follow-up appointments and testing during and after treatment is completed. There really are three parties involved, and each has to do their best to keep the others informed—the patient should not be passive bystander when it comes to the fl ow of information. If something seems missing, misunderstood, or contrary to expectation, the patient should bring this up right away.

As to warning signs, it all goes back to lack of communication between the three parties. For example, if the treatment plan is not consistently applied, or by the schedule agreed upon, this could indicate a problem. If treatment plans seem to change with no explanation, that could also be a red flag. The patient can be their own best advocate by seeing that both parties involved in the coordinated care are in touch and in agreement.

Even though there is no formal protocol or model for coordinated care, it can be different in other countries—especially smaller European countries where distances are not as great as in the US. There you find specialized treatment centers which are often certain hospitals for particular diseases. There are only certain facilities that offer treatments for MDS and diseases like it.

This would not work as well in a country the size of the US and the practice of coordinated care in the US is better for the situation that exists here. As the field of oncology expands—several major new drugs a year being approved, and major advances in many areas within oncology, it can be difficult for a community hematologist/oncologist to keep up with every single new detail. But there are specialists like me and others here at Moffitt as well as other referral centers who focus on this particular area, so coordinated care lets us help the community hematologist/oncologist with the particulars of MDS, while they can deliver excellent care and administer a treatment plan to their patients with MDS. Community hematologist/oncologists are very experienced clinicians with wide knowledge and superb skills in dealing with many different diseases and no doubt can deliver
excellent care to the patients near home with assistance from experts at large referral centers.