March 13, 2024
Tim Kong, Nicole Gaudin, Karyn Gordon, Maggie J. Cox, Amy W. Zhou, and Stephen T. Oh
March 13, 2024
Tim Kong, Nicole Gaudin, Karyn Gordon, Maggie J. Cox, Amy W. Zhou, and Stephen T. Oh
Luis E. Aguirre, Akriti Jain, Somedeb Ball, Najla Al Ali, Virginia O. Volpe, Sara Tinsley-Vance, David Sallman, Kendra Sweet, Jeffrey Lancet, Eric Padrom, Seongseok Yun, Andrew Kuykendall, Rami Komrokji
Myelofibrosis is the most aggressive subtype among classical BCR::ABL1 negative myeloproliferative neoplasms. About 90% of cases are driven by constitutive activation of 1 of 3 genes impacting the JAK/STAT pathway: JAK2, CALR, and MPL. Triple-negative myelofibrosis (TN-MF) accounts for only 5-10% of cases and carries the worst outcomes. Little has been described about this subset of disease. Given the marked heterogeneity surrounding disease biology, clonal architecture, clinical presentation, and poor outcomes in TN-MF, identification of features of interest and assessment of treatment response are areas in need of further investigation.
We collected and evaluated baseline clinical and molecular parameters from 626 patients with a diagnosis of myelofibrosis who presented to the H. Lee Moffitt Cancer Center in Tampa (Florida, US) between 2003-2021 and compared them based on presence or absence of the three classical phenotypic driver mutations.
A small proportion of patients (6%) harbored TN-MF which correlated with inferior outcomes, marked by a 4-year reduction in overall survival time compared to the non-TN cohort (mOS 37.4 months vs. 85.7 months; p=.009) and higher rates of leukemic transformation. More pronounced thrombocytopenia and anemia, lower LDH, EPO levels, as well as lower percentage of marrow blasts at baseline were more commonly seen in TN-MF (p<0.05). Similarly, patients with TN-MF had higher risk disease per DIPSS+ and GIPSS. Mutations impacting RNA splicing, epigenetic modification and signaling, specifically SRSF2, SETBP1, IDH2, CBL and GNAS, were more commonly seen among those lacking a classical phenotypic driver. The prevalence of co-mutant ASXL1/SRSF2 clones was significantly higher in TN-MF as was trisomy 8. TN patients had fewer responses (46.2% vs 63.4%) and shorter duration of response to ruxolitinib.
TN-MF is invariably associated with significantly decreased survival and more aggressive clinical behavior with higher rates of leukemic transformation and shorter duration of response to ruxolitinib. Mutations impacting RNA splicing, epigenetic modification and signaling (SRSF2, SETBP1, IDH2, CBL and GNAS) are more common in TN-MF, which likely drive its aggressive course and may account for suboptimal responses to JAK inhibition.
2023 brought a wave of positive developments for patients with myeloproliferative neoplasms (MPNs), particularly myelofibrosis. According to Raajit K. Rampal, MD, PhD, one study of particular interest was the phase 3 MANIFEST-2 trial (NCT04603495) of ruxolitinib (Jakafi) with pelabresib (CPI-0610).1
This study, in addition to the TRANSFORM-1 trial (NCT04472598), showed significant improvement in spleen size and potential benefits in symptom reduction with combination therapies compared with single-agent treatments, suggesting that these combinations could become valuable options for treating patients with myelofibrosis upfront.1,2
Other studies, including early data of TP-3654 and selinexor (Xpovio), show potential for further advancements in myelofibrosis treatment.
“There is a lot to be excited about for the first time in a very long time. There are all of these other small molecule inhibitors in clinical trials [and] I think we will learn a lot from that,” said Rampal, hematologic oncologist at Memorial Sloan Kettering Cancer Center, in an interview with Targeted OncologyTM.
Published: Mar 06, 2024
KRAKOW, Poland, March 6, 2024 /PRNewswire/ — Ryvu Therapeutics (WSE: RVU), a clinical-stage drug discovery and development company focusing on novel small molecule therapies that address emerging targets in oncology, announced today that preclinical data from its synthetic lethality pipeline and RVU120 project, as well as on MEN1703 (SEL24), will be presented at the upcoming 2024 AACR Annual Meeting, scheduled for April 5-10 in San Diego, California.
The addition of parsaclisib to stable-dose ruxolitinib treatment decreased spleen volume, improved symptom scores, and yielded acceptable safety among patients with primary or secondary myelofibrosis (MF), according to findings from a phase 2 trial published in Blood Advances.
Abdulraheem Yacoub, MD, The University of Kansas Cancer Center, Kansas City, Kansas, and coauthors explained that although ruxolitinib has demonstrated beneficial results among patients with intermediate- or high-risk myelofibrosis, “suboptimal response may occur, potentially because of signaling via the phosphoinositide 3-kinase (PI3K)/protein kinase B pathway.”
In this phase 2 trial, the study authors aimed to measure the potential benefit of adding PI3Kδ inhibitor parsaclisib to ruxolitinib treatment among patients with primary or secondary myelofibrosis who did not have optimal responses to ruxolitinib alone. The primary end points were dosing, efficacy, and safety of this treatment combination.
All patients included in this study stayed on a stable dose of ruxolitinib. Among these patients, 32 were administered parsaclisib at 10 or 20 mg once daily for 8 weeks, then once weekly afterward (daily-to-weekly dosing). Additionally, 42 patients were administered parsaclisib at 5 or 20 mg once daily for 8 weeks, and then 5 mg once daily afterward (all-daily dosing).
