Blinatumomab for MRD-Negative Acute Lymphoblastic Leukemia in Adults.

BACKGROUND: Many older adults with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) have a relapse despite having a measurable residual disease (MRD)-negative complete remission with combination chemotherapy. The addition of blinatumomab, a bispecific T-cell engager molecule that is approved for the treatment of relapsed, refractory, and MRD-positive BCP-ALL, may have efficacy in patients with MRD-negative remission. METHODS: In a phase 3 trial, we randomly assigned patients 30 to 70 years of age with BCR::ABL1-negative BCP-ALL (with :: indicating fusion) who had MRD-negative remission (defined as <0.01% leukemic cells in bone marrow as assessed on flow cytometry) after induction and intensification chemotherapy to receive four cycles of blinatumomab in addition to four cycles of consolidation chemotherapy or to receive four cycles of consolidation chemotherapy alone. The primary end point was overall survival, and relapse-free survival was a secondary end point. RESULTS: The data and safety monitoring committee reviewed the results from the third efficacy interim analysis and recommended that they be reported. Complete remission with or without full count recovery was observed in 395 of 488 enrolled patients (81%). Of the 224 patients with MRD-negative status, 112 were assigned to each group. The characteristics of the patients were balanced between the groups. At a median follow-up of 43 months, an advantage was observed in the blinatumomab group as compared with the chemotherapy-only group with regard to overall survival (at 3 years: 85% vs. 68%; hazard ratio for death, 0.41; 95% confidence interval [CI], 0.23 to 0.73; P = 0.002), and the 3-year relapse-free survival was 80% with blinatumomab and 64% with chemotherapy alone (hazard ratio for relapse or death, 0.53; 95% CI, 0.32 to 0.87). A higher incidence of neuropsychiatric events was reported in the blinatumomab group than in the chemotherapy-only group. CONCLUSIONS: The addition of blinatumomab to consolidation chemotherapy in adult patients in MRD-negative remission from BCP-ALL significantly improved overall survival. (Funded by the National Institutes of Health and others; E1910 ClinicalTrials.gov number, NCT02003222.).

Enhancer retargeting of CDX2 and UBTF::ATXN7L3 define a subtype of high-risk B-progenitor acute lymphoblastic leukemia.

Transcriptome sequencing has identified multiple subtypes of B-progenitor acute lymphoblastic leukemia (B-ALL) of prognostic significance, but a minority of cases lack a known genetic driver. Here, we used integrated whole-genome (WGS) and -transcriptome sequencing (RNA-seq), enhancer mapping, and chromatin topology analysis to identify previously unrecognized genomic drivers in B-ALL. Newly diagnosed (n = 3221) and relapsed (n = 177) B-ALL cases with tumor RNA-seq were studied. WGS was performed to detect mutations, structural variants, and copy number alterations. Integrated analysis of histone 3 lysine 27 acetylation and chromatin looping was performed using HiChIP. We identified a subset of 17 newly diagnosed and 5 relapsed B-ALL cases with a distinct gene expression profile and 2 universal and unique genomic alterations resulting from aberrant recombination-activating gene activation: a focal deletion downstream of PAN3 at 13q12.2 resulting in CDX2 deregulation by the PAN3 enhancer and a focal deletion of exons 18-21 of UBTF at 17q21.31 resulting in a chimeric fusion, UBTF::ATXN7L3. A subset of cases also had rearrangement and increased expression of the PAX5 gene, which is otherwise uncommon in B-ALL. Patients were more commonly female and young adult with median age 35 (range,12-70 years). The immunophenotype was characterized by CD10 negativity and immunoglobulin M positivity. Among 16 patients with known clinical response, 9 (56.3%) had high-risk features including relapse (n = 4) or minimal residual disease >1% at the end of remission induction (n = 5). CDX2-deregulated, UBTF::ATXN7L3 rearranged (CDX2/UBTF) B-ALL is a high-risk subtype of leukemia in young adults for which novel therapeutic approaches are required.

Obesity in adult acute myeloid leukemia is not associated with inferior response or survival even when dose capping anthracyclines: An ECOG-ACRIN analysis.

