First-Line Venetoclax Combinations in Chronic Lymphocytic Leukemia.

BACKGROUND: Randomized trials of venetoclax plus anti-CD20 antibodies as first-line treatment in fit patients (i.e., those with a low burden of coexisting conditions) with advanced chronic lymphocytic leukemia (CLL) have been lacking. METHODS: In a phase 3, open-label trial, we randomly assigned, in a 1:1:1:1 ratio, fit patients with CLL who did not have TP53 aberrations to receive six cycles of chemoimmunotherapy (fludarabine-cyclophosphamide-rituximab or bendamustine-rituximab) or 12 cycles of venetoclax-rituximab, venetoclax-obinutuzumab, or venetoclax-obinutuzumab-ibrutinib. Ibrutinib was discontinued after two consecutive measurements of undetectable minimal residual disease or could be extended. The primary end points were undetectable minimal residual disease (sensitivity, <10-4 [i.e., <1 CLL cell in 10,000 leukocytes]) as assessed by flow cytometry in peripheral blood at month 15 and progression-free survival. RESULTS: A total of 926 patients were assigned to one of the four treatment regimens (229 to chemoimmunotherapy, 237 to venetoclax-rituximab, 229 to venetoclax-obinutuzumab, and 231 to venetoclax-obinutuzumab-ibrutinib). At month 15, the percentage of patients with undetectable minimal residual disease was significantly higher in the venetoclax-obinutuzumab group (86.5%; 97.5% confidence interval [CI], 80.6 to 91.1) and the venetoclax-obinutuzumab-ibrutinib group (92.2%; 97.5% CI, 87.3 to 95.7) than in the chemoimmunotherapy group (52.0%; 97.5% CI, 44.4 to 59.5; P<0.001 for both comparisons), but it was not significantly higher in the venetoclax-rituximab group (57.0%; 97.5% CI, 49.5 to 64.2; P = 0.32). Three-year progression-free survival was 90.5% in the venetoclax-obinutuzumab-ibrutinib group and 75.5% in the chemoimmunotherapy group (hazard ratio for disease progression or death, 0.32; 97.5% CI, 0.19 to 0.54; P<0.001). Progression-free survival at 3 years was also higher with venetoclax-obinutuzumab (87.7%; hazard ratio for disease progression or death, 0.42; 97.5% CI, 0.26 to 0.68; P<0.001), but not with venetoclax-rituximab (80.8%; hazard ratio, 0.79; 97.5% CI, 0.53 to 1.18; P = 0.18). Grade 3 and grade 4 infections were more common with chemoimmunotherapy (18.5%) and venetoclax-obinutuzumab-ibrutinib (21.2%) than with venetoclax-rituximab (10.5%) or venetoclax-obinutuzumab (13.2%). CONCLUSIONS: Venetoclax-obinutuzumab with or without ibrutinib was superior to chemoimmunotherapy as first-line treatment in fit patients with CLL. (Funded by AbbVie and others; GAIA-CLL13 ClinicalTrials.gov number, NCT02950051; EudraCT number, 2015-004936-36.).

Reassessing the chronic lymphocytic leukemia International Prognostic Index in the era of targeted therapies.

ABSTRACT: We evaluated the chronic lymphocytic leukemia International Prognostic Index (CLL-IPI) in patients with CLL treated first line with targeted drugs (n = 991) or chemoimmunotherapy (n = 1256). With a median observation time of 40.5 months, the 3-year progression-free survival (PFS) rates for targeted drug-treated patients varied by CLL-IPI risk group: 96.5% (low), 87.6% (intermediate), 82.4% (high), and 78.7% (very high). Differences between consecutive CLL-IPI risk groups were observed for intermediate vs low and high vs intermediate, but not very high vs high. CLL-IPI factors ß2-microglobulin, immunoglobulin heavy variable (IGHV) status, and TP53 status each retained prognostic value for PFS. The 3-year overall survival (OS) rates by CLL-IPI risk groups were 100%, 96%, 93.9%, and 89.4%, respectively, with no differences between consecutive risk groups. Age, Binet stage, ß2-microglobulin, and TP53 status each retained prognostic value for OS. In chemoimmunotherapy patients (median observation time, 66.9 months), 3-year PFS rates for CLL-IPI risk groups were 78.1%, 51.4%, 40.1%, and 16.5%, respectively; corresponding 3-year OS rates were 97.4%, 93.1%, 81.8%, and 57.3%. In a matched-pair analysis, PFS differences in targeted therapies (n = 812) vs chemoimmunotherapy (n = 812) across all risk groups and OS differences in all but patients at low risk were demonstrated. The CLL-IPI maintains its prognostic value in predicting PFS outcomes with targeted drugs, but its impact in predicting survival appears diminished. Targeted therapies showed enhanced outcomes over chemoimmunotherapy, highlighting their effectiveness across various risk groups. Our findings support ongoing assessment of prognostic tools in CLL treatment evolution. These trials were registered at www.ClinicalTrials.gov as #NCT02345863, #NCT02401503, #NCT02689141, #NCT02445131, #NCT02758665, #NCT02950051, #NCT02242942, #NCT00262782, #NCT00281918, and #NCT01010061.

Acalabrutinib, venetoclax and obinutuzumab in relapsed CLL: Final efficacy and ctDNA analysis of the CLL2-BAAG trial.

