An Update on Current and Emergent Therapies for Essential Thrombocytosis

Daniel H. Foley, MD
Kristen Pettit, MD

Our understanding of pathophysiology driving Philadelphia chromosome–negative myeloproliferative neoplasms (MPNs) has evolved considerably over the past decade. As a result, the therapeutic landscape is shifting toward a goal of meaningful disease modification. For patients with essential thrombocytosis (ET), the immediate goals remain thrombosis risk reduction and symptom control, but newer therapies on the horizon are likely to change our treatment paradigms considerably for this disease.

How do you approach a new patient with ET?
When it comes to the treatment of patients with ET, the main goal of current approved therapy is to mitigate the risk of thrombotic events, as the treatments have minimal impact on disease progression. The choice of treatment is determined by an individual’s specific risk factors for these events. The International Prognostic Score for Thrombosis in ET revised score is used to stratify patients into 4 risk groups: very low risk, low risk, intermediate risk, and high risk. For the majority of low-risk patients, low-dose aspirin is recommended, as it aids in preventing clotting, but patients classified as intermediate or high risk are generally advised to undergo cytoreductive therapy.

What are the standard options for cytoreductive therapy?

The selection of the most suitable cytoreductive agent depends on factors such as the patient’s comorbidities, tolerability of the treatment, future family planning, and individual preferences. Hydroxyurea (HU) and pegylated interferon alfa (peg-IFN) are the primary options for frontline cytoreductive treatment. In the phase 3 study MPD-RC 112 [NCT01259856], which included patients with both ET and polycythemia vera (PV), HU and peg-IFN demonstrated comparable rates of complete response and thrombotic events after 12 months.However, over time peg-IFN has shown improved molecular responses in both ET and PV.1-4 Although the clinical implications of these molecular responses aren’t yet entirely clear, these findings are quite exciting to see in this disease that has been so difficult to target. A longer-acting interferon (ropeginterferon alfa-2b-njft; Besremi) is currently in evaluation for patients with ET and has been approved in the United States for patients with PV. In cases where initial treatment approaches do not yield satisfactory results, anagrelide is another option, though its use is often limited by toxicities (eg, headaches, dizziness, palpitations, and fluid retention).

What is on the horizon for treatment of ET?

As we delve deeper into understanding the biologic drivers of ET, promising new therapeutic directions are emerging, including JAK inhibitors, epigenetic agents, and mutation-specific biologic/immunologic therapies.Ruxolitinib (Jakafi), a JAK1/2 inhibitor already widely used for other MPNs, continues to be evaluated in ET. In a randomized study, MAJIC [NCT05057494], ruxolitinib was compared with best available therapy (BAT) for patients with ET who had resistance or intolerance to HU. Both treatments showed similar rates of hematologic response, thrombosis, and hemorrhage. However, ruxolitinib outperformed BAT in improving disease-related symptoms.5 Another ongoing trial called Ruxo-BEAT [NCT02577926] is further exploring the use of ruxolitinib in ET.

When it comes to epigenetic regulators, BET inhibitors and LSD1 inhibitors are emerging as potential therapeutic targets. Both BET inhibitors and LSD1 inhibitors have shown the ability to reduce cytokine production via different mechanisms and impair self-renewal of malignant hematopoietic stem cells, so they may have more significant disease-modifying activity compared with other agents.6,7 The BET inhibitor pelabresib (CPI-0610) is currently being evaluated for ET as well as myelofibrosis. The LSD1 inhibitor bomedemstat is also being studied for both ET and MF, and preliminary reports from the ET study show encouraging ability to control platelets and improve symptoms for many patients.8

Biologic and immunologic approaches are emerging as promising strategies as well. Recently, at the American Society of Hematology annual meeting in 2022, preclinical data were presented on a monoclonal antibody that targets mutant CALR, a key diver for approximately 25% of patients with ET.9 This antibody showed impressive potency in selectively targeting mutant CALR-driven oncogenic mechanisms. There are also other antibody-based therapies showing significant efficacy in preclinical studies, and these strategies are now moving toward the development phases.10 Furthermore, the discovery of T-cell responses against mutant CALR has sparked the development of vaccine-based treatment strategies.11,12 

What are your final thoughts regarding the future of ET?

The development of more targeted agents with the potential to meaningfully disrupt the mechanisms driving MPNs provides a lot of optimism for the future in these diseases. As these therapies move toward “prime time,” we will need to reassess our treatment goals for our patients. Hopefully we will be able to raise the bar for response from simply hematologic control and thrombosis prevention toward the more lofty aims of lengthening survival, improving quality of life, and lowering risk of disease progression.

REFERENCES:

1. Mascarenhas J, Kosiorek HE, Prchal JT, et al. A randomized phase 3 trial of interferon-alpha vs hydroxyurea in polycythemia vera and essential thrombocythemia. Blood. 2022;139(19):2931-2941. doi:10.1182/blood.2021012743

2. Masarova L, Patel KP, Newberry KJ, et al. Pegylated interferon alfa-2a in patients with essential thrombocythaemia or polycythaemia vera: a post-hoc, median 83 month follow-up of an open-label, phase 2 trial. Lancet Haematol. 2017;4(4):e165-e175. doi:10.1016/S2352-3026(17)30030-3

3.Quintás-Cardama A, Abdel-Wahab O, Manshouri T, et al. Molecular analysis of patients with polycythemia vera or essential thrombocythemia receiving pegylated interferon α-2a. Blood. 2013;122(6):893-901. doi:10.1182/blood-2012-07-442012

4.Kiladjian JJ, Cassinat B, Chevret S, et al. Pegylated interferon-alfa-2a induces complete hematologic and molecular responses with low toxicity in polycythemia vera. Blood. 2008;112(8):3065-3072. doi:10.1182/blood-2008-03-143537

5.Harrison CN, Mead AJ, Panchal A, et al. Ruxolitinib vs best available therapy for ET intolerant or resistant to hydroxycarbamide. Blood. 2017;130(17):1889-1897. doi:10.1182/blood-2017-05-785790

6.Kleppe M, Koche R, Zou L, et al. Dual targeting of oncogenic activation and inflammatory signaling increases therapeutic efficacy in myeloproliferative neoplasms. Cancer Cell. 2018;33(1):29-43.e27. doi:10.1016/j.ccell.2017.11.009

7.Jutzi JS, Kleppe M, Dias J, et al. LSD1 inhibition prolongs survival in mouse models of MPN by selectively targeting the disease clone. Hemasphere. 2018;2(3):e54. doi:10.1097/HS9.0000000000000054

