De novo isolated myeloid sarcoma: comparative analysis of survival in 19 consecutive cases.

Institutional database search (1999-2020) for acute myeloid leukaemia (AML) identified 109 cases of myeloid sarcoma (MS), of which 19 were isolated and presented de novo. The latter displayed longer survival (median 78 months), compared to MS with synchronous intramedullary AML (n = 32; median 16 months) and de novo AML without MS (n = 729; median 22 months; P = 0·13). However, the difference in survival was no longer apparent after accounting for bone marrow cytogenetic risk status (P = 0·67). Treatment-induced MS tumour resolution was not affected by the presence of intramedullary disease (P = 0·61). The current study clarifies the prognosis of de novo isolated MS, in the context of AML.

Safety and efficacy of INCB018424, a JAK1 and JAK2 inhibitor, in myelofibrosis.

BACKGROUND: Myelofibrosis is a Philadelphia chromosome­negative myeloproliferative neoplasm associated with cytopenias, splenomegaly, poor quality of life, and shortened survival. About half of patients with myelofibrosis carry a gain-of-function mutation in the Janus kinase 2 gene (JAK2 V617F) that contributes to the pathophysiology of the disease. INCB018424 is a potent and selective Janus kinase 1 (JAK1) and JAK2 inhibitor. METHODS: We conducted a phase 1−2 trial of INCB018424 in patients with JAK2 V617F−positive or JAK2 V617F−negative primary myelofibrosis, post­essential thrombocythemia myelofibrosis, or post­polycythemia vera myelofibrosis. RESULTS: A total of 153 patients received INCB018424 for a median duration of more than 14.7 months. The initial dose-escalation phase established 25 mg twice daily or 100 mg once daily as maximum tolerated doses, on the basis of reversible thrombocytopenia. A dose-dependent suppression of phosphorylated signal transducer and activator of transcription 3 (STAT3), a marker of JAK signaling, was demonstrated in patients with wild-type JAK2 and in patients with the JAK2 V617F mutation. We studied additional doses and established that a 15-mg twice-daily starting dose, followed by individualized dose titration, was the most effective and safest dosing regimen. At this dose, 17 of 33 patients (52%) had a rapid objective response (≥50% reduction of splenomegaly) lasting for 12 months or more, and this therapy was associated with grade 3 or grade 4 adverse events (mainly myelosuppression) in less than 10% of patients. Patients with debilitating symptoms, including weight loss, fatigue, night sweats, and pruritus, had rapid improvement. Clinical benefits were associated with a marked diminution of levels of circulating inflammatory cytokines that are commonly elevated in myelofibrosis. CONCLUSIONS: INCB018424 was associated with marked and durable clinical benefits in patients with myelofibrosis for whom no approved therapies existed. (Funded by Incyte; ClinicalTrials.gov number, NCT00509899.)

International Prognostic Scoring System-independent cytogenetic risk categorization in primary myelofibrosis.

Among 200 patients with primary myelofibrosis, karyotype at diagnosis was abnormal in 83 (42%). To assess their individual prognostic impact, specific cytogenetic abnormalities with more than or equal to 5 informative cases were identified and the rest grouped separately as "other abnormalities." Median survival in patients with sole +9 (n = 6), sole 20q- (n = 21), sole 13q- (n = 8), normal karyotype (n = 117), "other abnormalities" (n = 28), complex karyotype (n = 13), and sole +8 (n = 7) were "not reached," 112, 105, 80, 46, 34, and 28 months, respectively (P = .01). Accordingly, 4 cytogenetic risk groups were considered: (1) favorable (sole +9, 20q-, or 13q-), (2) normal, (3) unfavorable (complex karyotype or sole +8), and (4) "other abnormalities." Multivariable analysis confirmed the International Prognostic Scoring System (IPSS)-independent prognostic value of both 4-way and 2-way (ie, favorable/normal vs unfavorable/other abnormalities; IPSS-adjusted hazard ratio = 0.37; 95% confidence interval, 0.24-0.58) cytogenetic risk categorization (P < .01). The ability to prognostically dissect a specific IPSS category has major therapeutic implications.

Evaluating the serial use of the Myelofibrosis Symptom Assessment Form for measuring symptomatic improvement: performance in 87 myelofibrosis patients on a JAK1 and JAK2 inhibitor (INCB018424) clinical trial.

