Ibrutinib In Chronic Lymphocytic Leukemia Research Articles

A retrospective observational study of ibrutinib in chronic lymphocytic leukaemia in a real-life setting in France using the national claims database (OSIRIS).

Ibrutinib is a Bruton's tyrosine kinase inhibitor indicated for the first-line treatment and relapse of chronic lymphocytic leukaemia (CLL), Waldenström's macroglobulinemia (WM) and mantle cell lymphoma (MCL). This study aimed to describe the characteristics of CLL patients treated with ibrutinib and its effectiveness, safety, and treatment pattern in real life. All patients covered by the general health scheme (approximately 80% of the French population) with a first ibrutinib dispensation from August 1, 2017 (date of reimbursement in France) to December 31, 2020, were identified in the French National Health Insurance database (SNDS). An algorithm was developed to identify the disease (CLL, MCL or WM) for which ibrutinib was prescribed. This article focused on CLL patients. The time to next treatment (TTNT) was plotted using Kaplan‒Meier curves. During this period, 6,083 patients initiated ibrutinib, among whom 2,771 (45.6%) patients had CLL (mean age of 74 years; 61% of men). At ibrutinib initiation, 46.6% of patients had a cardiovascular comorbidity. Most patients (91.7%) were not hospitalized during the exposure period for one of the cardiovascular or bleeding events studied. Hospitalizations were more frequent in patients with a cardiovascular comorbidity (5.9% versus 11.0%, p-value < 0.0001) and aged over 70 (5.9% versus 9.4%, p-value < 0.0001). The median TTNT was not reached. This is one of the largest cohorts of ibrutinib-treated patients in the world. The profile of CLL patients treated with ibrutinib was in accordance with the marketing authorization and reimbursement. This study confirmed effectiveness and safety data.

Plain language summary of zanubrutinib or ibrutinib in chronic lymphocytic leukemia that is resistant to treatment or has come back after treatment.

This is a plain language summary of a research study called ALPINE. The study involved people who had been diagnosed with, and previously treated at least once for, relapsed or refractory chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). Lymphocytes help to find and fight off viruses and infections in the body, but when someone has CLL or SLL, the body creates abnormal lymphocytes, leaving the patient with a weakened immune system and susceptible to illness. In CLL, these lymphocytes are in the bone marrow and bloodstream, whereas for SLL, they are mostly found in the lymph nodes, such as those in the neck. The ALPINE study was designed to directly compare the cancer-fighting effects and side effects of zanubrutinib and ibrutinib as treatment for patients with relapsed or refractory CLL/SLL. After 30months, zanubrutinib was more effective than ibrutinib at reducing and keeping the cancer from coming back. Clinical Trial Registration: NCT03734016 (ClinicalTrials.gov).

Ибрутиниб в лечении хронического лимфолейкоза у пациентов старше 60 лет из групп высокого и очень высокого риска

Aim. To assess the efficacy and tolerability of ibrutinib in chronic lymphocytic leukemia (CLL) therapy for high- and very-high-risk patients over 60 years of age.&#x0D; Materials &amp; Methods. The study enrolled 18 CLL patients aged 60 and older. The patients were stratified by age: group 1 included 10 patients aged 60–70 years (median age 64.5 years) and group 2 included 8 patients aged ≥ 71 years (median age 75.8 years); there was equal number of men and women. All patients were subjected to molecular genetic analysis to identify poor prognosis factors and determine the IGHV gene mutation status. The cytogenetic analysis revealed karyotypic abnormalities including 17p deletion in 3 female patients aged 60, 66, and 77 years, respectively. All the patients had CLL without mutation in IGHV genes. They received ibrutinib 420 mg/day per os as first- and second-line therapies.&#x0D; Results. All patients showed aggravated comorbidity. The median follow-up was 28 months (range 18–42 months) in age group 1 and 46 months (range 12–78 months) in group 2. In group 1, a complete remission in 2 patients with del(17p) and a partial remission (PR) in 3 patients were achieved. PR with lymphocytosis was reported in the rest of 5 patients treated with ibrutinib for 12 months. In group 2, PR with the management of autoimmune complications in 5 out of 8 patients and PR with lymphocytosis in 3 patients were reported. The drug was well tolerated in both groups. No signs of severe hematological toxicity were observed in either of them.&#x0D; Conclusion. The choice of ibrutinib for high- and very-high-risk CLL patients aged 60 and older appeared to be optimal. This is also proved by the ease of administration of oral capsules, high efficacy, absence of tumor lysis syndrome, good tolerability, and acceptable toxicity profile.

Lymphocyte migration and retention properties affected by ibrutinib in chronic lymphocytic leukemia.