8.Gill H, Palandri F, Ross DM, et al. A phase 2 study of the LSD1 inhibitor bomedemstat (IMG-7289) for the treatment of essential thrombocythemia (ET). Blood. 2022;140(suppl 1):1784-1787. doi:10.1182/blood-2021-148210

9.Reis E, Buonpane R, Celik H, et al. Discovery of INCA033989, a monoclonal antibody that selectively antagonizes mutant calreticulin oncogenic function in myeloproliferative neoplasms (MPNs). Blood. 2022;140(suppl 1):14-15. doi:10.1182/blood-2022-159435

10.Tvorogov D, Thompson-Peach CAL, Foßelteder J, et al. Targeting human CALR-mutated MPN progenitors with a neoepitope-directed monoclonal antibody. EMBO Rep. 2022;23(4):e52904. doi:10.15252/embr.202152904

11.Holmström MO, Martinenaite E, Ahmad SM, et al. The calreticulin (CALR) exon 9 mutations are promising targets for cancer immune therapy. Leukemia. 2018;32(2):429-437. doi:10.1038/leu.2017.214

12.Holmström MO, Riley CH, Svane IM, Hasselbalch HC, Andersen MH. The CALR exon 9 mutations are shared neoantigens in patients with CALR mutant chronic myeloproliferative neoplasms. Leukemia. 2016;30(12):2413-2416. doi:10.1038/leu.2016.233

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PharmaEssentia and MPN Advocacy & Education International Launch New Educational Initiative to Empower People Living With Polycythemia Vera (PV)

PV&ME™ campaign features personal stories from people living with PV and their journeys navigating the rare blood cancer

BURLINGTON, Mass. & EAST LANSING, Mich.–(BUSINESS WIRE)–PharmaEssentia USA Corporation, a subsidiary of PharmaEssentia Corporation (TPEx:6446), a global biopharmaceutical innovator based in Taiwan leveraging deep expertise and proven scientific principles to deliver new biologics in hematology and oncology, and MPN Advocacy & Education International, a leading advocacy group dedicated to providing the knowledge, support and resources patients will need as they adjust to living with a myeloproliferative neoplasm (MPN), today announced a new educational initiative for the MPN community called PV&ME. The goal of the campaign is to bring to light the unique and challenging experiences of living with polycythemia vera (PV) in the hopes of raising awareness, empowering patients to advocate for themselves and ensuring newly diagnosed patients feel supported in their journeys. PV&ME features the stories of four inspiring individuals – Buzz, Deb, Patti and Steven – living with this chronic cancer and their perspectives on navigating diagnosis, addressing burdensome symptoms and seeking comprehensive care.

PV is the most common MPN and a long-term, potentially life-threatening cancer that has had limited treatment options for many years. Patients with PV are at a more significant increased risk of developing thromboembolic events than the general population with cardiovascular disease, due to increased blood cell counts. They also have a long-term risk of progression to myelofibrosis or transformation to acute myeloid leukemia.1-5

“People living with PV often face feelings of isolation as they navigate a long and confusing road to diagnosis and adjust to extreme fatigue or other often debilitating symptoms,” said Ann Brazeau, Chief Executive Officer, MPN Advocacy & Education International. “The stories shared in this new PV&ME campaign show just how important the right support and resources can be for this community. We hope this new initiative will help people with PV feel connected and empowered to advocate for themselves on their PV journeys.”

“At PharmaEssentia, we are committed to being an essential partner for the MPN community and know that a critical component of that is listening to and amplifying stories from individuals living with PV themselves,” said Raymond Urbanski, M.D., Ph.D., Senior Vice President and U.S. Head of Clinical Development and Medical Affairs at PharmaEssentia. “This MPN Awareness Day, we are proud to partner with MPN Advocacy & Education International to share these inspiring stories with the MPN community and help encourage patients to take a proactive approach in their care.”

The PV&ME educational video series launched on MPN Awareness Day (September 14) and can be found by visiting us.pharmaessentia.com/patients/patient-stories/. Throughout Blood Cancer Awareness Month, PharmaEssentia and MPN Advocacy & Education International will continue to share important educational content for the MPN community.

Follow PharmaEssentia USA on Twitter and LinkedIn for news and updates.

About Polycythemia Vera (PV)

Polycythemia vera (PV) is a cancer originating from a disease-initiating stem cell in the bone marrow resulting in a chronic increase of red blood cells, white blood cells, and platelets. PV may result in cardiovascular complications such as thrombosis and embolism, and often transforms to secondary myelofibrosis or leukemia. While the molecular mechanism underlying PV is still subject of intense research, current results point to a set of acquired mutations, the most important being a mutant form of JAK2.6

About PharmaEssentia

PharmaEssentia (TPEx: 6446), headquartered in Taipei, Taiwan, is a global and rapidly growing biopharmaceutical innovator. Leveraging deep expertise and proven scientific principles, PharmaEssentia aims to deliver effective new biologics for challenging diseases in the areas of hematology and oncology, with one approved product and a diversifying pipeline. Founded in 2003 by a team of Taiwanese-American executives and renowned scientists from U.S. biotechnology and pharmaceutical companies, today PharmaEssentia is expanding its global presence with operations in the U.S., Japan, China, and Korea, along with a world-class biologics production facility in Taichung, Taiwan.

For more information about PharmaEssentia USA, visit the website, LinkedIn or Twitter.

About MPN Advocacy & Education International

MPN Advocacy and Education International provides educational programs, materials, and resources for patients, caregivers, physicians, and entire healthcare teams to improve their understanding of myelofibrosis, polycythemia vera, and essential thrombocythemia. They are dedicated to making a difference in the lives of those affected by MPNs and strive to grow awareness and advocate on behalf of the MPN community.

For more information about MPN Advocacy and Education International, visit the website, Facebook or Twitter.

© 2023 PharmaEssentia Corporation. All rights reserved.

PharmaEssentia, the PharmaEssentia logo, and PV&ME are trademarks or registered trademarks of PharmaEssentia Corporation.

