An Update on Current and Emergent Therapies for Essential Thrombocytosis

Posted on September 27, 2023September 27, 2023 by mpn_admin

Sep 6, 2023

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.¹However, 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}

Momelotinib Could Represent Pivotal New Treatment Option in Myelofibrosis

Posted on September 6, 2023September 6, 2023 by mpn_admin

Sep 1, 2023

Ryan Scott

Aaron T. Gerds, MD, PhD, expands on the potential role of momelotinib in the treatment of patients with myelofibrosis who present with anemia, details the data from MOMENTUM, and explains what FDA approval of momelotinib could mean for the treatment of this patient population.

The benefits in symptom burden, spleen size, and transfusion dependence demonstrated by treatment momelotinib in patients with myelofibrosis represent a potential key advance for this treatment paradigm, according to Aaron T. Gerds, MD, PhD.

A new drug application (NDA) seeking the approval of momelotinib as a potential therapeutic option in patients with myelofibrosis is currently under review by the FDA, and the review period was extended to a target action date of September 16, 2023.¹

The NDA is supported by data from the phase 3 MOMENTUM trial (NCT04173494), which evaluated the agent in patients with symptomatic and anemic myelofibrosis who received a prior JAK inhibitor. Data showed that 25% of patients treated with momelotinib (n = 130) experienced a reduction in tumor symptom score of at least 50% at week 24 compared with 9% of patients treated with danazol (n = 65; proportion difference, 16%; 95% CI, 6%-26%; P = .0095).²

Additionally, 39% of patients in the momelotinib arm achieved a spleen volume reduction of at least 25% from baseline to week 24 vs 6% in the danazol arm (P < .0001); moreover, 22% and 3% of patients, respectively, experienced a reduction of 35% or more (P = .0011). At week 24, the rates of transfusion independence were 30% (95% CI, 22%-39%) for momelotinib and 20% (95% CI, 11%-32%) for danazol (noninferiority difference, 14%; 95% CI, 2%-25%; 1-sided P = .0016).

“The potential approval of momelotinib is incredibly important for patients. Having additional agents to treat myelofibrosis would be welcomed. As little as a couple of years ago, we only had 1 approved therapy to treat myelofibrosis,” Gerds said in an interview with OncLive®. Gerds is an assistant professor in the Department of Medicine, a member of the Developmental Therapeutics Program, and medical director of the Case Comprehensive Cancer Center in Cleveland, Ohio.

In the interview, Gerds expanded on the potential role of momelotinib in the treatment of patients with myelofibrosis who present with anemia, detailed the data from MOMENTUM, and explained what FDA approval of momelotinib could mean for the treatment of this patient population. Gerds also serves as an associate professor of Medicine in the Department of Hematology and Medical Oncology at the Cleveland Clinic Taussig Cancer Institute.

OncLive: How could the potential approval of momelotinib affect current and future practice patterns for patients with myelofibrosis?

Gerds: The [potential] approval of momelotinib could be another pivotal moment in the care of patients with myelofibrosis. I would argue that the first pivotal moment was the discovery of recurrent JAK2 mutations, followed several years later by the approval of ruxolitinib [Jakafi], the first JAK inhibitor.

Momelotinib provides an extra opportunity for patients, specifically patients who have anemia along with enlarged spleens and significant symptom burden. This drug promises to try to hit all 3 of those key elements of care in patients with myelofibrosis with a single pill.

What unmet needs exist for patients with myelofibrosis and anemia?

Anemia itself in these patients is a key unmet need. Roughly 40% of patients will be anemic at the time of diagnosis. It is common diagnostic and prognostic criteria that is used to predict who may have aggressive disease. Anemia will also develop in patients within the first year after diagnosis, and at some point, every patient will develop anemia as the [bone] marrow begins to fail. Therefore, anemia is something that is incredibly common and difficult to treat.

We can give red blood cell transfusions to combat anemia, but that comes with adverse effects, such as iron overload, transfusion reactions, and the development of alloantibodies. Moreover, blood is a valuable and somewhat scarce resource. The Red Cross is constantly trying to get us to donate more blood because it is a scarce commodity, and it is also expensive to do red blood cell transfusions. In general, it’s one of the biggest costs in delivering health care for patients with hematologic malignancies. For all these reasons, treating anemia is incredibly important.

Treatments for anemia are somewhat limited. I mentioned transfusions already, and there are also erythropoiesis stimulating agents [ESAs] that can be given. Another drug, luspatercept-aamt [Reblozyl], is already approved to treat anemia in patients with myelodysplastic syndrome and beta thalassemia. It is used off-label to treat anemia in patients with myelofibrosis. danazol is also commonly used.

We already have these 3 agents; however, none of them are perfect or work 100% of the time, and there are still many patients who suffer from anemia who have [myelofibrosis]. Any new agent that is coming along that can potentially treat anemia in a different mechanism of action is always welcome.

What is the mechanism of action of momelotinib, and what prompted this agent’s examination in patients with myelofibrosis?

Momelotinib, in terms of treating anemia, works very differently than ESAs, luspatercept, and danazol. It works by inhibiting ACVR1, also known as ALK2, which is a regulator of hepcidin. Hepcidin is a key piece in what we think about in hematology in iron regulation and red blood cell production. It is a hot topic in myeloproliferative neoplasms right now, and it has been in the world of hematology for some time.

Hepcidin is a master iron regulator that helps regulate the shuttling of iron out of the iron stores, making it available for the body to use, for example, to make red blood cells. In patients with myelofibrosis, they have anemia or an inflammatory block, meaning that hepcidin levels are very high and can shut a lot of those iron stores. By lowering the levels of hepcidin by blocking ACVR1, we can restore effective erythropoiesis by dropping that anemia or inflammatory block. That component of a patient’s anemia can be reversed, potentially by this medication.

