Ruxolitinib-treated Patients Research Articles

EE407 Treatment Patterns and Healthcare Resource Utilization in Ruxolitinib-Treated Patients with Myelofibrosis with and without Anemia: A Real-World Analysis

EE407 Treatment Patterns and Healthcare Resource Utilization in Ruxolitinib-Treated Patients with Myelofibrosis with and without Anemia: A Real-World Analysis

Ruxolitinib Adherence in Myelofibrosis and Polycythemia Vera: the "RAMP" Italian multicenter prospective study.

Ruxolitinib is beneficial in patients with myelofibrosis (MF) and polycythemia vera (PV). Information on ruxolitinib adherence is scant. The Ruxolitinib Adherence in Myelofibrosis and Polycythemia Vera (RAMP) prospective multicenter study (NCT06078319) included 189 ruxolitinib-treated patients. Patients completed the Adherence to Refills and Medications Scale (ARMS) and Distress Thermometer and Problem List (DTPL) at the earliest convenience, after registration in the study, and at later timepoints. At week-0, low adherence (ARMS > 14) and high distress (DT ≥ 4) were declared by 49.7% and 40.2% of patients, respectively. The main reason for low adherence was difficult ruxolitinib supply (49%), intentional (4.3%) and unintentional (46.7%) non-take. In multivariable regression analysis, low adherence was associated to male sex (p = 0.001), high distress (p < 0.001), and treatment duration ≥ 1year (p = 0.03). Over time, rates of low adherence and high distress remained stable, but unintentional non-take decreased from 47.9% to 26.0% at week-48. MF patients with stable high adherence/low distress were more likely to obtain/maintain the spleen response at week-24. Low adherence to ruxolitinib represents an unmet clinical need that require a multifaceted approach, based on reason behind it (patients characteristics and treatment duration). Its recognition may help distinguishing patients who are truly refractory and those in need of therapy optimization.

Investigation of Serum Albumin as a Dynamic Treatment-Specific Surrogate for Outcomes in Patients With Myelofibrosis Treated With Ruxolitinib.

Ruxolitinib improves splenomegaly and disease-related symptoms in most patients with myelofibrosis (MF), and it has been associated with a survival benefit in higher-risk patients with splenomegaly. Spleen volume reduction has been associated with a survival benefit in ruxolitinib-treated patients; however, its use as a surrogate is limited. We hypothesized that an anti-inflammatory response to ruxolitinib would correlate with improved patient outcomes. We interrogated serum albumin, an acute phase reactant and marker of nutritional status in 590 patients with MF and analyzed differential trajectories of albumin on the basis of ruxolitinib treatment. Additionally, we assessed the prognostic role of baseline albumin and change in albumin. We found that serum albumin levels tend to decrease in patients with MF; however, this tendency is abrogated by ruxolitinib treatment. To that end, baseline serum albumin level correlates with overall survival (OS) in patients with MF, independent of the variables that comprise the dynamic international prognostic scoring system; however, this correlation is limited to ruxolitinib-naïve patients. In ruxolitinib-treated patients, the change in serum albumin after ruxolitinib treatment, rather than the baseline value, is associated with improved OS, a finding not seen in ruxolitinib-naïve patients. These findings suggest that serum albumin, a ubiquitously available laboratory value, has specific relevance in patients with MF and reflects therapeutic response to ruxolitinib.

Outcomes and characteristics of nonmelanoma skin cancers in patients with myeloproliferative neoplasms on ruxolitinib

AbstractNonmelanoma skin cancers (NMSCs) in ruxolitinib-treated patients with myeloproliferative neoplasms behave aggressively, with adverse features and high recurrence. In our cohort, mortality from metastatic NMSC exceeded that from myelofibrosis. Vigilant skin assessment, counseling on NMSC risks, and prospective ruxolitinib-NMSC studies are crucial.

The Efficacy and Safety of Selinexor in Combination with Ruxolitinib in Ruxolitinib-Treated Myelofibrosis Patients： the Interim Analysis of a Prospective, Open-Label, Multicenter, Parallel-Cohort, Phase 2 Study