The phase 2 CLL2-BAAG trial tested the measurable residual disease (MRD)-guided triple combination of acalabrutinib, venetoclax and obinutuzumab after an optional bendamustine debulking in 45 patients with relapsed/refractory CLL (one patient was excluded from the analysis due to a violation of exclusion criteria). MRD was measured by flow cytometry (FCM, undetectable MRD <10-4) in peripheral blood (PB) and circulating tumor DNA (ctDNA) by digital droplet PCR (ddPCR) of variable-diversity-joining (VDJ) rearrangements and CLL-related mutations in plasma. MRD recurrence was defined as detectable ctDNA and/or MRD ≥10-4 after achieving both uMRD/undetectable ctDNA. The median number of previous treatments was 1 (range 1-4), 18 patients (40%) had received a BTK inhibitor (BTKi) and/or venetoclax prior to inclusion, 14/44 (31.8%) had TP53 aberrations, 34 (75.6%) had unmutated IGHV. With a median observation time of 36.3 months and all patients off treatment for a median of 21.9 months, uMRD <10-4 in PB was achieved in 42/45 patients (93.3%) at any time point, including 17/18 (94.4%) previously exposed to venetoclax/BTKi and 13/14 (92.9%) with TP53 aberrations. The estimated three-year progression-free and overall survival rates were 85.0% and 93.8%. Overall 585 paired FCM/ctDNA samples were analyzed and 18 MRD recurrences (5 with and 13 without clinical progression) occurred after the end of treatment. Twelve were first detected by ctDNA, three by FCM and three synchronously. Patients with earlier detection by ctDNA appeared to have genetically higher risk disease. In conclusion, time-limited MRD-guided acalabrutinib, venetoclax and obinutuzumab achieved deep remissions in almost all patients with relapsed/refractory CLL. The addition of ctDNA-based analyses to FCM MRD assessment seems to improve early detection of relapses. ClinicalTrials.gov Identifier: NCT03787264.

The proto-oncogene TCL1A deregulates cell cycle and genomic stability in CLL.

Upregulation of the proto-oncogene T-cell leukemia/lymphoma 1A (TCL1A) is causally implicated in various B-cell and T-cell malignancies. High-level TCL1A correlates with aggressive disease features and inferior clinical outcomes. However, the molecular and cell biological consequences of, particularly nuclear, TCL1A are not fully elucidated. We observed here in mouse models of subcellular site-specific TCL1A-induced lymphomagenesis that TCL1A exerts a strong transforming impact via nuclear topography. In proteomic screens of TCL1A-bound molecules in chronic lymphocytic leukemia (CLL) cells and B-cell lymphoma lines, we identified regulators of cell cycle and DNA repair pathways as novel TCL1A interactors, particularly enriched under induced DNA damage and mitosis. By functional mapping and in silico modeling, we specifically identified the mitotic checkpoint protein, cell division cycle 20 (CDC20), as a direct TCL1A interactor. According to the regulatory impact of TCL1A on the activity of the CDC20-containing mitotic checkpoint and anaphase-promoting complexes during mitotic progression, TCL1A overexpression accelerated cell cycle transition in B-cell lymphoma lines, impaired apoptotic damage responses in association with pronounced chromosome missegregation, and caused cellular aneuploidy in Eµ-TCL1A mice. Among hematopoietic cancers, CDC20 levels seem particularly low in CLL. CDC20 expression negatively correlated with TCL1A and lower expression marked more aggressive and genomically instable disease and cellular phenotypes. Knockdown of Cdc20 in TCL1A-initiated murine CLL promoted aneuploidy and leukemic acceleration. Taken together, we discovered a novel cell cycle-associated effect of TCL1A abrogating controlled cell cycle transition. This adds to our concept of oncogenic TCL1A by targeting genome stability. Overall, we propose that TCL1A acts as a pleiotropic adapter molecule with a synergistic net effect of multiple hijacked pathways.

Detecting measurable residual disease beyond 10-4 by an IGHV leader-based NGS approach improves prognostic stratification in CLL.

The sensitivity of conventional techniques for reliable quantification of minimal/measurable residual disease (MRD) in chronic lymphocytic leukemia (CLL) is limited to MRD 10-4. Measuring MRD <10-4 could help to further distinguish between patients with CLL with durable remission and those at risk of early relapse. We herein present an academically developed immunoglobulin heavy-chain variable (IGHV) leader-based next-generation sequencing (NGS) assay for the quantification of MRD in CLL. We demonstrate, based on measurements in contrived MRD samples, that the linear range of detection and quantification of our assay reaches beyond MRD 10-5. If provided with sufficient DNA input, MRD can be detected down to MRD 10-6. There was high interassay concordance between measurements of the IGHV leader-based NGS assay and allele-specific oligonucleotide quantitative polymerase chain reaction (PCR) (r = 0.92 [95% confidence interval {CI}, 0.86-0.96]) and droplet digital PCR (r = 0.93 [95% CI, 0.88-0.96]) on contrived MRD samples. In a cohort of 67 patients from the CLL11 trial, using MRD 10-5 as a cutoff, undetectable MRD was associated with superior progression-free survival (PFS) and time to next treatment. More important, deeper MRD measurement allowed for additional stratification of patients with MRD <10-4 but ≥10-5. PFS of patients in this MRD range was significantly shorter, compared with patients with MRD <10-5 (hazard ratio [HR], 4.0 [95% CI, 1.6-10.3]; P = .004), but significantly longer, compared with patients with MRD ≥10-4 (HR, 0.44 [95% CI, 0.23-0.87]; P = .018). These results support the clinical utility of the IGHV leader-based NGS assay.