BACKGROUND: Obesity (body mass index [BMI] ≥30 kg/m2 ) is an important epidemiological risk factor for developing acute myeloid leukemia (AML). Therefore, the authors studied the association of obesity with clinical and genetic phenotype and its impact on outcome in adults with AML. METHODS: The authors analyzed BMI in 1088 adults who were receiving intensive remission induction and consolidation therapy in two prospective, randomized therapeutic clinical trials of the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network: E1900 (ClinicalTrials.gov identifier NCT00049517; patients younger than 60 years) and E3999 (ClinicalTrials.gov identifier NCT00046930; patients aged 60 years or older). RESULTS: Obesity was prevalent at diagnosis (33%) and, compared with nonobesity, was associated with intermediate-risk cytogenetics group (p = .008), poorer performance status (p = .01), and a trend toward older age (p = .06). Obesity was not associated with somatic mutations among a selected 18-gene panel that was tested in a subset of younger patients. Obesity was not associated with clinical outcome (including complete remission, early death, or overall survival), and the authors did not identify any patient subgroup that had inferior outcomes based on BMI. Obese patients were significantly more likely to receive <90% of the intended daunorubicin dose despite protocol specification, particularly in the E1900 high-dose (90 mg/m2 ) daunorubicin arm (p = .002); however, this did not correlate with inferior overall survival on multivariate analysis (hazard ratio, 1.39; 95% confidence interval, 0.90-2.13; p = .14). CONCLUSIONS: Obesity is associated with unique clinical and disease-related phenotypic features in AML and may influence physician treatment decisions regarding daunorubicin dosing. However, the current study demonstrates that obesity is not a factor in survival, and strict adherence to body surface area-based dosing is not necessary because dose adjustments do not affect outcomes.

The increasingly blurred line between induction, consolidation and maintenance in acute myeloid leukaemia.

Since the early 1970s, the treatment of acute myeloid leukaemia (AML) has undergone a major transformation. Initially based on only two drugs, an anthracycline and cytosine arabinoside, the aim of therapy was to achieve a haematological response allowing patients to recover and go home. Back in those early days, cure was not a realistic expectation. Treatment was analogous to a heart attack; upon recovery and a short respite, recurrence and death inevitably followed. Over the subsequent decades, slow but remarkable progress was made such that a subgroup of young adults could become long-term survivors. This astonishing feat was achieved initially without the use of new drugs. Supportive care played a major role with the widespread availability of platelet transfusions and improved antimicrobial therapy, particularly antifungal. No less important was the better use of existing drugs and the development of allogeneic haematopoietic cell transplantation. While initially the focus was on maximal tolerated therapy, an understanding of the immunologic role of allogeneic transplantation, better genetic characterization of the biology of the disease, advanced tools for detection of minimal disease as well as the recent development of new drugs changed the focus to a more refined approach targeting patients who are more likely to respond. Clearly, the historical paradigm where the term AML was generic and applicable to all patients requires a rethinking from the traditional therapeutic demarcations of therapy into phases of induction, consolidation and maintenance. These evolving new concepts and paradigm will be herein considered.

Molecular classification improves risk assessment in adult BCR-ABL1-negative B-ALL.

Genomic classification has improved risk assignment of pediatric, but not adult B-lineage acute lymphoblastic leukemia (B-ALL). The international UKALLXII/ECOG-ACRIN E2993 (#NCT00002514) trial accrued 1229 adolescent/adult patients with BCR-ABL1- B-ALL (aged 14 to 65 years). Although 93% of patients achieved remission, 41% relapsed at a median of 13 months (range, 28 days to 12 years). Five-year overall survival (OS) was 42% (95% confidence interval, 39, 44). Transcriptome sequencing, gene expression profiling, cytogenetics, and fusion polymerase chain reaction enabled genomic subtyping of 282 patient samples, of which 264 were eligible for trial, accounting for 64.5% of E2993 patients. Among patients with outcome data, 29.5% with favorable outcomes (5-year OS 65% to 80%) were deemed standard risk (DUX4-rearranged [9.2%], ETV6-RUNX1/-like [2.3%], TCF3-PBX1 [6.9%], PAX5 P80R [4.1%], high-hyperdiploid [6.9%]); 50.2% had high-risk genotypes with 5-year OS of 0% to 27% (Ph-like [21.2%], KMT2A-AFF1 [12%], low-hypodiploid/near-haploid [14.3%], BCL2/MYC-rearranged [2.8%]); 20.3% had intermediate-risk genotypes with 5-year OS of 33% to 45% (PAX5alt [12.4%], ZNF384/-like [5.1%], MEF2D-rearranged [2.8%]). IKZF1 alterations occurred in 86% of Ph-like, and TP53 mutations in patients who were low-hypodiploid (54%) and BCL2/MYC-rearranged (33%) but were not independently associated with outcome. Of patients considered high risk based on presenting age and white blood cell count, 40% harbored subtype-defining genetic alterations associated with standard- or intermediate-risk outcomes. We identified distinct immunophenotypic features for DUX4-rearranged, PAX5 P80R, ZNF384-R/-like, and Ph-like genotypes. These data in a large adult B-ALL cohort treated with a non-risk-adapted approach on a single trial show the prognostic importance of genomic analyses, which may translate into future therapeutic benefits.

