Guidelines for the diagnosis and treatment of chronic lymphocytic leukemia: a report from the International Workshop on Chronic Lymphocytic Leukemia updating the National Cancer Institute-Working Group 1996 guidelines

IgG testing, immunoglobulin replacement therapy, and infection outcomes in patients with CLL or NHL: real-world evidence

ABSTRACT

Patients with chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL) can develop hypogammaglobulinemia, a form of secondary immune deficiency (SID), from the disease and treatments. Patients with hypogammaglobulinemia with recurrent infections may benefit from immunoglobulin replacement therapy (IgRT). This study evaluated patterns of immunoglobulin G (IgG) testing and the effectiveness of IgRT in real-world patients with CLL or NHL. A retrospective, longitudinal study was conducted among adult patients diagnosed with CLL or NHL. Clinical data from the Massachusetts General Brigham Research Patient Data Registry were used. IgG testing, infections, and antimicrobial use were compared before vs 3, 6, and 12 months after IgRT initiation. Generalized estimating equation logistic regression models were used to estimate odds ratios, 95% confidence intervals, and P values. The study population included 17 192 patients (CLL: n = 3960; median age, 68 years; NHL: n = 13 232; median age, 64 years). In the CLL and NHL cohorts, 67% and 51.2% had IgG testing, and 6.5% and 4.7% received IgRT, respectively. After IgRT initiation, the proportion of patients with hypogammaglobulinemia, the odds of infections or severe infections, and associated antimicrobial use, decreased significantly. Increased frequency of IgG testing was associated with a significantly lower likelihood of severe infection. In conclusion, in real-world patients with CLL or NHL, IgRT was associated with significant reductions in hypogammaglobulinemia, infections, severe infections, and associated antimicrobials. Optimizing IgG testing and IgRT are warranted for the comprehensive management of SID in patients with CLL or NHL.

Blinatumomab after R-CHOP bridging therapy for patients with Richter transformation: a phase 2 multicentre trial

Richter transformation (RT) is an aggressive lymphoma occurring in patients with chronic lymphocytic leukaemia. Here we investigated the anti-CD3/anti-CD19 T-cell-engager blinatumomab after R-CHOP (i.e. rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) in patients with untreated RT of diffuse large B-cell lymphoma histology (NCT03931642). In this multicentre phase 2 study, patients without complete response (CR) after two cycles of R-CHOP were eligible to receive an 8-week blinatumomab induction via continuous vein infusion with stepwise dosing until 112 μg/day. The primary endpoint was the CR rate after blinatumomab induction and secondary endpoint included safety, response duration, progression-free and overall survival. Thirty-nine patients started the first cycle of R-CHOP, 25 of whom received blinatumomab. After blinatumomab induction, five (20%) patients achieved CR, four (16%) achieved partial response, and six (24%) were stable. Considering the entire strategy, the overall response rate in the full-analysis-set was 46% (n = 18), with CR in 14 (36%) patients. The most common treatment-emergent adverse events of all grades in the blinatumomab-safety-set included fever (36%), anaemia (24%), and lymphopaenia (24%). Cytokine release syndrome (grade 1/2) was observed in 16% and neurotoxicity in 20% of patients. Blinatumomab demonstrated encouraging anti-tumour activity (the trial met its primary endpoint) and acceptable toxicity in patients with RT.

Unmutated IGHV at diagnosis in patients with early stage CLL independently predicts for shorter follow-up time to first treatment (TTFT)

The mutational status of the IGHV gene is routinely assessed in patients with chronic lymphocytic leukaemia (CLL), since it is both prognostic of clinical outcome and predictive of response to treatment. This study evaluates the IGHV mutational status, assessed in newly diagnosed CLL patients, as a stand-alone predictor of time to first treatment (TTFT). We analysed the data of 236 CLL patients, diagnosed at our centre between January 2004 and September 2020, with a minimum follow-up period of 3.0 years, Binet A-B and Rai 0-II stages. IGHV was unmutated in 38.1 % and mutated in 61.9 % of cases. The univariate analysis showed a statistically significant difference (p < 0.001) in TTFT based on unmutated (85.2 % at 14 years, 95 % CI = 63.3-94.5 %) or mutated (41.3 % at 14 years, 95 % CI = 29.5-51.8 %) and the need for treatment at 1, 3 and 5 years was of 20.0 % vs 4.1 % (p < 0.001), 42.7 % vs 11.4 % (p < 0.001) and 55.8 % vs 20.0 % (p < 0.001) in unmutated and mutated IGHV patients, respectively. Multivariate analysis confirmed that unmutated IGHV status negatively affects TTFT (p < 0.001), in addition to high-risk genomic aberration (p = 0.025), Rai stage I (p = 0.007) and II (p-value < 0.001). The difference in TTFT based on unmutated or mutated IGHV status remains statistically significant also when considering the subgroups by the genomic aberrations and Rai stages. Our findings suggest that, with the single analysis of the IGHV mutational status at CLL diagnosis, along with clinical and laboratory data, and without karyotype and TP53 data, clinicians will have prognostic and predictive indications for the first clinical treatment and appropriate follow-up of patients.

Acalabrutinib-based regimens in frontline or relapsed/refractory higher-risk CLL: pooled analysis of 5 clinical trials

ABSTRACT

Before targeted therapies, patients with higher-risk chronic lymphocytic leukemia (CLL), defined as del(17p) and/or TP53 mutation (TP53m), unmutated immunoglobulin heavy chain variable region genes (uIGHV), or complex karyotype (CK), had poorer prognosis with chemoimmunotherapy. Bruton tyrosine kinase inhibitors (BTKis) have demonstrated benefit in higher-risk patient populations with CLL in individual trials. To better understand the impact of the second-generation BTKi acalabrutinib, we pooled data from 5 prospective clinical studies of acalabrutinib as monotherapy or in combination with obinutuzumab (ACE-CL-001, ACE-CL-003, ELEVATE-TN, ELEVATE-RR, and ASCEND) in patients with higher-risk CLL in treatment-naive (TN) or relapsed/refractory (R/R) cohorts. A total of 808 patients were included (TN cohort, n = 320; R/R cohort, n = 488). Median follow-up was 59.1 months (TN cohort) and 44.3 months (R/R cohort); 51.3% and 26.8% of patients in the TN and R/R cohorts, respectively, remained on treatment at last follow-up. In the del(17p)/TP53m, uIGHV, and CK subgroups in the TN cohort, median progression-free survival (PFS) and median overall survival (OS) were not reached (NR). In the del(17p)/TP53m, uIGHV, and CK subgroups in the R/R cohort, median PFS was 38.6 months, 46.9 months, and 38.6 months, respectively, and median OS was 60.6 months, NR, and NR, respectively. The safety profile of acalabrutinib-based therapy in this population was consistent with the known safety profile of acalabrutinib in a broad CLL population. Our analysis demonstrates long-term benefit of acalabrutinib-based regimens in patients with higher-risk CLL, regardless of line of therapy.

Ibrutinib followed by ofatumumab consolidation in previously untreated patients with chronic lymphocytic leukemia (CLL): GELLC-7 trial from the Spanish group of CLL (GELLC)

Background

BTK inhibitors have been concurrently administered with anti-CD20 monoclonal antibodies (mAbs) in chronic lymphocytic leukemia (CLL). However, the optimal regimen for combining these two drugs remains pending.

Methods

This multi-center phase 2 study aimed to analyze whether consolidation with ofatumumab improved the response in patients with CLL receiving front-line treatment with ibrutinib. Patients received 12 cycles of ibrutinib monotherapy. Those who achieved CR after this induction were maintained on ibrutinib. Conversely, those who did not attain CR continued with ibrutinib in addition to a consolidation, which involved 7 doses of ofatumumab. The primary objective was the complete response (CR) rate at cycle 20. This study is registered within the EU Clinical Trials Register (EudraCT 2016-004937-26).