Final analysis of the CLL2-GIVe trial: obinutuzumab, ibrutinib, and venetoclax for untreated CLL with del(17p)/TP53mut.

The final analysis of the open-label, multicenter phase 2 CLL2-GIVe trial shows response and tolerability of the triple combination of obinutuzumab, ibrutinib, and venetoclax (GIVe regimen) in 41 previously untreated patients with high-risk chronic lymphocytic leukemia (CLL) with del(17p) and/or TP53 mutation. Induction consisted of 6 cycles of GIVe; venetoclax and ibrutinib were continued up to cycle 12 as consolidation. Ibrutinib was given until cycle 15 or up to cycle 36 in patients not achieving a complete response and with detectable minimal residual disease. The primary end point was the complete remission rate at cycle 15, which was achieved at 58.5% (95% CI, 42.1-73.7; P < .001). The last patient reached the end of the study in January 2022. After a median observation time of 38.4 months (range, 3.7-44.9), the 36-month progression-free survival was 79.9%, and the 36-month overall survival was 92.6%. Only 6 patients continued ibrutinib maintenance. Adverse events of concern were neutropenia (48.8%, grade ≥3) and infections (19.5%, grade ≥3). Cardiovascular toxicity grade 3 occurred as atrial fibrillation at a rate of 2.4% between cycles 1 and 12, as well as hypertension (4.9%) between cycles 1 and 6. The incidence of adverse events of any grade and grade ≥3 was highest during induction and decreased over time. Progressive disease was observed in 7 patients between cycles 27 and 42. In conclusion, the CLL2-GIVe regimen is a promising fixed-duration, first-line treatment for patients with high-risk CLL with a manageable safety profile.

Oncogenic role and target properties of the lysine-specific demethylase KDM1A in chronic lymphocytic leukemia.

In chronic lymphocytic leukemia (CLL), epigenetic alterations are considered to centrally shape the transcriptional signatures that drive disease evolution and underlie its biological and clinical subsets. Characterizations of epigenetic regulators, particularly histone-modifying enzymes, are very rudimentary in CLL. In efforts to establish effectors of the CLL-associated oncogene T-cell leukemia 1A (TCL1A), we identified here the lysine-specific histone demethylase KDM1A to interact with the TCL1A protein in B cells in conjunction with an increased catalytic activity of KDM1A. We demonstrate that KDM1A is upregulated in malignant B cells. Elevated KDM1A and associated gene expression signatures correlated with aggressive disease features and adverse clinical outcomes in a large prospective CLL trial cohort. Genetic Kdm1a knockdown in Eµ-TCL1A mice reduced leukemic burden and prolonged animal survival, accompanied by upregulated p53 and proapoptotic pathways. Genetic KDM1A depletion also affected milieu components (T, stromal, and monocytic cells), resulting in significant reductions in their capacity to support CLL-cell survival and proliferation. Integrated analyses of differential global transcriptomes (RNA sequencing) and H3K4me3 marks (chromatin immunoprecipitation sequencing) in Eµ-TCL1A vs iKdm1aKD;Eµ-TCL1A mice (confirmed in human CLL) implicate KDM1A as an oncogenic transcriptional repressor in CLL which alters histone methylation patterns with pronounced effects on defined cell death and motility pathways. Finally, pharmacologic KDM1A inhibition altered H3K4/9 target methylation and revealed marked anti-B-cell leukemic synergisms. Overall, we established the pathogenic role and effector networks of KDM1A in CLL via tumor-cell intrinsic mechanisms and its impacts in cells of the microenvironment. Our data also provide rationales to further investigate therapeutic KDM1A targeting in CLL.

High karyotypic complexity is an independent prognostic factor in patients with CLL treated with venetoclax combinations.

Complex karyotypes have been associated with inferior outcomes in chronic lymphocytic leukemia (CLL) treated with chemoimmunotherapy (CIT), whereas their prognostic impact in the context of venetoclax-based treatments is still debated. In this prospective analysis on karyotype complexity in CLL, we evaluated the impact of complex (≥3 chromosomal aberrations [CAs], CKTs) and highly complex karyotypes (≥5 CAs; hCKTs) as well as specific aberrations in previously untreated patients without TP53 aberrations undergoing either CIT or time-limited venetoclax-based therapies in the phase 3 GAIA/CLL13 trial. Karyotype analyses were available for 895 of 926 patients (96.7%), of whom 153 (17%) had a CKT and 43 (5%) hCKT. In the CIT arm, CKT was associated with shorter progression-free survival (PFS) (hazard ratio [HR] 2.58; 95% confidence interval [95% CI], 1.54-4.32; P < .001) and overall survival (HR, 3.25; 95% CI, 1.03-10.26; P = .044). In the pooled venetoclax arms, a multivariable analysis identified hCKTs (HR, 1.96; 95% CI, 1.03-3.72; P = .041), but not CKTs, as independent adverse prognosticators for PFS. The presence of translocations (unbalanced and/or balanced) was also independently associated with shorter PFSs in the venetoclax arms. CIT led to the acquisition of additional CAs (mean CAs, 2.0-3.4; from baseline to CLL progression), whereas karyotype complexity remained stable after venetoclax-based treatments (2.0, both time points). This analysis establishes highly complex karyotypes and translocations as adverse prognostic factors in the context of venetoclax-based combination treatments. The findings of this study support the incorporation of karyotyping into the standard diagnostic workup of CLL, because it identifies patients at high risk of poor treatment outcomes and thereby improves prognostication. This trial was registered at www.clinicaltrials.gov as #NCT02950051.