Background: Myelofibrosis is a chronic hematologic malignancy characterized by constitutional symptoms, bone marrow fibrosis, extramedullary hematopoiesis resulting in splenomegaly and a propensity toward leukemic progression. Although JAK inhibitors have improved patients' splenomegaly and symptom burden, the clinical management of MF is still challenging for its limited treatment options, especially when patients become less responsive or intolerable to Ruxolitinib (RUX) treatment. Selinexor (SEL) is a novel, first-in-class, oral selective inhibitor of nuclear export agent that binds the karyopherin protein exportin 1 (XPO1). Preclinical studies showed SEL decreased viable cells and colony formation both in newly diagnosed and RUX-exposed MF cells. ESSENTIAL trial showed SEL's sustained spleen responses as a single agent in JAKi refractory MF. Besides, a phase I study reported, with SEL plus RUX in treatment-Naïve MF, 92% patients(pts) achieved SVR35, 69% had symptom response and 65% had stable or improved Hgb levels. We have presented promising efficacy and safety data in real-world setting of SEL plus RUX regimen in MF patients in 2023 EHA. Here we are to report the efficacy and safety of the regimen in RUX-treated patients in a prospective clinical trial. Methods: This is a prospective, open-label, multi-center, parallel-cohort phase 2 study, examining SEL plus RUX regimen in RUX-treated MF pts. The study includes MF pts with suboptimal RUX responses or intolerable to RUX treatment. Pts are given SEL 40mg or 60mg QW plus RUX (dosage per investigator judgement, RUX intolerable pts will receive reduced dose of RUX). A total of 40 pts will be included into the study. The primary endpoint is spleen response assessed by palpation or CT/MRI scan per IWG-MRT and ELN response criteria. Key secondary endpoints include anemia response, symptom response defined as symptom resolution or alleviation according to TSS or physician's judgement, and safety. Results: Characteristics As of July 2023, 28 pts had received at least one dose of oral weekly SEL, including 12 suboptimal RUX responses pts and 16 RUX intolerable pts. The median age was 65 years old. Mean duration of prior RUX treatment was 24.5 months (range: 4-77). 18 pts had primary MF, 4 had post-PV MF, and 6 had post-ET MF. Median time from MF diagnosis to study enrollment was 5 years (0.25-29). JAK2, CALR and MPL mutations were present in 18 (64.28%), 5 (17.85%) and 1 (3.57%) pts respectively. All pts presented constitutional symptoms, 25 (89.29%) had splenomegaly, and 7 (25.00%) had packed red blood cell (PRBC) transfusion-dependent anemia. DIPSS risk category was intermediate 23 (82.14%), high risk 3 (10.71%) and unknown 2 (7.14%). Median treatment duration was 134 days (14-525) (Table 1). 15 pts (53.57%) discontinued SEL. Reasons for treatment discontinuation were death in 4 pts (3 from covid-19, 1 sepsis), participation in clinical trial in 2 pts, unsatisfactory response in 2, transplantation in 1, toxicity in 2, economic burden in 1 patient and lost to follow-up in 3. Efficacy Analysis The analysis of spleen response included 21 pts with spleen length assessment data by either palpation or CT/MRI. Spleen response is defined as length reduction more than 50% per IWG-MRT and ELN response criteria. 15 (71.42%) pts had a reduction in spleen volume and 8 (38.09%) achieved spleen response ( Figure 1). For symptom response, 27 pts are with available data. 23 (85.18%) pts had symptom alleviation, 9 (33.33%) achieved ≥50% reduction in TSS or symptom response assessed by physician, of which 1 achieved symptom resolution. There are 12 pts with PRBC transfusion-independent anemia (Hgb≤100g/L) at baseline and had received study treatment for at least 28 days. 10 (83.33%) pts had maintained stable or improved Hgb levels at the last follow up. 5/7 (71.42%) PRBC transfusion-dependent pts became transfusion independent (1 pt) or had reduced transfusion frequency (4 pts), and 2 pts remained stable. Safety The most common TEAEs were nausea 14 (50.00%), vomiting 9 (32.14%), decreased appetite 8 (28.57%), and anemia 7 (25.00%). The most frequent TEAEs ≥ Grade 3 were anemia 3(10.71%) and thrombocytopenia 2(7.14%). Conclusion: In this preliminary analysis, the combination of SEL and RUX showed encouraging efficacy and manageable safety in RUX-treated pts with myelofibrosis.

Energy expenditure in myelofibrosis patients treated with a JAK1/2 inhibitor.

Weight gain is a known adverse effect of ruxolitinib, a JAK1/2 inhibitor that is the mainstay of treatment for many patients with myelofibrosis. The mechanisms behind weight increase with ruxolitinib is incompletely understood, although decreased adipose tissue lipolysis and increased appetite due to blocking the effects of leptin in the hypothalamus have been proposed. In order to explore the metabolic changes in ruxolitinib-treated patients with myelofibrosis, we performed a pilot study to assess the feasibility of using a portable indirect calorimeter to quantify energy expenditure before and during ruxolitinib treatment and report the results of two patients. Waist circumference increased during ruxolitinib treatment in both patients. Energy expenditure initially increased followed by a decrease and then increase again, but to levels below baseline. These results suggest that weight gain secondary to ruxolitinib may be related to changes in whole body energy expenditure.

Ruxolitinib in cytopenic myelofibrosis: Response, toxicity, drug discontinuation, and outcome.