What were some of the key efficacy data from MOMENTUM?

The MOMENTUM study pitted momelotinib vs danazol, looking at a couple of key end points. The first was symptom burden reduction, and we also looked at spleen volume reduction—traditional end points for measuring response with JAK inhibitors in patients with myelofibrosis. Another key end point was transfusion independence, and that was the proportion of patients who were transfusion independent at weeks 24 and 48.

We saw that momelotinib outperformed danazol in terms of spleen volume reduction, as well as symptom burden reduction. Momelotinib was also statistically not inferior—this was a non-inferiority analysis—for transfusion independence at week 24 compared with danazol.

What does the safety profile look like for momelotinib in this population?

With respect to safety, one of the early concerns during the development of momelotinib was an increased risk of peripheral neuropathy. This was seen in some earlier studies. However, in subsequent investigations, such as the SIMPLIFY trials [NCT01969838; NCT02101268] and the MOMENTUM study, we did not see excess neuropathy in patients treated on momelotinib compared with best available therapy or danazol, respectively. The rates of peripheral neuropathy were similar in the 2 groups. That was a key take-home point in terms of safety data from the MOMENTUM study.

Certainly, some patients did develop cytopenias while on momelotinib, as well as danazol. There weren’t excess gastrointestinal toxicities, as we see with some of the other JAK inhibitors. There was no signal toward increased risk of non-melanoma skin cancers or bile reactivations. However, we certainly watch for those things whenever we’re treating a patient with a JAK inhibitor.

If it is approved, where do you see momelotinib fitting into the current treatment paradigm for this population?

With the potential approval of momelotinib, we will see what the uptake looks like in everyday practice. That will be a big part of what happens with this medication: how organically it is picked up by different oncologists and hematologists out there in the community. Clearly, it has efficacy in patients with anemia, so it would be right at home in the treatment of a patient who has myelofibrosis who needs spleen volume reduction and symptom control, and has anemia.

If we look closely at the MOMENTUM inclusion criteria, those patients did have prior exposure to a JAK inhibitor for at least one month, and they all had hemoglobin [levels] less than 10g/dL; that is where this drug tends to shine. However, the amount of JAK inhibition given to those patients prior to going on MOMENTUM was limited. We also do have up-front data in patients previously untreated [with a JAK inhibitor] from the SIMPLIFY trials. You could say that if a patient with myelofibrosis and is borderline anemic, they could also benefit from momelotinib, not just in the second line, but potentially in the frontline setting as well.

References

Verstovsek S, Gerds AT, Vannuchi AM, et al. Momelotinib versus danazol in symptomatic patients with anaemia and myelofibrosis (MOMENTUM): results from an international, double-blind, randomised, controlled, phase 3 study. Lancet. 2023;401(10373):269-280. doi:10.1016/S0140-6736(22)02036-0
GSK announces extension of FDA review period of momelotinib. News release. GlaxoSmithKline. June 16, 2023. Accessed August 31, 2023. https://www.gsk.com/en-gb/media/press-releases/gsk-announces-extension-of-fda-review-period-for-momelotinib/

CWP-291 by JW Pharmaceutical for Thrombocythemia Myelofibrosis: Likelihood of Approval

Posted on August 31, 2023August 31, 2023 by mpn_admin

August 30, 2023

GlobalData tracks drug-specific phase transition and likelihood of approval scores, in addition to indication benchmarks based off 18 years of historical drug development data. Attributes of the drug, company and its clinical trials play a fundamental role in drug-specific PTSR and likelihood of approval.

CWP-291 overview

CWP-291 (CWP-232291) is under development for the treatment of hematological tumors including relapsed or refractory acute myeloid leukemia (AML), chronic myelomonocytic leukemia-2, relapsed and refractory multiple myeloma, gastric cancer, myelofibrosis (PMF), post-polycythemia vera (PPMF), castration-resistant prostate cancer (CRPC) and post-essential thrombocythemia (PTMF). The drug candidate is administered intravenously. It acts as Sam68 inhibitor. It was also under development for the treatment solid tumors such as breast cancer, liver, lung cancer and myelodysplastic syndrome.

JW Pharmaceutical overview

JW Pharmaceutical, a subsidiary of JW Holdings Corp, is a provider of generic drugs. The company develops and markets analgesics, antipyretics and cold remedies, antidote agents, antimicrobials, anticancer agents, and others. It offers multivitamins and antianemia agents, contact lens care and ophthalmic agents, antifungal agents, cardiovascular agents, and gastrointestinal agents. JW Pharmaceutical also offers topicals, amino acid solutions, flexible IV containers, IV solutions, respiratory agents, nephrology agents, CNS, urology agents and diabetic agents. The company offers products for cardiovascular, gastrointestinal, nephrology and antianemia, anticancer and neuropsychiatry. It operates through its production and manufacturing facilities in South Korea. JW Pharmaceutical is headquartered in Seoul, South Korea.

Dr Halpern on the Investigation of Upfront Ruxolitinib and Navitoclax in Myelofibrosis

Posted on August 31, 2023August 31, 2023 by mpn_admin

Aug 28, 2023

Anna B. Halpern, MD

Anna B. Halpern, MD, physician, assistant professor, Clinical Research Division, Fred Hutch; assistant professor, hematology, University of Washington School of Medicine, discusses investigational efforts being developed to expand on the use of ruxolitinib and navitoclax in earlier treatment lines for patients with myelofibrosis.

In cohort 3 of the phase 2 REFINE trial (NCT03222609), the combination of ruxolitinib and navitoclax was evaluated in the upfront setting for patients (n=32) who had not been previously exposed to a JAK inhibitor. The study’s primary end point was spleen volume reduction of 35% or greater from baseline at week 24.

