International collaborations over the years have produced a series of prognostic models for primary myelofibrosis (PMF), including the recently unveiled mutation-enhanced international prognostic ...scoring systems for transplant-age patients (MIPSS70 and MIPSS70-plus). In the current study, we considered the feasibility of a genetically inspired prognostic scoring system (GIPSS) that is exclusively based on genetic markers. Among 641 cytogenetically annotated patients with PMF and informative for previously recognized adverse mutations, multivariable analysis identified "VHR" karyotype, "unfavorable" karyotype, absence of type 1/like CALR mutation and presence of ASXL1, SRSF2, or U2AF1Q157 mutation, as inter-independent predictors of inferior survival; the respective HRs (95% CI) were 3.1 (2.1-4.3), 2.1 (1.6-2.7), 2.1 (1.6-2.9), 1.8 (1.5-2.3), 2.4 (1.9-3.2), and 2.4 (1.7-3.3). Based on HR-weighted risk points, a four-tiered GIPSS model was devised: low (zero points; n = 58), intermediate-1 (1 point; n = 260), intermediate-2 (2 points; n = 192), and high (≥3 points; n = 131); the respective median (5-year) survivals were 26.4 (94%), 8.0 (73%), 4.2 (40%), and 2 (14%) years; the model was internally validated by bootstrapping and its predictive accuracy was shown to be comparable to that of MIPSS70-plus. GIPPS offers a low-complexity prognostic tool for PMF that is solely dependent on genetic risk factors and, thus, forward-looking in its essence.
Imetelstat, a telomerase inhibitor, induced complete or partial responses in 21% of patients with refractory myelofibrosis. In some patients, reversal of marrow fibrosis was documented and the burden ...of mutant clones decreased. Myelosuppression was the key toxic effect.
Allogeneic stem-cell transplantation is currently the only method of treatment for patients with myeloproliferative neoplasm–associated myelofibrosis that has been shown to induce long-term disease-free remission.
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Unfortunately, allogeneic stem-cell transplantation is associated with a relatively high rate of treatment-related death and complications, including chronic graft-versus-host disease. Furthermore, many older patients are not eligible for this intervention. Other treatment strategies, including the use of Janus kinase (JAK) inhibitors, are palliative and lack selective anticlonal activity.
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Ruxolitinib and other JAK inhibitors can alleviate constitutional symptoms and reduce spleen size, but they often cannot induce complete or partial remissions, reversal of bone marrow fibrosis, . . .
Current cytogenetic risk stratification in primary myelofibrosis (PMF) is two-tiered: 'favorable' and 'unfavorable'. Recent studies have suggested prognostic heterogeneity within the unfavorable risk ...category. In 1002 consecutive patients, we performed stepwise analysis of impact on survival from individual and prognostically ordered cytogenetic abnormalities, leading to a revised three-tiered risk model: 'very high risk (VHR)'-single/multiple abnormalities of -7, i(17q), inv(3)/3q21, 12p-/12p11.2, 11q-/11q23, or other autosomal trisomies not including + 8/ + 9 (e.g., +21, +19); 'favorable'-normal karyotype or sole abnormalities of 13q-, +9, 20q-, chromosome 1 translocation/duplication or sex chromosome abnormality including -Y; 'unfavorable'-all other abnormalities. Median survivals for VHR (n = 75), unfavorable (n = 190) and favorable (n = 737) risk categories were 1.2 (HR 3.8, 95% CI 2.9-4.9), 2.9 (HR 1.7, 95% CI 1.4-2.0) and 4.4 years and survival impact was independent of clinically derived prognostic systems, driver and ASXL1/SRSF2 mutations. The revised model was also effective in predicting leukemic transformation: HRs (95% CI) were 4.4 (2.0-9.4) for VHR and 2.0 (1.2-3.4) for unfavorable. The impact of driver mutations on survival was confined to favorable and that of ASXL1/SRSF2 mutations to favorable/unfavorable cytogenetic risk categories. The current study clarifies the prognostic hierarchy of genetic risk factors in PMF and provides a more refined three-tiered cytogenetic risk model.
A total of 410 patients with blast phase myeloproliferative neoplasm (MPN-BP) were retrospectively reviewed: 248 from the Mayo Clinic and 162 from Italy. Median survival was 3.6 months, with no ...improvement over the last 15 years. Multivariable analysis performed on the Mayo cohort identified high risk karyotype, platelet count < 100 × 10
/L, age > 65 years and transfusion need as independent risk factors for survival. Also in the Mayo cohort, intensive chemotherapy resulted in complete remission (CR) or CR with incomplete count recovery (CRi) rates of 35 and 24%, respectively; treatment-specified 3-year/5-year survival rates were 32/10% for patients receiving allogeneic stem cell transplant (AlloSCT) (n = 24), 19/13% for patients achieving CR/CRi but were not transplanted (n = 24), and 1/1% in the absence of both AlloSCT and CR/CRi (n = 200) (p < 0.01). The survival impact of AlloSCT (HR 0.2, 95% CI 0.1-0.3), CR/CRi without AlloSCT (HR 0.3, 95% CI 0.2-0.5), high risk karyotype (HR 1.6, 95% CI 1.1-2.2) and platelet count < 100 × 10
/L (HR 1.6, 95% CI 1.1-2.2) were confirmed to be inter-independent. Similar observations were made in the Italian cohort. The current study identifies the setting for improved short-term survival in MPN-BP, but also highlights the limited value of current therapy, including AlloSCT, in securing long-term survival.