Patients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype. Prognostic correlates of cytopenic phenotype were explored in 886 ruxolitinib-treated patients with primary/secondary MF (PMF/SMF) included in the RUX-MF retrospective study. Cytopenia was defined as: leukocyte count <4×109 /L and/or hemoglobin <11/<10g/dL (males/females) and/or platelets <100×109 /L. Overall, 407 (45.9%) patients had a cytopenic MF, including 249 (52.4%) with PMF. In multivariable analysis, high molecular risk mutations (p=.04), intermediate 2/high Dynamic International Prognostic Score System (p<.001) and intermediate 2/high Myelofibrosis Secondary to Polycythemia Vera and Essential Thrombocythemia Prognostic Model (p<.001) remained associated with cytopenic MF in the overall cohort, PMF, and SMF, respectively. Patients with cytopenia received lower average ruxolitinib at the starting (25.2mg/day vs. 30.2mg/day, p<.001) and overall doses (23.6mg/day vs. 26.8mg/day, p<.001) and achieved lower rates of spleen (26.5% vs. 34.1%, p=.04) and symptom (59.8% vs. 68.8%, p=.008) responses at 6months compared with patients with the proliferative phenotype. Patients with cytopenia also had higher rates of thrombocytopenia at 3months (31.1% vs. 18.8%, p<.001) but lower rates of anemia (65.6% vs. 57.7%, p=.02 at 3months and 56.6% vs. 23.9% at 6months, p<.001). After competing risk analysis, the cumulative incidence of ruxolitinib discontinuation at 5years was 57% and 38% in patients with cytopenia and the proliferative phenotype (p<.001), whereas cumulative incidence of leukemic transformation was similar (p=.06). In Cox regression analysis adjusted for Dynamic International Prognostic Score System score, survival was significantly shorter in patients with cytopenia (p<.001). Cytopenic MF has a lower probability of therapeutic success with ruxolitinib as monotherapy and worse outcome. These patients should be considered for alternative therapeutic strategies.

Ruxolitinib-induced reactivation of cytomegalovirus and Epstein-Barr virus in graft-versus-host disease

ObjectivesSteroid-refractory graft-versus-host disease (SR-GVHD) is a challenging complication of allogeneic hematopoietic stem cell transplantation, and leads to high morbidity and mortality rates. The orally administered, selective Janus-associated kinase 1/2 inhibitor ruxolitinib gives overall response rates (ORR) of more than 70 % in acute and chronic SR-GVHD. However, several studies have highlighted an elevated risk of cytomegalovirus (CMV) reactivation in patients with ruxolitinib-treated SR-GVHD. MethodsWe therefore analyzed risk of CMV and Epstein-Barr virus (EBV) primary infection or reactivation in 57 patients with ruxolitinib-treated GVHD, while taking account of the competing risk (CR) of death prior to the first reactivation. ResultsInitiation of ruxolitinib treatment was a significant adverse prognostic factor for the CR of first CMV reactivation (hazard ratio (HR)= 1.747, 95 % confidence interval (CI): 1.33–2.92, p < 0.0001) and first EBV reactivation (HR=2.657, 95 % CI: 1.82–3.87, p < 0.0001) during GVHD. In our cohort of ruxolitinib-treated patients, the ORR (48 % and 58 % for acute and chronic GVHD, respectively) and the toxicity profile (haematological adverse events in 29.8 % of the patients) were similar to the literature values. ConclusionGiven ruxolitinib’s efficacy in SR-GVHD, use of this drug should not be limited by the fear of viral reactivation; however, our present results emphasize the importance of monitoring the viral load.

High Incidence of Herpes Zoster in Patients Using Ruxolitinib for Myeloproliferative Neoplasms: Need for Prophylaxis.

High Incidence of Herpes Zoster in Patients Using Ruxolitinib for Myeloproliferative Neoplasms: Need for Prophylaxis.

The third dose of mRNA SARS-CoV-2 vaccines enhances the spike-specific antibody and memory B cell response in myelofibrosis patients.

Vaccination against SARS-CoV-2 using mRNA-based vaccines has been highly recommended for fragile subjects, including myelofibrosis patients (MF). Available data on the immune responsiveness of MF patients to mRNA SARS-CoV-2 vaccination, and the impact of the therapy with the JAK inhibitor ruxolitinib, are still fragmented. Here, we profile the spike-specific IgG and memory B-cell response in MF patients, treated or not with ruxolitinib, after the second and the third dose of SARS-CoV-2 BNT162b2 (BioNTech) and mRNA-1273 (Moderna) vaccines. Plasma and peripheral blood mononuclear cells samples were collected before vaccination, post the second and the third doses and tested for spike-specific antibodies, ACE2/RBD antibody inhibition binding activity and spike-specific B cells. The third vaccine dose significantly increased the spike-specific IgG titers in both ruxolitinib-treated and untreated patients, and strongly enhanced the percentage of subjects with antibodies capable of in vitro blocking ACE2/RBD interaction, from 50% up to 80%. While a very low frequency of spike-specific B cells was measured in blood 7 days after the second vaccination dose, a strong and significant increase was elicited by the third dose administration, generating a B cell response similar to the one detected in healthy controls. Despite the overall positive impact of the third dose in MF patients, two patients that were under active concomitant immunosuppressive treatment at the time of vaccination, and a patient that received lymphodepleting therapies in the past, remained low responders. The third mRNA vaccine dose strongly increases the SARS-CoV-2 specific humoral and B cell responses in MF patients, promoting a reactivation of the immune response similar to the one observed in healthy controls.

