Determinants of lenalidomide response with or without erythropoiesis-stimulating agents in myelodysplastic syndromes: the HOVON89 trial.

A randomized phase-II study was performed in low/int-1 risk MDS (IPSS) to study efficacy and safety of lenalidomide without (arm A) or with (arm B) ESA/G-CSF. In arm B, patients without erythroid response (HI-E) after 4 cycles received ESA; G-CSF was added if no HI-E was obtained by cycle 9. HI-E served as primary endpoint. Flow cytometry and next-generation sequencing were performed to identify predictors of response. The final evaluation comprised 184 patients; 84% non-del(5q), 16% isolated del(5q); median follow-up: 70.7 months. In arm A and B, 39 and 41% of patients achieved HI-E; median time-to-HI-E: 3.2 months for both arms, median duration of-HI-E: 9.8 months. HI-E was significantly lower in non-del(5q) vs. del(5q): 32% vs. 80%. The same accounted for transfusion independency-at-week 24 (16% vs. 67%), but similar in both arms. Apart from presence of del(5q), high percentages of bone marrow lymphocytes and progenitor B-cells, a low number of mutations, absence of ring sideroblasts, and SF3B1 mutations predicted HI-E. In conclusion, lenalidomide induced HI-E in patients with non-del(5q) and del(5q) MDS without additional effect of ESA/G-CSF. The identified predictors of response may guide application of lenalidomide in lower-risk MDS in the era of precision medicine. (EudraCT 2008-002195-10).

ESMO-Magnitude of Clinical Benefit Scale for haematological malignancies (ESMO-MCBS:H) version 1.0.

BACKGROUND: The European Society for Medical Oncology (ESMO)-Magnitude of Clinical Benefit Scale (MCBS) has been accepted as a robust tool to evaluate the magnitude of clinical benefit reported in trials for oncological therapies. However, the ESMO-MCBS hitherto has only been validated for solid tumours. With the rapid development of novel therapies for haematological malignancies, we aimed to develop an ESMO-MCBS version that is specifically designed and validated for haematological malignancies. METHODS: ESMO and the European Hematology Association (EHA) initiated a collaboration to develop a version for haematological malignancies (ESMO-MCBS:H). The process incorporated five landmarks: field testing of the ESMO-MCBS version 1.1 (v1.1) to identify shortcomings specific to haematological diseases, drafting of the ESMO-MCBS:H forms, peer review and revision of the draft based on re-scoring (resulting in a second draft), assessment of reasonableness of the scores generated, final review and approval by ESMO and EHA including executive boards. RESULTS: Based on the field testing results of 80 haematological trials and extensive review for feasibility and reasonableness, five amendments to ESMO-MCBS were incorporated in the ESMO-MCBS:H addressing the identified shortcomings. These concerned mainly clinical trial endpoints that differ in haematology versus solid oncology and the very indolent nature of nevertheless incurable diseases such as follicular lymphoma, which hampers presentation of mature data. In addition, general changes incorporated in the draft version of the ESMO-MCBS v2 were included, and specific forms for haematological malignancies generated. Here we present the final approved forms of the ESMO-MCBS:H, including instructions. CONCLUSION: The haematology-specific version ESMO-MCBS:H allows now full applicability of the scale for evaluating the magnitude of clinical benefit derived from clinical studies in haematological malignancies.

Addition of the nuclear export inhibitor selinexor to standard intensive treatment for elderly patients with acute myeloid leukemia and high risk myelodysplastic syndrome.

Treatment results of AML in elderly patients are unsatisfactory. In an open label randomized phase II study, we investigated whether addition of the XPO1 inhibitor selinexor to intensive chemotherapy would improve outcome in this population. 102 AML patients > 65 years of age (median 69 (65-80)) were randomly assigned to standard chemotherapy (3 + 7) with or without oral selinexor 60 mg twice weekly (both arms n = 51), days 1-24. In the second cycle, cytarabine 1000 mg/m2 twice daily, days 1-6 with or without selinexor was given. CR/CRi rates were significantly higher in the control arm than in the investigational arm (80% (95% C.I. 69-91%) vs. 59% (45-72%; p = 0.018), respectively). At 18 months, event-free survival was 45% for the control arm versus 26% for the investigational arm (Cox-p = 0.012) and overall survival 58% vs. 33%, respectively (p = 0.009). AML and infectious complications accounted for an increased death rate in the investigational arm. Irrespective of treatment, MRD status after two cycles appeared to be correlated with survival. We conclude that the addition of selinexor to standard chemotherapy does negatively affect the therapeutic outcome of elderly AML patients. (Netherlands Trial Registry number NL5748 (NTR5902), www.trialregister.nl ).