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib is widely used for treatment of patients with relapsed/refractory or treatment-naïve chronic lymphocytic leukemia (CLL). A prominent effect of ibrutinib is to disrupt the retention of CLL cells from supportive lymphoid tissues, by altering BTK-dependent adhesion and migration. To further explore the mechanism of action of ibrutinib and its potential impact on non-leukemic cells, we quantified multiple motility and adhesion parameters of human primary CLL cells and non-leukemic lymphoid cells. In vitro, ibrutinib affected CCL19-, CXCL12- and CXCL13-evoked migration behavior of CLL cells and non-neoplastic lymphocytes, by reducing both motility speed and directionality. De-phosphorylation of BTK induced by ibrutinib in CLL cells was associated with defective polarization over fibronectin and inability to assemble the immunological synapse upon B-cell receptor engagement. In patients' samples collected during a 6-month monitoring of therapy, chemokine-evoked migration was repressed in CLL cells and marginally reduced in T cells. This was accompanied by profound modulation of the expression of chemokine receptors and adhesion molecules. Remarkably, the relative expression of the receptors governing lymph node entry (CCR7) versus exit (S1PR1) stood out as a reliable predictive marker of the clinically relevant treatment-induced lymphocytosis. Together, our data reveal a multifaceted modulation of motility and adhesive properties of ibrutinib on both CLL leukemic cell and T-cell populations and point to intrinsic differences in CLL recirculation properties as an underlying cause for variability in treatment response.

Functional consequences of inhibition of Bruton's tyrosine kinase by ibrutinib in chronic lymphocytic leukemia.

The leukemic B cells from patients with chronic lymphocytic leukemia (CLL) require interactions with non-malignant cells and matrix in the tissue microenvironment to survive and grow. These interactions are mediated through the B-cell antigen receptor (BCR), C-X-C chemokine receptor type 4 (CXCR4), and a variety of integrins, including VLA-4. Exciting each receptor type leads to activation of Bruton's tyrosine kinase (BTK), which in turn helps initiate trophic signals that prevent cell death and promote cell activation and growth as well as allowing cells to return to anatomic sites for rescue signals. These represent the two major functional actions targeted by inhibitors of Btk. Here we relate some of the therapeutic actions of ibrutinib, a Btk inhibitor that is extremely helpful for patients with CLL, certain Diffuse Large B-cell Lymphomas (ABC type), and other non-Hodgkin's lymphomas, emphasizing that ibrutinib's value results from blocking beneficial signals, not by inducing lethal ones.

Population-level impact of ibrutinib for chronic lymphocytic leukemia in British Columbia, Canada

Ibrutinib has dramatically changed the treatment landscape for chronic lymphocytic leukemia (CLL) since its availability in British Columbia (BC), Canada in 2014. We analyzed patterns of use and real-world survival outcomes in 370 patients who received ibrutinib for first-line (1 L, n = 35) and relapsed/refractory (R/R, n = 335) CLL between 2014–2018 in BC. Dose reductions and interruptions were frequent in 32% and 27%, respectively. With a median follow-up of 27.6 months, 35% of patients discontinued ibrutinib, primarily for adverse events (AEs) rather than progressive disease. Over the course of treatment, 87% of patients experienced at least one adverse event. The 2-year overall survival (OS) and event-free survival (EFS) were excellent at 83.9% and 76.1%, respectively, with medians not reached. However, patients who discontinued ibrutinib had a median OS of 32.5 months and median EFS of only 3.8 months from time of discontinuation, highlighting the need to minimize toxicity in the real-world.

A Fixed-Duration Immunochemotherapy Approach Combined with Ibrutinib in CLL Produces Deep and Sustained MRD Responses: 5.5-Year Results from the Icll-07 Filo Trial