Findings

Between September 8, 2017, and May 21, 2018, 84 patients (median age, 69 years) were included. After completion of 12 cycles of ibrutinib (n = 80), 4 patients (5%) were in CR, 67 (84%) in partial response (PR), and 6 patients (7%) had a PR with lymphocytosis (PRL). After consolidation with ofatumumab, 20 patients improved the response from PR to CR and 6 patients with PRL obtained a PR. Seventy-one patients (85%) completed 20 cycles of treatment, with a CR rate of 24/71 (34%). According to the intention-to-treat analysis at cycle 20, the ORR was 69/84 (82.2%), with a CRR of 24/84 (28.6%). Progression-free survival and overall survival at 48-months were 89.9% (CI: 82.4-95.5) and 92.2% (CI: 85.3-97.1), respectively.

Interpretation

These findings underscore the potential for a consolidation strategy in CLL, wherein the addition of a mAb in patients with low tumor burden might enhance the quality of the response.

Funding

The study was funded by Janssen that also supplied ibrutinib, whereas ofatumumab was supplied by Novartis.

Richter Syndrome Presenting as Subcutaneous Nodules and a Dermal Plaque

ABSTRACT

Richter syndrome (RS) describes a phenomenon in which a patient with chronic lymphocytic leukemia (CLL) develops an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL). Reports of cutaneous RS remain exceedingly rare. We report a 61-year-old woman with relapsed/refractory CLL presenting with several subcutaneous nodules on her arms and legs and a single dermal plaque on her abdomen. Skin biopsy revealed a diagnosis of DLBCL, ABC-type, and her clinical status rapidly deteriorated following diagnosis. We review the variety of clinical presentations of cutaneous RS, its association with CLL, risk factors for RS development in CLL patients, and the distinctive histopathologic and immunophenotypic features of DLBCL. We hope to highlight the importance of prompt skin biopsy in patients with CLL presenting with progressive skin lesions and increase awareness of this aggressive clinical syndrome.

RNA Sequencing Reveals Candidate Genes and Pathways Associated with Resistance to MDM2 Antagonist Idasanutlin in TP53 Wild-Type Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a genetically and clinically diverse hematological cancer affecting middle-aged and elderly individuals. Novel targeted therapy options are needed for patients who relapse following initial responses or who are intrinsically resistant to current treatments. There is a growing body of investigation currently underway on MDM2 inhibitors in clinical trials, reflecting the increasing interest in including these drugs in cancer treatment regimens. One of the developed compounds, idasanutlin (RG7388), has shown promise in early-stage clinical trials. It is a second-generation MDM2-p53-binding antagonist with enhanced potency, selectivity, and bioavailability. In addition to the TP53 status, which is an important determinant of the response, we have shown in our previous studies that the SF3B1 mutational status is also an independent predictive biomarker of the ex vivo CLL patient sample treatment response to RG7388. The objective of this study was to identify novel biomarkers associated with resistance to RG7388. Gene set enrichment analysis of differentially expressed genes (DEGs) between RG7388-sensitive and -resistant CLL samples showed that the increased p53 activity led to upregulation of pro-apoptosis pathway genes while DNA damage response pathway genes were additionally upregulated in resistant samples. Furthermore, differential expression of certain genes was detected, which could serve as the backbone for novel combination treatment approaches. This research provides preclinical data to guide the exploration of drug combination strategies with MDM2 inhibitors, leading to future clinical trials and associated biomarkers that may improve outcomes for CLL patients.

Improved efficacy and safety of zanubrutinib versus ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia (R/R CLL) in China: a subgroup of ALPINE

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) has different epidemiology in Chinese vs. Western patients, but there are few studies of CLL/SLL in large populations of Chinese patients. ALPINE is a global phase 3 trial investigating Bruton tyrosine kinase inhibitors zanubrutinib vs. ibrutinib to treat relapsed/refractory (R/R) CLL/SLL. Here we report results from the subgroup of Chinese patients. Adults with R/R CLL/SLL were randomized 1:1 to receive zanubrutinib (160 mg twice-daily) or ibrutinib (420 mg once-daily) until disease progression or unacceptable toxicity. Endpoints included overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety. Data were analyzed descriptively. Ninety patients were randomized in China (zanubrutinib, n = 47; ibrutinib, n = 43). Baseline characteristics were balanced between groups, with fewer male patients in the zanubrutinib vs. ibrutinib group (55.3% vs. 69.8%). Median age was 60.5 years, 11% had del(17p) mutation, and 32% had tumor protein 53 (TP53) mutation. With median 25.3 months follow-up, ORR was 80.9% with zanubrutinib vs. 72.1% with ibrutinib. PFS was improved with zanubrutinib vs. ibrutinib (HR = 0.34 [95% CI, 0.15, 0.77]), and the HR for OS was 0.45 (95% CI, 0.14, 1.50). Rates of Grade ≥ 3 treatment-emergent adverse events (TEAEs; 64.4% vs. 72.1%), AEs leading to discontinuation (6.4% vs. 14.0%), and serious TEAEs (35.6% vs. 51.2%) were lower with zanubrutinib vs. ibrutinib. Zanubrutinib demonstrated improved ORR, PFS, and OS vs. ibrutinib and a more favorable safety profile in patients with R/R CLL/SLL in China. These results are consistent with the full global population of ALPINE. ClinicalTrials.gov: NCT03734016, registered November 7, 2018.

Maintenance low-dose fixed duration lenalidomide and rituximab following bendamustine and rituximab induction in previously untreated chronic lymphocytic leukemia and small lymphocytic lymphoma

Lenalidomide (LEN) and rituximab (RTX) have independently improved progression-free survival (PFS) in CLL, leading to interest in use of LEN + RTX (R2) following induction chemoimmunotherapy. Patients with previously untreated CLL received bendamustine + RTX (BR) for 6 cycles, then 24 cycles of R2. LEN dosing was 5-10 mg daily; RTX was given odd cycles (12 doses). The primary endpoint is PFS; secondary endpoints are response and overall survival. Thirty-six patients enrolled, median age 64.5 years. Twenty-nine received R2; 12 completed a full course R2 (33.3%), 5 completed R2 with premature discontinuation of LEN. Dose reductions/holds were most often for neutropenia. Complete response was achieved in 33.3%. After median >4 years follow-up, 2-year and 3-year PFS were 86.1% and 69.4%. Five-year overall survival was 92.3%. R2 maintenance may improve PFS after BR induction, and a lower dose of 5 mg/day and ≤1 year of R2 may be most tolerable (NCT00974233).

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.

Unveiling the dynamics and molecular landscape of a rare chronic lymphocytic leukemia subpopulation driving refractoriness: insights from single-cell RNA sequencing

Early identification of resistant cancer cells is currently a major challenge, as their expansion leads to refractoriness. To capture the dynamics of these cells, we made a comprehensive analysis of disease progression and treatment response in a chronic lymphocytic leukemia (CLL) patient using a combination of single-cell and bulk genomic methods. At diagnosis, the patient presented with unfavorable genetic markers, including notch receptor 1 (NOTCH1) mutation and loss(11q). The initial and subsequent treatment lines did not lead to a durable response and the patient developed refractory disease. Refractory CLL cells featured substantial dysregulation in B-cell phenotypic markers such as human leukocyte antigen (HLA) genes, immunoglobulin (IG) genes, CD19 molecule (CD19), membrane spanning 4-domains A1 (MS4A1; previously known as CD20), CD79a molecule (CD79A) and paired box 5 (PAX5), indicating B-cell de-differentiation and disease transformation. We described the clonal evolution and characterized in detail two cell populations that emerged during the refractory disease phase, differing in the presence of high genomic complexity. In addition, we successfully tracked the cells with high genomic complexity back to the time before treatment, where they formed a rare subpopulation. We have confirmed that single-cell RNA sequencing enables the characterization of refractory cells and the monitoring of their development over time.