First-line venetoclax combinations versus chemoimmunotherapy in fit patients with chronic lymphocytic leukaemia (GAIA/CLL13): 4-year follow-up from a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: In the primary analysis report of the GAIA/CLL13 trial, we found that venetoclax-obinutuzumab and venetoclax-obinutuzumab-ibrutinib improved undetectable measurable residual disease (MRD) rates and progression-free survival compared with chemoimmunotherapy in patients with previously untreated chronic lymphocytic leukaemia. However, to our knowledge, no data on direct comparisons of different venetoclax-based combinations are available. METHODS: GAIA/CLL13 is an open-label, randomised, phase 3 study conducted at 159 sites in ten countries in Europe and the Middle East. Eligible patients were aged 18 years or older, with a life expectancy of at least 6 months, an Eastern Cooperative Oncology group performance status of 0-2, a cumulative illness rating scale score of 6 or lower or a single score of 4 or lower, and no TP53 aberrations. Patients were randomly assigned (1:1:1:1), with a computer-generated list stratified by age, Binet stage, and regional study group, to either chemoimmunotherapy, venetoclax-rituximab, venetoclax-obinutuzumab, or venetoclax-obinutuzumab-ibrutinib. All treatments were administered in 28-day cycles. Patients in the chemoimmunotherapy group received six cycles of treatment, with patients older than 65 years receiving intravenous bendamustine (90 mg/m2, days 1-2), whereas patients aged 65 years or younger received intravenous fludarabine (25 mg/m2, days 1-3) and intravenous cyclophosphamide (250 mg/m2, days 1-3). Intravenous rituximab (375 mg/m2, day 1 of cycle 1; 500 mg/m2, day 1 of cycles 2-6) was added to chemotherapy. In the experimental groups, patients received daily venetoclax (400 mg orally) for ten cycles after a 5-week ramp-up phase starting on day 22 of cycle 1. In the venetoclax-rituximab group, intravenous rituximab (375 mg/m2, day 1 of cycle 1; 500 mg/m2, day 1 of cycles 2-6) was added. In the obinutuzumab-containing groups, obinutuzumab was added (cycle 1: 100 mg on day 1, 900 mg on day 2, and 1000 mg on days 8 and 15; cycles 2-6: 1000 mg on day 1). In the venetoclax-obinutuzumab-ibrutinib group, daily ibrutinib (420 mg orally, from day 1 of cycle 1) was added until undetectable MRD was reached in two consecutive measurements (3 months apart) or until cycle 36. The planned treatment duration was six cycles in the chemoimmunotherapy group, 12 cycles in the venetoclax-rituximab and the venetoclax-obinutuzumab group and between 12 and 36 cycles in the venetoclax-obinutuzumab-ibrutinib group. Coprimary endpoints were the undetectable MRD rate in peripheral blood at month 15 for the comparison of venetoclax-obinutuzumab versus standard chemoimmunotherapy and investigator-assessed progression-free survival for the comparison of venetoclax-obinutuzumab-ibrutinib versus standard chemoimmunotherapy, both analysed in the intention-to-treat population (ie, all patients randomly assigned to treatment) with a split α of 0·025 for each coprimary endpoint. Both coprimary endpoints have been reported elsewhere. Here we report a post-hoc exploratory analysis of updated progression-free survival results after a 4-year follow-up of our study population. Safety analyses included all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT02950051, recruitment is complete, and all patients are off study treatment. FINDINGS: Between Dec 13, 2016, and Oct 13, 2019, 1080 patients were screened and 926 were randomly assigned to treatment (chemoimmunotherapy group n=229; venetoclax-rituximab group n=237; venetoclax-obinutuzumab group n=229; and venetoclax-obinutuzumab-ibrutinib group n=231); mean age 60·8 years (SD 10·2), 259 (28%) of 926 patients were female, and 667 (72%) were male (data on race and ethnicity are not reported). At data cutoff for this exploratory follow-up analysis (Jan 31, 2023; median follow-up 50·7 months [IQR 44·6-57·9]), patients in the venetoclax-obinutuzumab group had significantly longer progression-free survival than those in the chemoimmunotherapy group (hazard ratio [HR] 0·47 [97·5% CI 0·32-0·69], p<0·0001) and the venetoclax-rituximab group (0·57 [0·38-0·84], p=0·0011). The venetoclax-obinutuzumab-ibrutinib group also had a significantly longer progression-free survival than the chemoimmunotherapy group (0·30 [0·19-0·47]; p<0·0001) and the venetoclax-rituximab group (0·38 [0·24-0·59]; p<0·0001). There was no difference in progression-free survival between the venetoclax-obinutuzumab-ibrutinib and venetoclax-obinutuzumab groups (0·63 [0·39-1·02]; p=0·031), and the proportional hazards assumption was not met for the comparison between the venetoclax-rituximab group versus the chemoimmunotherapy group (log-rank p=0·10). The estimated 4-year progression-free survival rate was 85·5% (97·5% CI 79·9-91·1; 37 [16%] events) in the venetoclax-obinutuzumab-ibrutinib group, 81·8% (75·8-87·8; 55 [24%] events) in the venetoclax-obinutuzumab group, 70·1% (63·0-77·3; 84 [35%] events) in the venetoclax-rituximab group, and 62·0% (54·4-69·7; 90 [39%] events) in the chemoimmunotherapy group. The most common grade 3 or worse treatment-related adverse event was neutropenia (114 [53%] of 216 patients in the chemoimmunotherapy group, 109 [46%] of 237 in the venetoclax-rituximab group, 127 [56%] of 228 in the venetoclax-obinutuzumab group, and 112 [48%] of 231 in the venetoclax-obinutuzumab-ibrutinib group). Deaths determined to be associated with study treatment by the investigator occurred in three (1%) patients in the chemoimmunotherapy group (n=1 due to each of sepsis, metastatic squamous cell carcinoma, and Richter's syndrome), none in the venetoclax-rituximab and venetoclax-obinutuzumab groups, and four (2%) in the venetoclax-obinutuzumab-ibrutinib group (n=1 due to each of acute myeloid leukaemia, fungal encephalitis, small-cell lung cancer, and toxic leukoencephalopathy). INTERPRETATION: With more than 4 years of follow-up, venetoclax-obinutuzumab and venetoclax-obinutuzumab-ibrutinib significantly extended progression-free survival compared with both chemoimmunotherapy and venetoclax-rituximab in previously untreated, fit patients with chronic lymphocytic leukaemia, thereby supporting their use and further evaluation in this patient group, while still considering the higher toxicities observed with the triple combination. FUNDING: AbbVie, Janssen, and F Hoffmann-La Roche.