BL-8040 CXCR4 antagonist is safe and demonstrates antileukemic activity in combination with cytarabine for the treatment of relapsed/refractory acute myelogenous leukemia: An open-label safety and efficacy phase 2a study.

BACKGROUND: CXCR4 mediates the retention and survival of acute myelogenous leukemia blasts in bone marrow and contributes to their resistance to chemotherapy. The authors evaluated a combination of the high-affinity CXCR4 antagonist BL-8040 with high-dose cytarabine (HiDAC) chemotherapy in a phase 2a study of patients with relapsed and refractory AML. METHODS: Forty-two patients received treatment with BL-8040 monotherapy for 2 days followed by a combination of BL-8040 with HiDAC for 5 days. Six escalating BL-8040 dose levels were investigated (0.5, 0.75, 1.0, 1.25, 1.5, and 2.0 mg/kg), and 1.5 mg/kg was selected as the dose for the expansion phase (n = 23). RESULTS: BL-8040 in combination with HiDAC was safe and well tolerated at all dose levels. Clinical response was observed with BL-8040 doses ≥1.0 mg/kg. The composite response rate (complete remissions plus complete remissions with incomplete hematologic recovery of platelets or neutrophils) was 29% (12 of 42) in all patients and 39% (9 of 23) in the 1.5-mg/kg phase. The median overall survival was 8.4 months for all patients, 10.8 months in the 1.5-mg/kg phase, and 21.8 months for responding patients in the 1.5-mg/kg cohort. Two days of BL-8040 monotherapy triggered the mobilization of blasts into peripheral blood, with significantly higher mean fold-changes in responders versus nonresponders. This was accompanied by a decrease in bone marrow blasts. CONCLUSIONS: The current results demonstrate the efficacy of CXCR4 targeting with BL-8040 and support continued clinical development in acute myelogenous leukemia.

Prognostic effect of gender on outcome of treatment for adults with acute myeloid leukaemia.

There are conflicting reports in the literature suggesting that one gender or the other has a better survival with acute myeloid leukaemia (AML). The present study was done in an attempt to resolve the issue. The effect of gender was examined on 3546 newly diagnosed patients with AML, including 548 patients with acute promyelocytic leukaemia (APL) enrolled in 10 multi-institutional treatment studies from March 1984 to November 2008. Kaplan-Meier estimates were used to estimate event-time distributions for survival and multivariate models were used to examine the gender effect after adjusting for multiple risk factors. P values were based on two-sided tests. Non-APL female patients had a significantly better overall (OS) but not disease-free survival (DFS) than males, irrespective of age, initial white blood cell count, or dose of daunorubicin. No differences were observed for obese or FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD)-positive patients. Female patients with APL had a significantly better OS and DFS than male patients with APL, and differences in survival were greater for patients with t(15;17) + other cytogenetic abnormalities compared with those with t(15;17) only. Gender is an independent prognostic variable in patients with AML. Whether these survival differences are due to hormonal, genetic or pharmacokinetic differences between the sexes or differential toxin exposure such as smoking is unknown. However, the former seems less likely as patient age did not influence the survival advantage for female patients.

Maintenance Tyrosine Kinase Inhibitors Following Allogeneic Hematopoietic Stem Cell Transplantation for Chronic Myelogenous Leukemia: A Center for International Blood and Marrow Transplant Research Study.