An overview of prognostic markers in patients with CLL

Chronic lymphocytic leukemia (CLL) is a low-grade B-cell lymphoproliferative disorder. It is the most prevalent type of leukemia in the western countries, with a median age at diagnosis of 70 years. In 2023, it is estimated that there will be 18,740 new cases of CLL, and an estimated 4,490 people will die of this disease. It represents 1.0% of all new cancer cases in the U.S. The rate of new cases was 4.6 per 100,000 men and women per year based on 2016-2020 cases, age-adjusted. Death rates from CLL are higher among older adults, or those 75 and older. The death rate was 1.1 per 100,000 men and women per year based on 2016-2020 deaths, age-adjusted. A common question that patients with CLL ask during their first clinic visit is: "How long will it be before I would need treatment?" Although this might seem like a simple question, the answer is not straight forward. CLL is a heterogenous disease, with a variable clinical course. Some patients may present with an aggressive disease requiring early initiation of treatment, while others have an indolent course and some, having so called smoldering CLL, may never need treatment. The variability in disease course can make predicting disease prognosis a complicated process. This brings forth the importance of establishing prognostic models that can predict disease course, time to treatment, and survival outcomes in such a heterogenous disease. The Rai and Binet staging systems were developed in the late 1970s to early 1980s. They separated patients into different stages based on clinical characteristics and laboratory findings. These simple staging systems are still in use; however, several prognostic markers need to be added for an individualized assessment and, with the recent development of genomic techniques leading to better understanding of CLL at the molecular level, newer prognostic markers have emerged.

The CIpP activator, TR-57, is highly effective as a single agent and in combination with venetoclax against CLL cells in vitro

Despite advances in treatment, a significant proportion of patients with chronic lymphocytic leukemia (CLL) will relapse with drug-resistant disease. The imipridones, ONC-201 and ONC-212, are effective against a range of different cancers, including acute myeloid leukemia (AML) and tumors of the brain, breast, and prostate. These drugs induce cell death through activation of the mitochondrial protease, caseinolytic protease (CIpP), and the unfolded protein response (UPR). Here we demonstrate that the novel imipridone analog, TR-57, has efficacy as a single agent and synergises with venetoclax against CLL cells under in vitro conditions that mimic the tumor microenvironment. Changes in protein expression suggest TR-57 activates the UPR, inhibits the AKT and ERK1/2 pathways and induces pro-apoptotic changes in the expression of proteins of the BCL-2 family. The study suggests that TR-57, as a single agent and in combination with venetoclax, may represent an effective treatment option for CLL.

Conditional survival to assess prognosis in patients with chronic lymphocytic leukemia

Biomarkers in chronic lymphocytic leukemia (CLL) allow assessment of prognosis. However, the validity of current prognostic biomarkers based on a single assessment point remains unclear for patients who have survived one or more years. Conditional survival (CS) studies that address how prognosis may change over time, especially in prognostic subgroups, are still rare. We performed CS analyses to estimate 5-year survival in 1-year increments, stratified by baseline disease characteristics and known risk factors in two community-based cohorts of CLL patients (Freiburg University Hospital (n = 316) and Augsburg University Hospital (n = 564)) diagnosed between 1984 and 2021. We demonstrate that 5-year CS probability is stable (app. 75%) for the entire CLL patient cohort over 10 years. While age, sex, and stage have no significant impact on CS, patients with high-risk disease features such as non-mutated IGHV, deletion 17p, and high-risk CLL-IPI have a significantly worse prognosis at diagnosis, and 5-year CS steadily decreases with each additional year survived. Our results confirm that CLL patients have a stable survival probability with excess mortality and that the prognosis of high-risk CLL patients declines over time. We infer that CS-based prognostic information is relevant for disease management and counseling of CLL patients.

Safety and long-term survival results of the addition of inotuzumab ozogamicin to the conditioning regimen of allogeneic stem cell transplantation: A single-center phase 1,2 trial

Here we report on the first prospective study evaluating the safety and long-term survival when an escalating dose of inotuzumab ozogamicin (INO) (0.6, 1.2, or 1.8 mg/m2 on day 13) was added to one alkylator-containing conditioning regimen in patients with relapsed CD22 (+) lymphoid malignancies who were candidates for hematopoietic stem cell transplantation (HSCT). Twenty-six patients were enrolled. Six (23%) of these patients entered the phase 1 study: four were treated at an INO dose of 0.6 mg/m2 and two at dose of 1.2 mg/m2. None of these patients experienced dose-limiting toxicities. The remaining 20 (77%) patients entered the phase 2 part of the study at the maximum dose of 1.8 mg/m2. One patient developed VOD; this patient had received nivolumab immediately before HSCT while simultaneously experiencing hyperacute graft-vs-host disease (GVHD). Treatment-related mortality (TRM) at 5 years was 12%. With a median follow-up of 48.7 months, the 5-year overall survival (OS) and progression-free survival (PFS) rates were 84% and 80%, respectively. Compared with a historical cohort who received same conditioning for HSCT but without INO (n = 56), the INO group showed no significant differences in incidence of liver toxicity, engraftment time, TRM, or risk of acute GVHD. Patients with lymphoma who received INO had a trend for a better 5-year OS (93% versus 68%) and PFS (93% versus 58%) than those in the control group. In conclusion, our results showed that INO is safe with no increased risk of VOD when combined with one alkylator-containing regimen of HSCT.

Placental circulating T cells: a novel, allogeneic CAR-T cell platform with preserved T-cell stemness, more favorable cytokine profile, and durable efficacy compared to adult PBMC-derived CAR-T

BACKGROUND

Chimeric antigen receptor (CAR)-T cell quality and stemness are associated with responsiveness, durability, and memory formation, which benefit clinical responses. Autologous T cell starting material across patients with cancer is variable and CAR-T expansion or potency can fail during manufacture. Thus, strategies to develop allogeneic CAR-T platforms including the identification and expansion of T cell subpopulations that correspond with CAR-T potency are an active area of investigation. Here, we compared CAR-T cells generated from healthy adult peripheral blood T cells versus placental circulating T (P-T) cells.

METHODS

CAR-T cells from healthy adult peripheral blood mononuclear cells (PBMCs) and P-T cells were generated using the same protocol. CAR-T cells were characterized in detail by a combination of multiparameter flow cytometry, functional assays, and RNA sequencing. In vivo antitumor efficacy and persistence of CAR-T cells were evaluated in a Daudi lymphoma xenograft model.

RESULTS

P-T cells possess stemness advantages compared with T cells from adult PBMCs. P-T cells are uniformly naïve prior to culture initiation, maintain longer telomeres, resist immune checkpoint upregulation, and resist further differentiation compared with PBMC T cells during CD19 CAR-T manufacture. P-T CD19 CAR-T cells are equally cytotoxic as PBMC-CD19 CAR-T cells but produce less interferon gamma in response to lymphoma. Transcriptome analysis shows P-T CD19 CAR-T cells retain a stem-like gene signature, strongly associate with naïve T cells, an early memory phenotype, and a unique CD4 T cell signature compared with PBMC-CD19 CAR-T cells, which enrich for exhaustion and stimulated memory T cell signatures. Consistent with functional data, P-T CD19 CAR-T cells exhibit attenuated inflammatory cytokine and chemokine gene signatures. In a murine in vivo model, P-T CD19 CAR-T cells eliminate lymphoma beyond 90 days. PBMC-CD19 CAR-T cells provide a non-durable benefit, which only delays disease onset.

CONCLUSION

We identified characteristics of T cell stemness enriched in P-T CD19 CAR-T which are deficient in PBMC-derived products and translate into response durability in vivo. Our findings demonstrate that placental circulating T cells are a valuable cell source for allogeneic CAR-T products. Stemness advantages inherent to P-T cells translate to in vivo persistence advantages and long-term durable activity.