1 Griesshammer M, Kiladjian J-J, Besses C. Thromboembolic events in polycythemia vera. Ann Hematol. 2019;98:1071–82. DOI: 10.1007/s00277-019-03625-x
2 Antithrombotic Trialists (ATT) Collaboration. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet. 2009;373:1849-1860. https://doi.org/10.1016/S0140-6736(09)60503-1
Yusef S, et al. Cholesterol lowering in intermediate-risk persons without cardiovascular disease. NEJM. 2016;374(21):2021-2031. DOI: 10.1056/NEJMoa1600176
Risk and Prevention Study Collaborative Group;​ Roncaglioni M, et al. N-3 fatty acids in patients with multiple cardiovascular risk factors. NEJM. 2013;368:1800-1808. DOI: 10.1056/NEJMoa1205409
5 Barbui T, et al. In contemporary patients with polycythemia vera, rates of thrombosis and risk factors delineate a new clinical epidemiology. Blood. 2014;124:3021-3023. https://doi.org/10.1182/blood-2014-07-591610
6 Cerquozzi S, Tefferi A. Blast transformation and fibrotic progression in polycythemia vera and essential thrombocythemia: a literature review of incidence and risk factors. Blood Cancer J. 2015;5, e366; DOI:10.1038/bcj.2015.95

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MPN-Associated Anemia: What Nurses Should Look Out For

Sharon Bledsoe, MSN, MBA, BSN, RN

When treating patients with blood cancers such as myeloproliferative neoplasms (MPNs), it is essential for oncology nurses to explain to patients what to expect and what symptoms they should call about. And when the patients talk, it is essential that their nurses are attentive, explained Sharon Bledsoe, MSN, MBA, BSN, RN.

“Make sure that you listen to your patient and that you absolutely follow up with all of their labs and watch and monitor their trends,” Bledsoe, a senior research nurse at The University of Texas MD Anderson Cancer Center, said in an interview with Oncology Nursing News®.

In the case of myelofibrosis (a type of MPN), patients may experience a slow downward trend in hemoglobin levels, as the bone marrow scarring inhibits the body’s ability to produce healthy red blood cells. In turn, patients end up developing anemia. Patients with myelofibrosis-associated anemia may experience a change in their typical MPN-related symptoms, increased fatigue, night sweats, or fever, according to Bledsoe.

However, decreases in blood levels for patients with myelofibrosis may not be as sharp or apparent for patients with myelofibrosis as they are for other malignancies, such as acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML), Bledsoe explained.

“It’s a slow trend. It’s not usually a sudden trend when you’re dealing with myelofibrosis, and it can progress slower than ALL or AML or any of those other blood cancers,” she said.

While the trend may be slow, it is important to catch anemia quickly, according to Bledsoe, so that treatments — namely blood transfusions or JAK inhibitors — can be started in a timely manner and ensure the best outcome for the patient.

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Improved Molecular Understanding of AP/BP MPN Better Informs Management Approaches

Tony Berberabe, MPH

Developing an optimal treatment strategy for patients with accelerated- or blast-phase myeloproliferative neoplasms (MPN AP or MPN BP) requires consideration of a patient’s ability to tolerate intensive induction as initial therapy, their eligibility for allogeneic stem cell transplant (ASCT), and whether prior cytoreduction is necessary, according to a presentation by Olatoyosi Odenike, MD, at the 2023 SOHO Annual Meeting.

Few treatment options are available for patients with MPN that is in AP (10% or more blasts) or BP (20% or more blasts), with only ASCT offering the potential for cure, although only a minority of patients are eligible for this intervention. From a targeted therapy perspective, single agent hypomethylating agents (HMAs) or HMAs in combination with ruxolitinib (Jakafi®; Incyte) or venetoclax (Venclexta®; Genentech and AbbVie)can also be considered.

The paucity of approaches coupled with a median overall survival of 3 months for patients who present with BP and 12 to 18 months for patients in the AP adds “urgency to determine who is at highest risk for transformation because that is when intervention can have the most impact,” said Odenike, a professor of medicine and director, Leukemia Program at the University of Chicago Medicine in Illinois.

The treatment choices for initial therapy are affected by the patient’s fitness and ability to undergo intensive induction. However, the choice for pursuing intensive or less intensive induction is somewhat unclear, as prospective randomized trials are lacking. “But retrospective trials that evaluate intense vs less intense approaches portray outcomes evenly, with no clear survival advantage of 1 approach over the other,” Odenike said, bringing up a study by McNamara, et al.2

For this analysis, intensive therapy was defined as chemotherapy; less intensive therapy could include low dose cytarabine, HMAs, or a clinical trial intervention. In the analysis, when intensive therapy was stratified by receipt of ASCT, many of the supposed benefits were found more closely tied to the transplant itself.2 The investigators also noted that patients who underwent intensive therapy but didn’t proceed to transplant had worse outcomes than those who received less intensive therapy.2

“Retrospective studies are subject to all kinds of bias,” Odenike said. “But this study is suggestive that we should have a path forward to transplant if we decide to go the intensive route.”

Molecularly Complex

The high mutational burden and molecular complexity of AP and BP MPN contributes to its poor outcomes, with almost half of patients exhibiting mutations in 4 or more genes. As more is learned about the genes implicated in the disease, the role of targeted therapies becomes more important.

“It’s interesting to think about targeted therapies, since we are starting to better understand the molecular underpinnings of MPNs in general, including when they progress to the accelerated or blast phase,” Odenike said.

Distinct molecular differences exist between AP and BP MPN, which has been referred to as secondary acute myeloid leukemia (AML), and de novo AML, Odenike said. In many cases, AP/BP MPN appears to be enriched for IDH1 and IDH2, making it a potential path for targeted therapies. In particular, IDH1/2 mutations occur in about 25% of patients with BP and leads to epigenetic dysregulation.

IDH1/2 inhibitors have been shown to be active in IDH mutant AML, making these an established treatment for this disease.3,4 For patients with AP/BP MPN, clinical responses to IDH1/2 inhibitors have been positive, with 1 trial reporting a median duration of treatment of 258 days5 and others reporting significant clinical responses to IDH1/2 inhibition.6

As one of the only curative interventions, the focus on getting patients to ASCT and achieving the best responses is paramount. Better responses are seen with ASCT when patients are first cytoreduced and in remission, but outcomes are overall inferior compared with AML that arises de novo, according to Odenike. The same chemotherapy regimens to treat AML are available, but outcomes are not optimal. “Even when the patient is able to have an ASCT, the outcomes are only modestly improved. So, to me, this is a call to action,” Odenike said.

Investigational efforts to explore approaches in the myeloid space are currently focused on epigenomic modulators, novel posttranslational modulators, immune checkpoint inhibitors, and novel targeted agents, including BCL2/BCLXL, IDH1/2, kinase, and MDM2 inhibitors.