It remains unknown whether the administration of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1 after allogeneic hematopoietic cell transplantation (HCT) is associated with improved outcomes for patients with chronic myelogenous leukemia (CML). In this registry study, we analyzed clinical outcomes of 390 adult patients with CML who underwent transplantation between 2007 and 2014 and received maintenance TKI following HCT (n = 89) compared with no TKI maintenance (n = 301), as reported to the Center for International Blood and Marrow Transplant Research. All patients received TKI therapy before HCT. The majority of patients had a disease status of first chronic phase at HCT (n = 240; 62%). The study was conducted as a landmark analysis, excluding patients who died, relapsed, had chronic graft-versus-host disease, or were censored before day +100 following HCT. Of the 89 patients who received TKI maintenance, 77 (87%) received a single TKI and the other 12 (13%) received multiple sequential TKIs. The most common TKIs used for maintenance were dasatinib (n = 50), imatinib (n = 27), and nilotinib (n = 27). As measured from day +100, the adjusted estimates for 5-year relapse (maintenance, 35% versus no maintenance, 26%; P = .11), leukemia-free survival (maintenance, 42% versus no maintenance, 44%; P = .65), or overall survival (maintenance, 61% versus no maintenance, 57%; P = .61) did not differ significantly between patients receiving TKI maintenance or no maintenance. These results remained unchanged in multivariate analysis and were not modified by disease status before transplantation. In conclusion, our data from this day +100 landmark analysis do not demonstrate a significant impact of maintenance TKI therapy on clinical outcomes. The optimal approach to TKI administration in the post-transplantation setting in patients with CML remains undetermined.

How we treat older patients with acute myeloid leukaemia.

After decades when intensive chemotherapy remained the only effective anti-acute myeloid leukaemia (AML) treatment, a torrent of novel, less toxic agents are about to revolutionise AML therapy. Prolonged remissions with good quality of life become achievable for many patients previously considered only for palliative care because they could not tolerate intensive therapy. As treatment options multiply, the importance of genetic profile is recognised, even for advanced-age patients for whom cure is unlikely. With lack of randomised comparative trials for most treatment regimens, one can only extrapolate data from existing studies to make evidence-based decisions. We herein present seven common clinical scenarios illustrating the complexity of treating older AML patients and describe our approach to their management. In each case, up-to-date data on relevant agents to be offered to a particular patient are discussed. The current review is limited to the drugs, available and approved in the Western world and many promising agents, still under investigation, are not discussed.

At three years, patients with acute lymphoblastic leukaemia are still at risk for relapse. Results of the international MRC UKALLXII/ECOG E2993 trial.

Late relapse [>3 years from complete remission (CR)] in acute lymphoblastic leukaemia (ALL), is unusual. Data from the MRC UKALLXII/ECOG E2993 trial are presented to evaluate the incidence and characteristics of late relapse in adult ALL. Of 1,909 patients, 1,752 (92%) achieved CR and among these 757 (43·2%) relapsed; 691 (91·3%) within three years and 66 (8·7%) beyond. Among these 66 patients, median time to relapse was 47 (37-144) months. Relapse beyond three years occurred in 3·8% of all who achieved CR. The cumulative risk of relapse was 40%, 43% and 45% at three, five and ten years respectively. Out of the 1 752 patients who achieved CR, 11·7% underwent autologous and 40·6% allogeneic transplant, while in CR1. Of the autologous patients, 43·2% relapsed early and 3·4% relapsed late. However, among the allogeneic patients, 13·2% relapsed early and only 1·3% late. The five-year overall survival from relapse was 5·8% and 20% in the early and late relapse patients respectively. In conclusion, late relapse in adults with ALL is not uncommon, and is associated with better outcome after relapse compared to early relapse.

Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia.