Evaluating ivosidenib for the treatment of acute myeloid leukemia.

INTRODUCTION: Acute myeloid leukemia (AML) is the most common type of acute leukemia in adults, but the results for patients with AML are still unsatisfactory. The discovery of new mutations in AML, including IDH mutations, has opened the door for treatment with targeted agents. Ivosidenib is a selective, potent inhibitor of the IDH1 mutant protein. AREAS COVERED: This review summarizes the mechanism of action, safety profile and efficacy of ivosidenib for patients with IDH1-mutated AML. The authors then provide their expert perspectives on the use of the drug including their future perspectives. EXPERT OPINION: Ivosidenib is a promising, most probably practice changing, new drug for the treatment of IDH1-mutated AML. Current phase III trials are ongoing to evaluate the addition of ivosidenib to the current standards-of-care. In the near future, more drug combinations are awaited. Challenges for the future include the development of resistance and establishing the duration of maintenance therapy.

Correction: Lenalidomide added to standard intensive treatment for older patients with AML and high-risk MDS.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Lenalidomide added to standard intensive treatment for older patients with AML and high-risk MDS.

More effective treatment modalities are urgently needed in patients with acute myeloid leukemia (AML) of older age. We hypothesized that adding lenalidomide to intensive standard chemotherapy might improve their outcome. After establishing a safe lenalidomide, dose elderly patients with AML were randomly assigned in this randomized Phase 2 study (n = 222) to receive standard chemotherapy ("3 + 7") with or without lenalidomide at a dose of 20 mg/day 1-21. In the second cycle, patients received cytarabine 1000 mg/m2 twice daily on days 1-6 with or without lenalidomide (20 mg/day 1-21). The CR/CRi rates in the two arms were not different (69 vs. 66%). Event-free survival (EFS) at 36 months was 19% for the standard arm versus 21% for the lenalidomide arm and overall survival (OS) 35% vs. 30%, respectively. The frequencies and grade of adverse events were not significantly different between the treatment arms. Cardiovascular toxicities were rare and equally distributed between the arms. The results of the present study show that the addition of lenalidomide to standard remission induction chemotherapy does not improve the therapeutic outcome of older AML patients. This trial is registered as number NTR2294 in The NederlandsTrial Register (www.trialregister.nl).

Improved survival for children and young adolescents with acute myeloid leukemia: a Dutch study on incidence, survival and mortality.

Variation in survival of pediatric acute myeloid leukemia (pAML) over time and between Western European countries exists. The aim of the current study is to assess the progress made for the Dutch pAML population (0-17 years) during 1990-2015, based on trends in incidence, survival and mortality. Data from the population-based Netherlands Cancer Registry were merged with leukemia-related characteristics and treatment specifics from the Dutch Childhood Leukemia Study Group (Dutch Childhood Oncology Group (DCOG) from 2002 onwards). Mortality data (1980-2016) were obtained from the cause of death registry of Statistics Netherlands. Trend analyses were performed over time and by treatment protocol. Between 1990 and 2015, a total of 635 children aged 0-17 years were diagnosed with AML for an average of 25 patients (range 18-36) per year. There was a slight increase in the incidence at age 1-4 years (average annual percentage change (AAPC) of +2.2% per year (95% CI 0.8-3.5, p < 0.01)). Overall, the 5-year survival significantly improved over the past 26 years and nearly doubled from 40% in the early 1990s to 74% in 2010-2015. Multivariable analysis showed a 49% reduction in risk of death for pAML patients treated according to the latest DB-AML 01 protocol (p = 0.03). The continuing decrease of mortality (AAPC -2.8% per year (95% CI -4.1 to -1.5)) supports the conclusion of true progress against pAML in the Netherlands.

Distinct factors determine the kinetics of disease relapse in adults transplanted for acute myeloid leukaemia.