Odenike closed with a schema detailing how she treats patients with Philadelphia-negative MPN. In the accelerated and blast phase, she advocates for next-generation sequencing, to identify the molecular profile. “I recommend clinical trial enrollment if available,” she said. “If the patient has a TP53 mutation, those patients generally don’t do well with intensive therapy. With other mutations, I have relative equipoise between intensive and a less intensive approach. But I would only treat using an intensive approach if I had a plan to quickly move the patient to transplant and if the patient is fit.”

References

  1. Odenike O. Managing accelerated- and blast-phase MPN. Presented at: 11th Annual Meeting of the Society of Hematologic Oncology (SOHO 2023). September 7, 2023. Houston, Texas.
  2. McNamara CJ, Panzarella T, Kennedy JA, et al. The mutational landscape of accelerated- and blast-phase myeloproliferative neoplasms impacts patient outcomes. Blood Adv. 2018;2(20):2658–2671. doi:10.1182/bloodadvances.2018021469
  3. Green A, Beer P. Somatic Mutations of IDH1 and IDH2 in the Leukemic Transformation of Myeloproliferative Neoplasms. N Engl J Med. 2010;362(4):369-370. doi: 10.1056/NEJMc0910063
  4. Stein EM, DiNardo CD, Pollyea DA, et al. Enasidenib in mutant IDH2 relapsed or refractory acute myeloid leukemia. Blood. 2017;130(6):722-731. doi:10.1182/blood-2017-04-779405
  5. Patel AA, Cahill K, Charnot-Katsikas A, et al. Clinical outcomes of IDH2-mutated advanced-phase Ph-negative myeloproliferative neoplasms treated with enasidenib. Br J Haematol. 2020;190(1):e48-e51. doi:10.1111/bjh.16709
  6. Chifotides HT, Masarova L, Alfayez M, et al. Outcome of patients with IDH1/2-mutated post–myeloproliferative neoplasm AML in the era of IDH inhibitors. Blood Adv. 2020;4(21):5336–5342. doi:10.1182/bloodadvances.2020001528

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Research Nurse Breaks Down Myelofibrosis-Related Anemia

Brielle Benyon

Anemia is a common and potentially dangerous condition that can occur in patients with myelofibrosis, a type of myeloproliferative neoplasm. While anemia is a blanket term that describes low hemoglobin levels, myelofibrosis-related anemia behaves quite differently than anemia in patients with a blood cancer diagnosis, explained Sharon Bledsoe.

Bledsoe, a senior research nurse at The University of Texas MD Anderson Cancer Center in Houston, recently explained myelofibrosis-related anemia, including its cause and treatment.

CURE®: What causes anemia in patients with myelofibrosis?

Myelofibrosis is basically a disease in which the bone marrow gets replaced by connective tissue in a process called fibrosis. The bone marrow’s main objective is to produce blood cells, and in producing the blood cells — the red blood cells, the white blood cells and the platelets. When the fibrosis interferes with the production of the cells, scar tissue starts to form in the bone marrow, and the bone marrow is the soft spongy tissue in the center of the bones.

As the scar tissue starts to grow, the bone marrow loses its ability to make enough healthy blood cells. So, it produces too many abnormal blood cells. The lifespan of a true red blood cell or of a normal human red blood cell is 120 days, which is about roughly four months. When you have a patient dealing with myelofibrosis, with the scarring and all of that, they’re producing the red blood cells, but they’re not maturing; when they’re not mature, they die off faster. So, they’re producing a whole lot a whole lot, but they’re dying fast. Then you have the anemia that starts because they’re not living for enough time, so they’re not getting four months of life; within days, weeks, they’re dying off.

How is myelofibrosis-associated anemia treated?

When patients’ (hemoglobin levels) start to get low, we start to monitor their trends. We monitor their hemoglobin; we start to monitor in to see if they’re if they are going to need a transfusion. And if they need transfusions, how often are they needing the transfusions? So we’re going to monitor all of that, whether they need the transfusions and how often they need the transfusions.

That’s one way that it’s treated.

And then doctors may put them on drugs that will help the anemia, drugs like danazol and Jakafi (ruxolitinib). When those red blood cells are being produced so quickly, there’s not enough room within the bone marrow, so (they) go into the spleen, or into the liver, which is now causing them to have enlarged spleens and enlarged liver. And sometimes, because it can’t be treated, the spleen has to be removed.

(Jakafi) can take the spleen size down. However, with (Jakafi), you fall into the area where they can get skin cancers, secondary skin cancers, squamous cell carcinoma, basal cell carcinoma and things like that; you have to really, really watch for that. In treating the anemia, you have to watch for so many other things that may crop up.

What is the difference between myelofibrosis-related anemia and general anemia that is experienced in patients without an MPN?

There is a major difference, because anemia that a person would have that doesn’t have cancer presents differently than the anemia (related to MPNs). For a person who has a blood cancer, their anemia is going to come with other things (such as) possibly filling up faster (when eating), night sweats (and) extreme fatigue. And some of them have (feelings of) wanting to faint because the hemoglobin is so low.

In a person that has just routine anemia, they won’t have those types of symptoms, they’ll just probably feel a little tired or a little sluggish.

What advice do you have for patients with myelofibrosis who may be experiencing anemia?

We tell the patients to let us know if you have increased fatigue, let us know if any of your symptoms change, you have increased fatigue, you have increased night sweats, you start having fevers or things like that, let us know if any of those things are taking place. That way, I can give that information to the to the oncologist and then they know what to do for the patient.

Make sure that you are proactive as a patient, if there’s something that’s wrong, and you know that it hasn’t been an issue before, make sure that you follow up and follow through, don’t just accept (symptoms). If you have to go to 5 doctors, go to as many as it takes to get the diagnosis, because with time, time loss is not time that can be regained. So, you need to be proactive and monitor your care and know what your norms are and what’s not normal for you.

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Research Developments Advancing Involving CALR-Mutated MPNs

September 6, 2023

Vicki Moore, PhD

A review article published in the Journal of Cellular and Molecular Medicine details recent progress in the development of antibodies targeting mutated calreticulin, aimed at providing a novel therapy option for myeloproliferative neoplasms (MPN). The review was authored by Frederike Kramer, PhD, and Ann Mullally, MD, of Harvard Medical School in Boston, Massachusetts.

Calreticulin is encoded by the CALR gene and alterations in this gene are common drivers of the development of MPN. In most cases, these occur as 1 of 2 mutations in exon 9 of this gene, as Kramer and Mullally explained in their review. Approximately half of the patients with a CALR mutation have a 52-bp deletion, whereas approximately 30% of patients with a CALR mutation have an insertion of 5 bp in the sequence of this gene.