Six-year follow-up and subgroup analyses of a phase 2 trial of venetoclax for del(17p) chronic lymphocytic leukemia

ABSTRACT

Chromosome 17p deletion (del[17p]) is associated with poor prognosis in patients with chronic lymphocytic leukemia (CLL). Venetoclax is approved for treatment of previously untreated and relapsed/refractory (R/R) CLL, including patients with del(17p), based on the open-label, multicenter, phase 2 M13-982 trial (NCT01889186). Here, we detail the 6-year follow-up analysis for M13-982. A total of 158 patients with previously untreated (n = 5) or R/R (n = 153) del(17p) CLL received 400 mg venetoclax daily after initial ramp-up until progressive disease. After a median follow-up of 70 months, the best objective response rate (ORR) was 77% (21% complete remission [CR] and 49% partial remission [PR]), with a median duration of response (DOR) of 39.3 months (95% confidence interval [CI], 31.1-50.5). The median progression-free survival (PFS) was 28.2 months (95% CI, 23.4-37.6), and median overall survival (OS) was 62.5 months (95% CI, 51.7-not reached), with 16% of patients remaining on treatment after 6 years. Multivariable analysis did not identify statistically significant correlation between patient subgroups defined by clinical or laboratory variables and ORR or PFS. The most common grade ≥3 adverse events were neutropenia (42%), infections (33%), anemia (16%), and thrombocytopenia (16%). Post hoc comparative analyses of PFS and OS from treatment initiation, from a 24-month landmark, and by minimal residual disease status were performed between patients with del(17p) in the M13-982 and MURANO studies in the interest of understanding these data in another context. These long-term data show the continued benefits of venetoclax in patients with del(17p) CLL. The trial was registered at www.clinicaltrials.gov as #NCT01889186.

Follow-up from the A041202 study shows continued efficacy of ibrutinib regimens for older adults with CLL

ABSTRACT

A041202 (NCT01886872) is a phase 3 study comparing bendamustine plus rituximab (BR) with ibrutinib and the combination of ibrutinib plus rituximab (IR) in previously untreated older patients with chronic lymphocytic leukemia (CLL). The initial results showed that ibrutinib-containing regimens had superior progression-free survival (PFS) and rituximab did not add additional benefits. Here we present an updated analysis. With a median follow-up of 55 months, the median PFS was 44 months (95% confidence interval [CI], 38-54) for BR and not yet reached in either ibrutinib-containing arm. The 48-month PFS estimates were 47%, 76%, and 76% for BR, ibrutinib, and IR, respectively. The benefit of ibrutinib regimens over chemoimmunotherapy was consistent across subgroups of patients defined by TP53 abnormalities, del(11q), complex karyotype, and immunoglobulin heavy chain variable region (IGHV). No significant interaction effects were observed between the treatment arm and del(11q), the complex karyotype, or IGHV. However, a greater difference in PFS was observed among the patients with TP53 abnormalities. There was no difference in the overall survival. Notable adverse events with ibrutinib included atrial fibrillation (afib) and hypertension. Afib was observed in 11 patients (pts) on BR (3%) and 67 pts on ibrutinib (18%). All-grade hypertension was observed in 95 pts on BR (27%) and 263 pts on ibrutinib (55%). These data show that ibrutinib regimens prolong PFS compared with BR for older patients with treatment-naïve CLL. These benefits were observed across subgroups, including high-risk groups. Strikingly, within the ibrutinib arms, there was no inferior PFS for patients with abnormalities in TP53, the highest risk feature observed in CLL. These data continue to demonstrate the efficacy of ibrutinib in treatment-naïve CLL.

Gene Mutations Associated With Chronic Lymphocytic Leukemia (CLL) Among Saudi CLL Patients and Treatment Outcomes: A Single-Center Experience

Background Chronic lymphocytic leukemia (CLL) starts in white blood cells in the peripheral blood (stages 0 and 1). In CLL, leukemia cells often build up slowly. Many gene mutations are associated with CLL, such as trisomy 12, 13q14 deletion, and 17q deletion. Due to the lack of patients' disease characteristics, gene mutations, and treatment outcomes data among Saudi patients, this study aimed to identify the relation between the gene mutations of CLL and the treatment in King Abdulaziz Medical City (KAMC), Riyadh. Methods This cross-sectional study used data from the BESTCare hospital information system. The study included all patients diagnosed with CLL and confirmed by flow cytometry in KAMC, Riyadh, between January 2010 and October 2020. The data included demographic information, mutation type or chromosome, present comorbidity, and type of treatment. Results The study included 100 CLL patients. According to different types of clusters of differentiation (CD), CD5 was positive in 84 (84%) patients, and 88 (88%) patients were positive for CD19. Cytogenetic remarkers were tested, revealing that 21 (21%) patients with trisomy 12 and 20 (20%) were positive for 13q14 deletion. Observation of patients' disease status based on the cytogenetic remarkers showed that out of 15 patients with trisomy, 12 (80%) had not progressed and were stable and alive. Out of 20 patients with 13q14 deletion, 16 (80%) were alive and 13 (65%) patients were stable. Conclusion CLL patients in KAMC, Riyadh, displayed trisomy 12, which is characterized by the worst prognosis of disease status, as the most frequently detected cytogenetic aberration followed by 13q deletion. However, most patients were stable and alive.

Five-year follow-up of a phase 2 study of ibrutinib plus fludarabine, cyclophosphamide, and rituximab as initial therapy in CLL

ABSTRACT

We previously reported high rates of undetectable minimal residual disease <10-4 (uMRD4) with ibrutinib plus fludarabine, cyclophosphamide, and rituximab (iFCR) followed by 2-year ibrutinib maintenance (I-M) in treatment-naïve chronic lymphocytic leukemia (CLL). Here, we report updated data from this phase 2 study with a median follow-up of 63 months. Of 85 patients enrolled, including 5 (6%) with deletion 17p or TP53 mutation, 91% completed iFCR and 2-year I-M. Five-year progression-free survival (PFS) and overall survival were 94% (95% confidence interval [CI], 89%-100%) and 99% (95% CI, 96%-100%), respectively. No additional deaths have occurred with this extended follow-up. No difference in PFS was observed by immunoglobulin heavy-chain variable region gene status or duration of I-M. High rates of peripheral blood (PB) uMRD4 were maintained (72% at the end of iFCR, 66% at the end of 2-year I-M, and 44% at 4.5 years from treatment initiation). Thirteen patients developed MRD conversion without clinical progression, mostly (77%) after stopping ibrutinib. None had Bruton tyrosine kinase (BTK) mutations. One patient had PLCG2 mutation. Six of these patients underwent ibrutinib retreatment per protocol. Median time on ibrutinib retreatment was 34 months. The cumulative incidence of atrial fibrillation was 8%. Second malignancy or nonmalignant hematologic disease occurred in 13%, mostly nonmelanoma skin cancer. Overall, iFCR with 2-year I-M achieved durably deep responses in patients with diverse CLL genetic markers. Re-emergent clones lacked BTK mutation and retained sensitivity to ibrutinib upon retreatment. This trial is registered at www.clinicaltrials.gov as #NCT02251548.

Leukemic cell-secreted interleukin-9 suppresses cytotoxic T cell-mediated killing in chronic lymphocytic leukemia

The tumor microenvironment (TME) plays a central role in the pathogenesis of chronic lymphocytic leukemia (CLL), contributing to disease progression and chemoresistance. Leukemic cells shape the TME into a pro-survival and immunosuppressive niche through contact-dependent and contact-independent interactions with the cellular components of the TME. Immune synapse (IS) formation is defective in CLL. Here we asked whether soluble factors released by CLL cells contribute to their protection from cytotoxic T cell (CTL)-mediated killing by interfering with this process. We found that healthy CTLs cultured in media conditioned by leukemic cells from CLL patients or Eμ-TCL1 mice upregulate the exhaustion marker PD-1 and become unable to form functional ISs and kill target cells. These defects were more pronounced when media were conditioned by leukemic cells lacking p66Shc, a proapoptotic adapter whose deficiency has been implicated in disease aggressiveness both in CLL and in the Eμ-TCL1 mouse model. Multiplex ELISA assays showed that leukemic cells from Eμ-TCL1 mice secrete abnormally elevated amounts of CCL22, CCL24, IL-9 and IL-10, which are further upregulated in the absence of p66Shc. Among these, IL-9 and IL-10 were also overexpressed in leukemic cells from CLL patients, where they inversely correlated with residual p66Shc. Using neutralizing antibodies or the recombinant cytokines we show that IL-9, but not IL-10, mediates both the enhancement in PD-1 expression and the suppression of effector functions in healthy CTLs. Our results demonstrate that IL-9 secreted by leukemic cells negatively modulates the anti-tumor immune abilities of CTLs, highlighting a new suppressive mechanism and a novel potential therapeutical target in CLL.