QTc interval prolongation can lead to life‐threatening complications such as Torsade de Pointes (TdP), ventricular tachycardia (VT) and sudden cardiac death (SCD). It can occur with tyrosine kinase ...inhibitors (TKIs) but comparative real‐world analyses on the incidence and complication rates are scarce. We retrospectively reviewed all cancer patients treated with TKI therapy at Mayo Clinic between January 2005 and December 2018 and had at least two ECGs (before and after TKI). For each TKI type, we determined the administration rate and incidence of QTc prolongation. QTc prolongation was defined as a corrected QT interval (by Fridericia formula) ≥450 ms in men and ≥470 ms in women. A total of 618 cancer patients were included with 902 TKI administrations, of which 654 (72.5%) were accounted for by pazopanib, sunitinib, imatinib, nilotinib and dasatinib. QTc prolongation (any grade) was reported in 28.8%, most commonly with nilotinib (38.7%) and dasatinib (41.7%). A QTc interval ≥500 ms and a QTc increase ≥60 ms was documented in 46 and 63 administrations, respectively. Life‐threatening toxicity was seen in 14 cases (5.4% of QTc prolongation cases) including VT in 9, SCD in 3 and TdP in two administrations. The response to QTc prolongation was: discontinuation in 68%, dose reduction in 13.5%, temporary hold in 8.1% and no action in 10.4%. In conclusion, QTc prolongation with TKI therapy is very common (∼1/3 of cases) and in 5% (1.7% overall) associated with life‐threatening complications. These data support recommendations for careful ECG monitoring in cancer patients undergoing TKI therapy.
What's new?
While tyrosine kinase inhibitors (TKIs) are superior cancer therapies and increase the efficacy of classical chemotherapeutics, significant toxicities limit their use. Among these, QTc prolongation represents a major concern, though real‐world clinical data are sparse. Here, among 618 cancer patients treated with TKIs at the Mayo Clinic, approximately one‐third experienced QTc prolongation, and this was noted in particular with BCR‐ABL and VEGF TKIs. Overall, high‐grade QTc prolongations were observed in one‐fifth of patients. About 5 percent of patients had life‐threatening complications. These data highlight the importance of QTc interval monitoring and reduction of contributing factors during TKI therapy.
Between October 2007 and July 2013, 183 Mayo Clinic patients (median age 65 years; 58% males) with high/intermediate risk myelofibrosis (MF) were enrolled in consecutive phase 1/2 JAK2 inhibitor ...(JAKi) clinical trials with momelotinib (n = 79), ruxolitinib (n = 50), fedratinib (n = 23) and BMS-911543 (n = 31). Using conventional criteria, the respective response rates for spleen and "transfusion-dependent anemia" were 47%, 32%, 83%, 62% and 51%, 30%, 10%, 44%, respectively, favoring momelotinib for anemia response (p = 0.02) and fedratinib for spleen response (p < 0.01). All study patients were followed to death or 2022, during which time 177 (97%) drug discontinuations, 27 (15%) leukemic transformations, and 22 (12%) allogeneic stem cell transplants (ASCT) were recorded. 5/10-year survival rate for all 183 patients was 41%/16% and not significantly different across the four drug cohorts (p = 0.33). Multivariable analysis of pre-treatment variables identified age >65 years (HR 3.5), absence of type 1/like CALR mutation (HR 2.8), baseline transfusion need (HR 2.1), and presence of ASXL1/SRSF2 mutation (HR 1.6) as risk factors for overall survival; subsequent HR-based modeling segregated three risk categories with 5/10-year survival rates of 84%/60%, 44%/14%, and 21%/5% (p < 0.01). In addition, spleen (p < 0.01) and anemia (p = 0.01) responses were independently associated with improved short-term survival while long-term survival was secured only by ASCT (5/10-year survival rate 91%/45% vs 47%/19% in non-transplanted patients; p < 0.01). The current retrospective study suggests the value of specific pre-treatment variables in identifying long-lived MF patients receiving JAKi and also confirms recent observations on the favorable impact of treatment response on short-term and of ASCT on long-term survival.
We retrospectively reviewed 72 anemic patients with myelofibrosis (MF; median age 68 years), who were JAK2 inhibitor‐naïve at the time of study entry to a phase‐1/2 momelotinib clinical trial. Driver ...mutation profile included JAK2 69%, CALR 17%, MPL 8%, and triple‐negative 6%; other mutations included ASXL1 39% and SRSF2 17%. Momelotinib was administered at a median dose of 300 mg daily. Anemia response was assessed by formal criteria and documented in 44% of all patients with hemoglobin levels below the sex‐adjusted reference range (n = 72), 48% of those with hemoglobin <10 g/dl (n = 54), and 46% of those who were transfusion‐dependent at the time of study entry (n = 28). Anemia response was more likely with post‐essential thrombocythemia MF (83% vs 37%; p = .001), lower serum ferritin (p = .003), and shorter time from diagnosis to momelotinib therapy (p = .001); the first two variables were also predictive in transfusion‐dependent patients. Post‐momelotinib median survival was 3.2 years; in univariate analysis, survival was superior in anemia responders (median 3.8 vs. 2.8 years; p = .14) and in the presence of type 1/like CALR mutation and inferior in the presence of age > 65 years, ASXL1/SRSF2 mutation, unfavorable karyotype, DIPSS‐plus high risk, red cell transfusion need and higher serum ferritin. Multivariable analysis confirmed the favorable impact of anemia response on survival (p = .02; HR 0.5, 3/5/10‐year survival; 69%/38%/25%). This survival advantage was also noted in transfusion‐dependent patients (3.7 vs. 1.9 years; p = .01; HR 0.3) and appeared to be restricted to patients with an unfavorable genetic profile. The current study suggests a short‐term survival benefit associated with anemia response in momelotinib‐treated patients with MF.
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