T-cell acute lymphoblastic leukaemia (T-ALL) is a haematological malignancy with a dismal overall prognosis, including a relapse rate of up to 25%, mainly because of the lack of non-cytotoxic targeted therapy options. Drugs that target the function of key epigenetic factors have been approved in the context of haematopoietic disorders, and mutations that affect chromatin modulators in a variety of leukaemias have recently been identified; however, 'epigenetic' drugs are not currently used for T-ALL treatment. Recently, we described that the polycomb repressive complex 2 (PRC2) has a tumour-suppressor role in T-ALL. Here we delineated the role of the histone 3 lysine 27 (H3K27) demethylases JMJD3 and UTX in T-ALL. We show that JMJD3 is essential for the initiation and maintenance of T-ALL, as it controls important oncogenic gene targets by modulating H3K27 methylation. By contrast, we found that UTX functions as a tumour suppressor and is frequently genetically inactivated in T-ALL. Moreover, we demonstrated that the small molecule inhibitor GSKJ4 (ref. 5) affects T-ALL growth, by targeting JMJD3 activity. These findings show that two proteins with a similar enzymatic function can have opposing roles in the context of the same disease, paving the way for treating haematopoietic malignancies with a new category of epigenetic inhibitors.

Synergistic antileukemic therapies in NOTCH1-induced T-ALL.

The Notch1 gene is a major oncogenic driver and therapeutic target in T-cell acute lymphoblastic leukemia (T-ALL). However, inhibition of NOTCH signaling with γ-secretase inhibitors (GSIs) has shown limited antileukemic activity in clinical trials. Here we performed an expression-based virtual screening to identify highly active antileukemic drugs that synergize with NOTCH1 inhibition in T-ALL. Among these, withaferin A demonstrated the strongest cytotoxic and GSI-synergistic antileukemic effects in vitro and in vivo. Mechanistically, network perturbation analyses showed eIF2A-phosphorylation-mediated inhibition of protein translation as a critical mediator of the antileukemic effects of withaferin A and its interaction with NOTCH1 inhibition. Overall, these results support a role for anti-NOTCH1 therapies and protein translation inhibitor combinations in the treatment of T-ALL.

Shifting therapeutic paradigms in induction and consolidation for older adults with acute myeloid leukemia.

PURPOSE OF REVIEW: As the age and life expectancy of the general population rise, the number of acute myeloid leukemia (AML) patients suitable for therapy is expected to dramatically increase. The population of older adults with AML, while already comprising the vast majority of AML patients, has not been specifically addressed in terms of unique age-related features, such as existence of comorbidities, frailty, and disease biology. RECENT FINDINGS: Over the past decade, major improvements in the approach to the management of older adults with AML included: incorporation of new comorbidity scores specifically oriented to this patient population that can predict individual fitness to treatment, refined knowledge of the unique mutational landscape, and incorporating new combinations and novel agents designed to target the AML biology. Particularly, the recent exciting description of age-related clonal hematopoiesis and its evolution to AML may open new avenues for intervention prior to development of full-blown leukemia. SUMMARY: The rising awareness of the unique biology and special needs of older adults with AML has resulted in the design of new studies aiming to target the aberrant mutations and clinical characteristics in this patient population.

Hematopoietic Cell Transplantation in the Treatment of Adult Acute Lymphoblastic Leukemia: Updated 2019 Evidence-Based Review from the American Society for Transplantation and Cellular Therapy.

The role of hematopoietic cell transplantation (HCT) in adults with acute lymphoblastic leukemia (ALL) is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the recommendations. A panel of ALL experts developed consensus on the treatment recommendations based on the evidence. Allogeneic HCT offers a survival benefit in selected patients with ALL, and this review summarizes the standard indications as well as the areas of controversy. There is now greater experience with pediatric-inspired chemotherapy regimens that has transformed upfront therapy for adult ALL, resulting in higher remission rates and overall survival. This in turn has increased the equipoise around decision making for ALL in first complete remission (CR1) when there is no measurable residual disease (MRD) at the end of induction and/or consolidation. Randomized studies are needed for adults with ALL to compare allogeneic HCT in CR1 with pediatric-inspired chemotherapy alone. Indications for transplantation in the evolving landscape of MRD assessments and novel targeted and immune therapeutics remain important areas of investigation.

Determinants of fatal bleeding during induction therapy for acute promyelocytic leukemia in the ATRA era.