BACKGROUND: Disease recurrence remains the major cause of death in adults with acute myeloid leukaemia (AML) treated using either intensive chemotherapy (IC) or allogenic stem cell transplantation (allo-SCT). AIMS: The timely delivery of maintenance drug or cellular therapies represent emerging strategies with the potential to reduce relapse after both treatment modalities, but whilst the determinants of overall relapse risk have been extensively characterized the factors determining the timing of disease recurrence have not been characterized. MATERIALS AND METHODS: We have therefore examined, using a series of sequential landmark analyses, relapse kinetics in a cohort of 2028 patients who received an allo-SCT for AML in CR1 and separately 570 patients treated with IC alone. RESULTS: In the first 3 months after allo-SCT, the factors associated with an increased risk of relapse included the presence of the FLT3-ITD (P < 0.001), patient age (P = 0.012), time interval from CR1 to transplant (P < 0.001) and donor type (P = 0.03). Relapse from 3 to 6 months was associated with a higher white cell count at diagnosis (P = 0.001), adverse-risk cytogenetics (P < 0.001), presence of FLT3-ITD mutation (P < 0.001) and time interval to achieve first complete remission (P = 0.013). Later relapse was associated with adverse cytogenetics, mutated NPM1, absence of chronic graft-versus-host disease (GVHD) and the use of in vivo T-cell depletion. In patients treated with IC alone, the factors associated with relapse in the first 3 months were adverse-risk cytogenetics (P < 0.001) and FLT3-ITD status (P = 0.001). The factors predicting later relapse were the time interval from diagnosis to CR1 (P = 0.22) and time interval from CR1 to IC (P = 0.012). DISCUSSION AND CONCLUSION: Taken together, these data provide novel insights into the biology of disease recurrence after both allo-SCT and IC and have the potential to inform the design of novel maintenance strategies in both clinical settings.

Measurable residual disease testing in acute myeloid leukaemia.

There is considerable interest in developing techniques to detect and/or quantify remaining leukaemia cells termed measurable or, less precisely, minimal residual disease (MRD) in persons with acute myeloid leukaemia (AML) in complete remission defined by cytomorphological criteria. An important reason for AML MRD-testing is the possibility of estimating the likelihood (and timing) of leukaemia relapse. A perfect MRD-test would precisely quantify leukaemia cells biologically able and likely to cause leukaemia relapse within a defined interval. AML is genetically diverse and there is currently no uniform approach to detecting such cells. Several technologies focused on immune phenotype or cytogenetic and/or molecular abnormalities have been developed, each with advantages and disadvantages. Many studies report a positive MRD-test at diverse time points during AML therapy identifies persons with a higher risk of leukaemia relapse compared with those with a negative MRD-test even after adjusting for other prognostic and predictive variables. No MRD-test in AML has perfect sensitivity and specificity for relapse prediction at the cohort- or subject levels and there are substantial rates of false-positive and -negative tests. Despite these limitations, correlations between MRD-test results and relapse risk have generated interest in MRD-test result-directed therapy interventions. However, convincing proof that a specific intervention will reduce relapse risk in persons with a positive MRD-test is lacking and needs testing in randomized trials. Routine clinical use of MRD-testing requires further refinements and standardization/harmonization of assay platforms and results reporting. Such data are needed to determine whether results of MRD-testing can be used as a surrogate end point in AML therapy trials. This could make drug-testing more efficient and accelerate regulatory approvals. Although MRD-testing in AML has advanced substantially, much remains to be done.

Comparative value of post-remission treatment in cytogenetically normal AML subclassified by NPM1 and FLT3-ITD allelic ratio.

Post-remission treatment (PRT) in patients with cytogenetically normal (CN) acute myeloid leukemia (AML) in first complete remission (CR1) is debated. We studied 521 patients with CN-AML in CR1, for whom mutational status of NPM1 and FLT3-ITD was available, including the FLT3-ITD allelic ratio. PRT consisted of reduced intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (alloHSCT) (n=68), myeloablative conditioning (MAC) alloHSCT (n=137), autologous hematopoietic stem cell transplantation (autoHSCT) (n=168) or chemotherapy (n=148). Favorable overall survival (OS) was found for patients with mutated NPM1 without FLT3-ITD (71±4%). Outcome in patients with a high FLT3-ITD allelic ratio appeared to be very poor with OS and relapse-free survival (RFS) of 23±8% and 12±6%, respectively. Patients with wild-type NPM1 without FLT3-ITD or with a low allelic burden of FLT3-ITD were considered as intermediate-risk group because of similar OS and RFS at 5 years, in which PRT by RIC alloHSCT resulted in better OS and RFS as compared with chemotherapy (hazard ratio (HR) 0.56, P=0.022 and HR 0.50, P=0.004, respectively) or autoHSCT (HR 0.60, P=0.046 and HR 0.60, P=0.043, respectively). The lowest cumulative incidence of relapse (23±4%) was observed following MAC alloHSCT. These results suggest that alloHSCT may be preferred in patients with molecularly intermediate-risk CN-AML, while the choice of conditioning type may be personalized according to risk for non-relapse mortality.