BACKGROUND: Symptomatic burden from constitutional symptoms, anemia, and splenomegaly-related symptoms are common and morbidity inducing in patients with myelofibrosis (MF). The authors previously developed a MF-specific instrument for capturing the burden of MF-associated disease-related symptoms, the Myelofibrosis Symptom Assessment Form. METHODS: The authors evaluated the usefulness of serial administration of the Myelofibrosis Symptom Assessment Form as an instrument for the assessment of symptomatic burden and improvement in conjunction with the therapeutic clinical trial of the open label phase 2 trial of the JAK1 and JAK2 inhibitor INCB018424 in patients with MF. RESULTS: The analysis cohort of 87 patients treated in this trial demonstrated that the instrument was comprehensive and sensitive to symptoms present at trial enrollment. In addition, baseline Myelofibrosis Symptom Assessment Form symptom scores correlated well with objective parameters such as splenomegaly and impaired performance status assessed by the 6-minute walk test. Serial administration while on therapy with INCB018424 demonstrated the instrument to be sensitive to symptomatic change, and that improvements in symptoms correlated well with objective improvements in both weight loss and performance status (6-minute walk test). CONCLUSIONS: The use of the Myelofibrosis Symptom Assessment Form in this phase 2 trial helped characterize the symptomatic improvements observed with use of INCB018424 in MF patients. In an era of many targeted therapies undergoing testing for MF with potential symptomatic benefit, the Myelofibrosis Symptom Assessment Form may provide a useful tool for objective symptomatic assessment and potentially allow some nonrandomized comparison between therapeutic agents.

Phase 1 study of CWP232291 in patients with relapsed or refractory acute myeloid leukemia and myelodysplastic syndrome.

CWP232291 (CWP291) is a small-molecule inhibitor of Wnt signaling that causes degradation of ß-catenin via apoptosis induction through endoplasmic reticulum stress activation. This first-in-human, open-label, dose-escalation study to evaluate the safety, maximum tolerated dose (MTD), and preliminary efficacy of CWP291 enrolled 69 patients with hematologic malignancies (acute myeloid leukemia [AML], n = 64; myelodysplastic syndrome, n = 5) in 15 dose-escalation cohorts of 4 to 334 mg/m2 using a modified 3+3 design and 1 dose-expansion cohort. CWP291 was administered IV daily for 7 days every 21 days. The most common treatment-emergent adverse events (TEAEs) were nausea (n = 44, 64%), vomiting (n = 32, 46%), diarrhea (n = 25, 36%), and infusion-related reactions (n = 20, 29%). Grade ≥3 TEAEs in >3 patients (5%) were pneumonia (n = 8, 12%); hypophosphatemia (n = 6, 8%); leukocytosis, nausea, cellulitis, sepsis, and hypokalemia (n = 5 each, 7% each); and hypertension (n = 4, 6%). Dose-limiting toxicities included nausea (n = 3) and abdominal pain, anaphylactic reaction, myalgia, and rash (n = 1, each); the MTD was defined at 257 mg/m2. CWP232204, the active metabolite of CWP291, showed pharmacokinetic linearity on both days 1 and 7, and a terminal half-life of ∼12 hours. Among 54 response-evaluable AML patients, there was one complete response at a dose of 153 mg/m2 and one partial response at 198 mg/m2; bone marrow blast percentage reduced from a median of 58.3% to 3.5% and 15.0% to 4.2%, respectively. Future studies will explore CWP291, with a mechanism of action aimed at eradication of earlier progenitors via Wnt pathway blockade, as combination therapy. This trial was registered at www.clinicaltrials.gov as #NCT01398462.

Primary Myelodysplastic Syndromes: The Mayo Clinic Experience With 1000 Patients.

OBJECTIVES: To share our 25 years of experience with patients with primary myelodysplastic syndromes (MDS) and to describe the natural history of the disease including presenting clinical and laboratory characteristics and long-term disease outcomes. PATIENTS AND METHODS: One thousand consecutive patients with primary MDS evaluated at Mayo Clinic between January 1, 1989, and May 1, 2014, were considered. The Revised International Prognostic Scoring System and other risk models were applied for risk stratification. Separate analyses were conducted for patients diagnosed before 2005 (n=531) and after 2005 (n=469). RESULTS: Eighty-five percent of patients were older than 60 years (median age, 72 years), with 69% being men. The median follow-up period was 27 months (range, 0-300 months), during which time 808 (81%) deaths and 129 (13%) leukemic transformations were documented. Median survival and leukemic transformation rates were similar in patients diagnosed before or after 2005, despite the significantly higher use of hypomethylating agents in the latter group: 33 months vs 28 months (P=.46) and 13% vs 10% (P=.92), respectively. Revised International Prognostic Scoring System risk distribution was similar in patients diagnosed before or after 2005 (P=.23): 17% were categorized as very low, 36% low, 21% intermediate, 15% high, and 11% very high risk, with a median survival of 72, 43, 24, 18, and 7 months, respectively (P<.001). We found Revised International Prognostic Scoring System cytogenetic risk categorization to be suboptimal in its performance, whereas contemporary prognostic models were broadly similar in their performance. CONCLUSION: The poor outcome in patients with MDS does not appear to have improved over time. Current risk stratification systems for MDS are not substantially different from each other. There is a dire need for drugs that are truly disease modifying and risk models that incorporate prognostically relevant mutations.