P1069: RETROSPECTIVE COMPARISON OF PATIENT OUTCOMES ON PACRITINIB VERSUS RUXOLITINIB IN PATIENTS WITH MYELOFIBROSIS AND THROMBOCYTOPENIA

Background: Pacritinib is a JAK2/IRAK1 inhibitor for patients with myelofibrosis and thrombocytopenia. Unlike the JAK1/2 inhibitor ruxolitinib, which is used at lower doses in patients with thrombocytopenia, pacritinib has been studied at full dose regardless of platelet count. Aims: We retrospectively analyzed the phase 3 PERSIST-2 study, comparing pacritinib with ruxolitinib, with a focus on disease symptomatology. Methods: PERSIST-2 enrolled patients with platelet counts ≤100 x 109/L and randomized them 1:1:1 to pacritinib 200 mg twice daily (BID), pacritinib 400 mg once daily (QD), or best available therapy (BAT). This analysis focused on the 200-mg BID dose and patients who received ruxolitinib prior to week 24. Endpoints included the percentage of patients with ≥35% spleen volume reduction (SVR), ≥50% modified total symptom score (mTSS) reduction, and improvement in disease symptoms measured by Patient Global Impression of Change (PGIC). Safety analyses were based on all treated patients; efficacy analyses were based on the intention-to-treat population randomized at least 22 weeks prior to study end. The Fisher Exact test was used to describe differences in response. Logistic regression was used to adjust for differences in baseline characteristics. Results: Safety analysis included 106 patients on pacritinib and 44 on ruxolitinib; efficacy analysis included 74 on pacritinib and 32 on ruxolitinib (median daily dose of 10 mg). Baseline characteristics were similar between the groups, including median platelet count (55 vs 61 x 109/L) and percentage receiving RBC transfusion (46% vs 43%). The following differences in baseline characteristics were accounted for in multivariable modeling: percentage of patients with grade 3 fibrosis (58% vs 36%), primary myelofibrosis (77% vs 50%), ≥1% peripheral blasts (45% vs 61%), and prior JAK2 inhibitor (48% vs 73%). Patients treated with pacritinib vs ruxolitinib achieved higher rates of SVR (22% vs 3%, p=0.02) and numerically higher rates of mTSS response (35% vs 19%; p=0.11) at week 24 (Figure 1A). A greater percentage of patients on pacritinib reported “much” or “very much” improved symptoms (35% vs 16%, p=0.06; Figure 1A). Among ruxolitinib-treated patients with an available PGIC measure at week 24, 50% reported either no improvement or worsening symptoms, while 76% of pacritinib-treated patients reported improvement (Figure 1B). After adjusting for imbalances in baseline characteristics, there was no diminution of treatment effect on SVR or mTSS, and the hazard ratio for survival on pacritinib vs ruxolitinib was 0.46 [95% CI: 0.15-1.43]. Fatal adverse events occurred at slightly lower rates on pacritinib vs ruxolitinib (8% vs 11%). Bleeding occurred at similar rates on pacritinib and ruxolitinib (43% vs 41%). There were low rates of herpes zoster reactivation (n=0 vs 1), fungal skin infection (n=0 vs 1), pulmonary aspergillosis (n=1 vs 0), deep venous thrombosis (n=0 vs 1), and pulmonary embolism (n=1 vs 0) on pacritinib and ruxolitinib, respectively. Image:Summary/Conclusion: Pacritinib yielded higher response rates and a similar safety profile to lower-dose ruxolitinib in patients with myelofibrosis who have moderate or severe thrombocytopenia.

Ruxolitinib in addition to standard of care for the treatment of patients admitted to hospital with COVID-19 (RUXCOVID): a randomised, double-blind, placebo-controlled, phase 3 trial

BackgroundCOVID-19 is associated with acute respiratory distress and cytokine release syndrome. The Janus kinase (JAK)1/JAK2 inhibitor ruxolitinib reduces inflammatory cytokine concentrations in disorders characterised by cytokine dysregulation, including graft-versus-host disease, myelofibrosis, and secondary hemophagocytic lymphohistiocytosis. We assessed whether treatment with the JAK1/JAK2 inhibitor ruxolitinib would be beneficial in patients with COVID-19 admitted to hospital.MethodsRUXCOVID was an international, randomised, double-blind, phase 3 trial of ruxolitinib plus standard of care versus placebo plus standard of care in patients with COVID-19. Patients who were hospitalised but not on mechanical ventilation or in the intensive care unit [ICU] were randomly assigned (2:1) to oral ruxolitinib 5 mg twice per day or placebo for 14 days (14 additional days were allowed if no improvement). The primary endpoint was a composite of death, respiratory failure (invasive ventilation), or ICU care by day 29, analysed by logistic regression including region, treatment, baseline clinical status, age, and sex as covariates. This trial is registered with ClinicalTrials.gov, NCT04362137.FindingsBetween May 4 and Sept 19, 2020, 432 patients were randomly assigned to ruxolitinib (n=287) or placebo (n=145) plus standard of care; the mean age was 56·5 years (SD 13·3), 197 (46%) were female, and 235 (54%) were male. The primary objective was not met: the composite endpoint occurred in 34 (12%) of 284 ruxolitinib-treated patients versus 17 (12%) of 144 placebo-treated patients (odds ratio 0·91, 95% CI 0·48–1·73; p=0·77). By day 29, nine (3%) of 286 ruxolitinib-treated patients had died compared with three (2%) of 145 placebo-treated patients; 22 (8%) of 286 ruxolitinib-treated patients had received invasive ventilation compared with ten (7%) of 145 placebo-treated patients; and 30 (11%) of 284 ruxolitinib-treated patients had received ICU care compared with 17 (12%) of 144 placebo-treated patients. In an exploratory analysis, median time to recovery was 1 day faster with ruxolitinib versus placebo (8 days vs 9 days; hazard ratio 1·10, 95% CI 0·89–1·36). Adverse events included headache (23 [8%] of 281 on ruxolitinib vs 11 [8%] of 143 on placebo) and diarrhoea (21 [7%] vs 12 [8%]).InterpretationRuxolitinib 5 mg twice per day showed no benefit in the overall study population. A larger sample is required to determine the clinical importance of trends for increased efficacy in patient subgroups.FundingNovartis and Incyte.