An exploratory analysis of this cohort was presented at the 2022 ASH Annual Meeting and Exposition, Halpern begins. Findings showed that navitoclax plus ruxolitinib produced a spleen volume reduction of at least 35% at week 24 across specific patient subsets, she details. These subsets consisted of patients 75 years of age or older, those with a high Dynamic International Prognostic Scoring System score, and those with HMR mutations. The percentage of patients who experienced optimal spleen volume reduction in these subgroups are 50%, 33%, and 47%, respectively.

Notably, changes in bone marrow fibrosis and reductions in the variant allele frequency (VAF) of the driver gene mutation were seen with the combination regimen in many patients, Halpern continues. Half of patients achieved a greater than 20% reduction in VAF from baseline at week 12 or 24, while a greater than 50% VAF reduction from baseline occurred in 18% of patients. When comparing those with or without HMR mutations, no differences in greater than 20% VAF reduction from baseline to week 12 or 24 were observed between populations.

These results indicate the potential disease-modifying ability of ruxolitinib and navitoclax, suggesting that reductions in bone marrow fibrosis and VAF may serve as biomarkers for disease modification, Halpern states. Notably, long-term outcomes cannot be definitively assessed as correlates for leukemia, progression, and survival, she adds. The viability of these 2 biomarker candidates should be assessed more short term, and in larger study populations, Halpern concludes.

Dr Halpern on the MANIFEST Trial of Pelabresib and Ruxolitinib in Myelofibrosis

Posted on August 14, 2023August 14, 2023 by mpn_admin

Aug 10, 2023

Anna B. Halpern, MD

Anna B. Halpern, MD, physician, assistant professor, Clinical Research Division, Fred Hutch, assistant professor, hematology, University of Washington School of Medicine, discusses key efficacy data from the phase 1/2 MANIFEST trial (NCT02158858) investigating the BET inhibitor pelabresib (CPI-0610) plus ruxolitinib (Jakafi), and highlights the agents clinical significance in patients with myelofibrosis.

The global, open-label, nonrandomized, multicohort study evaluated the efficacy of the JAK inhibitor combination therapy vs pelabresib alone for treatment-naive or pretreated patient populations, Halpern begins. The trial involved 4 separate cohorts. These cohorts included the use of pelabresib in patients with JAK inhibitorpretreated myelofibrosis, pelabresib plus ruxolitinib in patients with ruxolitinib-pretreated myelofibrosis, pelabresib plus ruxolitinib in patients with JAK inhibitor–naïve myelofibrosis, and pelabresib alone in patients with essential thrombocythemia.

Halpern reports that results from the JAK inhibitor–naïve cohort showed that pelebresib plus ruxolitinib reduced spleen volume by at least 35% in 68% of patients, emphasizeing that total symptom score decreased by at least 50% in 56% of patients at 24 weeks. The data cutoff date for these findings was July 29, 2022.

Moreover, exploratory analysis revealed that 28% of patients had a grade 1 or greater improvement in fibrosis, while 29.5% experienced a greater than 25% reduction in JAK2 V617F VAF by week 24, Halpern details. These outcomes are of particular interest because they may indicate the disease-modifying ability of this combination, Halpern explains.

Based on these findings, the ongoing randomized, double-blind, phase 3 MANIFEST-2 trial (NCT04603495) is evaluating upfront pelabresib plus ruxolitinib vs ruxolitinib alone in a larger cohort of patients with JAK inhibitor–naïve myelofibrosis, Halpern concludes. Enrollment to this study was completed in May 2023, and topline findings are anticipated to report out in late 2023.

BMS-986158–Based Combos May Provide Another Viable Treatment Approach in Myelofibrosis

Posted on August 14, 2023August 14, 2023 by mpn_admin

August 4, 2023

Courtney Flaherty

Haifa Kathrin Al-Ali, MD, provides background on the phase 1/2 study of BMS-986158, presents initial efficacy and safety data from the study, and discusses her hope that novel combination regimens like these could achieve the challenging goal of disease modification in myelofibrosis in the future.

The investigational, oral BET inhibitor BMS-986158 administered with either first-line ruxolitinib (Rituxan) or second-line fedratinib (Inrebic) showcased early efficacy and tolerability in patients with intermediate- or high-risk myelofibrosis. These data suggest that strategies combining BET and JAK inhibition can not only address myelofibrosis-related symptoms but may show potential for disease modification, according to Haifa Kathrin Al-Ali, MD.

Findings from the dose-escalation portion of the phase 1/2 CA011-023 trial (NCT04817007) were reported at the 2023 EHA Congress, and showed that both regimens had manageable toxicity profiles. In part 1A of the study, 82% of patients given BMS-986158 plus ruxolitinib experienced an any-grade treatment-related adverse effect (TRAE); this percentage was 75% in part 1B, which evaluated BMS-986158 plus fedratinib. Dose-limiting toxicities (DLTs) occurred in 2 patients in part 1A and 3 patients in part 1B.

Early efficacy data demonstrated that first-line BMS-986158 plus ruxolitinib led to spleen volume reduction (SVR) that became particularly robust by week 24. By week 48, 80% of patients (95% CI, 28%-100%) given the first-line ruxolitinib combination (n = 5) and 50% of those given the second-line fedratinib regimen experienced an SVR of at least 35%. In the ruxolitinib arm, the mean spleen volume change was –46.7% at week 12, –59.9% at week 24, and –56.3% at week 48; in the fedratinib arm, these percentages were –29.1%, -30.8%, and -33.0%, respectively.

“There is still a way to go, but these preliminary data are quite encouraging,” said Al-Ali, a professor of Translational Oncology and head of the Krukenberg Cancer Center at the University Hospital of Halle (Saale) in Germany.