Introduction In previously untreated, medically fit patients with chronic lymphocytic leukemia (CLL), the availability of targeted agents has led to research interest in achieving deep, durable remissions and improving survival outcomes. The phase II ICLL-07 (NCT02666898) trial by the French Innovative Leukemia Organization (FILO) evaluated a fixed-duration (15-month) immunochemotherapy approach (no more than 4 fludarabine/cyclophosphamide [FC]-obinutuzumab cycles). Primary analysis showed the approach was safe and 62.2% (84/135) of all patients enrolled achieved complete response (CR) with bone marrow (BM) minimal residual disease (MRD) <0.01% (Michallet et al Lancet Haematol 2019;6:e470-9). Follow-up at median 37 months from treatment start showed a persistent MRD benefit beyond end of treatment, high survival rates, and low long-term toxicity (Michallet et al Blood 2021;137:1019-23). Here we report long-term results at median 64 months from treatment start (data cut-off 20 May 2022). Methods Between 27 October 2015 and 16 May 2017, 135 previously untreated, medically fit patients with CLL were enrolled from 27 FILO centers. All received obinutuzumab 1000 mg (8 infusions over 6 cycles) plus ibrutinib (420 mg/day for 9 months). Following evaluation at D1 M9 (N=130 evaluable), those in CR with BM MRD <0.01% then continued only ibrutinib 420 mg/day for 6 additional months (I arm; n=10); otherwise, patients received 4 cycles of FC-obinutuzumab 1000 mg alongside continuing ibrutinib 420 mg/day for 6 additional months (I-FCG arm; n=115). Beyond end of treatment, patients were followed for peripheral blood (PB) MRD every 6 months, response every 3 months, progression-free/overall survival (PFS/OS), and safety. MRD was assessed by 8-color flow cytometry, using a highly sensitive (10-6) technique developed by the FILO group that enables subdivision of classical MRD <0.01% into low-level positive MRD <0.01% and undetectable MRD. Results At D1 M16, undetectable PB MRD rates were 80.0% (8/10) in the I arm and 92.5% (99/107) in the I-FCG arm. Beyond end of treatment, in the I arm the undetectable PB MRD rate decreased rapidly, and by M40 all patients had PB MRD positivity (≥0.01% or low-level positive <0.01%). In the I-FCG arm, the undetectable PB MRD rate was 76.3% (61/80) at M40, and of patients currently investigated at M64, 50/62 (80%) still had undetectable PB MRD (Figure 1). Four relapses occurred beyond end of treatment, including 2 CLL progressions (both Richter's syndrome). Throughout follow-up, no differences in undetectable PB MRD rates were apparent in the I-FCG arm according to the IGHV -mutated versus unmutated status (currently at M64: 20/27 versus 25/35, P=0.26). Overall 4-year PFS and OS rates (95% confidence intervals) were 95.5% (92% to 99 %) and 96.2% (93% to 99.5%), respectively. Of 12 deaths overall, 7 occurred beyond end of treatment, with 5 since last publication due to Richter's syndrome at M50, COVID at M50, lung cancer at M50, myelodysplastic syndrome at M60, and acute myeloid leukemia at M69. Other serious adverse events since last publication were metastatic prostate adenocarcinoma at M50 and suspicion of cerebrovascular accident at M65. Conclusion Long-term results from the ICLL-07 trial in previously untreated, medically fit patients with CLL demonstrated that that our fixed-duration (15-month) immunochemotherapy approach produced deep and sustained undetectable PB MRD responses that were correlated to PFS, without excess toxicity. These long-term MRD results remain the best to date even compared to the new targeted therapy combinations ie ibrutinib +veneteclax or obinutuzumab + venetoclax A randomized trial is needed to compare our approach with a chemotherapy-free strategy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Effectiveness and Safety of Ibrutinib for Chronic Lymphocytic Leukemia in Routine Clinical Practice: 3-Year Follow-up of the Belgian Ibrutinib Real-World Data (BiRD) Study

The multicenter observational BiRD study investigated the real-world effectiveness and safety of ibrutinib in patients with chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL) and Waldenström’s macroglobulinemia (WM) in Belgium. This interim analysis reports results for patients with CLL, with a median follow-up of 34 months. Overall, patients had predominantly relapsed/refractory disease (73%) and were elderly (median age 72 years) with high-risk features such as del17p and/or TP53 mutations (59%). Patients were included either prospectively or retrospectively, and the total patient population effectiveness results were adjusted with left truncation. In the effectiveness population (N = 221: prospective, n = 71; retrospective, n = 150), the overall response rate was 90.0%. Median progression-free survival was 38.3 months (prospective, not estimable; retrospective, 51.5 months) and median overall survival was not yet estimable in the total, prospective and retrospective groups. Treatment-emergent adverse events (TEAEs) for the prospective and retrospective groups are reported separately. Any-grade TEAEs of interest in the prospective/retrospective groups included infections (67.1%/60.1%), diarrhea (20.5%/10.5%), hypertension (16.4%/9.8%) and atrial fibrillation (12.3%/7.2%). Major bleeding was reported in 5.5%/3.3% of prospective/retrospective patients, with little difference observed between those receiving versus not receiving antithrombotic treatment. Discontinuations due to toxicity were reported in 10.5% of patients. Results from this interim analysis show treatment with ibrutinib to be effective and tolerable, with no new safety signals observed. Future analyses will report on longer-term follow-up.