These types of mutations in CALR lead to a frameshift that causes formation of an altered C-terminus in calreticulin, resulting in the absence of an endoplasmic reticulum retention signal. The altered calreticulin is thus directed toward the cell’s surface, where it shows aberrant binding to the thrombopoietin receptor protein (MPL), with the interaction ultimately contributing to activation of the JAK-STAT signaling pathway and cell transformation.

Currently, patients with MPN are often treated with cytoreductive therapies. Allogeneic stem cell transplantation can be curative for patients with CALR-mutated MPN, but this approach carries risks of morbidity and mortality.

However, the interaction of altered calreticulin and MPL provides a possible substrate for a potential targeted treatment approach. Monoclonal antibodies (mAbs) directed at altered calreticulin have been the subject of research, and a range of studies have generated results indicating this may be a possible approach to treatment of CALR-mutated MPN.

Additional immunological approaches to treating MPN that have been under investigation involve peptide vaccination directed at altered calreticulin and T cell-directed targeting agents. Antibody-drug conjugates could also present a possible avenue of treatment, with these agents potentially binding to both mutated calreticulin and MPL within a complex, rather than binding to mutated calreticulin that has simply been secreted.

“Recent advances in identifying the mechanisms by which mutant calreticulin causes MPN paved the path for immunological targeting of CALR-mutant MPN cells, and specific mutant calreticulin targeting mAbs have been developed and found to be efficacious in preclinical mouse models,” the authors wrote in their report, also noting safety and efficacy with these agents have not yet been evaluated in this patient population.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of disclosures.

Reference

Kramer F, Mullally A. Antibody targeting of mutant calreticulin in myeloproliferative neoplasms. J Cell Mol Med. Published online August 7, 2023. doi:10.1111/jcmm.17896

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An Update on Current and Emergent Therapies for Essential Thrombocytosis

Daniel H. Foley, MD
Kristen Pettit, MD

The therapeutic landscape for myeloproliferative neoplasms is shifting toward a goal of meaningful disease modification.

Our understanding of pathophysiology driving Philadelphia chromosome–negative myeloproliferative neoplasms (MPNs) has evolved considerably over the past decade. As a result, the therapeutic landscape is shifting toward a goal of meaningful disease modification. For patients with essential thrombocytosis (ET), the immediate goals remain thrombosis risk reduction and symptom control, but newer therapies on the horizon are likely to change our treatment paradigms considerably for this disease.

How do you approach a new patient with ET?
When it comes to the treatment of patients with ET, the main goal of current approved therapy is to mitigate the risk of thrombotic events, as the treatments have minimal impact on disease progression. The choice of treatment is determined by an individual’s specific risk factors for these events. The International Prognostic Score for Thrombosis in ET revised score is used to stratify patients into 4 risk groups: very low risk, low risk, intermediate risk, and high risk. For the majority of low-risk patients, low-dose aspirin is recommended, as it aids in preventing clotting, but patients classified as intermediate or high risk are generally advised to undergo cytoreductive therapy.

What are the standard options for cytoreductive therapy?

The selection of the most suitable cytoreductive agent depends on factors such as the patient’s comorbidities, tolerability of the treatment, future family planning, and individual preferences. Hydroxyurea (HU) and pegylated interferon alfa (peg-IFN) are the primary options for frontline cytoreductive treatment. In the phase 3 study MPD-RC 112 [NCT01259856], which included patients with both ET and polycythemia vera (PV), HU and peg-IFN demonstrated comparable rates of complete response and thrombotic events after 12 months.However, over time peg-IFN has shown improved molecular responses in both ET and PV.1-4 Although the clinical implications of these molecular responses aren’t yet entirely clear, these findings are quite exciting to see in this disease that has been so difficult to target. A longer-acting interferon (ropeginterferon alfa-2b-njft; Besremi) is currently in evaluation for patients with ET and has been approved in the United States for patients with PV. In cases where initial treatment approaches do not yield satisfactory results, anagrelide is another option, though its use is often limited by toxicities (eg, headaches, dizziness, palpitations, and fluid retention).

What is on the horizon for treatment of ET?

As we delve deeper into understanding the biologic drivers of ET, promising new therapeutic directions are emerging, including JAK inhibitors, epigenetic agents, and mutation-specific biologic/immunologic therapies.Ruxolitinib (Jakafi), a JAK1/2 inhibitor already widely used for other MPNs, continues to be evaluated in ET. In a randomized study, MAJIC [NCT05057494], ruxolitinib was compared with best available therapy (BAT) for patients with ET who had resistance or intolerance to HU. Both treatments showed similar rates of hematologic response, thrombosis, and hemorrhage. However, ruxolitinib outperformed BAT in improving disease-related symptoms.5 Another ongoing trial called Ruxo-BEAT [NCT02577926] is further exploring the use of ruxolitinib in ET.

When it comes to epigenetic regulators, BET inhibitors and LSD1 inhibitors are emerging as potential therapeutic targets. Both BET inhibitors and LSD1 inhibitors have shown the ability to reduce cytokine production via different mechanisms and impair self-renewal of malignant hematopoietic stem cells, so they may have more significant disease-modifying activity compared with other agents.6,7 The BET inhibitor pelabresib (CPI-0610) is currently being evaluated for ET as well as myelofibrosis. The LSD1 inhibitor bomedemstat is also being studied for both ET and MF, and preliminary reports from the ET study show encouraging ability to control platelets and improve symptoms for many patients.8

Biologic and immunologic approaches are emerging as promising strategies as well. Recently, at the American Society of Hematology annual meeting in 2022, preclinical data were presented on a monoclonal antibody that targets mutant CALR, a key diver for approximately 25% of patients with ET.9 This antibody showed impressive potency in selectively targeting mutant CALR-driven oncogenic mechanisms. There are also other antibody-based therapies showing significant efficacy in preclinical studies, and these strategies are now moving toward the development phases.10 Furthermore, the discovery of T-cell responses against mutant CALR has sparked the development of vaccine-based treatment strategies.11,12 

What are your final thoughts regarding the future of ET?

The development of more targeted agents with the potential to meaningfully disrupt the mechanisms driving MPNs provides a lot of optimism for the future in these diseases. As these therapies move toward “prime time,” we will need to reassess our treatment goals for our patients. Hopefully we will be able to raise the bar for response from simply hematologic control and thrombosis prevention toward the more lofty aims of lengthening survival, improving quality of life, and lowering risk of disease progression.