Treatment and outcome of 2904 CML patients from the EUTOS population-based registry.

The European Treatment and Outcome Study (EUTOS) population-based registry includes data of all adult patients newly diagnosed with Philadelphia chromosome-positive and/or BCR-ABL1+ chronic myeloid leukemia (CML) in 20 predefined countries and regions of Europe. Registration time ranged from 12 to 60 months between January 2008 and December 2013. Median age was 55 years and median observation time was 29 months. Eighty percent of patients were treated first line with imatinib, and 17% with a second-generation tyrosine kinase inhibitor, mostly according to European LeukemiaNet recommendations. After 12 months, complete cytogenetic remission (CCyR) and major molecular response (MMR) were achieved in 57% and 41% of patients, respectively. Patients with high EUTOS risk scores achieved CCyR and MMR significantly later than patients with low EUTOS risk. Probabilities of overall survival (OS) and progression-free survival for all patients at 12, 24 and 30 months was 97%, 94% and 92%, and 95%, 92% and 90%, respectively. The new EUTOS long-term survival score was validated: the OS of patients differed significantly between the three risk groups. The probability of dying in remission was 1% after 24 months. The current management of patients with tyrosine kinase inhibitors resulted in responses and outcomes in the range reported from clinical trials. These data from a large population-based, patient sample provide a solid benchmark for the evaluation of new treatment policies.

Treatment, trial participation and survival in adult acute myeloid leukemia: a population-based study in the Netherlands, 1989-2012.

Large, comprehensive population-based studies in acute myeloid leukemia (AML) are scarce. We conducted a nationwide population-based study on treatment, trial participation and survival among all adult patients diagnosed with AML (n=12,032) and acute promyelocytic leukemia (APL; n=585) in the Netherlands between 1989-2012. Patients were categorized into four periods and four age groups (18-40, 41-60, 61-70 and >70 years). The application of allogeneic stem cell transplantation increased over time among AML patients up to age 70 years. For APL patients, the use of chemotherapy increased across all age groups. When a clinical trial was open for accrual in the Netherlands, the inclusion rates were 68%, 57%, 30% and 12% for AML patients in the four age groups, respectively (data for APL unavailable). Relative survival improved over time among AML (up to age 70 years) and APL patients. In the period 2007-2012, 5-year relative survival rates were 54%, 38%, 14% and 2% for AML patients and 84%, 75%, 54% and 37% for APL patients in the four age groups, respectively. As survival remained poor for older AML patients over the last two decades, clinical trials and active participation in those trials, are warranted that explore innovative treatment strategies for this elderly population.

Prognosis of long-term survival considering disease-specific death in patients with chronic myeloid leukemia.

In patients with chronic myeloid leukemia (CML), first-line imatinib treatment leads to 8-year overall survival (OS) probabilities above 80%. Many patients die of reasons unrelated to CML. This work tackled the reassessment of prognosis under particular consideration of the probabilities of dying of CML. Analyses were based on 2290 patients with chronic phase CML treated with imatinib in six clinical trials. 'Death due to CML' was defined by death after disease progression. At 8 years, OS was 89%. Of 208 deceased patients, 44% died of CML. Higher age, more peripheral blasts, bigger spleen and low platelet counts were significantly associated with increased probabilities of dying of CML and determined a new long-term survival score with three prognostic groups. Compared with the low-risk group, the patients of the intermediate- and the high-risk group had significantly higher probabilities of dying of CML. The score was successfully validated in an independent sample of 1120 patients. In both samples, the new score differentiated probabilities of dying of CML better than the Sokal, Euro and the European Treatment and Outcome Study (EUTOS) score. The new score identified 61% low-risk patients with excellent long-term outcome and 12% high-risk patients. The new score supports the prospective assessment of long-term antileukemic efficacy and risk-adapted treatment.

Peripheral blood minimal residual disease may replace bone marrow minimal residual disease as an immunophenotypic biomarker for impending relapse in acute myeloid leukemia.

As relapses are common in acute myeloid leukemia (AML), early relapse prediction is of high importance. Although conventional minimal residual disease (MRD) measurement is carried out in bone marrow (BM), peripheral blood (PB) would be an advantageous alternative source. This study aims to investigate the specificity of leukemia-associated immunophenotypes used for MRD detection in blood samples. Consistency of PB MRD as compared with BM MRD was determined in flow cytometric data of 205 paired BM and PB samples of 114 AML patients. A significant correlation was found between PB and BM MRD (r=0.67, P<0.001), while median PB MRD percentage was factor 4-5 lower compared with BM MRD. Primitive blast (CD34+/CD117+/CD133+) frequency was significantly lower in PB (median factor 23.7), indicating that PB MRD detection is more specific than BM. Cumulative incidence of relapse 1 year after induction therapy was 29% for PB MRD-negative and 89% for PB MRD-positive patients (P<0.001). Three-year OS was 52% for MRD-negative and 15% for MRD-positive patients (P=0.034). Similar differences were found after consolidation therapy. As PB MRD appeared to be an independent predictor for response duration, the highly specific PB MRD assay may have a prominent role in future MRD assessment in AML.