Obinutuzumab (GA-101), ibrutinib, and venetoclax (GIVe) frontline treatment for high-risk chronic lymphocytic leukemia.

Despite considerable treatment advances with targeted therapies for patients with chronic lymphocytic leukemia (CLL) deemed high-risk [del(17p) and/or TP53 mutation], the outcome is still inferior compared with other CLL patients. Combining multiple agents with distinct mechanisms of action may further improve outcomes. CLL2-GIVe is an open-label, multicenter trial which enrolled patients with previously untreated CLL with del(17p) and/or TP53 mutation. Patients received induction therapy with obinutuzumab (GA-101), ibrutinib, and venetoclax (GIVe) for cycles 1 through 6 and consolidation therapy with venetoclax and ibrutinib for cycles 7 through 12. Ibrutinib monotherapy was continued for cycles 13 through 36 in patients not reaching a complete response (CR) with serial undetectable minimal residual disease (uMRD) after consolidation. The primary endpoint was CR rate at cycle 15 (final restaging). Secondary endpoints included MRD, survival, and safety. All 41 patients enrolled between September 2016 and August 2018 received study treatment and were included in efficacy and safety populations. With a CR rate of 58.5% at cycle 15, the primary endpoint was met (95% CI: 42.1-73.7; P < .001). At final restaging, 78.0% of patients had uMRD in peripheral blood (PB); 65.9% of patients had uMRD in bone marrow (BM). Estimated progression-free survival (PFS) and overall survival (OS) rates at 24 months were both 95.1%. Adverse events were reported in all patients; most were low grade (grade ≥3: 23.9%). Two deaths were reported (cardiac failure and ovarian carcinoma), neither related to study treatment. The CLL2-GIVe treatment regimen has a manageable safety profile and is a first-line treatment of good efficacy for patients with high-risk CLL.

The CLL12 trial: ibrutinib vs placebo in treatment-naïve, early-stage chronic lymphocytic leukemia.

Observation is the current standard of care for patients with early-stage asymptomatic chronic lymphocytic leukemia (CLL), as chemotherapy-based interventions have failed to prolong survival. We hypothesized that early intervention with ibrutinib would be well tolerated and lead to superior disease control in a subgroup of early-stage patients with CLL. The phase 3, double-blind, placebo-controlled CLL12 trial randomly assigned asymptomatic, treatment-naïve Binet stage A CLL patients at increased risk of progression in a 1:1 ratio to receive ibrutinib (n = 182) or placebo (n = 181) at a dose of 420 mg daily. At a median follow-up of 31 months, the study met its primary endpoint by significantly improving event-free survival in the ibrutinib group (median, not reached vs 47.8 months; hazard ratio = 0.25; 95% confidence interval = 0.14-0.43, P < .0001). Compared with placebo, ibrutinib did not increase overall toxicity, yielding similar incidence and severity of adverse events (AEs). The most common serious AEs were atrial fibrillation, pneumonia, and rash in the ibrutinib group, and basal cell carcinoma, pneumonia, and myocardial infarction in the placebo group. Ibrutinib-associated risk for bleeding (33.5%) was decreased by prohibiting the use of oral anticoagulants through an amendment of the study protocol and by avoiding CYP3A4 drug-drug interactions. Ibrutinib confirms efficacy in CLL patients at an early stage with an increased risk of progression. However, the results do not justify changing the current standard of "watch and wait." This trial was registered at www.clinicaltrials.gov as #NCT02863718.