Japanese phase Ib study of the oral PI3K-δ and -γ inhibitor duvelisib in patients with relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma

This phase Ib, open-label, single-arm, multicenter study assessed the efficacy and safety of duvelisib, an oral dual inhibitor of phosphatidylinositol 3-kinase-δ and -γ, in Japanese patients with relapsed or refractory (r/r) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Duvelisib was administered orally at 25 mg twice a day (BID) until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) and all responses were assessed by an independent review committee. Nine CLL patients and 1 SLL patient were enrolled. ORR was 80% (95% confidence interval 44.4, 97.5) for all 10 patients. All 6 patients previously treated with a Bruton's tyrosine kinase (BTK) or BCL2 inhibitor achieved a partial response. The most common adverse events were neutropenia (50%), diarrhea (40%), anemia, hypokalemia, constipation and rash (30% each). The most common grade ≥ 3 adverse events were neutropenia (50%), anemia (30%) and thrombocytopenia (20%). Duvelisib 25 mg BID showed favorable efficacy and a manageable safety profile in selected Japanese patients with r/r CLL/SLL, including patients previously treated with BTK or BCL2 inhibitors (Clinical trial registration: jRCTs2080224791).

Global miRNA profiling reveals key molecules that contribute to different chronic lymphocytic leukemia incidences in Asian and Western populations

It has been known for decades that the incidence of chronic lymphocytic leukemia (CLL) is significantly lower in Asia than in Western countries, but the reason responsible for this difference still remains a major knowledge gap. Using GeneChip® miRNA array to analyze the global microRNA expression in B lymphocytes from Asian and Western CLL patients and healthy individuals, we have identified microRNA with CLL-promoting or suppressive functions that are differentially expressed in Asian and Western individuals. In particular, miR-4485 is upregulated in CLL patients of both ethnic groups, and its expression is significantly lower in Asian healthy individuals. Genetic silencing of miR-4485 in CLL cells suppresses leukemia cell growth, whereas ectopic expression of miR-4485 promotes cell proliferation. Mechanistically, miR-4485 exerts its CLL-promoting activity by inhibiting the expression of TGR5 and activating the ERK1/2 pathway. In contrast, miR-138, miR-181a, miR- 181c, miR-181d, and miR-363 with tumor-suppressive function are highly expressed in Asian healthy individuals. Our study suggests that differential expression of several important microRNA with pro- or anti-CLL functions in Asian and Western B lymphocytes likely contributes to the difference in CLL incidence between the two ethnic groups, and that miR-4485 and its downstream molecule TGR5 could be potential therapeutic targets.

p66Shc deficiency in CLL cells enhances PD-L1 expression and suppresses immune synapse formation

Introduction: Escape from immunosurveillance is a hallmark of chronic lymphocytic leukemia (CLL) cells. In the protective niche of lymphoid organs, leukemic cells suppress the ability of T lymphocytes to form the immune synapse (IS), thereby hampering T-cell mediated anti-tumoral activities. By binding its cognate receptor PD-1 at the surface of T lymphocytes, the inhibitory ligand PD-L1, which is overexpressed in CLL cells, mediates the T-cell suppressive activities of CLL cells. However, the molecular mechanism underlying PD-L1 overexpression in CLL cells remains unknown. We have previously reported a defective expression of the pro-apoptotic and pro-oxidant adaptor p66Shc in CLL cells, which is causally related to an impairment in intracellular reactive oxygen species (ROS) production and to the activation of the ROS-sensitive transcription factor NF-κB. The fact that PD-L1 expression is regulated by NF-κB suggests a mechanistic relationship between p66Shc deficiency and PD-L1 overexpression in CLL cells. Methods: 62 treatment-naive CLL patients and 43 healthy donors were included in this study. PD-L1 and p66Shc expression was quantified in B cells by flow cytometry and qRT-PCR. IS architecture and local signaling was assessed by flow cytometry and confocal microscopy. CD8+ cell killing activity was assessed by flow cytometry. Results: Here we show that residual p66Shc expression in leukemic cells isolated both from CLL patients and from the CLL mouse model Eμ-TCL1 inversely correlated with PD-L1 expression. We also show that the PD-L1 increase prevented leukemic cells from forming ISs with T lymphocytes. Reconstitution of p66Shc, but not of a ROS-defective mutant, in both CLL cells and the CLL-derived cell line MEC-1, enhanced intracellular ROS and decreased PD-L1 expression. Similar results were obtained following treatment of CLL cells with H2O2 as exogenous source of ROS, that normalized PD-L1 expression and recovered IS formation. Discussion: Our data provide direct evidence that the p66Shc-deficiency-related ROS depletion in CLL cells concurs to enhance PD-L1 expression and provides a mechanistic basis for the suppression of T cell-mediated anti-tumoral functions in the immunosuppressive lymphoid niche.

Expression Pattern and Prognostic Significance of the Long Non-Coding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 in Chronic Lymphocytic Leukemia

Dysregulated expression of the long non-coding RNA MALAT1 has been implicated in the pathogenesis and progression of a variety of cancers, including hematological malignancies, but it has been poorly investigated in chronic lymphocytic leukemia (CLL). In this study, the expression of MALAT1 was measured using a quantitative reverse-transcriptase polymerase chain reaction in the peripheral blood mononuclear cells of 114 unselected, newly diagnosed CLL patients in order to analyze its association with clinical, laboratory, and molecular patients' characteristics at diagnosis, as well as its prognostic relevance. MALAT1 was found to be upregulated in CLL patients in comparison to healthy controls, and expression levels were not related to age, leukocyte, lymphocyte and platelet count, serum β2-microglobulin, and IGHV somatic hypermutational status. On the other hand, high MALAT1 expression was associated with several favorable prognostic markers (high hemoglobin, low serum lactate dehydrogenase, earlier clinical stages, CD38-negative status), but also with unfavorable cytogenetics. Furthermore, an association between high MALAT1 levels and longer time to first treatment and overall survival in IGHV-unmutated CLL subtype was observed. In summary, our results imply that high MALAT1 expression at diagnosis may be a predictor of better prognosis and point to MALAT1 expression profiling as a candidate biomarker potentially useful in clinical practice.

Maintenance therapy for chronic lymphocytic leukaemia

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is the most common lymphoproliferative disease in adults and currently remains incurable. As the progression-free period shortens after each successive treatment, strategies such as maintenance therapy are needed to improve the degree and duration of response to previous therapies. Monoclonal antibodies, immunomodulatory agents, and targeted therapies are among the available options for maintenance therapy. People with CLL who achieve remission after previous therapy may choose to undergo medical observation or maintenance therapy to deepen the response. Even though there is widespread use of therapeutic maintenance agents, the benefits and harms of these treatments are still uncertain.

OBJECTIVES

To assess the effects and safety of maintenance therapy, including anti-CD20 monoclonal antibody, immunomodulatory drug therapy, anti-CD52 monoclonal antibody, Bruton tyrosine kinase inhibitor, and B-cell lymphoma-2 tyrosine kinase inhibitor, for individuals with CLL.

SEARCH METHODS

We conducted a comprehensive literature search for randomised controlled trials (RCTs) with no language or publication status restrictions. We searched CENTRAL, MEDLINE, Embase, and three trials registers in January 2022 together with reference checking, citation searching, and contact with study authors to identify additional studies.

SELECTION CRITERIA

We included RCTs with prospective identification of participants. We excluded cluster-randomised trials, cross-over trial designs, and non-randomised studies. We included studies comparing maintenance therapies with placebo/observation or head-to-head comparisons.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We assessed risk of bias in the included studies using Cochrane's RoB 1 tool for RCTs. We rated the certainty of evidence for the following outcomes using the GRADE approach: overall survival (OS), health-related quality of life (HRQoL), grade 3 and 4 adverse events (AEs), progression-free survival (PFS), treatment-related mortality (TRM), treatment discontinuation (TD), and all adverse events (AEs).