Updated recommendations on the use of ruxolitinib for the treatment of myelofibrosis

ABSTRACT Objectives Myelofibrosis is a rare bone marrow disorder associated with a high symptom burden, poor prognosis, and shortened survival. While allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment for myelofibrosis, the only approved and reimbursed pharmacotherapy for non-HSCT candidates in Belgium is ruxolitinib. Methods These updated recommendations are based on a consensus reached during two meetings and provide guidance for ruxolitinib administration in myelofibrosis patients considering the particularities of Belgian reimbursement criteria. Results and Discussion In Belgium, ruxolitinib is indicated and reimbursed for transplant-ineligible myelofibrosis patients from intermediate-2- and high-risk groups and from the intermediate-1-risk group with splenomegaly. Our recommendation is to also make ruxolitinib available in the pre-transplant setting for myelofibrosis patients with splenomegaly or heavy symptom burden. Before ruxolitinib initiation, complete blood cell counts are recommended, and the decision on the optimal dosage should be based on platelet count and clinical parameters. In anemic patients, we recommend starting doses of ruxolitinib of 10 mg twice daily for 12 weeks and we propose the use of erythropoiesis-stimulating agents in patients with endogenous erythropoietin levels ≤500 mU/mL. Increased vigilance for opportunistic infections and second primary malignancies is needed in ruxolitinib-treated myelofibrosis patients. Ruxolitinib treatment should be continued as long as there is clinical benefit (reduced splenomegaly or symptoms), and we recommend progressive dose tapering when stopping ruxolitinib. Conclusion Based on new data and clinical experience, the panel of experts discussed ruxolitinib treatment in Belgian myelofibrosis patients with a focus on dose optimization/monitoring, adverse events, and interruption/rechallenge management.

Baseline Serum Ferritin Differentially Predicts W24 Transfusion Independence Response for Momelotinib and Ruxolitinib in Patients with Myelofibrosis

Baseline Serum Ferritin Differentially Predicts W24 Transfusion Independence Response for Momelotinib and Ruxolitinib in Patients with Myelofibrosis

High Throughput Single-Cell Simultaneous Genotyping and Chromatin Accessibility Reveals Genotype to Phenotype Relationship in Human Myeloproliferation