During a Targeted Oncology™ Case-Based Roundtable™ event, Raajit K. Rampal, MD, gave an overview of the classification, risk assessment, and current therapy options for patients with myelofibrosis.
RAAJIT K. RAMPAL, MD, PHD: Nothing has changed in terms of the 2022 [World Health Organization] classification, unlike what has happened with myelodysplastic syndrome.1 JAK-STAT signaling is a hallmark of MPN pathogenesis, and all of the mutations that we’re aware of at the moment—JAK2, CALR [calreticulin], and MPL—function in the JAK-STAT pathway. MPL is the thrombopoietin receptor which complexes with JAK [Janus kinase].
CALR is interesting, because CALR was discovered in 2013 but we think at the moment CALR complexes with MPL and results in the aberrant activation of MPL, but CALR does traffic to the cell surface.2,3 That makes it a target for immunotherapy. That is the target of a couple of clinical trials; one is open [LIMBER (NCT06034002)] and the other is about to open, which is really interesting [and] could change everything in MPNs.
All that being said, there are still at least 8% to 15% of myelofibrosis cases that are “triple negative.”2,3 If you look at those cases by gene expression profiling, they have the JAK-STAT signature. The issue with those cases is that we haven’t identified the particular lesion that occurs there, but it is a JAK-STAT–activated lesion, regardless of what the actual driver is. Those are the important things to think about with regards to how the disease is driven.
by Tanvi Verma 1, Nikolaos Papadantonakis2, Deniz Peker Barclift1 and Linsheng Zhang
The European Commission granted marketing authorization to momelotinib (Omjjara) for patients with primary myelofibrosis who have disease-related splenomegaly or moderate to severe anemia, according to a press release from GSK.1
This indication also covers patients with post polycythemia vera myelofibrosis or post essential thrombocythemia myelofibrosis who are JAK inhibitor naïve or received previous treatment with ruxolitinib (Jakafi). The authorization is based on results from the phase 3 MOMENTUM trial (NCT04173494), which analyzed the use of momelotinib and danazol in patients with symptomatic and anemic myelofibrosis.2
“The challenges of living with myelofibrosis can be burdensome, and symptomatic patients can experience spleen enlargement, fatigue, night sweats, and bone pain. Until now, there have been no options specifically indicated to treat these symptoms in patients who also experience anemia. The authorization of [momelotinib] brings a new treatment option with a differentiated mechanism of action to these patients in the European Union,” Nina Mojas, senior vice president of Oncology Global Product Strategy at GSK, said in the press release.
In the trial, the total symptom score response at week 24 was 24.6% (95% CI, 17.49%-32.94%) for patients receiving momelotinib vs 9.2% (95% CI, 3.46%-19.02%) in the danazol arm (P = .0095). Additionally, a reduction of splenic volume by 25% occurred in 40.0% (95% CI, 31.51%-48.95%) of patients in the momelotinib arm vs 6.2% (95% CI, 1.70%-15.01%; P <.0001) in the danazol arm. A 35% reduction in spleen volume was also observed in 23.1% (95% CI, 16.14%-31.28%) in the momelotinib arm and 3.1% (95% CI, 0.37%-10.68%; P = .0006) in the danazol arm.
In September 2023, the FDA approved momelotinib for patients with intermediate- or high-risk myelofibrosis, including primary and secondary myelofibrosis, who are experiencing anemia.3 In November 2023, the European Medicine’s Agency’s Committee for Medicinal Products for Human Use expressed a positive opinion for momelotinib.4 The positive opinion was one of the final steps leading to the approval of the drug in the European Union.
“I think [momelotinib] will make an immediate impact. There clearly are individuals now who are on JAK inhibitors like ruxolitinib or fedratinib [Inrebic] who have significant anemia who will immediately be potential candidates,” Ruben A. Mesa, MD, FACP, said in an interview with CancerNetwork® prior to the FDA approval. Mesa is the president of the Enterprise Cancer Service Line and senior vice president at Atrium Health; executive director of the National Cancer Institute-designated Atrium Health Wake Forest Baptist Comprehensive Cancer Center; and vice dean for Cancer Programs at Wake Forest University School of Medicine.
Eytan M. Stein, Amir T. Fathi, Wael A. Harb, Gozde Colak, Andrea Fusco & James K. Mangan
Pelabresib (CPI-0610), a BET protein inhibitor, is in clinical development for hematologic malignancies, given its ability to target NF-κB gene expression. The MANIFEST phase 1 study assessed pelabresib in patients with acute leukemia, high-risk myelodysplastic (MDS) syndrome, or MDS/myeloproliferative neoplasms (MDS/MPNs) (NCT02158858). Forty-four patients received pelabresib orally once daily (QD) at various doses (24–400 mg capsule or 225–275 mg tablet) on cycles of 14 d on and 7 d off. The most frequent drug-related adverse events were nausea, decreased appetite, and fatigue. The maximum tolerated dose (MTD) was 225 mg tablet QD. One patient with chronic myelomonocytic leukemia (CMML) showed partial remission. In total, 25.8% of acute myeloid leukemia (AML) patients and 38.5% of high-risk MDS patients had stable disease. One AML patient and one CMML patient showed peripheral hematologic response. The favorable safety profile supports the ongoing pivotal study of pelabresib in patients with myelofibrosis using the recommended phase 2 dose of 125 mg tablet QD.