REFERENCES:

1. Mascarenhas J, Kosiorek HE, Prchal JT, et al. A randomized phase 3 trial of interferon-alpha vs hydroxyurea in polycythemia vera and essential thrombocythemia. Blood. 2022;139(19):2931-2941. doi:10.1182/blood.2021012743

2. Masarova L, Patel KP, Newberry KJ, et al. Pegylated interferon alfa-2a in patients with essential thrombocythaemia or polycythaemia vera: a post-hoc, median 83 month follow-up of an open-label, phase 2 trial. Lancet Haematol. 2017;4(4):e165-e175. doi:10.1016/S2352-3026(17)30030-3

3.Quintás-Cardama A, Abdel-Wahab O, Manshouri T, et al. Molecular analysis of patients with polycythemia vera or essential thrombocythemia receiving pegylated interferon α-2a. Blood. 2013;122(6):893-901. doi:10.1182/blood-2012-07-442012

4.Kiladjian JJ, Cassinat B, Chevret S, et al. Pegylated interferon-alfa-2a induces complete hematologic and molecular responses with low toxicity in polycythemia vera. Blood. 2008;112(8):3065-3072. doi:10.1182/blood-2008-03-143537

5.Harrison CN, Mead AJ, Panchal A, et al. Ruxolitinib vs best available therapy for ET intolerant or resistant to hydroxycarbamide. Blood. 2017;130(17):1889-1897. doi:10.1182/blood-2017-05-785790

6.Kleppe M, Koche R, Zou L, et al. Dual targeting of oncogenic activation and inflammatory signaling increases therapeutic efficacy in myeloproliferative neoplasms. Cancer Cell. 2018;33(1):29-43.e27. doi:10.1016/j.ccell.2017.11.009

7.Jutzi JS, Kleppe M, Dias J, et al. LSD1 inhibition prolongs survival in mouse models of MPN by selectively targeting the disease clone. Hemasphere. 2018;2(3):e54. doi:10.1097/HS9.0000000000000054

8.Gill H, Palandri F, Ross DM, et al. A phase 2 study of the LSD1 inhibitor bomedemstat (IMG-7289) for the treatment of essential thrombocythemia (ET). Blood. 2022;140(suppl 1):1784-1787. doi:10.1182/blood-2021-148210

9.Reis E, Buonpane R, Celik H, et al. Discovery of INCA033989, a monoclonal antibody that selectively antagonizes mutant calreticulin oncogenic function in myeloproliferative neoplasms (MPNs). Blood. 2022;140(suppl 1):14-15. doi:10.1182/blood-2022-159435

10.Tvorogov D, Thompson-Peach CAL, Foßelteder J, et al. Targeting human CALR-mutated MPN progenitors with a neoepitope-directed monoclonal antibody. EMBO Rep. 2022;23(4):e52904. doi:10.15252/embr.202152904

11.Holmström MO, Martinenaite E, Ahmad SM, et al. The calreticulin (CALR) exon 9 mutations are promising targets for cancer immune therapy. Leukemia. 2018;32(2):429-437. doi:10.1038/leu.2017.214

12.Holmström MO, Riley CH, Svane IM, Hasselbalch HC, Andersen MH. The CALR exon 9 mutations are shared neoantigens in patients with CALR mutant chronic myeloproliferative neoplasms. Leukemia. 2016;30(12):2413-2416. doi:10.1038/leu.2016.233

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Current Approaches to Diagnose and Treat Primary Myelofibrosis

Targeted Oncology Staff

During a Targeted Oncology™ Case-Based Roundtable™ event, Rami Komrokji, MD, discussed elements to diagnosing myelofibrosis and how to approach risk stratification before treatment.

KOMROKJI: MF could be either primary de novo or coming from secondary from essential thrombocythemia [ET] or polycythemia vera [PT]. [Concerning] the major criteria listed [by the World Health Organization (WHO)], I always bring up the 2 points that not every fibrosis in the bone marrow is myelofibrosis.1 You can see it in lymphomas, hairy cell leukemia, connective tissue disease, etc, and you don’t need fibrosis in the early stages of myelofibrosis to make the diagnosis. The classical megakaryocytic atypia is enough and in the prefibrotic MF, that’s enough to diagnose the disease.

Prefibrotic MF is a relatively new entity that we talk about. Many patients in practice are labeled as ET, and sometimes it’s hard to tease those [differences] out. But those are the patients who we would think have ET, and in 3 to 4 years, they have overt MF. Usually, it will it take a decade to get there, but if a patient had ET and then in 3 or 4 years was in [overt] MF, those probably were patients with prefibrotic MF. There are few clues…most of the time, those patients will have high LDH [lactate dehydrogenase], on the bone marrow there will be more hypercellular granulocytic hyperplasia. There is more clustering of the megakaryocytes.

Currently, we manage them almost the same, but those are the patients who will transform earlier, at higher risk of leukemia. Maybe in the future, those are the patients we will target with some more interventions to try to prevent the overt MF.

The presence of a clonal marker excludes other diseases. [However], myelodysplastic syndrome [MDS] with fibrosis is sometimes hard to distinguish. Fibrosis can be seen in MDS; it’s typically associated with bad outcomes and the new WHO classification with the blast increase has MDS with fibrosis [as a] category on its own. In the clinical phenotype, they typically don’t have the hepatosplenomegaly as much as constitutional symptoms. They’re cytopenic, more like MDS. If a good pathologist sees myeloid or erythroid dysplasia, that will favor MDS with fibrosis. The megakaryocytes are tricky because you always see megakaryocytic atypia in MPNs [myeloproliferative neoplasms], and it depends on how experienced the hematopathologist is. If they are mistakenly calling them dysplasia, that could be deceiving. There are some minor criteria: the anemia, leukocytosis, splenomegaly, LDH, and leukoerythroblastosis.

What is the role of risk stratification when treating patients with MF?

Once we establish the diagnosis, we want to risk stratify the patients and there are many models in MF, 3 or 4 clinical and 2 molecular. I like the MIPSS70 [MIPSS70: Mutation-Enhanced International Prognostic Score System for Transplantation-Age Patients With Primary Myelofibrosis] most because it’s comprehensive and it was designed to look at the question of transplant or not in younger patients not counting the age as a factor.2 Anemia, transfusion dependency, thrombocytopenia, and leukocytosis… [lead to poor prognosis]. Circulating blasts, unfavorable karyotype, [etc], all of those are weighed in these models. Molecular models…account for bad mutations like ASXL1SRFS2, or absence of calreticulin. But at the end, we are putting the patients into a spectrum of a low-risk disease, where the survival spans many years, to a high-risk disease where the survival is less than 2 years.