MAIN RESULTS

We identified 11 RCTs (2393 participants) that met the inclusion criteria, including seven trials comparing anti-CD20 monoclonal antibodies (mAbs) (rituximab or ofatumumab) with observation in 1679 participants; three trials comparing immunomodulatory drug (lenalidomide) with placebo/observation in 693 participants; and one trial comparing anti-CD 52 mAbs (alemtuzumab) with observation in 21 participants. No comparisons of novel small molecular inhibitors were found. The median age of participants was 54.1 to 71.7 years; 59.5% were males. The type of previous induction treatment, severity of disease, and baseline stage varied among the studies. Five trials included early-stage symptomatic patients, and three trials included advanced-stage patients (Rai stage III/IV or Binet stage B/C). Six trials reported a frequent occurrence of cytogenic aberrations at baseline (69.7% to 80.1%). The median follow-up duration was 12.4 to 73 months. The risk of selection bias in the included studies was unclear. We assessed overall risk of performance bias and detection bias as low risk for objective outcomes and high risk for subjective outcomes. Overall risk of attrition bias, reporting bias, and other bias was low. Anti-CD20 monoclonal antibodies (mAbs): rituximab or ofatumumab maintenance versus observation Anti-CD20 mAbs maintenance likely results in little to no difference in OS (hazard ratio (HR) 0.94, 95% confidence interval (CI) 0.73 to 1.20; 1152 participants; 3 studies; moderate-certainty evidence) and likely increases PFS significantly (HR 0.61, 95% CI 0.50 to 0.73; 1255 participants; 5 studies; moderate-certainty evidence) compared to observation alone. Anti-CD20 mAbs may result in: an increase in grade 3/4 AEs (rate ratio 1.34, 95% CI 1.06 to 1.71; 1284 participants; 5 studies; low-certainty evidence); little to no difference in TRM (risk ratio 0.82, 95% CI 0.39 to 1.71; 1189 participants; 4 studies; low-certainty evidence); a slight reduction to no difference in TD (risk ratio 0.93, 95% CI 0.72 to 1.20; 1321 participants; 6 studies; low-certainty evidence); and an increase in all AEs (rate ratio 1.23, 95% CI 1.03 to 1.47; 1321 participants; 6 studies; low-certainty evidence) compared to the observation group. One RCT reported that there may be no difference in HRQoL between the anti-CD20 mAbs (ofatumumab) maintenance and the observation group (mean difference -1.70, 95% CI -8.59 to 5.19; 480 participants; 1 study; low-certainty evidence). Immunomodulatory drug (IMiD): lenalidomide maintenance versus placebo/observation IMiD maintenance therapy likely results in little to no difference in OS (HR 0.91, 95% CI 0.61 to 1.35; 461 participants; 3 studies; moderate-certainty evidence) and likely results in a large increase in PFS (HR 0.37, 95% CI 0.19 to 0.73; 461 participants; 3 studies; moderate-certainty evidence) compared to placebo/observation. Regarding harms, IMiD maintenance therapy may result in an increase in grade 3/4 AEs (rate ratio 1.82, 95% CI 1.38 to 2.38; 400 participants; 2 studies; low-certainty evidence) and may result in a slight increase in TRM (risk ratio 1.22, 95% CI 0.35 to 4.29; 458 participants; 3 studies; low-certainty evidence) compared to placebo/observation. The evidence for the effect on TD compared to placebo is very uncertain (risk ratio 0.71, 95% CI 0.47 to 1.05; 400 participants; 2 studies; very low-certainty evidence). IMiD maintenance therapy probably increases all AEs slightly (rate ratio 1.41, 95% CI 1.28 to 1.54; 458 participants; 3 studies; moderate-certainty evidence) compared to placebo/observation. No studies assessed HRQoL. Anti-CD52 monoclonal antibodies (mAbs): alemtuzumab maintenance versus observation Maintenance with alemtuzumab may have little to no effect on PFS, but the evidence is very uncertain (HR 0.55, 95% CI 0.32 to 0.95; 21 participants; 1 study; very low-certainty evidence). We did not identify any study reporting the outcomes OS, HRQoL, grade 3/4 AEs, TRM, TD, or all AEs.

AUTHORS' CONCLUSIONS

There is currently moderate- to very low-certainty evidence available regarding the benefits and harms of maintenance therapy in people with CLL. Anti-CD20 mAbs maintenance improved PFS, but also increased grade 3/4 AEs and all AEs. IMiD maintenance had a large effect on PFS, but also increased grade 3/4 AEs. However, none of the above-mentioned maintenance interventions show differences in OS between the maintenance and control groups. The effects of alemtuzumab maintenance are uncertain, coupled with a warning for drug-related infectious toxicity. We found no studies evaluating other novel maintenance interventions, such as B-cell receptor inhibitors, B-cell leukaemia-2/lymphoma-2 inhibitors, or obinutuzumab.

Low-burden TP53 mutations represent frequent genetic events in CLL with an increased risk for treatment initiation

TP53 aberrations predict chemoresistance and represent a contraindication for the use of standard chemoimmunotherapy in chronic lymphocytic leukaemia (CLL). Recent next-generation sequencing (NGS)-based studies have identified frequent low-burden TP53 mutations with variant allele frequencies below 10%, but the clinical impact of these low-burden TP53 mutations is still a matter of debate. In this study, we aimed to scrutinise the subclonal architecture and clinical impact of TP53 mutations using a sensitive, NGS-based mutation analysis in a 'real-world' cohort of 901 patients with CLL. In total, 225 TP53 mutations were identified in 17.5% (158/901) of the patients; 48% of these alterations represented high-burden mutations, while 52% were low-burden TP53 mutations. Low-burden mutations as sole alterations were identified in 39% (62/158) of all mutated cases with 82% (51/62) of these being represented by a single low-burden TP53 mutation. Patients harbouring low-burden TP53 mutations had significantly lower time to first treatment compared to patients with wild-type TP53. Our study has expanded the knowledge on the frequency, clonal architecture, and clinical impact of low-burden TP53 mutations. By demonstrating that patients with sole low-burden TP53 variants represent more than one-third of patients with TP53 mutations and have an increased risk for treatment initiation, our findings strengthen the need to redefine the threshold of TP53 variant reporting to below 10% in the routine diagnostic setting.

Association of Cytogenetics Aberrations and IGHV Mutations with Outcome in Chronic Lymphocytic Leukemia Patients in a Real-World Clinical Setting

Immunoglobulin heavy chain variable ( IGHV ) region mutations, TP53 mutation, fluorescence in situ hybridization (FISH), and cytogenetic analysis are the most important prognostic biomarkers used in chronic lymphocytic leukemia (CLL) patients in our daily practice. In real-life environment, there are scarce studies that analyze the correlation of these factors with outcome, mainly referred to time to first treatment (TTFT) and overall survival (OS). This study aimed to typify IGHV mutation status, family usage, FISH aberrations, and complex karyotype (CK) and to analyze the prognostic impact in TTFT and OS in retrospective study of 375 CLL patients from a Spanish cohort. We found unmutated CLL (U-CLL) was associated with more aggressive disease, shorter TTFT (48 vs. 133 months, p  < 0.0001), and shorter OS (112 vs. 246 months, p  < 0.0001) than the mutated CLL. IGHV3 was the most frequently used IGHV family (46%), followed by IGHV1 (30%) and IGHV4 (16%). IGHV5-51 and IGHV1-69 subfamilies were associated with poor prognosis, while IGHV4 and IGHV2 showed the best outcomes. The prevalence of CK was 15% and was significantly associated with U-CLL. In the multivariable analysis, IGHV2 gene usage and del13q were associated with longer TTFT, while VH1-02, +12, del11q, del17p, and U-CLL with shorter TTFT. Moreover, VH1-69 usage, del11q, del17p, and U-CLL were significantly associated with shorter OS. A comprehensive analysis of genetic prognostic factors provides a more precise information on the outcome of CLL patients. In addition to FISH cytogenetic aberrations, IGHV and TP53 mutations, IGHV gene families, and CK information could help clinicians in the decision-making process.