In an interview with OncLive®, Al-Ali provided background on the phase 1/2 study of BMS-986158, presented initial efficacy and safety data from the study, and discussed her hope that novel combination regimens like these could achieve the challenging goal of disease modification in myelofibrosis in the future.

OncLive: What was the rationale for investigating the use of BET inhibitors as monotherapy or in combination with JAK inhibitors in myelofibrosis?

Al-Ali: We know that in patients [with myelofibrosis] there is a NF-κB–mediated pro-inflammatory cytokine profile. [This] leads to a dysregulated bone marrow microenvironment and osteoblastic differentiation, which contributes to the bone marrow fibrosis. It’s rational to use BET inhibitors because they have been shown to reduce or inhibit the expression of BET-targeted oncogenes like c-MYC and MYC.

Please describe the design of this study. Which patients were included this analysis, and what were the key objectives of the research?

This is an open-label, phase 1b/2 study. It mainly included patients with myelofibrosis who had splenomegaly and [had] either intermediate-1 [disease] plus symptoms, intermediate-2 [disease], or high-risk [disease, according to the Dynamic International Prognostic Scoring System]. The trial consisted of a dose-escalation phase followed by a dose-expansion phase. In the dose-escalation phase, there were also 2 parts. Part 1A [involved] first-line treatment with the BET inhibitor plus ruxolitinib in patients who had no previous exposure to ruxolitinib. [Part 1B consisted of] the second-line combination, [where] the BET inhibitor was combined with 400 mg of fedratinib and [was administered] once daily [to] patients with either intolerance or resistance to ruxolitinib.

This was a phase 1 study. [At the 2023 EHA Congress,] we presented the data from the dose-escalation phase, so the primary objective is always safety. The secondary objective was efficacy in terms of SVR. There were some exploratory analyses on JAK2 allele burden as well as bone marrow fibrosis.

According to data presented at the congress, what should be known about the safety of BMS-986158?

Regarding safety, [we] found that both the first-line combination with ruxolitinib or the second-line combination with fedratinib were feasible, tolerable, and the safety profiles were manageable. The main AE was thrombocytopenia, which is a class effect; it’s manageable and transient with dose modification or dose holding. The second major AEs were gastrointestinal [toxicities, including] diarrhea and nausea. Generally, these [effects] were mild, never led to the discontinuation of patients from the trial and were quite manageable.

What were the efficacy findings reported with these combinations?

Regarding efficacy, there are very promising results [showing] SVR of at least 35% from baseline by MRI. In the first-line cohort, there was a rapid and relevant reduction from baseline spleen volume [of at least 35%] in [73%] of patients [at week 12]. This seemed to be sustainable. Looking at SVR at week 24, 100% of patients [experienced] SVR. This is a phase 1 [study], and we should be careful, but these are encouraging results.

[Similar results were seen] with the second-line treatment, although the [duration of] follow-up was shorter. At week 12, at least [38%] of the patients [experienced] more than a 35% reduction in spleen volume. These are also encouraging results.

Finally, evidence for disease modification might be seen regarding JAK2 allele burden reduction. [This was] seen quite early, starting by cycle 6 in all the patients [with] JAK2-mutated [disease]. Additionally, in patients with follow-up bone marrow biopsies that could be evaluated, there seems to be a significant reduction in at least 1 grade of fibrosis by week 12 or week 24. [The study includes a] small number of patients, and these are preliminary, encouraging data. This bone marrow fibrosis regression seems to be associated with a hematological, [specifically] anemic, response.

You mentioned that potential evidence for disease modification may have been observed with this in the form of JAK2 allele burden reduction. In myelofibrosis, what efforts are currently underway to develop disease-modifying therapies that go beyond standard approaches focused on symptom management?

One of the major challenges [in myelofibrosis] is to see [clear evidence of successful] disease modification. All the biomarkers you can measure, like bone marrow fibrosis or a reduction in allele mutational burden, should have a clinical outcome correlation. This is a big challenge.

In the future, it is crucial to move away from only SVR and symptom improvement. We have great drugs that could do that. We have to wait for data from phase 3 randomized trials, and we need time to learn and [understand] the benefit of these combination treatments. My wish is to [achieve] sustainable, durable, clinical responses for patients with these combinations, but this is still an area with a lot of unanswered questions.

Are any next steps planned for the investigation of BMS-986158 in this disease?

The next step [for this research] is going further with the trial. The expansion phase has started for the first-line combination treatment in patients who are ruxolitinib naïve. The same will hopefully be happening for the second-line treatment. If these all [show] positive signals, we will move to a phase 3 clinical trial.

What is your main takeaway message for colleagues regarding this presentation?

The takeaway message is that it is feasible to have these combinations. We have learned how to dose [them] and how to manage AEs, which is the first step [for] every treatment. We have [also] shown encouraging preliminary clinical data regarding SVR, [as well as] some encouraging translational aspects like reduction in JAK allele burden or improvement in bone marrow fibrosis.

Overall, what was most exciting about this year’s EHA Congress?

[This year’s EHA Congress has] been particularly exciting. It is almost [solely] a myeloproliferative neoplasm congress because [there are] so many new, exciting datasets [being presented]—not only for a myelofibrosis, but also for polycythemia vera and essential thrombocythemia. At the end of the day, the most important winners will be the patients.

Reference

Ayala R, Lopez N, Abulafia AS, et al. BMS-986158, a potent BET inhibitor, as monotherapy and in combination with ruxolitinib or fedratinib in intermediate- or high-risk myelofibrosis (MF): results from a phase 1/2 study. Presented at the 2023 EHA Congress; June 8-11, 2023; Frankfurt, Germany. Abstract S213.