In hematopoiesis, changes in chromatin accessibility define priming and commitment of hematopoietic precursors towards cellular fates. In turn, somatic mutations in hematopoietic stem and progenitor cells (HSPCs) drive the onset and progression of myeloid disorders, such as myeloproliferative neoplasms (MPNs), and reshape differentiation topologies.To chart how somatic mutations disrupt the epigenetic landscape in human clonal outgrowths, we developed Genotyping of Targeted loci with Chromatin Accessibility (GoT-ChA), linking genotypes to chromatin accessibility across thousands of single cells. Crucially, GoT-ChA captures genotypes directly from genomic DNA (Fig. 1a), and thus independently of the genomic location or expression of the target. We tested GoT-ChA via cell line mixing studies targeting either TP53 R248Q (Fig. 1b), or JAK2 V617F (Fig. 1c), assigning cell line identity solely based on chromatin accessibility. Notably, GoT-ChA resulted in genotyping of 54% of cells with 96.9% accuracy for TP53 R248Q and 60% of cells with 99.7% accuracy for JAK2 V617F. These data show the transformative advantage of targeting DNA directly, as prior high-throughput droplet methods to target the lowly expressed JAK2 via cDNA resulted in genotyping of only ~7% of cells (Nam et al, Nature, 2019).Next, we applied GoT-ChA to CD34 + cells from JAK2 V617F-mutant myelofibrosis (MF) samples (Fig. 1d). We clustered cells based on chromatin profiles, revealing the expected cell populations in hematopoiesis (Fig. 1d-e), and then projected genotyping status onto the differentiation map (Fig. 1f). In further validation of genotyping accuracy, copy number inference showed a sample that contained a partial deletion of chromosome 20 (Fig. 1g) concordant with our genotyping. Furthermore, GoT-ChA can be integrated with recent protocols to allow for high mitochondrial genome coverage (Lareau et al, Nature Biotechnology, 2020). We observed mitochondrial mutations that were highly concordant with JAK2 V617F (Fig. 1h), allowing genotyping of >85% of cells.Within MPN samples, wildtype (WT) and mutated (MUT) cells were intermingled across the differentiation topology. Nonetheless, we observed an increase in the mutant fraction within erythroid progenitors (EP; Fig. 1i). Moreover, pseudo-temporal ordering of chromatin accessibility revealed that the mutant cell fraction increased along erythroid or megakaryocyte differentiation in untreated MPN (Fig 1j), in line with clinical phenotypes.Chromatin accessibility profiles can provide clues to the underlying regulatory network through transcription factor (TF) motif accessibility. Uniquely, GoT-ChA enables de novo differential motif accessibility, directly comparing WT and MUT cells co-existing within the same bone marrow. Mutant HSPCs showed increased motif accessibility (FDR < 0.05) for TFs associated with erythropoiesis (Fig. 1k), suggestive of increased erythroid priming. Within EP clusters, we observed increased motif accessibility of STAT5A and STAT5B, downstream targets of JAK2 (Fig. 1l-m). These data demonstrated a cell-type specific effect of the JAK2 V617F mutation.Ruxolitinib is a frontline JAK1/2 inhibitor for MF. Despite improvements in quality of life, ruxolitinib does not clearly target the MPN clone or prevent progression of disease. In ruxolitinib-treated patients the MUT cell fraction was uniformly distributed along the differentiation (Fig.1i-j), demonstrating an abrogation of the fitness advantage of JAK2 V617F in committed progenitors, but not in HSPCs. Consistently, STAT5A motif accessibility remained increased in MUT cells at intermediate stages of erythroid maturation but decreased to similar levels as WT cells at later stages (Fig. 1n-o).Overall, GoT-ChA radically expands the single-cell multi-omics toolkit and obviates limiting dependencies on target gene transcription, allowing high throughput somatic genotype-to-phenotype mapping. Applied to JAK2 V617F-mutated MPN, GoT-ChA uncovered a cell-type specific fitness advantage with erythroid commitment, that was reversed upon JAK2 inhibitor treatment. The reshaping of the differentiation topography traced back to differential transcription factor activity driving uncommitted vs. committed JAK2 V617F progenitors. Thus, single-cell multi-omics with GoT-ChA enables to chart the epigenetic underpinnings of hematopoietic clonal outgrowth. [Display omitted] DisclosuresMimitou: Immunai: Current Employment. Hoffman: Protagonist Therapeutics, Inc.: Consultancy; Kartos Therapeutics, Inc.: Research Funding; Novartis: Other: Data Safety Monitoring Board, Research Funding; AbbVie Inc.: Other: Data Safety Monitoring Board, Research Funding. Abdel-Wahab: Prelude Therapeutics: Consultancy; LOXO Oncology: Consultancy, Research Funding; Merck: Consultancy; Foundation Medicine Inc: Consultancy; H3B Biomedicine: Consultancy, Research Funding; Lilly: Consultancy; AIChemy: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Envisagenics Inc.: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees. Smibert: Immunai: Current Employment.

The Slower Antibody Response in Myelofibrosis Patients after Two Doses of mRNA SARS-CoV-2 Vaccine Calls for a Third Dose.

Immunization with mRNA SARS-CoV-2 vaccines has been highly recommended and prioritized in fragile subjects, including patients with myelofibrosis (MF). Available data on the vaccine immune response developed by MF patients and the impact of ruxolitinib treatment are still too fragmented to support an informed decision on a third dose for this category of subjects. Here, we show that 76% of MF patients develop spike-specific IgG after the second mRNA SARS-CoV-2 vaccine dose, but the response has a slower kinetics compared to healthy subjects, suggesting a reduced capability of their immune system to promptly react to vaccination. A reduced ACE2/RBD binding inhibition activity of spike-specific antibodies was also observed, especially in ruxolitinib-treated patients. Our results, showing slow kinetics of antibody responses in MF patients following vaccination with mRNA SARS-CoV-2 vaccines, support the need for a third vaccine dose.

Ruxolitinib-treated polycythemia vera patients and their risk of secondary malignancies