Lifetime exposure to brominated trihalomethanes in drinking water and swimming pool attendance are associated with chronic lymphocytic leukemia: a Multicase-Control Study in Spain (MCC-Spain)

BACKGROUND

Chronic lymphocytic leukemia (CLL) etiology is poorly understood, and carcinogenic chemicals in drinking and recreational water are candidates.

OBJECTIVE

To evaluate the association between drinking-water exposure to trihalomethanes (THMs) and nitrate as well as lifetime swimming pool attendance and CLL.

METHODS

During 2010-2013, hospital-based CLL cases and population-based controls were recruited in Spain, providing information on residential histories, type of water consumed and swimming pool attendance. Average THMs and nitrate levels in drinking water were linked to lifetime water consumption. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using mixed models.

RESULTS

Final samples for residential tap water analyses and swimming pool attendance analyses were 144 cases/1230 controls and 157 cases/1240 controls, respectively. Mean (SD) values for average lifetime residential brominated THMs and chloroform in tap water (μg/L), and ingested nitrate (mg/day) were 48.1 (35.6), 18.5 (6.7) and 13.7 (9.6) respectively in controls; and 72.9 (40.7), 17.9 (5.4), and 14.1 (8.8) in CLL cases. For each 10 μg/L increase of brominated THMs and chloroform lifetime-average levels, the ORs (95% CI) were 1.22 (1.14, 1.31) and 0.54 (0.34, 0.87), respectively. For each 5 mg/day increase of ingested nitrate, the OR of CLL was 0.91 (0.80, 1.04). The OR of lifetime pool users (vs. non-users) was 2.38 (1.61, 3.52). Upon performing annual frequency of attending pools analysis through categorization, the second and third categories showed an ORs of 2.36 (1.49, 3.72) and 2.40 (1.51, 3.83), respectively, and P-trend of 0.001.

IMPACT STATEMENT

This study identifies an association of long-term exposure to THMs in drinking water, at concentrations below the regulatory thresholds and WHO guidelines, and swimming pool attendance, with chronic lymphocytic leukemia (CLL). These unprecedented findings are highly relevant since CLL is an incurable cancer with still unknown etiology and because the widespread exposure to chlorination by-products that remain in drinking and recreational water worldwide. Despite the demonstrated carcinogenicity in animals of several chlorination by-products, little is known about their potential risks on human health. This study makes a significant contribution to the search for environmental factors involved in the etiology of CLL and to the evidence of the health impact of these high prevalent water contaminants.

Treatment of Chronic Lymphocytic Leukemia in the Personalized Medicine Era

Chronic lymphocytic leukemia is a lymphoproliferative disorder marked by the expansion of monoclonal, mature CD5+CD23+ B cells in peripheral blood, secondary lymphoid tissues, and bone marrow. The disease exhibits significant heterogeneity, with numerous somatic genetic alterations identified in the neoplastic clone, notably mutated TP53 and immunoglobulin heavy chain mutational statuses. Recent studies emphasize the pivotal roles of genetics and patient fragility in treatment decisions. This complexity underscores the need for a personalized approach, tailoring interventions to individual genetic profiles for heightened efficacy. The era of personalized treatment in CLL signifies a transformative shift, holding the potential for improved outcomes in the conquest of this intricate hematologic disorder. This review plays a role in elucidating the evolving CLL treatment landscape, encompassing all reported genetic factors. Through a comprehensive historical analysis, it provides insights into the evolution of CLL management. Beyond its retrospective nature, this review could be a valuable resource for clinicians, researchers, and stakeholders, offering a window into the latest advancements. In essence, it serves as a dynamic exploration of our current position and the promising prospects on the horizon.

Intraocular sarcoid-like reaction in patients with chronic lymphocytic leukemia

OBJECTIVE

To investigate the frequency and clinical features of intraocular paraneoplastic sarcoid-like reaction (SLR) in patients with chronic lymphocytic leukemia (CLL).

METHODS

Retrospective review of patients with CLL from January 1, 1980, to December 31, 2020. Eye examinations were searched for 22 keywords suggestive of SLR, and charts were manually reviewed.

RESULTS

Of 4209 unique patients with CLL, 1021 (24%) had at least 1 eye examination on record, and 324 (8%) had 1 or more keyword eye examination findings. After manual review, 12 patients (<1%) were identified as having probable SLR with characteristic features (n = 7), possible but not classic (n = 1), or suspect but less likely (n = 4). All patients (n = 8) with probable or possible SLR were White, and half (n = 4) were male. Intraocular SLR was diagnosed a mean of 49.7 months after the CLL diagnosis (n = 7) or preceded the CLL diagnosis by 1 month (n = 1). Involvement was bilateral in 5 patients, with 13 total affected eyes and mean presenting Snellen visual acuity of 20/50. Common characteristic features on initial examination included vitreous cell (n = 13), anterior-chamber cell (n = 10), keratic precipitates (n = 9), posterior synechiae (n = 6), chorioretinal lesions (n = 5), and vitreous haze (n = 5). Treatment included topical corticosteroids alone (n = 5), with sub-Tenon corticosteroids (n = 1), or with steroid-sparing immunosuppressive agents (n = 1) or oral corticosteroids alone (n = 1). After a mean follow-up of 19.8 months, final mean visual acuity was 20/30.

CONCLUSION

Intraocular SLRs affect fewer than 1% of patients with CLL. SLR should be on the differential diagnosis list for any CLL patient with ocular complaints, and most patients can be managed successfully with corticosteroids.

Synthesis and Pro-Apoptotic Effects of Nitrovinylanthracenes and Related Compounds in Chronic Lymphocytic Leukaemia (CLL) and Burkitt's Lymphoma (BL)

Chronic lymphocytic leukaemia (CLL) is a malignancy of the immune B lymphocyte cells and is the most common leukaemia diagnosed in developed countries. In this paper, we report the synthesis and antiproliferative effects of a series of (E)-9-(2-nitrovinyl)anthracenes and related nitrostyrene compounds in CLL cell lines and also in Burkitt's lymphoma (BL) cell lines, a rare form of non-Hodgkin's immune B-cell lymphoma. The nitrostyrene scaffold was identified as a lead structure for the development of effective compounds targeting BL and CLL. The series of structurally diverse nitrostyrenes was synthesised via Henry-Knoevenagel condensation reactions. Single-crystal X-ray analysis confirmed the structure of (E)-9-chloro-10-(2-nitrobut-1-en-1-yl)anthracene (19f) and the related 4-(anthracen-9-yl)-1H-1,2,3-triazole (30a). The (E)-9-(2-nitrovinyl)anthracenes 19a, 19g and 19i-19m were found to elicit potent antiproliferative effects in both BL cell lines EBV-MUTU-1 (chemosensitive) and EBV+ DG-75 (chemoresistant) with >90% inhibition at 10 μM. Selected (E)-9-(2-nitrovinyl)anthracenes demonstrated potent antiproliferative activity in CLL cell lines, with IC50 values of 0.17 μM (HG-3) and 1.3 μM (PGA-1) for compound 19g. The pro-apoptotic effects of the most potent compounds 19a, 19g, 19i, 19l and 19m were demonstrated in both CLL cell lines HG-3 and PGA-1. The (E)-nitrostyrene and (E)-9-(2-nitrovinyl)anthracene series of compounds offer potential for further development as novel chemotherapeutics for CLL.

Chimeric Antigen Receptor T-cell Therapy for Chronic Lymphocytic Leukemia: What is the supporting evidence so far?

While acknowledging that newer therapies have improved survival rates in chronic lymphocytic leukemia (CLL), patients with high-risk disease features are at an increased risk of treatment failure. Allogeneic hematopoietic cell transplantation (allo-HCT) was traditionally offered as front-line consolidation in high-risk CLL; however, with the emergence of targeted therapies like Bruton tyrosine kinase (BTK) and B-cell lymphoma 2 (BCL-2) inhibitors, the role of allo-HCT has been relegated to later stages of the disease. Patients with relapsed/refractory (R/R) CLL who have failed both BTK and BCL-2 inhibitors represent a therapeutic challenge owing to a poor prognosis. Chimeric antigen receptor T-cell (CAR T) therapies targeting CD19 have improved response rates and overall survival in various types of R/R B-cell non-Hodgkin lymphomas. For CLL, no approved CAR T-cell therapies are yet available. Emerging data appear to show a therapeutic benefit of CAR T-cell therapy in patients with R/R CLL, even after failing an allo-HCT.