Karyopharm Receives FDA Fast Track Designation for Selinexor for the Treatment of Myelofibrosis

Posted on July 18, 2023July 18, 2023 by mpn_admin

– Regulatory Designation Includes Primary Myelofibrosis, Post-Essential Thrombocythemia Myelofibrosis and Post-Polycythemia Vera Myelofibrosis –

– Pivotal Phase 3 Study of Selinexor and Ruxolitinib in Treatment-Naïve Myelofibrosis Initiated in June 2023 –

NEWTON, Mass., July 17, 2023 /PRNewswire/ — Karyopharm Therapeutics Inc. (Nasdaq: KPTI), a commercial-stage pharmaceutical company pioneering novel cancer therapies, today announced that the United States Food and Drug Administration (FDA) has granted Fast Track Designation to the development program of selinexor for the treatment of patients with myelofibrosis, including primary myelofibrosis, post-essential thrombocythemia myelofibrosis, and post-polycythemia vera myelofibrosis.

“Fast Track Designation for selinexor highlights its potential to address the unmet medical need in myelofibrosis, an important acknowledgement as we continue our pivotal Phase 3 study,” said Reshma Rangwala, MD, PhD, Chief Medical Officer of Karyopharm. “Selinexor’s unique mechanism of action, XPO1 inhibition, is a novel and potentially fundamental mechanism in myelofibrosis. We have been highly encouraged by the efficacy and safety data observed to date [in our Phase 1 study] with selinexor in combination with ruxolitinib in patients with treatment-naïve myelofibrosis and believe selinexor has the potential to shift the treatment paradigm. We look forward to continued interaction with the FDA as we advance the development of this promising treatment for patients in need.”

In June 2023, Karyopharm initiated a pivotal Phase 3 clinical trial (XPORT-MF-034) (NCT04562389) to assess the efficacy and safety of once-weekly selinexor 60 mg in combination with ruxolitinib in JAKi-naïve patients with myelofibrosis. Updated data from the Phase 1 study were presented at the American Association for Cancer Research Annual Meeting 2023, American Society of Clinical Oncology 2023 and European Hematology Association 2023, which showed rapid, deep and sustained spleen responses and robust symptom improvement in patients treated with selinexor 60 mg in combination with ruxolitinib as of the April 10, 2023 cut-off date. Top-line data from the Phase 3 study is expected in 2025. The Company plans to expand its clinical development program in myelofibrosis by investigating selinexor in other JAKi-naïve settings, such as novel combinations, to benefit the greatest number of patients.

Fast Track Designation is intended to facilitate development and expedite review of drugs to treat serious and life-threatening conditions so that an approved product can reach the market expeditiously. Features of Fast Track Designation include frequent interactions with the FDA review team, and if relevant criteria are met, eligibility for Priority Review and Rolling Review.

Further information about the Phase 3 study can be found at www.clinicaltrials.gov.

About Karyopharm Therapeutics
Karyopharm Therapeutics Inc. (Nasdaq: KPTI) is a commercial-stage pharmaceutical company pioneering novel cancer therapies. Since its founding, Karyopharm has been an industry leader in oral Selective Inhibitor of Nuclear Export (SINE) compound technology, which was developed to address a fundamental mechanism of oncogenesis: nuclear export dysregulation. Karyopharm’s lead SINE compound and first-in-class, oral exportin 1 (XPO1) inhibitor, XPOVIO® (selinexor), is approved in the U.S. and marketed by the Company in three oncology indications and has received regulatory approvals in various indications in a growing number of ex-U.S. territories and countries, including Europe and the United Kingdom (as NEXPOVIO®) and China. Karyopharm has a focused pipeline targeting multiple high unmet need cancer indications, including in multiple myeloma, endometrial cancer, myelodysplastic neoplasms and myelofibrosis. For more information about our people, science and pipeline, please visit www.karyopharm.com, and follow us on Twitter at @Karyopharm and LinkedIn.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Such forward-looking statements include those regarding the ability of selinexor to treat patients with myelofibrosis; and expectations related to the clinical development of selinexor and potential regulatory submissions of selinexor. Such statements are subject to numerous important factors, risks and uncertainties, many of which are beyond Karyopharm’s control, that may cause actual events or results to differ materially from Karyopharm’s current expectations. For example, there can be no guarantee that Karyopharm will successfully commercialize XPOVIO or that any of Karyopharm’s drug candidates, including selinexor and eltanexor, will successfully complete necessary clinical development phases or that development of any of Karyopharm’s drug candidates will continue. Further, there can be no guarantee that any positive developments in the development or commercialization of Karyopharm’s drug candidate portfolio will result in stock price appreciation. Management’s expectations and, therefore, any forward-looking statements in this press release could also be affected by risks and uncertainties relating to a number of other factors, including the following: the adoption of XPOVIO in the commercial marketplace, the timing and costs involved in commercializing XPOVIO or any of Karyopharm’s drug candidates that receive regulatory approval; the ability to obtain and retain regulatory approval of XPOVIO or any of Karyopharm’s drug candidates that receive regulatory approval; Karyopharm’s results of clinical trials and preclinical studies, including subsequent analysis of existing data and new data received from ongoing and future studies; the content and timing of decisions made by the U.S. Food and Drug Administration and other regulatory authorities, investigational review boards at clinical trial sites and publication review bodies, including with respect to the need for additional clinical studies; the ability of Karyopharm or its third party collaborators or successors in interest to fully perform their respective obligations under the applicable agreement and the potential future financial implications of such agreement; Karyopharm’s ability to enroll patients in its clinical trials; unplanned cash requirements and expenditures; development or regulatory approval of drug candidates by Karyopharm’s competitors for products or product candidates in which Karyopharm is currently commercializing or developing; the direct or indirect impact of the COVID-19 pandemic or any future pandemic on Karyopharm’s business, results of operations and financial condition; and Karyopharm’s ability to obtain, maintain and enforce patent and other intellectual property protection for any of its products or product candidates. These and other risks are described under the caption “Risk Factors” in Karyopharm’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2023, which was filed with the Securities and Exchange Commission (SEC) on May 4, 2023, and in other filings that Karyopharm may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by law, Karyopharm expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise.