Why is it important to use prognostic models for MF?

The disease risk value in practice is deciding on transplant. If somebody is not eligible for stem cell transplant [SCT], you may argue that those models are not that important. Somebody who’s very low risk will rarely be symptomatic, because if they have any symptoms, they probably move up to intermediate-1 risk.

If somebody’s survival estimate is 2 to 3 years, or an intermediate-2 or higher risk by any of those models, we think of the SCT earlier on in the course of the disease [to consider if they are] eligible for transplant by functional status and comorbidities, not necessarily by age. The second thing is [having] enough disease risk to justify the SCT. In patients who have higher risk, the timing of the transplant is probably early on. In patients with lower risk, even if they are eligible for SCT, the optimal timing is probably to try to delay the SCT. It’s always a hard decision because you don’t want to go too early [because of] upfront transplant-related mortality. But you also never want to go into an MPN accelerated phase or acute myelocytic leukemia from MPN because those diseases have terrible outcomes.

What recommendations are there for treatment of higher-risk myelofibrosis?

Once we label the patients intermediate or higher risk, we are assessing the symptoms and deciding on treatment. We rarely see patients who just [have] transfusion-dependent anemia. Those patients are probably not the classical candidates for JAK2 inhibitors, at least the classical ruxolitinib [Jakafi] or fedratinib [Inrebic].

[For] most patients…you’re treating either constitutional symptoms or splenomegaly. For those patients, JAK2 inhibitors are reasonable. The National Comprehensive Cancer Network guidelines split that choice of JAK2 inhibitor based on the platelet count.3 If it’s below 50 × 109/L, pacritinib [Vonjo] is the choice; if it’s above 50 × 109/L, [the choice is] ruxolitinib or fedratinib. Most [physicians] are more used to ruxolitinib, [it has] more data…but fedratinib is a reasonable option as well. Sometimes I think even a platelet cutoff of 100 × 109/L would be reasonable to consider pacritinib; the platelet cutoff of 50 × 109/L was for the truly unmet need and accelerated approval of pacritinib.

If patients are candidates for SCT, many times we do start the JAK2 inhibitors before the SCT because the SCT will still take 3 to 4 months to happen. If patients have a big spleen [and] poor performance from the disease, shrinking the spleen and getting them ready for SCT is reasonable.

The 3 available JAK2 inhibitors, ruxolitnib, fedratinib, and pacritinib…have different targets. Ruxolitinib targets JAK1/JAK2, [and has] potent JAK1 [activity]. Pacritinib has different targets; it doesn’t have any JAK1 activity. It has some ACVR1 [activity] so some anemia response can be explained through that [and] other inflammatory pathways like IRAK1. Fedratinib also has some FLT3 activity and some JAK1 activity. Momelotinib has JAK1 and ACVR1 activity.

The choices are based on the cytopenia profile. Fedratinib most of the time is positioned as second line after ruxolitinib in patients that are still proliferative. Ruxolitinib is the first line in patients that are proliferative, not cytopenic. Pacritinib is for thrombocytopenia and when we have approval for momelotinib, hopefully that will be for the anemia phenotype.

References:

1. Barbui T, Thiele J, Gisslinger H, et al. The 2016 WHO classification and diagnostic criteria for myeloproliferative neoplasms: document summary and in-depth discussion. Blood Cancer J. 2018;8(2):15. doi:10.1038/s41408-018-0054-y

2. Guglielmelli P, Lasho TL, Rotunno G, et al. MIPSS70: Mutation-Enhanced International Prognostic Score System for Transplantation-Age Patients With Primary Myelofibrosis. J Clin Oncol. 2018;36(4):310-318. doi:10.1200/JCO.2017.76.4886

3. NCCN. Clinical Practice Guidelines in Oncology. Myeloproliferative neoplasms, version 2.2023. Accessed September 7, 2023. https://tinyurl.com/yw9ka77m

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Health Outcomes in Hematologic Malignancies Impacted By Insurance, Marital, and Economic Status

Hayley Virgil

Findings from a systematic review of several observational studies reveal that increasing disparities in survival outcomes within hematologic malignancies can be primarily attributed to 5 social determinants of health: lack of access to health insurance, treatment at a non-academic facility, low income or education level, and unmarried status.

Key takeaways from the review were presented at the 2023 Society of Hematologic Oncology (SOHO) Annual Meeting. The analysis examined survival outcomes in several subgroups of patients with hematologic cancers and compared them with the overall population. Investigators were able to conclude that although survival was improving overall, disparities were only growing.

Results showed that insurance status was significantly associated with survival in the multivariate analysis (76%), subgroup analysis (12%), and unadjusted analysis (3%), and not significant in a small portion (9%). Findings were similar regarding facility type (56%, 17%, 6%, and 22%, respectively). Distance traveled did show some significant association in multivariate (18%) and subgroup analyses (27%), but was primarily found to not be significant (55%). The association of both provider expertise and marital status proved significant in the multivariate analysis (100% each).

When assessing the impact of economic stability and education on outcomes, income had a significant association in the multivariate analysis (63%), as well as in a subgroup (4%) and unadjusted analyses (8%). Similar findings were reported with regard to high school education (44%; 6%; 17%; and 33%, respectively). Employment and nineth grade education were not significantly associated with survival (100%). Poverty was insignificant in the multivariate analysis (26%), and a subgroup (26%), vs not significant in 50% of patients.

“When we compare those [survival] curves with the overall population of the United States, we can see that those improvements have not reached everybody,” Marisol Miranda-Galvis, DDS, MS, PhD, research project manager at Georgia Cancer Center, said during a presentation on the analysis. “There are obvious reasons that could explain those differences, but our interest is to identify what those actions are that clinicians could implement in clinical practice, regardless of limitations, that could help to close that gap.”

Investigators defined social determinants of health (SDH) as a “set of non-biologic factors that shape the environment of daily life that influence health outcomes.” Such factors include education access and quality, health care access and quality, social and community context, economic stability, and neighborhood/built environment. The goal of the analysis was two-fold: identify the SDH that have been assessed with regard to their impact on outcomes and determine which SDH were linked with worse treatment-related outcomes.

To be included in the systematic review, several criteria were required during the literature search:

  • Patients must have had a hematologic cancer,
  • Any SDH,
  • No comparisons,
  • Any treatment survival measures,
  • Observational studies held in the United States.