A simple one-tube assay for immunophenotypical quantification of leukemic stem cells in acute myeloid leukemia.

Relapses after initial successful treatment in acute myeloid leukemia are thought to originate from the outgrowth of leukemic stem cells. Their flow cytometrically assessed frequency is of importance for relapse prediction and is therefore assumed to be implemented in future risk group profiling. Since current detection methods are complex, time- and bone marrow consuming (multiple-tubes approach), it would be advantageous to have a broadly applicable approach that enables to quantify leukemia stem cells both at diagnosis and follow-up. We compared 15 markers in 131 patients concerning their prevalence, usefulness and stability in CD34(+)CD38(-) leukemic stem cell detection in healthy controls, acute myeloid leukemia diagnosis and follow-up samples. Ultimately, we designed a single 8-color detection tube including common markers CD45, CD34 and CD38, and specific markers CD45RA, CD123, CD33, CD44 and a marker cocktail (CLL-1/TIM-3/CD7/CD11b/CD22/CD56) in one fluorescence channel. Validation analyses in 31 patients showed that the single tube approach was as good as the multiple-tube approach. Our approach requires the least possible amounts of bone marrow, and is suitable for multi-institutional studies. Moreover, it enables detection of leukemic stem cells both at time of diagnosis and follow-up, thereby including initially low-frequency populations emerging under therapy pressure.

Frontline nilotinib in patients with chronic myeloid leukemia in chronic phase: results from the European ENEST1st study.

The Evaluating Nilotinib Efficacy and Safety in Clinical Trials as First-Line Treatment (ENEST1st) study included 1089 patients with newly diagnosed chronic myeloid leukemia in chronic phase. The rate of deep molecular response (MR(4) (BCR-ABL1⩽0.01% on the International Scale or undetectable BCR-ABL1 with ⩾10,000 ABL1 transcripts)) at 18 months was evaluated as the primary end point, with molecular responses monitored by the European Treatment and Outcome Study network of standardized laboratories. This analysis was conducted after all patients had completed 24 months of study treatment (80.9% of patients) or discontinued early. In patients with typical BCR-ABL1 transcripts and ⩽3 months of prior imatinib therapy, 38.4% (404/1052) achieved MR(4) at 18 months. Six patients (0.6%) developed accelerated or blastic phase, and 13 (1.2%) died. The safety profile of nilotinib was consistent with that of previous studies, although the frequencies of some nilotinib-associated adverse events were lower (for example, rash, 21.4%). Ischemic cardiovascular events occurred in 6.0% of patients. Routine monitoring of lipid and glucose levels was not mandated in the protocol. These results support the use of frontline nilotinib, particularly when achievement of a deep molecular response (a prerequisite for attempting treatment-free remission in clinical trials) is a treatment goal.

The myelodysplastic syndromes flow cytometric score: a three-parameter prognostic flow cytometric scoring system.

The prognosis of myelodysplastic syndromes (MDS) is currently estimated by using the revised International Prognostic Scoring System (IPSS-R). Several studies have shown that further refinement of prognostication for MDS can be achieved by adding flow cytometric parameters. However, widespread implementation of flow cytometry for the prognosis of MDS is hampered by complexity of the analysis. Therefore, the aim of this study was to construct a robust and practical flow cytometric score that could be implemented as a routine procedure. To achieve this, bone marrow aspirates of 109 MDS patients were analyzed by flow cytometry. A second cohort consisting of 103 MDS patients was used to validate the MDS flow cytometric score (MFS). The parameters forming the MFS were sideward light scatter and CD117 expression of myeloid progenitor cells and CD13 expression on monocytes. Three MFS risk categories were formed. Patients with MDS and intermediate MFS scores had significantly better overall survival (OS) compared with the patients with high MFS scores. The MFS further refined prognostication within the IPSS-R low-risk category, by identifying patients with worse OS in case of high MFS. In conclusion, a practical three parameter flow cytometric prognostic score was constructed enabling further refinement of prognostication of MDS.