EXCEED-ET Investigates an Alternative Option for Disease Modification in Essential Thrombocytopenia

Posted on July 18, 2023July 18, 2023 by mpn_admin

July 16, 2023

Nichole Tucker

An overperforming JAK-STAT pathway, including the presence of JAK2, CALR, and MPL gene mutations leads to high platelet count in patients with essential thrombocytopenia (ET).1 Safe and potent therapies are needed for these populations, especially for those requiring cytoreduction, regardless of their prior exposure to hydroxyurea and/or anagrelide, according to Lucia Masarova, MD, et al.

There is also an unmet need for treatments that can reduce the risk of thrombohemorrhagic events, ultimately stopping or preventing the development of post-ET myelofibrosis.¹

Ropeginterferon alfa-2b-njf (Besremi) is a next-generation interferon alfa agent. It is FDA-approved to treat another myeloproliferative neoplasm (MPN), polycythemia vera (PV). In ET, ropeginterferon alfa-2b-njf is being investigated for the treatment of adult patients in a single-arm, multicenter trial (EXCEED-ET; NCT05482971).

At the American Society of Clinical Oncology (ASCO) 2023 Annual Meeting, Masarova, assistant professor, Department of Leukemia, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, presented the EXCEED-ET study design, noting its potential to fill an unmet need for new therapies to treat adults with ET.

“Eventually, we can hopefully add it to something and maybe keep on some agents that have been around to help control the counts. At the same time, maybe we can do a low-dose interferon for a longer time as a disease modification agent, and hopefully you will wake up in an era where there’s going to be no ET or PV,” Masarova told Targeted Oncology^TM, in an interview.

In the interview, Masarova, discussed EXCEED-ET in detail and provided insights into the treatment options for ET and PV.

Targeted Oncology: In terms of disease modification, what is the current state of treatment in MPNs?

Masarova: We hope there will be a goal of therapy in the coming decades. Currently, the therapy goals are kind of focused more in controlling the accounts displaying the symptoms and getting deeper responses. Right now, with some therapies that showed us that we could decrease the allele burden, or we could alter the bone marrow fibrosis, or the bone marrow morphology is going to be the disease modification. As of now, there is no agent that would do it, except for the interferon, which showed quite promisingly that we can bring it into the landscape of the disease.

What does the treatment landscape currently look like for ET?

ET is considered a benign disease. People live with it for a very long time. Currently, treatment is for only those we call high-risk disease patients. Patients that had thrombosis in the past, and then patients that are over the age of 60 years and have a dAkt mutation, and that’s according to the revised International Prognostic Score of Thrombosis for Essential Thrombocytopenia score. Those patients are treated to decrease the risk of thrombosis, but not to do anything else. This is modified just to simply increase the thrombosis risk. That is hydroxyurea, it’s a standard frontline agent, which is an easy to take oral drug. However, it could lead to some resistance or about 30% patients can become.

Because ET also affects younger people, plenty of younger females, they don’t really want to take chemotherapy forever, which I don’t blame them for. They are interested in taking something else. The standard interferon, recombinant or pegylated, which is called the peginterferon alfa-2a [Pegasys]. We’ve recently used this for the couple years has been around for MPNs, particularly for ET and the PV. That is about 40 years almost. This treatment has a lot of data, and a lot of implications. This may be a disease modifying agent, which is an agent that could decrease the allele burden, eradicate the malignant clone, and ultimately change the disease behavior. We were excited. We had novel interferon called ropeginterferon-alpha-2b-njft approved in patients with progressive disease back in 2021. That has been preceded by approval in European Union in 2019. That’s an excellent option in terms of interferons. The normal alternative with the ropeginterferon, which is the novel mono-pegylated form, is kind of more convenient because it’s used every other week. Once we reached complete hematologic control, it’s used once a month. That’s a significant improvement in inconvenience for patients and in tolerability as well as compliance issues. We were excited to get it in PV, and we have it in some studies in PV to expand the access and maybe try a different schedule, and you move it to ET patients. That’s something that we’re going to be looking at.

Then, for patients with PV refractory to hydroxyurea, we have approved sunitinib [Sutent] which is the JAK inhibitor that has solid data in the field after hydroxyurea based on results from the RESPONSE [NCT01243944] and RESPONSE-2 [NCT02038036] trials. It will be 10 years since we had refractory patients treated with ruxolitinib [Jakafi]. It’s an excellent drug for controlling the symptoms and spleen count.

Last year, we had a very excited study called MAGIC-PV [ISRCTN61925716], which was reported by our European colleagues that showed the advantage of ruxolitinib for decreasing the rate of thrombosis hemorrhage. It also actual improved event-free survival, death, and adverse events in terms of progression to myelofibrosis. So, it was exciting. If we consider disease modification is what’s going to be preventing the disease to go into myelofibrosis, I think that will be exciting to see how far we can get in that field.

Can you discuss the rationale of the EXCEED-ET study [NCT05482971]?