Fludarabine, cyclophosphamide, and rituximab as first-line treatment in patients with chronic lymphocytic leukemia: A long-term analysis of the German CLL Study Group (GCLLSG) registry.

Long-term data of chronic lymphocytic leukemia (CLL) patients with favorable risk who were treated with fludarabine, cyclophosphamide, and rituximab (FCR) within clinical trials show good efficacy. We here report long-term data collected within the GCLLSG registry. Altogether, 417 CLL patients who received first-line treatment with FCR were analyzed, of which 293 (70.3%) were treated outside of clinical trials. The median observation time from first-line was 95.8 (interquartile range 58.7-126.8) months. Focusing on data of 194 (46.5%) patients who received FCR first-line treatment after 2013 (start of data collection within GCLLSG registry), responses were documented in 85% of the patients, non-responses in 15%, and for 3.6% the assessment was missing. Median event-free survival (EFS, time until disease progression, subsequent treatment, or death) was 60.2 months with a 5-year EFS-rate of 50.6%. Patients with higher-risk disease, characterized by unmutated IGHV (N = 78), had a median EFS of 45.4 months with a 5-year EFS rate of 36.3%, while the median EFS was 77.5 months with a 5-year EFS rate of 60.3% in patients with mutated IGHV (N = 40). Median overall survival was not reached with a 5-year survival rate of 92.7%. In summary, first-line FCR was associated with long EFS, especially in patients exhibiting a mutated IGHV status.

Hybrid immunity to SARS-CoV-2 in patients with chronic lymphocytic leukemia.

OBJECTIVE: Preventing severe COVID-19 remains a priority globally, particularly in the immunocompromised population. As shown in healthy individuals, immunity against SARS-CoV-2 can be yielded by previous infection, vaccination, or both (hybrid immunity). The objective of this observation study was to investigate hybrid immunity in patients with chronic lymphocytic leukemia (CLL). METHODS/RESULTS: Blood samples of six patients with CLL were collected 55 days after fourth COVID-19 vaccination. All patients had a SARS-CoV-2 infection within 12 months before the second booster (fourth vaccination). SARS-CoV-2 spike receptor binding domain (RBD)-specific IgG antibodies were detectable in 6/6 (100.0%) CLL patients after four compared to 4/6 (66.7%) after three vaccinations. The median number of SARS-CoV-2 spike-specific T cells after repeated booster vaccination plus infection was 166 spot-forming cells (SFC) per million peripheral blood mononuclear cells. Overall, 5/5 (100%) studied patients showed a detectable increase in T cell activity. CONCLUSION: Our data reveal an increase of cellular and humoral immune response in CLL patients after fourth COVID-19 vaccination combined with SARS-CoV-2 infection, even in those undergoing B cell-depleting treatment. Patients with prior vaccination failure now show a specific IgG response. Future research should explore the duration and effectiveness of hybrid immunity considering various factors like past infection and vaccination rates, types and numbers of doses, and emerging variants.

Durable remissions following combined targeted therapy in patients with CLL harboring TP53 deletions and/or mutations.

Fifty-one of 189 evaluable patients from 3 prospective phase 2 trials evaluating a sequential targeted treatment had high-risk chronic lymphocytic leukemia (CLL) with a 17p deletion, TP53 mutation, or both. Twenty-seven patients started treatment with bendamustine debulking before induction and maintenance treatment, which was ibrutinib/ofatumumab (IO) in 21 patients, ibrutinib/obinutuzumab (IG) in 13, and venetoclax/obinutuzumab (AG) in 17. The primary end point was overall response rate after 8 months of induction treatment, which was 81%, 100%, and 94% for IO, IG, and AG, respectively. Minimal residual disease (MRD) was undetectable (uMRD) in peripheral blood (<10-4 by flow cytometry) in 0%, 23%, and 82% of patients, respectively. Median progression-free survival (PFS) was 45 months. Seventeen patients discontinued maintenance treatment due to uMRD: 9 progressed, 2 died without progression (median PFS, 28 months after discontinuation of treatment), and 6 remained in remission after a median observation time of 46 months (range, 6-47 months) after treatment discontinuation. Thus, MRD-guided fixed-duration therapies combining obinutuzumab with venetoclax or ibrutinib can induce deep and durable remissions in CLL patients with high-risk genetic lesions, which can persist after treatment discontinuation (due to a predefined fixed-duration or MRD-guided early termination). The median PFS was 45 months. These trials were registered at www.clinicaltrials.gov as #NCT02345863, #NCT02401503, and #NCT02689141.

MARCKS affects cell motility and response to BTK inhibitors in CLL.