Sequential treatment with bendamustine, obinutuzumab (GA101) and Ibrutinib in chronic lymphocytic leukemia (CLL): final results of the CLL2-BIG trial

Sequential treatment with bendamustine, obinutuzumab (GA101) and Ibrutinib in chronic lymphocytic leukemia (CLL): final results of the CLL2-BIG trial

P1130: ACALABRUTINIB IN TREATMENT-NAIVE OR RELAPSED/REFRACTORY WALDENSTRÖM MACROGLOBULINEMIA: 5-YEAR FOLLOW-UP OF A PHASE 2, SINGLE-ARM STUDY

Background: Bruton tyrosine kinase (BTK) inhibitors are effective in the treatment of Waldenström macroglobulinemia (WM). Acalabrutinib is a highly selective, potent, covalent BTK inhibitor that demonstrated less toxicity and improved tolerability in a head-to-head trial versus ibrutinib in chronic lymphocytic leukemia. Aims: The aim of this trial was to determine the efficacy and safety of acalabrutinib in patients with treatment-naive (TN) or relapsed/refractory (R/R) WM. Interim results at 25 months (mo) of median follow-up have been previously reported. At a 5-year median follow-up, we report the final results of this trial. Methods: In this single-arm, multicenter, phase 2 trial, after informed consent was obtained, patients with TN or R/R WM received 100 mg oral acalabrutinib twice daily (or 200 mg acalabrutinib once daily, later switched to 100 mg twice daily). The primary endpoint was investigator-assessed overall response rate (ORR). Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. Efficacy parameters were based on the modified 3rd International Workshop on Waldenström Macroglobulinemia (IWWM) criteria (Kimby 2006). Mutation data were available for a minority of patients and therefore are not reported. Results: Of 106 patients treated with acalabrutinib, 14 were TN and 92 were R/R; median age was 69 years (range 39–90); 94% had ECOG PS ≤1; median serum IgM was 3615 mg/dL (range 291–9740). Patients with R/R disease had a median of 2 prior therapies (range 1–7). ORR was 93% (95% CI: 66, 100) in the TN cohort and 95% (88, 98) in the R/R cohort; major response rates (≥partial response) were 79% (49, 95) and 82% (72, 89), respectively. Median DOR was not estimable (NE) (12, NE) in the TN cohort and 65 mo (55, NE) in the R/R cohort; the estimated 66-mo DOR was 90% (TN; 47, 99) and 45% (R/R; 27, 61). At a 63.7-mo median follow-up, median PFS rate was NE (TN; 19, NE) and 68 mo (R/R; 53, NE); estimated 66-mo PFS rate was 84% (TN; 48, 96) and 52% (R/R; 39, 63). Median OS rate was NE for the TN and R/R cohorts; estimated 66-mo OS rate was 91% (TN; 51, 99) and 71% (R/R; 60, 80). Of the patients who remained on treatment, 7 (50%) were in the TN cohort and 43 (47%) were in the R/R cohort. The main reasons for discontinuing acalabrutinib were adverse events (AEs) (4 [29%] patients in the TN cohort, 15 [16%] patients in the R/R cohort) and progressive disease (PD) (1 [7%] patient in the TN cohort, 20 [22%] patients in the R/R cohort). The most common AEs and selected events of clinical interest are listed in the Table. There were 12 grade 5 AEs (11 and 1 patients in the R/R and TN cohorts, respectively); 1 (intracranial hematoma [R/R]) was considered treatment-related. Image:Summary/Conclusion: Acalabrutinib is a highly effective treatment that achieved durable responses with a favorable safety profile in patients with TN or R/R WM.

Characterization of low-grade arthralgia, myalgia, and musculoskeletal pain with ibrutinib therapy: pooled analysis of clinical trials in patients with chronic lymphocytic leukemia and mantle cell lymphoma

Joint and muscle pain, including arthralgia, myalgia, and musculoskeletal pain, are among the common adverse events (AEs) reported for ibrutinib, a once-daily Bruton’s tyrosine kinase inhibitor approved for the treatment of various B-cell malignancies, including chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). This pooled analysis from nine clinical trials of ibrutinib in CLL and MCL (N = 1178) evaluated patterns of these AEs. Any grade arthralgia, myalgia, and musculoskeletal pain occurred in 18%, 10%, and 6% of patients, respectively. AEs were primarily low-grade (grade 1/2: 97‒99%) and occurred during the first year of treatment; most resolved (67%–80%) at first occurrence. Few (<5%) patients required ibrutinib dose modification; no patients discontinued ibrutinib due to these AEs. Among patients evaluated for concomitant medication use, all those receiving concomitant medications after the first AE occurrence experienced AE resolution. These data suggest that these AEs were not treatment-limiting during ibrutinib therapy.