The EXCEED-ET study is getting the ropeginterferon, which is the novel interferon into the space of ET. It is phase 1/2 study that gets the ropeginterferon in patients in North America. The patients are hydroxyurea-refractory or hydroxyurea-naive. Patients that have ET platelets over 450,000 need the therapy with some symptoms, and do not have a contraindication for interferons, which also had to be mentioned that the drugs could not be used in patients that have previous autoimmune disease, psychiatric diseases, or neurological because it could aggravate their symptoms. But those patients, if they would be eligible, they could be getting the full access to the drug. Also, with patients with ET, the escalation is going to be a lot faster to 250 micrograms, every other week, 350, and then 500 is the maximum dose that has been explored. However, I have to say the approval of ropeginterferon for PV had even higher dose, and the maximum-tolerated dose was not reached. This is a perfectly safe dose that we have patients on. We’re going to see how it’s going to do in ET patients. There is a core treatment period, which continues after the 4 weeks of escalation of up to 56 weeks. The patients will be dosed every other week with a tolerable dose. We will be monitoring the primary end points of durability of control, hematologic control, platelets less than 450, white cells less than 10. That will basically sustain 80% of 36 consecutive weeks. Then, the key secondary end points are going to include all important end points in ET patients, such as complete hematologic response, composite hematologic response, that includes control of spleen, control of symptoms, absence of disease progression, and absence of thromboembolic events. Then, it’s going to also have this excited end point, which is basically a decline or allele burden. We’ll be checking the allo burden, what we call the molecular response, and then bone marrow morphology response.

Also, there are a couple other exploratory or pharmacokinetic studies that we’re going to be conducting. It’s a study that does not allow patients that were exposed to interferon. For example, patients and [peginterferon alfa-2a] would not be eligible. However, with a plan amendment, there is going to be measurement of neutralizing antibodies against ropeginterferon. If patients are not detected to carry those, they will be still eligible.

If positive, how do you see this study impacting the field?

I’m excited about it. I’ve used interferons in the off-label setting ever since I came to MD Anderson, and it’s been proven to be an effective therapy for young people. I have a lot of patients come in from everywhere and they don’t want to do chemotherapy, they seek the agent. So far, we’ve been only able to give them the [peginterferon alfa-2a], where we have to deal with insurance companies, because it was off-label setting.

Last year, we published 15 years follow-up on our phase 2 study. But this is going to open the use of the agent, I’m excited about the less frequent interactions, which my patients are excited about as well. I’m going to be really comparing and lucky for me, I’ve seen the tolerance of the [peginterferon alfa-2a] in these patients. I will really be comparing them to the ropeginterferon, seeing what this agent could offer, and seeing the results in PV. I’m quite excited about it. I don’t think we will have any data about what we call the disease modification or how we call it in the next 10 years, maybe because it’s a very low progressing disease, but I’m looking forward to seeing whether we’re going to see elimination or absence of disease progression to myelofibrosis. I also wonder if we will see minimization of the thromboembolic events. That will be the ultimate disease modification change.

Afterwards, hopefully we can add it to something and maybe keep patients on some agents that have been around and help control the counts. At the same time, maybe we can do a low dose interferon for a longer time as a disease modification agent, and hopefully you will wake up in an era where there’s going to be no ET or PV.

_REFERENCE:

_{Masarova L, Mascarenhas J, Qin A, et al. EXCEED-ET: A single-arm multicenter study to assess the efficacy, safety, and tolerability of ropeginterferon alfa-2b-njft (P1101) in North American adults with essential thrombocythemia. J Clin Oncol. 2023;41(suppl 16): TPS7088- TPS7088. doi:10.1200/JCO.2023.41.16_suppl.TPS7088}

Pelabresib Combo Improves Spleen/Symptom Burden in JAKi-Naïve Myelofibrosis

Posted on July 13, 2023July 13, 2023 by mpn_admin

July 9, 2023

Russ Conroy

Combination treatment with pelabresib (CPI-0610) and ruxolitinib (Jakafi) was well tolerated and demonstrated enduring improvements in spleen and symptom burden among patients with JAK inhibitor treatment–naïve patients with myelofibrosis, according to findings from arm 3 of the phase 2 MANIFEST study (NCT02158858).

At week 24, 68% (95% CI, 57%-78%) of patients who received the combination achieved a spleen volume reduction of at least 35% (SVR35), which included a median SVR of –50% (range, –84% to 28%). Additionally, SVR35 responses at 24 weeks were observed in 70% and 67% of patients with intermediate-1– and intermediate-2– or high-risk disease based on Dynamic International Prognostic Scoring System (DIPSS) criteria, respectively, and 82% and 66% of patients based on International Prognostic Scoring System (IPSS) criteria. Kaplan-Meier estimates indicated that 93.5% (95% CI, 87.4%-99.7%) of those with a SVR35 response maintained their response at 36 weeks after onset.

A total symptom score reduction of at least 50% (TSS50) was reported in 56% (95% CI, 45%-67%) of patients at week 24, with a best TSS50 response at any time of 83% and a median change in TSS of –59% (range, –100% to 225%). Additionally, 43% of patients had a TSS50 response at 48 weeks, which included a median change in TSS of –54.8% (range, –100% to 307.1%).

At 24 weeks, study treatment yielded an absolute change in hemoglobin levels from baseline between –1 and at least 1.5 g/dL in 55% of patients; hemoglobin levels improved in 36% of patients, including a mean change of 1.3 g/dL and a median of 0.8 g/dL. Moreover, 24% of patients had a mean hemoglobin increase of at least 1.5 g/dL from baseline over any 12-week period while forgoing red blood cell transfusions.

“To our knowledge, the MANIFEST trial in JAK inhibitor treatment-naïve patients is the first study with a rational combination of BET [inhibitor] pelabresib and ruxolitinib that showed clinically meaningful durable improvements in splenomegaly and symptoms, was associated with biomarker findings indicating potential disease modification, and demonstrated a generally favorable safety profile,” the study authors stated. “This combination has the potential to improve the standard of care for treatment-naïve patients with myelofibrosis and warrants further investigation.”