The review included a total of 24,353 patients (range, 95-132,402). The most common study setting was national (63.4%), and the most common data source was the National Cancer Database (41.5%). Several types of hematologic malignancies were included in the review, including Hodgkin lymphoma, non-Hodgkin lymphoma, and Burkitt lymphoma (34.1%); multiple myeloma and polymyositis (31.7%); acute myeloid leukemia, acute lymphocytic leukemia, and myelodysplastic syndrome (29.3%); and chronic myeloid leukemia and chronic lymphocytic leukemia (4.9%).

In a population of 57 patients, the outcomes evaluated in the included studies were overall survival (73.2%), early mortality (10.7%), cancer-specific survival (8.9%), progression-free survival (3.6%), and disease-free survival and treatment-related mortality (1.8% each).

SDH that were evaluated were health care access (53.0%), including insurance status (47.1%) and facility type (28.5%); economic stability (25.0%), including income (81.8%) and poverty (12.1%); education access (14.4%), including high school education (94.7%); and social context (7%), including marital status (100%).

When looking specifically at health care access (n = 70) and social context (n = 10), Miranda-Galvis shared several key takeaways.

“In terms of health care access, this domain was evaluating insurance status; those with Medicaid, Medicare, and who were uninsured had lower survival rates compared with those with private or military health coverage,” she said. “In terms of facility type where the patients were treated, those who didn’t receive treatment at an academic institution or research institution presented with a [worse] mortality compared with those who received treatment at community, comprehensive, or integrated cancer centers.”

Several economic stability (n = 33) and education (n = 19) factors were also associated with a survival disadvantage, including having a lower income and education level. The impact of poverty rate appeared inconclusive, while no significant correlations were observed from unemployment rate, and ninth grade education level.

Reference

Miranda-Galvis M, Tjioe K, Balas A, Cortes J. Cancer disparities in survival of patients with hematologic malignancies in the context of social determinants of health: a systematic review. Presented at: 2023 Society of Hematologic Oncology (SOHO) Annual Meeting; September 6-9, 2023; Houston, TX. Abstract MDS-044.

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Socio-Racial Factors May Impact Primary Myelofibrosis Outcomes

Russ Conroy

Mohammad Bakri Hammami, MD, highlights a need to address socio-racial disparities among Black and non-Black patients with primary myelofibrosis to ensure that everyone receives high-quality treatment.

Investigators retrospectively reviewed socio-racial characteristics as potential determinants of survival in patients with primary myelofibrosis and compared the dataset with single-center outcomes of patients treated at Montefiore Medical Center.

Investigators identified that certain socio-racial factors, including race, sex, and age, may potentially affect survival outcomes in patients with primary myelofibrosis, according to data from a retrospective review that were presented at the 2023 Society of Hematologic Oncology (SOHO) Annual Meeting.

Data collected from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2020 highlighted a median overall survival (OS) of 47 months in the overall population with primary myelofibrosis. Additionally, investigators reported an estimated OS rate of 69% at 2 years and 41% at 5 years.

According to presenting author Mohammad Bakri Hammami, MD, an internal medicine resident at Albert Einstein College of Medicine and Jacobi Medical Center, patient age significantly correlated with OS (HR, 1.042; 95% CI, 1.038-1.046; P <.001) in the SEER cohort. Additionally, investigators observed statistically significant worse OS outcomes in male patients compared with their female counterparts (HR, 1.399; 95% CI, 1.277-1.533; <.001), as well as in Black patients compared with non-Black patients (HR, 1.202; 95% CI, 1.016-1.422; P <.032).

Hammami noted that patients pulled from the SEER database who were diagnosed with primary myelofibrosis after 2011 experienced significantly better survival with respect to cause-specific and all-cause mortality (P = .001). Being married was also a protective factor against all-cause mortality (P = .001).

In a cohort of patients with primary myelofibrosis treated at Montefiore Medical Center, the 2-year and 5-year OS rates, respectively, were 92% and 63%. The most common treatment modalities administered to Black and non-Black patients in the Montefiore cohort, respectively, included ruxolitinib (Jakafi; 50.0% and 43.9%), hydroxyurea (20.0% and 19.5%), and fedratinib (Inrebic; 10.0% and 0.0%). Additionally, 10.0% of Black patients and 14.6% of non-Black patients were treated as part of a clinical trial. Overall, Hammami stated that there were “no real differences” in the rates of treatment modalities between Black and non-Black patients treated at Montefiore.

In an analysis of genetic mutations in patients receiving treatment at Montefiore, Black and non-Black patients, respectively, typically had JAK2 (70% and 78%), CALR (20% and 16%), and ASXL1 (40% and 5%) mutations. According to Hammami, there was a generally similar distribution of genetic mutations in patients regardless of race, which was consistent with prior reports.

“There is a real role for social factors in terms of survival, especially when it comes to Black and non-Black patients,” Hammami said. “There is a need to focus on addressing these factors when we want to provide high-quality care to these patients.”

Investigators retrospectively reviewed socio-racial characteristics as potential determinants of survival in patients with primary myelofibrosis and compared the dataset with single-center outcomes of patients treated at Montefiore Medical Center. Patients with no histological confirmation of disease or active follow up were not included in the analysis. Additionally, investigators assessed medical records from patients treated at Montefiore Medical Center from 2007 to 2023.

Across the 17 SEER registries, investigators assessed data from 5403 patients. The overall population consisted of patients who were White (82.0%), Black (8.4%), and Asian or from the Pacific Islands (7.7%).

Among non-Black and Black patients included in the SEER cohort, respectively, the mean age was 69 years and 64 years (P <.001); most patients were male (60.7% vs 52.1%; P <.001). Additionally, the majority of non-Black patients were married (57.4%), whereas most Black patients were unmarried (63.4%; P <.001). Hammami also highlighted that 55.0% of non-Black patients had an annual income of over $70,000, while 59.6% of Black patients earned less than $70,000 per year.

The Montefiore cohort consisted of 51 patients, including 43 who were censored and 8 who died due to cancer. Additionally, 57% of patients were male, and 49% were married. The median patient age in this cohort was 66 years. The Montefiore population consisted of patients who were White (35%), Black (20%), Asian (10%), or another or unknown race (35%).

Reference

Hammami MB, Yang J, Thakur R, et al. Examining racial disparities in the incidence and survival of myelofibrosis: insights from SEER database and an institutional cohort (2000-2020). Presented at: 2023 Society of Hematologic Oncology (SOHO). Annual Meeting; September 6-9, 2023; Houston, TX. Abstract MPN-470.

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