Targeting PAK1 Overcomes Resistance to Ibrutinib in Chronic Lymphocytic Leukemia

Objective:Chronic lymphocytic leukemia (CLL) is a lymphoproliferative disorder that mainly affects the elderly and is characterized by the expansion of small mature B-cells. New targeted drugs, such as the BTK inhibitor ibrutinib, have greatly improved patient survival but have also posed the challenge of drug resistance. The three-dimensional (3D) spatial structure of chromatin is highly dynamic and varies greatly between cell types and developmental stages, with the maintenance of chromatin homeostasis being of major significance in disease prevention. Accumulating evidence has suggested that changes in 3D genomic structures play an important role in cell development and differentiation, disease progression, as well as drug resistance. Nevertheless, the characteristics and functional significance of chromatin conformation in the resistance of CLL to ibrutinib remain unclear. In this study, we aimed to investigate the mechanism underlying ibrutinib resistance through multi-omics profiling, including the study of chromatin conformation. Thus, we would be able to demonstrate the importance of chromatin spatial organization in CLL and highlight the oncogenic factors contributing to CLL development and mediating ibrutinib resistance.Methods:An ibrutinib-resistant cell line was established by exposing cells to increasing doses of ibrutinib. High-throughput chromosome conformation capture (Hi-C), assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq), bulk RNA sequencing (RNA-seq), and Tandem Mass Tag (TMT) were performed to explore differences between ibrutinib-resistant and parental cells. Peripheral blood mononuclear cells (PBMCs) from 53 CLL patients were collected for RNA-seq. Mitochondrial respiration and glycolysis were assessed via Seahorse analysis. The growth-inhibitory effects of tested drugs were evaluated via a CCK8 assay, and the combination index (CI), indicating synergy, was calculated using CompuSyn software. Apoptosis was detected via annexin V staining.Results:Between ibrutinib-resistant and parental cells changes in some chromosomes, including chr11 were observed (Figure 1A). p21-activated kinase 1 (PAK1), which is located on chr11 and frequently overexpressed or excessively activated in almost all cancer types and involved in almost every stage of cancer progression, was first explored for its role in CLL progression and drug resistance. The oncogene PAK1 was observed locate in a region where B-to-A compartment switching occurred (Figure 1B). Consistent with the results of ATAC-seq, RNA-seq, and TMT, Hi-C analysis revealed a transcriptional upregulation of PAK1 in ibrutinib-resistant CLL cells (Figure 1C). Functional analysis demonstrated that PAK1 overexpression significantly promoted cell proliferation, while knockdown markedly suppressed cell viability (Figure 1D). Cell viability assays indicated that the depletion of PAK1 increased ibrutinib sensitivity (Figure 1E). In addition, PAK1 positively regulates glycolysis and oxidative phosphorylation in CLL cells (Figure 1F and G).To verify the results of sequencing and further explore the role of PAK1 in CLL, B-cells from healthy volunteers and PBMCs from CLL patients were collected. The level of PAK1 mRNA expression was significantly higher in CLL primary cells than in B-cells from healthy volunteers (Figure 1H). Kaplan-Meier survival analysis of qRT-PCR data confirmed that patients with high PAK1 expression had a significantly lower OS (Figure 1I).IPA-3, the small molecular inhibitor of PAK1 suppressed the proliferation of ibrutinib-resistant and parental CLL cells in a dose-dependent manner. The combination of IPA-3 and ibrutinib exerted potent cell growth inhibition (Figure 1J), and the combination index (CI) calculated using the CompuSyn software confirmed the synergistic effect (CI<1) of this combinatorial therapy (Figure 1K).Conclusions:In the current study, we have provided a genome-wide view of alterations in 3D chromatin organization between ibrutinib-resistant and parental CLL cells and confirmed the oncogenic role of PAK1 in CLL. Most importantly, our research provides promising therapeutic targets for overcoming ibrutinib resistance. In particular, the treatment of CLL patients with a combination of IPA-3 and ibrutinib may improve clinical outcomes. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Real-World Characteristics and Outcome of Patients Treated With Single-Agent Ibrutinib for Chronic Lymphocytic Leukemia in Spain (IBRORS-LLC Study)