Validation of a new three-color fluorescence in situ hybridization (FISH) method to detect CHIC2 deletion, FIP1L1/PDGFRA fusion and PDGFRA translocations.

The PDGRFA locus has become a gene of interest based on mutational activation in various myeloid neoplasms and the availability of targeted therapies (i.e., imatinib mesylate) to its overexpression. We studied a new FISH method to detect CHIC2 deletion, FIP1L1/PDGFRA fusion and PDGFRA translocation in patients with myeloid neoplasms associated with eosinophilia. A total of 46 specimens were studied, including 15 from patients with a CHIC2 abnormality and six patients with an abnormality involving PDGFRA. Our results revealed this new FISH assay accurately detects these abnormalities and will be a useful clinical test for patients with myeloid neoplasms and eosinophilia.

The Myelofibrosis Symptom Assessment Form (MFSAF): an evidence-based brief inventory to measure quality of life and symptomatic response to treatment in myelofibrosis.

Quality of life (QoL) in patients with myelofibrosis (MF) is severely compromised by severe constitutional symptoms (i.e. fatigue, night sweats, fever, weight loss), pruritus, and symptoms from frequently massive hepatosplenomegaly. Given that no current instrument of patient reported outcomes (PRO) exists that covers the unique spectrum of symptomatology seen in MF patients, we sought to develop a new PRO instrument for MF patients for use in therapeutic clinical trials. Utilizing data from an international Internet-based survey of 458 patients with MF we created a 20-item instrument (MFSAF: Myelofibrosis Symptom Assessment Form) which measures the symptoms reported by >10% of MF patients and includes a measure of QoL. We subsequently validated the MFSAF in a prospective trial of MF patients involving patient and provider feedback, as well as comparison to other validated instruments used in cancer patients. The MFSAF results were highly correlated with other instruments, judged comprehensive and understandable by patients, and should be considered for evaluation of MF symptoms in therapeutic trials.

MPL515 mutations in myeloproliferative and other myeloid disorders: a study of 1182 patients.

Recently, a gain-of-function MPL mutation, MPLW515L, was described in patients with JAK2V617F-negative myelofibrosis with myeloid metaplasia (MMM). To gain more information on mutational frequency, disease specificity, and clinical correlates, genomic DNA from 1182 patients with myeloproliferative and other myeloid disorders and 64 healthy controls was screened for MPL515 mutations, regardless of JAK2V617F mutational status: 290 with MMM, 242 with polycythemia vera, 318 with essential thrombocythemia (ET), 88 with myelodysplastic syndrome, 118 with chronic myelomonocytic leukemia, and 126 with acute myeloid leukemia (AML). MPL515 mutations, either MPLW515L (n = 17) or a previously undescribed MPLW515K (n = 5), were detected in 20 patients. The diagnosis of patients with mutant MPL alleles at the time of molecular testing was de novo MMM in 12 patients, ET in 4, post-ET MMM in 1, and MMM in blast crisis in 3. Six patients carried the MPLW515L and JAK2V617F alleles concurrently. We conclude that MPLW515L or MPLW515K mutations are present in patients with MMM or ET at a frequency of approximately 5% and 1%, respectively, but are not observed in patients with polycythemia vera (PV) or other myeloid disorders. Furthermore, MPL mutations may occur concurrently with the JAK2V617F mutation, suggesting that these alleles may have functional complementation in myeloproliferative disease.

Chronic basophilic leukemia: a distinct clinico-pathologic entity?

OBJECTIVE: We sought to better define a group of rare and poorly understood myeloproliferative disorders that are characterized by prominent chronic basophilia in the absence of the Philadelphia chromosome (Ph) or its molecular equivalent. METHODS: We screened our institution's electronic database from 1975 onwards, and identified four such cases. Clinical data and bone marrow pathology were carefully reviewed for these patients. RESULTS: Two patients had prominent manifestations of basophil mediator-release and another presented with pituitary dysfunction. Bone marrow examination uniformly revealed trilineage hyperplasia with basophilia and eosinophilia, dysplastic megakaryocytic hyperplasia, and the absence of megakaryocyte clustering. An abnormal pattern of atypical mast cells was noted in two cases. While disease palliation was effectively achieved with hydroxyurea for one patient, transformation to acute myeloid leukemia was eventually observed in this case. Another patient has achieved long-term disease-free survival after undergoing allogeneic stem cell transplantation. CONCLUSIONS: Our observations reveal a striking pathologic similarity among all four cases, and suggest this disease, which may be aggressive with the potential to transform into acute leukemia, to possibly represent a distinct clinico-pathologic entity (chronic basophilic leukemia).