Acute promyelocytic leukemia (APL) is commonly complicated by a complex coagulopathy. Uncertainty remains as to which markers of bleeding risk are independent predictors. Drawing from 5 large clinical trials that included all-trans retinoic acid (ATRA) as part of induction, we assessed known determinants of bleeding at baseline and evaluated them as potential predictors of hemorrhagic death (HD) in the first 30 days of treatment. The studies included were ALLG APML3 (single arm of ATRA + idarubicin ± prednisone), ALLG APML4 (single arm of ATRA + idarubicin + arsenic trioxide + prednisone), CALGB C9710 (single arm of ATRA + cytarabine + daunorubicin), Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) E2491 (intergroup I0129, consisting of daunorubicin + cytarabine vs ATRA), and SWOG S0521 (single-arm induction of ATRA + cytarabine + daunorubicin). A total of 1009 patients were included in the original trials, of which 995 had sufficient data to be included in our multivariate analysis. In this final cohort, there were 37 HD cases during the first 30 days following induction, for an estimated cumulative incidence of 3.7% (95% confidence interval [CI], 2.6% to 5.0%). Using multivariate Cox proportional hazards regression, the hazard ratio of HD in the first 30 days was 2.17 (95% CI, 0.84-5.62) for an ECOG performance status of 3-4 vs 0-2 and 5.20 (95% CI, 2.70-10.02) for a white blood cell count of ≥20 000/µL vs <20 000/µL. In this large cohort of APL patients, high white blood cell count emerged as an independent predictor of early HD.

A randomized trial of three novel regimens for recurrent acute myeloid leukemia demonstrates the continuing challenge of treating this difficult disease.

To improve the outcome of relapsed/refractory acute myeloid leukemia (AML), a randomized phase II trial of three novel regimens was conducted. Ninety patients were enrolled and were in first relapse or were refractory to induction/re-induction chemotherapy. They were randomized to the following regimens: carboplatin-topotecan (CT), each by continuous infusion for 5 days; alvocidib (formerly flavopiridol), cytarabine, and mitoxantrone (FLAM) in a timed sequential regimen; or sirolimus combined with mitoxantrone, etoposide, and cytarabine (S-MEC). The primary objective was attainment of a complete remission (CR). A Simon two-stage design was used for each of the three arms. The median age of the patients in the FLAM arm was older at 62 years compared with 55 years for the CT arm and the S-MEC arm. The overall response was 14% in the CT arm (5/35, 90% CI 7%-35%), 28% in the FLAM arm (10/36, 90% CI, 16%-43%), and 16% in the S-MEC arm (3/19, 90% CI, 4%-36%). There were nine treatment-related deaths, seven of which occurred in the FLAM arm with four of these in elderly patients. We conclude that the FLAM regimen had an encouraging response rate and should be considered for further clinical development but should be used with caution in elderly patients.

Ibrutinib-associated invasive fungal diseases in patients with chronic lymphocytic leukaemia and non-Hodgkin lymphoma: An observational study.

BACKGROUND: Invasive fungal diseases (IFD) are life-threatening infections most commonly diagnosed in acute leukaemia patients with prolonged neutropenia and are uncommonly diagnosed in patients with lymphoproliferative diseases. OBJECTIVES: Following the initial report of aspergillosis diagnosed shortly after beginning ibrutinib for chronic lymphocytic leukaemia, a survey was developed to seek additional cases of IFD during ibrutinib treatment. METHODS: Local and international physicians and groups were approached for relevant cases. Patients were included if they met the following criteria: diagnosis of chronic lymphocytic leukaemia/non-Hodgkin lymphoma; proven or probable IFD; and ibrutinib treatment on the date IFD were diagnosed. Clinical and laboratory data were captured using REDCap software. RESULT: Thirty-five patients with IFD were reported from 22 centres in eight countries: 26 (74%) had chronic lymphocytic leukaemia. The median duration of ibrutinib treatment before the onset of IFD was 45 days (range 1-540). Aspergillus species were identified in 22 (63%) of the patients and Cryptococcus species in 9 (26%). Pulmonary involvement occurred in 69% of patients, cranial in 60% and disseminated disease in 60%. A definite diagnosis was made in 21 patients (69%), and the mortality rate was 69%. Data from Israel regarding ibrutinib treated patients were used to evaluate a prevalence of 2.4% IFD. CONCLUSIONS: The prevalence of IFD among chronic lymphocytic leukaemia/non-Hodgkin lymphoma patients treated with ibrutinib appears to be higher than expected. These patients often present with unusual clinical features. Mortality from IFD in this study was high, indicating that additional studies are urgently needed to identify patients at risk for ibrutinib-associated IFD.