Recently, there has been increased concern about a risk of secondary malignancies (SM) occurring in myelofibrosis (MF) patients receiving ruxolitinib (RUX). In polycythemia vera (PV), on the other hand, only limited data on the risk of SM under RUX treatment are available. To investigate the association between RUX therapy in PV and SM, we conducted a retrospective, single-center study that included 289 PV patients. RUX was administered to 32.9% (95/289) of patients for a median treatment duration of 48.0 months (range 1.0–101.6). Within a median follow-up of 97 months (1.0–395.0) after PV diagnosis, 24 SM occurred. Comparing the number of PV patients with RUX-associated SM (n = 10, 41.7%) with the 14 (58.3%) patients who developed SM without RUX, no significant difference (p = 0.34, chi square test) was found. No increased incidences of melanoma, lymphoma, or solid “non-skin” malignancies were observed with RUX (p = 0.31, p = 0.60, and p = 0.63, respectively, chi square test). However, significantly more NMSC occurred in association with RUX treatment (p = 0.03, chi-squared test). The “SM-free survival” was not significantly different by log rank test for all 289 patients (p = 0.65), for the patients (n = 208; 72%) receiving cytoreductive therapy (p = 0.48) or for different therapy sequences (p = 0.074). In multivariate analysis, advanced age at PV diagnosis (HR 1.062 [95% CI 1.028, 1.098]) but not administration of RUX (HR 1.068 [95% CI 0.468, 2.463]) was associated with an increased risk for SM (p = 0.005). According to this retrospective analysis, no increased risk of SM due to RUX treatment could be substantiated for PV.

Survival in Primary Myelofibrosis: A Population-based Analysis in the Netherlands

Survival in Primary Myelofibrosis: A Population-based Analysis in the Netherlands

Which Patients with Myelofibrosis Should Receive Allogeneic Stem Cell Transplantation? A Decision Analysis Based on the Systematic Review of 4,341 Patients

▪Allogeneic transplantation (ASCT) offers a chance of cure for younger patients with myelofibrosis (MF) and non-relapse mortality (NRM) has progressively declined thus making transplant feasible also in older patients. Since JAK2 inhibitors recently showed to ameliorate survival of intermediate-2 and high-risk patients, the selection of candidates for ASCT has become particularly complex. The large number of predictive variables influencing the decision to transplant MF patients makes exhaustive multivariate analyses unfeasible. Moreover, no case-control study could yet include a large portion of patients assigned to ruxolitinib. Therefore, we implemented a decision model simulating a cohort of 10,000 55 year-old patients newly diagnosed intermediate 2 MF: patients were assigned either to ASCT or to ruxolitinib. Patients assigned to ASCT were allowed to move monthly among 4 Markov health states (pre-transplant, post-transplant, relapse and death) according to pooled data from a systematic review of transplant reports published (EMBASE) from January 2010 to May 2017 and reporting at least 30 patients. We retrieved 50 publications (4 prospective studies) reporting 4,341 MF patients receiving ASCT mostly (62%) from matched donors, mostly after the year 2000. Median age at transplant was 55 years and median time elapsed from diagnosis was 21 months. IPSS at transplant was mainly intermediate-2 (40%) or high (21%), however, 216 ASCT were performed after blast transformation. At a median follow-up of 38 months, 2-year non-relapse mortality (NRM) was 25% (95%CI: 21.4-28.6%) and cumulative incidence of relapse 22% (95%CI: 17.5-26.5%). On the other arm of the decision model, patients assigned to ruxolitinib had a 0.0105 monthly chance of moving from the alive to the dead state, according to the survival rates reported by COMFORT trials (Vannucchi'15, Verstovsek '17). The same probability of death was assigned to patients waiting for ASCT. Based on the above input data, the model outputs confirmed an appropriate calibration: 5-year cumulative NRM was 25% and 5-year survival in ruxolitinib-treated patients was 59%. The above model forecast 101 versus 99 mean survival from diagnosis if ASCT is included into the treatment pathway. However, very large confidence intervals surrounded the above estimates, therefore, sensitivity analysis explored the impact of different age, IPSS risk and molecular profile, based on the hazard ratios reported by multivariate analyses (Gangat'11, Guglielmelli'17, Palandri'17, Kroger'17, Panagiota'14, Bregante'16, Ditchowasky'12). Despite the long survival yield of ruxolitinib, ASCT provided a survival gain higher than 6 months in intermediate-2 patients younger than 50 years and in high risk patients younger than 65 years. On converse, patients with intermediate-1 risk (- 39 months) or carrying CALR mut 1 (-41 months) were expected to achieve a shorter survival with ASCT. The model allowed to explore complex combinations of clinical and genetic profiles: results are reported in the Figure. ASCT advantage over ruxolitinib was questioned in high-risk older patients harboring CALR mut1, while ASCT was expected to provide a longer survival in intermediate-1 patients lacking any of the three funding mutations. Despite its simplicity, the present decision model has the potential to test several clinical scenarios, depending on the clinical response to ruxolitinib, the presence of multiple detrimental mutations or the availability of alternative donors. Still the model has some limitations mainly related to the assumed multiplicative interactions among predictive variables and to the assumed exponential shape of survival curves. Secondly, the model was calibrated as to project the same five-year survival as ruxolitinib-treated patients of COMFORT studies, but longer follow-up survival data are still missing. Moreover, survival gains of a few months should be carefully balanced against quality of life detriments imposed by ASCT. Nevertheless, results are consistent with recent consensus recommendations and, as a larger portion of patient is tested for funding and non-funding mutations, integration and validation of the model will be possible by retrospective databases. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Promising Results of a Phase 1/2 Clinical Trial of Ruxolitinib in Patients with Chronic Myelomonocytic Leukemia