BackgroundIbrutinib demonstrated remarkable efficacy and favorable tolerability in patients with untreated or relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL), including those with high-risk genetic alterations. The IBRORS-CLL study assessed the characteristics, clinical management and outcome of CLL patients receiving ibrutinib in routine clinical practice in Spain. PatientsObservational, retrospective, multicenter study in CLL patients who started single-agent ibrutinib as first-line treatment or at first or second relapse between January 2016 and January 2019. ResultsA total of 269 patients were included (median age: 70.9 years; cardiovascular comorbidity: 55.4%, including hypertension [47.6%] and atrial fibrillation [AF] [7.1%]). Overall, 96.7% and 69% of patients underwent molecular testing for del(17p)/TP53 mutation and IGHV mutation status. High-risk genetic features included unmutated IGHV (79%) and del(17p)/TP53 mutation (first-line: 66.3%; second-line: 23.1%). Overall, 84 (31.2%) patients received ibrutinib as first-line treatment, and it was used as second- and third-line therapy in 121 (45.0%) and 64 (23.8%) patients. The median progression-free survival and overall survival were not reached irrespective of del(17p)/TP53, or unmutated IGHV. Common grade ≥3 adverse events were infections (12.2%) and bleeding (3%). Grade ≥3 AF occurred in 1.5% of patients. ConclusionThis real-world study shows that single-agent ibrutinib is an effective therapy for CLL, regardless of age and high-risk molecular features, consistent with clinical trials. Additionally, single-agent ibrutinib was well tolerated, with a low rate of cardiovascular events. This study also emphasized a high molecular testing rate of del(17p)/TP53 mutation and IGHV mutation status in clinical practice according to guideline recommendations.

The impact of increasing karyotypic complexity and evolution on survival in patients with CLL treated with ibrutinib

AbstractComplex karyotype, defined as ≥3 cytogenetic abnormalities, is prognostic of survival in patients treated with ibrutinib or venetoclax in relapsed/refractory (RR) chronic lymphocytic leukemia (CLL). Recent studies re-evaluating this dichotomous variable have shown that higher numbers of cytogenetic abnormalities (ie, ≥5) have a worse overall survival in patients treated with chemoimmunotherapy. We sought to determine if increasing karyotypic complexity, treated as a continuous variable, was prognostic of survival for patients treated with ibrutinib for CLL. We conducted a retrospective analysis of all patients with CLL treated with single-agent ibrutinib or in combination with an anti–CD20 antibody at our institution. We included 456 patients with both treatment-naive and RR disease. Median number of prior therapies was 2 (range, 0-13), 30% of patients had presence of del(17p), and 75% expressed unmutated IGHV. Fifty percent had ≥3 cytogenetic abnormalities, including 30% with ≥5. In a multivariable analysis, increasing karyotypic complexity was an independent predictor of shorter progression-free survival (hazard ratio, 1.07; 95% confidence interval, 1.04-1.10; P < .0001) and overall survival (hazard ratio, 1.09; 95% confidence interval, 1.05-1.12; P < .0001). Furthermore, we found that presence of clonal evolution determined by cytogenetic analysis at progression was prognostic of subsequent survival (P = .02). This solidifies karyotypic complexity as an important prognostic factor for patients with CLL treated with ibrutinib. Further research should consider sequential karyotypic analysis as a determination of risk of progression and death in patients with CLL.

Acute gout flare of bilateral first metatarsophalangeal joints due to ibrutinib use in chronic lymphocytic leukemia

Bruton tyrosine kinase inhibitors represent important tools in the therapeutic armamentarium against chronic lymphocytic leukemia (CLL) and other B-lymphoproliferative disorders. We describe herein a unique 65-year-old patient who presented with bilateral foot pain four months after starting treatment with ibrutinib for CLL. Of note, the patient had previously been diagnosed with gout, and was taking allopurinol prophylactically at the time of the event. Compliance with allopurinol was in excess of 99%. Yet, he was diagnosed with acute gout flare of bilateral first metatarsophalangeal (MTP) joints.Management & Outcome: Ibrutinib dose was reduced by one third, and the patient's gout flare up was treated with ibuprofen as needed. After symptoms abated, ibrutinib was continued at 2/3rds of the dose, with an excellent CLL control. The patient tolerated this dose without any further adverse effects.Discussion/Conclusions: We have reported a unique side effect of acute bilateral first MTP joint gout flare likely triggered by ibrutinib use for CLL while the patient was taking a xanthine oxidase inhibitor. The mechanism by which ibrutinib caused this phenomenon remains to be elucidated.

Cryptococcus gattii in Patients with Lymphoid Neoplasms: An Illustration of Evolutive Host-Fungus Interactions.