Investigators of the global, open-label, nonrandomized phase 2 MANIFEST study evaluated pelabresib in combination with ruxolitinib in a cohort of JAK inhibitor treatment-naïve patients with myelofibrosis. Patients received an initial dose of 125 mg of pelabresib once daily for 14 days followed by a 7-day pause in combination with continuous ruxolitinib twice a day. Patients could receive a maximum pelabresib dose of 175 mg once daily.

The study’s primary end point was SVR35 from baseline to 24 weeks measured by imaging. The secondary end point was TSS50, and exploratory end points included bone marrow fibrosis improvement based on blinded central hematopathologist review following European consensus guideline criteria for reticulin fibrosis grading and improvement in anemia and transfusion requirements.

Patients who had not been exposed to treatment with JAK inhibitors and BET inhibitors and had confirmed diagnoses of primary myelofibrosis, or post–essential thrombocythemia or post–polycythemia vera myelofibrosis were eligible for enrollment on the trial. Additional eligibility criteria included having a spleen volume of at least 450 cm³, intermediate-2– or high-risk disease based on DIPSS criteria, and at least 2 measurable symptoms using the Myelofibrosis Symptom Assessment Form v4.0.

Overall, 84 patients received at least 1 dose of the study treatment, 53 of whom remained on treatment at the time of data cutoff. The median patient age was 68 years (range, 37-85), and 70% were male. Additionally, 24% had intermediate-1, 61% had intermediate-2, and 16% had high-risk disease by DIPSS criteria. In terms of mutations, investigators most frequently observed JAK2V617F (74%), ASXL1 (46%), CALR (21%), and MPL (8%).

Blinded central pathology review of bone marrow samples indicated at least 1 grade improvement in reticulin fibrosis at week 24 in 28% of evaluable patients, including 7% who had improvements of 2 grades. Among 24 patients with grade 1 or 2 reticulin fibrosis at baseline, 4 had worsening conditions, including 2 patients each with grade 1 and 2 fibrosis. Investigators observed no significant relationship between reticulin fibrosis improvement and clinical end points in the study,

Overall, 96% of patients experienced at least 1 treatment-emergent adverse effect (TEAE), and 63% had grade 3 or higher TEAEs. The most frequent hematologic TEAEs included thrombocytopenia (52%) and anemia (42%), and the most common nonhematologic TEAEs included diarrhea (35%), fatigue (33%), musculoskeletal pain (30%), respiratory tract infection (29%), and constipation (25%).

Pelabresib dose reductions were necessary among 37% of patients, and 36% had ruxolitinib dose reductions due to TEAEs. There were 5 deaths during study treatment or within 30 days following the final pelabresib dose, including 4 determined to be unrelated to pelabresib treatment. One patient died to multiorgan failure due to sepsis secondary to pneumonia, which investigators deemed to be related to pelabresib.

Reference

Mascarenhas J, Kremyanskaya M, Patriarca A, et al. MANIFEST: pelabresib in combination with ruxolitinib for Janus kinase inhibitor treatment-naïve myelofibrosis. J Clin Oncol. Published online March 7, 2023. doi:10.1200/JCO.22.01972

Examining Pelabresib for Patients With Myelofibrosis

Posted on July 10, 2023July 10, 2023 by mpn_admin

July 9, 2023

Joseph Scandura, MD, PhD

Joseph M. Scandura, MD, PhD, Weill Cornell Medicine, discusses next steps for research of pelabresib (CPI-0610) for use in patients with myeloproliferative neoplasms.

Pelabresib is an oral, small molecule inhibitor of BET, which has the potential to downregulate the expression of genes that reside within the pathogenic pathways that underlie MPN progression.

One study evaluating pelabresib is the phase 3 MANIFEST-2 trial (NCT04603495). In this multicenter, double-blind, placebo-controlled trial, investigators are examining the safety and efficacy of pelabresib plus ruxolitinib (Jakafi) vs ruxolitinib alone in patients with JAK inhibitor-naïve myelofibrosis.

Patients aged 18 years and older with primary, post-polycythemia vera, or post-essential thrombocytopenia myelofibrosis, who had advanced disease requiring therapy, splenomegaly by computed tomography or magnetic resonance imaging, and were symptomatic were eligible for enrollment. Patients must also have had a prognostic risk-factor score of intermediate-1 or higher per the Dynamic International Prognostic Scoring System.

In the study, patients were randomly assigned in a 1:1 ratio to receive ruxolitinib in addition to oral pelabresib or matched placebo daily for 14 days, which was followed by 7 days off treatment. The starting dose of pelabresib was 125 mg daily. Then, ruxolitinib was given to patients twice a day in doses of 10 mg or 15 mg. Dose increases for both were allowed per protocol criteria.

Transcription:

0:10 | The first one is that we need to wait for the data to mature. My personal bias is, all of these biomarkers are invaluable until we know outcomes such as survival or time to treatment failure or event-free survival. Until we know that, we are just kind of stuck in this circular loop of what should be, what we hope will be, what our intuitive beliefs are, but we do not really know what any of these things mean until we have those outcomes. That just takes time.

0:46 | The nice thing is there are a number of phase 3 studies, randomized trials, collaborative studies. MANIFEST-2 is a randomized phase 3 study, and that will allow us to address and follow up on some of these findings, and hopefully get to those answers about whether or not these changes that we’re observing in the short-term are predicting these long-term beneficial outcomes. It just takes time for that data to mature

REFERENCE

Phase 3 study of pelabresib (CPI-0610) in myelofibrosis (MF) (MANIFEST-2) (MANIFEST-2). ClinicalTrials.gov. Updated April 6, 2023. Accessed July 6, 2023. https://clinicaltrials.gov/ct2/show/NCT04603495