▪Introduction: Chronic myelomonocytic leukemia (CMML) is a myeloid neoplasm characterized by GM-CSF hypersensitivity, marrow dysplasia, blood monocytosis, and a propensity for acute myeloid leukemia transformation. The overall survival is estimated at 34 months with no drug therapies known to improve survival. We previously reported results of a phase 1 study demonstrating that ruxolitinib, a JAK1/2 inhibitor, is safe and has clinical activity in CMML at doses up to 20mg BID. To confirm efficacy we performed a phase 2 clinical trial and here report the combined results of the phase 1 and 2 clinical studies. Methods: All CMML WHO subtypes were included without regard to previous therapy. Key exclusion criteria included an ANC < 0.25x103 c/dL and a platelet count < 35x103c/dL. The use of GM-CSF analogs was prohibited. The Kaplan-Meier method was used to estimate survival and log-rank test to determine statistical significance. Somatic mutations were identified at baseline using a 49 gene targeted next generation sequencing panel (RainDance Technologies) and a custom 46-plex Luminex assay was used to profile baseline cytokine levels (R&D). The study was registered at clinicaltrials.gov NCT01776723 Results: Between April 2015 and October 2016, 29 patients were enrolled in the phase 2 study resulting in a combined 49 CMML patients treated with ruxolitinib. In phase 2, 56 percent of patients had the proliferative subtype (MPN-CMML) defined by WBC >13x109/L and 28% had higher-risk disease by the Global MD Anderson Scoring System. Six patients (20%) received a prior hypomethylating agent and 85% of patients were WHO subtype CMML-1. Therapy-emergent toxicities were similar to those reported in phase 1. The mean duration of therapy was 219 days (range, 6-675 days). Three hematologic responses, including bi- or trilineage responses (2 HI-E, 2 HI-P, 1 HI-N), one marrow CR, and one partial bone marrow response per 2006 IWG criteria were observed. Six of 13 patients (46%) with splenomegaly had a 50% or greater reduction in spleen size by physical exam. When combining IWG and spleen responses, the overall response rate was 46% (n=11 of 24), including clinical benefit by MDS/MPN IWG response criteria. Using the Myeloproliferative Symptom Assessment Form (MPN-SAF) administered electronically daily, a reduction in total symptom score was noted. The median OS (mOS) from start of treatment was 28 months (95% CI 18-38), and, for CMML-MDS and CMML-MPN, was 32 months and 28 months respectively, (p=0.3). To evaluate whether ruxolitinib may have disease-modifying properties in CMML, analysis of mOS from time of diagnosis was performed comparing all ruxolitinib treated patients (n=49) to an historical dataset with over 1800 CMML patients (Padron et al 2015). The mOS at the time of diagnosis in CMML ruxolitinib-treated CMML patients was 69 months compared to 31 months in the historical CMML cohort (p=0.03). Adjusting for age, Global MD Anderson model, CMML WHO subtype, CMML-MPN, and the interval from diagnosis, treatment with ruxolitinib was associated with improved OS (HR 0.42, p <0.005). Although no mutation or class of mutations was associated with response, peripheral blood plasma levels of CXCL9 (p=0.02) and decreased levels of CCL5 (p=0.018) and RAGE (p=0.016) were statistically associated with higher likelihood of response. Conclusions: Ruxolitinib has promising activity in CMML patients with particular benefit in those with proliferative symptoms and may have disease-modifying activity. The MPN-SAF may be a useful tool to measure symptom burden in the context of ruxolitinib therapy for CMML. Overexpression of cytokines and soluble innate immune receptors is associated with a higher likelihood of response to ruxolitinib therapy. Further clinical study is warranted to validate the biomarkers of response and disease modifying capacity of ruxolitinib in CMML. DisclosuresPadron:Incyte: Honoraria, Research Funding. Lancet:Bio-Path Holdings: Consultancy; Celgene: Consultancy; Boehringer Ingelheim: Consultancy; Jazz Pharmaceuticals: Consultancy; BioSight: Consultancy; Erytech: Consultancy; Janssen: Consultancy; Pfizer: Other: Institutional research funding, Research Funding; Novartis: Consultancy. Mesa:Promedico: Research Funding; Ariad: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy; Gilead Sciences, Inc.: Research Funding; Celgene Corporation: Research Funding; Galena Biopharma, Inc.: Consultancy; Incyte Corporation: Research Funding; CTI BioPharma Corp.: Research Funding. Roboz:AbbVie, Agios, Amgen, Amphivena, Array Biopharma Inc., Astex, AstraZeneca, Celator, Celgene, Clovis Oncology, CTI BioPharma, Genoptix, Immune Pharmaceuticals, Janssen Pharmaceuticals, Juno, MedImmune, MEI Pharma, Novartis, Onconova, Pfizer, Roche Pharmace: Consultancy; Cellectis: Research Funding. Steensma:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Equity Ownership; Takeda: Consultancy; Celgene: Consultancy; Janssen: Consultancy, Research Funding; H3 Biosciences: Consultancy; Onconova: Consultancy; Pfizer: Consultancy. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees. Komrokji:Novartis: Honoraria, Speakers Bureau; Celgene: Honoraria.