Recent outbreaks of Cryptococcus gattii (CG) infections in North America have sparked renewed interest in the pathogenic potential of CG, and have underscored notable differences with Cryptococcus neoformans in terms of geographic distribution, pathogen virulence, and host susceptibility. While cases of CG are increasingly reported in patients with a wide variety of underlying conditions, only very few have been reported in patients with lymphoid neoplasms. Herein, we report a case of autochthonous CG meningitis in a patient receiving ibrutinib for chronic lymphocytic leukemia in France, and review available data on the clinical epidemiology of CG infections in patients with lymphoid neoplasms. We also summarise recent data on the host responses to CG infection, as well as the potential management pitfalls associated with its treatment in the haematological setting. The clinical epidemiology, clinical presentation, and course of disease during infections caused by CG involve complex interactions between environmental exposure to CG, infecting genotype, pathogen virulence factors, host susceptibility, and host immune responses. Future treatment guidelines should address the challenges associated with the management of antifungal treatments in the onco-haematological setting and the potential drug-drug interactions.

BRD4 Inhibitors Enhance the Anti-Tumor Activity of Targeted Therapy in Chronic Lymphocytic Leukemia

Background: The development of drugs targeting BTK and BCL2 has dramatically improved the therapeutic landscape in chronic lymphocytic leukemia (CLL). However, resistance to these agents has been reported due to non-recurrent changes in oncogenic pathways and gene expression signatures. The bromodomain and extra terminal (BET) family proteins (BRD2, BRD3, BRD4 and BRDT) are epigenetic reader proteins that recognize acetylated lysine residues in histones. They play a critical role in mediating gene transcription and have been considered as highly promising targets in several diseases including cancer. Of these, the BRD4 protein is highly enriched in super enhancers and regulates transcription of relevant oncogenes such as MYC, CDK genes, cyclin-D1, BCL2 and MCL-1. BRD4 inhibitors (BRD4i) block the transcription of these key oncogenes through the displacement of BRDs and other epigenetic modifiers from chromatin. In this study, we investigated the preclinical activity of two BRD4i, AZD5153 and PLX51107, and their cooperative role with the BCL2 inhibitor venetoclax and BTK inhibitor ibrutinib in CLL. Methods: Primary tumor cells were isolated from 36 CLL patients. Peripheral blood mononuclear cells were isolated via histopaque-1077 (Sigma-Aldrich, St Louis MO) from peripheral blood apheresis samples from consenting adults under RPCCC protocol CIC-01-16. B-cells were then isolated from enriched lymphocytes by MACS separation using a human B-cell Isolation Kit II. CLL cells were seeded at 3 x106/mL in a 384 well tissue culture plates and exposed to different doses of AZD5153 (1-20uM) or PLX51107 (1-20uM) as a single agent or in combination with venetoclax (1-100nM) or ibrutinib (50-1000nM) for 48 and 72hrs (Selleck Chemicals, Houston TX). Cell viability was assessed using Cell Titer-glo (Promega, Madison WI) with all data being normalized to untreated controls. Synergy was calculated using Calcusyn (Cambridge, UK) software to determine Coefficient of Synergy (CI) values. In addition, CLL cells were plated in 6 well plates and exposed to AZD5153 or PLX51107 alone or in combination with either venetoclax or ibrutinib for 24 hrs. Induction of apoptosis and changes in B-cell receptor signaling, BCL2 and NF-kB pathway related proteins were evaluated by flow cytometry or Western blotting respectively. Results: The study included 33 treatment naïve and 3 relapsed/refractory CLL patients. Deletion 11q was detected in 6 patients and del 17p was seen in 1 patient. Both AZD5153 and PLX51107 displayed time and dose dependent induction of apoptosis of CLL cells. Activity was observed in both treatment naïve and relapsed/refractory samples. Moreover, activity was observed in del 17p or ATM deletion samples. Synergistic activity was observed between BRD4is and venetoclax. PLX51107 exhibited synergy with venetoclax in 83% of the samples tested. Similarly, AZD5153 exhibited synergistic effects when combined with venetoclax in 61% of the samples. To a lesser degree, BRD4is exhibited synergistic activity when combined with ibrutinib, (44% with PLX51107 and 39% with AZD5153). Induction of apoptosis was observed in CLL cells exposed to either BRD4i. Morevoer, an increase in the percentage of apoptosis was observed when BRD4i was combined with venetoclax. Western blotting showed a accumulation of p21, reduced levels of C-MYC, as well as modulation of BCL-2 family member proteins such as BCL2, MCL-1 following BRD4i ex vivo exposure. Conclusions: Our data indicate that BRD4 inhibition results in apoptosis of primary tumor cells isolated from patients with various subtypes of CLL. PLX51107 and AZD5153 exhibit synergistic effects when combined with venetoclax and to a lesser degree with ibrutinib. Modulation of BCL-2 family members following BRD4 inibition could play a role in the synergistic activity observed in our studies. A better understanding of the key signaling pathways involved in proliferation and survival of CLL cells impacted by BRD4i in combination with venetoclax and ibrutinib would provide a proof-of-concept rationale for studies validating BRD4i as epigenetic approach to target BCR signaling in CLL. Disclosures Hernandez-Ilizaliturri: Karyopharm: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Amgen: Consultancy; Gilead: Consultancy; Pharmacyclics: Consultancy; Seattle Genetics: Consultancy; Astra Zeneca: Consultancy; Epyzome: Consultancy.