Bruton tyrosine kinase (BTK) inhibitors are highly active drugs for the treatment of chronic lymphocytic leukemia (CLL). To understand the response to BTK inhibitors on a molecular level, we performed (phospho)proteomic analyses under ibrutinib treatment. We identified 3466 proteins and 9184 phosphopeptides (representing 2854 proteins) in CLL cells exhibiting a physiological ratio of phosphorylated serines (pS), threonines (pT), and tyrosines (pY) (pS:pT:pY). Expression of 83 proteins differed between unmutated immunoglobulin heavy-chain variable region (IGHV) CLL (UM-CLL) and mutated IGHV CLL (M-CLL). Strikingly, UM-CLL cells showed higher basal phosphorylation levels than M-CLL samples. Effects of ibrutinib on protein phosphorylation levels were stronger in UM-CLL, especially on phosphorylated tyrosines. The differentially regulated phosphopeptides and proteins clustered in pathways regulating cell migration, motility, cytoskeleton composition, and survival. One protein, myristoylated alanine-rich C-kinase substrate (MARCKS), showed striking differences in expression and phosphorylation level in UM-CLL vs M-CLL. MARCKS sequesters phosphatidylinositol-4,5-bisphosphate, thereby affecting central signaling pathways and clustering of the B-cell receptor (BCR). Genetically induced loss of MARCKS significantly increased AKT signaling and migratory capacity. CD40L stimulation increased expression of MARCKS. BCR stimulation induced phosphorylation of MARCKS, which was reduced by BTK inhibitors. In line with our in vitro findings, low MARCKS expression is associated with significantly higher treatment-induced leukocytosis and more pronounced decrease of nodal disease in patients with CLL treated with acalabrutinib.

Treatment with idelalisib in patients with chronic lymphocytic leukemia - real world data from the registry of the German CLL Study Group.

Idelalisib in combination with rituximab is an efficacious treatment for patients suffering from chronic lymphocytic leukemia (CLL) with known limitations due to toxicities. However, the benefit after prior Bruton tyrosine kinase inhibitor (BTKi) therapy remains unclear. For this analysis, 81 patients included in a non-interventional registry study of the German CLL study group (registered at www.clinicaltrials.gov as # NCT02863692) meeting the predefined criteria of a confirmed diagnosis of CLL and being treated with idelalisib containing regimens outside clinical trials were considered. 11 patients were treatment naïve (13.6%) and 70 patients (86.4%) pretreated. Patients had median of one prior therapy line (range 0-11). Median treatment duration with idelalisib was 5.1 months (range 0-55.0 months). Of 58 patients with documented treatment outcome, 39 responded to idelalisib containing therapy (67.2%). Patients treated with the BTKi ibrutinib as last prior treatment prior to idelalisib responded in 71.4% compared to a response rate of 61.9% in patients without prior ibrutinib. Median event free survival (EFS) was 15.9 months with a 16 versus 14 months EFS in patients with ibrutinib as last prior treatment or not, respectively. Median overall survival was 46.6 months. In conclusion, treatment with idelalisib appears to have a valuable impact in patients being refractory to prior ibrutinib therapy even though there are limitations in our analysis due to the low number of patients included.

Venetoclax and Obinutuzumab in Patients with CLL and Coexisting Conditions.

BACKGROUND: The BCL2 inhibitor venetoclax has shown activity in patients with chronic lymphocytic leukemia (CLL), but its efficacy in combination with other agents in patients with CLL and coexisting conditions is not known. METHODS: In this open-label, phase 3 trial, we investigated fixed-duration treatment with venetoclax and obinutuzumab in patients with previously untreated CLL and coexisting conditions. Patients with a score of greater than 6 on the Cumulative Illness Rating Scale (scores range from 0 to 56, with higher scores indicating more impaired function of organ systems) or a calculated creatinine clearance of less than 70 ml per minute were randomly assigned to receive venetoclax-obinutuzumab or chlorambucil-obinutuzumab. The primary end point was investigator-assessed progression-free survival. The safety of each regimen was also evaluated. RESULTS: In total, 432 patients (median age, 72 years; median Cumulative Illness Rating Scale score, 8; median creatinine clearance, 66.4 ml per minute) underwent randomization, with 216 assigned to each group. After a median follow-up of 28.1 months, 30 primary end-point events (disease progression or death) had occurred in the venetoclax-obinutuzumab group and 77 had occurred in the chlorambucil-obinutuzumab group (hazard ratio, 0.35; 95% confidence interval [CI], 0.23 to 0.53; P<0.001). The Kaplan-Meier estimate of the percentage of patients with progression-free survival at 24 months was significantly higher in the venetoclax-obinutuzumab group than in the chlorambucil-obinutuzumab group: 88.2% (95% CI, 83.7 to 92.6) as compared with 64.1% (95% CI, 57.4 to 70.8). This benefit was also observed in patients with TP53 deletion, mutation, or both and in patients with unmutated immunoglobulin heavy-chain genes. Grade 3 or 4 neutropenia occurred in 52.8% of patients in the venetoclax-obinutuzumab group and in 48.1% of patients in the chlorambucil-obinutuzumab group, and grade 3 or 4 infections occurred in 17.5% and 15.0%, respectively. All-cause mortality was 9.3% in the venetoclax-obinutuzumab group and 7.9% in the chlorambucil-obinutuzumab group. These differences were not significant. CONCLUSIONS: Among patients with untreated CLL and coexisting conditions, venetoclax-obinutuzumab was associated with longer progression-free survival than chlorambucil-obinutuzumab. (Funded by F. Hoffmann-La Roche and AbbVie; ClinicalTrials.gov number, NCT02242942.).

Prognostic and predictive impact of genetic markers in patients with CLL treated with obinutuzumab and venetoclax.

Genetic parameters are established prognostic factors in chronic lymphocytic leukemia (CLL) treated with chemoimmunotherapy, but are less well studied with novel compounds. We assessed immunoglobulin heavy variable chain (IGHV) mutation status, common genomic aberrations, and gene mutations in 421 untreated patients within the CLL14 trial (NCT02242942), comparing obinutuzumab+chlorambucil (GClb) vs obinutuzumab+venetoclax (VenG). The incidences of genomic aberrations considering the hierarchical model were del(17p) 7%, del(11q) 18%, +12 18%, and del(13q) 35%, whereas IGHV was unmutated in 60% of patients. NOTCH1 mutations were most common (23%), followed by SF3B1 (16%), ATM (13%), and TP53 (10%). Although the overall response rate (ORR) for GClb was lower in patients with del(17p), del(11q), mutated TP53, ATM, and BIRC3, none of these parameters reduced complete remission (CR) rate and ORR with VenG. At a median follow-up of 28 months, del(17p) and mutated TP53 were the only abnormalities with an effect on progression-free survival (PFS) for both treatment groups: GClb (hazard ratio [HR], 4.6 [P < .01]; HR, 2.7 [P < .01], respectively) and VenG (HR, 4.4 [P < .01]; HR, 3.1 [P < .01], respectively). No other factors affected outcome with VenG, whereas for GClb del(11q), BIRC3, NOTCH1, and unmutated IGHV were associated with shorter PFS. Multivariable analysis identified del(17p), del(11q), unmutated IGHV, and mutated TP53, BIRC3, and SF3B1 as independent prognostic factors for PFS with GClb, whereas for VenG, only del(17p) was significant. VenG was superior to GClb across most genetic subgroups. Patients with adverse genetic markers had the strongest benefit from VenG, particularly subjects with unmutated IGHV, which was identified as a predictive factor in a multivariable treatment-interaction analysis.

Integrative prognostic models predict long-term survival after immunochemotherapy in chronic lymphocytic leukemia patients.

Chemoimmunotherapy with fludarabine, cyclophosphamide and rituximab (FCR) can induce long-term remissions in patients with chronic lymphocytic leukemia. Treatment efficacy with Bruton's tyrosine kinase inhibitors was found similar to FCR in untreated chronic lymphocytic leukemia patients with a mutated immunoglobulin heavy chain variable (IGHV) gene. In order to identify patients who specifically benefit from FCR, we developed integrative models including established prognostic parameters and gene expression profiling (GEP). GEP was conducted on n=337 CLL8 trial samples, "core" probe sets were summarized on gene levels and RMA normalized. Prognostic models were built using penalized Cox proportional hazards models with the smoothly clipped absolute deviation penalty. We identified a prognostic signature of less than a dozen genes, which substituted for established prognostic factors, including TP53 and IGHV gene mutation status. Independent prognostic impact was confirmed for treatment, ß2-microglobulin and del(17p) regarding overall survival and for treatment, del(11q), del(17p) and SF3B1 mutation for progression-free survival. The combination of independent prognostic and GEP variables performed equal to models including only established non-GEP variables. GEP variables showed higher prognostic accuracy for patients with long progression-free survival compared to categorical variables like the IGHV gene mutation status and reliably predicted overall survival in CLL8 and an independent cohort. GEP-based prognostic models can help to identify patients who specifically benefit from FCR treatment. The CLL8 trial is registered under EUDRACT-2004- 004938-14 and clinicaltrials gov. Identifier: NCT00281918.

Bendamustine, followed by ofatumumab and ibrutinib in chronic lymphocytic leukemia (CLL2-BIO): primary endpoint analysis of a multicenter, open-label phase-II trial.

The introduction of targeted agents has revolutionized the treatment of chronic lymphocytic leukemia but only few patients achieve complete remissions and minimal residual disease negativity with ibrutinib monotherapy. This multicenter, investigator-initiated phase-II study evaluates a sequential treatment with two cycles of bendamustine debulking for patients with a higher tumor load, followed by ofatumumab and ibrutinib induction and maintenance treatment. An all-comer population, irrespective of prior treatment, physical fitness and genetic factors was included. The primary endpoint was the investigator assessed overall response rate at the end of induction treatment. Of 66 patients enrolled, one patient with early treatment discontinuation was excluded from the efficacy analysis as predefined by the protocol. Thirty-nine patients (60%) were treatment-naive and 26 patients (40%) had relapsed/refractory CLL, 21 patients (32%) had a del(17p) and/or TP53 mutation and 45 patients (69%) had an unmutated IGHV status. At the end of the induction, 60 of 65 patients (92%) responded and 9 (14%) achieved minimal residual disease negativity (<10-4) in peripheral blood. No unexpected or cumulative toxicities occurred, most common CTC °III/IV adverse events were neutropenias, anaemia, infusion-related reactions, and diarrhoea. This sequential treatment of bendamustine debulking, followed by ofatumumab and ibrutinib was well tolerated without unexpected safety signals and showed a good efficacy with an overall response rate of 92%. Ongoing maintenance treatment aims at deeper responses with minimal residual disease negativity. However, ibrutinib should still be used as a single agent outside clinical trials. Clinicaltrials.gov number: NCT02689141.