Platelet function and bleeding in chronic lymphocytic leukemia and mantle cell lymphoma patients on ibrutinib

BackgroundTherapy with irreversible Bruton's tyrosine kinase inhibitor ibrutinib in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) is associated with bleeding. ObjectivesTo propose the predictive markers of such bleeding, as well as mechanisms responsible for decreased bleeding at later therapy stages. Patients/MethodsWe investigate platelet functional activity in 50 CLL and 16 MCL patients on ibrutinib using flow cytometry and light transmission aggregometry. ResultsPrior to treatment, both patient groups had decreased platelet counts; impaired aggregation with adenosine diphosphate (ADP); and decreased binding of CD62P, PAC1, and annexin V upon stimulation. Bleeding in patients treated with ibrutinib was observed in 28 (56%) CLL patients, who had decreased aggregation with ADP and platelet count before therapy. Their platelet count on therapy did not change, platelet aggregation with ADP steadily improved, and aggregation with collagen first decreased and then increased in anticorrellation with bleeding. Bleeding in MCL was observed in 10 (62%) patients, who had decreased dense granule release before therapy. ADP and ristocetin induced platelet aggregation in ibrutinib‐treated MCL patients increased on therapy, while collagen‐induced aggregation evolved similarly to CLL patients. ConclusionsOur results suggest that ibrutinib‐dependent bleeding in CLL patients involves three mechanisms: decreased platelet count (the most important discriminator between bleeding and non‐bleeding patients), impaired platelet response to ADP caused by CLL, and inhibition by ibrutinib. Initially, ibrutinib shifts the balance to bleeding, but then it is restored because of the improved response to ADP.

DAPK3 participates in the mRNA processing of immediate early genes in chronic lymphocytic leukaemia.

Cross‐linking of the B‐cell receptor (BCR) induces transcriptional activation of immediate early genes (IEGs) including EGR1 and DUSP2 in chronic lymphocytic leukaemia (CLL). Here, we have shown that this transcriptional activation correlated with histone H3 threonine 6 and 11 phosphorylation. Both transcription and histone post‐translational modifications are repressed by ibrutinib, a small molecule inhibitor used in CLL treatment. Moreover, we have identified the death‐associated protein kinase 3 (DAPK3), as the kinase mediating these histone phosphorylation marks in response to activation of the BCR signalling pathway with this kinase being recruited to RNA polymerase II in an anti‐IgM‐dependent manner. DAPK inhibition mimics ibrutinib‐induced repression of both IEG mRNA and histone H3 phosphorylation and has anti‐proliferative effect comparable to ibrutinib in CLL in vitro. DAPK inhibitor does not repress transcription itself but impacts on mRNA processing and has a broader anti‐tumour effect than ibrutinib, by repressing both anti‐IgM‐ and CD40L‐dependent activation.

Combining ibrutinib and checkpoint blockade improves CD8+ T-cell function and control of chronic lymphocytic leukemia in Em-TCL1 mice.

Ibrutinib is a Bruton’s tyrosine kinase (BTK) inhibitor approved for the treatment of multiple B-cell malignancies, including chronic lymphocytic leukemia (CLL). In addition to blocking B-cell receptor signaling and chemokine receptor-mediated pathways in CLL cells, that are known drivers of disease, ibrutinib also affects the microenvironment in CLL via targeting BTK in myeloid cells and IL-2–inducible T-cell kinase (ITK) in T cells. These non-BTK effects were suggested to contribute to the success of ibrutinib in CLL. By using the Eμ-TCL1 adoptive transfer mouse model of CLL, we observed that ibrutinib effectively controls leukemia development, but also results in significantly lower numbers of CD8+ effector T cells, with lower expression of activation markers, as well as impaired proliferation and effector function. Using CD8+ T cells from a T-cell receptor (TCR) reporter mouse, we verified that this is due to a direct effect of ibrutinib on TCR activity, and demonstrate that co-stimulation via CD28 overcomes these effects. Most interestingly, combination of ibrutinib with blocking antibodies targeting PD-1/PD-L1 axis in vivo improved CD8+ T-cell effector function and control of CLL. In summary, these data emphasize the strong immunomodulatory effects of ibrutinib and the therapeutic potential of its combination with immune checkpoint blockade in CLL.