Prognostic Potential of Galectin-9 mRNA Expression in Chronic Lymphocytic Leukemia

Galectin-9 (Gal-9), very poorly characterized in chronic lymphocytic leukemia (CLL), was chosen in our study to examine its potential role as a CLL biomarker. The relation of Gal-9 expression in malignant B-cells and other routinely measured CLL markers, as well as its clinical relevance are poorly understood. Gal-9 mRNA expression was quantified with RT-qPCR in purified CD19+ B-cells of 100 CLL patients and analyzed in the context of existing clinical data. Our results revealed the upregulation of Gal-9 mRNA in CLL cells. High Gal-9 mRNA expression was closely associated with unfavorable prognostic markers. In addition, Gal-9 expression in leukemic cells was significantly elevated in CLL patients who did not respond to the first-line therapy compared to those who did respond. This suggests its potential predictive value. Importantly, Gal-9 was an independent predictor for the time to treatment parameters. Thus, we can suggest an adverse role of Gal-9 expression in CLL. Interestingly, it is possible that Gal-9 expression is induced in B-cells by EBV infection, so we determined the patients' EBV status. Our suggestion is that EBV coinfection could worsen prognosis in CLL, partly due to Gal-9 expression upregulation caused by EBV.

Efficacy and Safety of Bruton Tyrosine Kinase Inhibitor Plus Anti-CD20 Antibody Therapy Compared With Chemoimmunotherapy as Front-line Treatment for Chronic Lymphocytic Leukemia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Treatment with chemoimmunotherapy (CIT) is considered an appropriate front-line treatment option for chronic lymphocytic leukemia (CLL). However, outcomes remain suboptimal. Bruton tyrosine kinase inhibitor (BTKi) combined with anti-CD20 antibody is an effective treatment for treatment-naïve, relapsed/refractory CLL patients. A systematic review and meta-analysis of randomized controlled trials was performed to compare the efficacy and safety of CIT versus BTKi + anti-CD20 antibody as front-line treatment for CLL patients. The endpoints of interest included progression-free survival (PFS), overall survival (OS), overall response rate (ORR), complete response (CR) rate, and safety. Four trials (including 1479 patients) were available as of December 2022 and fulfilled the eligibility criteria. BTKi + anti-CD20 antibody treatment significantly prolonged PFS [hazard ratio (HR), 0.25; 95% confidence interval (CI), 0.15-0.42] compared with CIT, while the combination therapy did not significantly improve OS compared with CIT (HR, 0.73; 95% CI, 0.50-1.06). We observed consistent benefits for PFS among patients with unfavorable features. Although pooled analysis indicated that the addition of BTKi to anti-CD20 antibody led to a higher ORR than CIT [risk ratio (RR), 1.16; 95% CI, 1.13-1.20], there was no difference in CR between the two arms (RR, 1.10; 95% CI, 0.27-4.55). The risk of grade ≥3 adverse effects (AE) was comparable between the two groups (RR, 1.04; 95% CI, 0.92-1.17). The BTKi + anti-CD20 antibody therapy has superior outcomes compared with CIT among patients with treatment-naïve CLL, without excess of toxicity. Future studies should compare next-generation targeted agent combinations versus CIT to determine the optimal management of CLL patients.

Acalabrutinib and steroid for autoimmune thrombocytopenia due to relapsed chronic lymphocytic leukemia with severe bone marrow infiltration

Thrombocytopenia is a frequent complication in chronic lymphocytic leukemia (CLL). Differentiating autoimmune thrombocytopenia from thrombocytopenia due to bone marrow infiltration is necessary for appropriate treatment, but sometimes difficult. Here we report a 60-year-old male patient with CLL who had achieved complete response after treatment with fludarabine, cyclophosphamide, and rituximab two years prior to presentation. He was admitted with severe thrombocytopenia that was unresponsive to intravenous immunoglobulin. Imaging studies revealed systemic enlarged lymph nodes and bone marrow aspiration was hypercellular with > 95% lymphocytes and scant megakaryocytes. Acalabrutinib 200 mg/day was administered for the treatment of CLL exacerbation. A gradual decrease in CLL cells and recovery of megakaryocytes in bone marrow were observed, but platelet counts remained low. Systemic administration of prednisolone 0.5 mg/kg, in addition to acalabrutinib, was started, considering the contribution of autoimmune thrombocytopenia; platelet recovery was rapid and sustained for more than a year. Even if bone marrow examination suggested thrombocytopenia due to direct leukemic infiltration, it is difficult to exclude the possibility of concomitant immunogenic thrombocytopenia. We conclude that for CLL patients with severe thrombocytopenia, repeating bone marrow examination and concurrent immunosuppressive therapies and treatment of the underlying CLL may be beneficial.

Evidence-Based Management of Chronic Lymphocytic Leukemia: Consensus Statements from the Gulf Region

INTRODUCTION

Despite recent advances in diagnosis, prognostication, and treatment options, chronic lymphocytic leukemia (CLL) is still a largely incurable disease. New concepts on diagnosis, staging, treatment, and follow-up on CLL have been incorporated throughout recent years. The lack of regional consensus guidelines has led to varying practices in the management of patients with CLL in the region. This manuscript aims to reach a consensus among expert hematologists regarding the definitions, classifications, and related practices of CLL. The experts developed a set of statements utilizing their personal experience together with the current literature on CLL management. This consensus aims to provide guidance for healthcare professionals involved in the management of CLL and serves as a step in developing regional guidelines.

METHODS

Eight experts responded to 50 statements regarding the diagnosis, staging, treatment, and prognosis of CLL with three potential answering alternatives ranging between agree, disagree, and abstain. This consensus adopted a modified Delphi consensus methodology. A consensus was reached when at least 75% of the agreement to the answer was reached. This manuscript presents the scientific insights of the participating attendees, panel discussions, and the supporting literature review.

RESULTS

Of the 50 statements, a consensus was reached on almost all statements. Statements covered CLL-related topics, including diagnostic evaluation, staging, risk assessment, different patient profiles, prognostic evaluation, treatment decisions, therapy sequences, response evaluation, complications, and CLL during the COVID-19 pandemic.

CONCLUSION

In recent years, CLL management has progressed significantly, with many diagnostic tests and several novel treatments becoming available. This consensus gathers decades of consolidated principles, novel research, and promising prospects for the management of this disease.

FCRL1 immunoregulation in B cell development and malignancy

Immunotherapeutic targeting of surface regulatory proteins and pharmacologic inhibition of critical signaling pathways has dramatically shifted our approach to the care of individuals with B cell malignancies. This evolution in therapy reflects the central role of the B cell receptor (BCR) signaling complex and its co-receptors in the pathogenesis of B lineage leukemias and lymphomas. Members of the Fc receptor-like gene family (FCRL1-6) encode cell surface receptors with complex tyrosine-based regulation that are preferentially expressed by B cells. Among them, FCRL1 expression peaks on naïve and memory B cells and is unique in terms of its intracellular co-activation potential. Recent studies in human and mouse models indicate that FCRL1 contributes to the formation of the BCR signalosome, modulates B cell signaling, and promotes humoral responses. Progress in understanding its regulatory properties, along with evidence for its over-expression by mature B cell leukemias and lymphomas, collectively imply important yet unmet opportunities for FCRL1 in B cell development and transformation. Here we review recent advances in FCRL1 biology and highlight its emerging significance as a promising biomarker and therapeutic target in B cell lymphoproliferative disorders.

A personalized stepwise dynamic predictive algorithm of the time to first treatment in chronic lymphocytic leukemia

Personalized prediction is ideal in chronic lymphocytic leukemia (CLL). Although refined models have been developed, stratifying patients in risk groups, it is required to accommodate time-dependent information of patients, to address the clinical heterogeneity observed within these groups. In this direction, this study proposes a personalized stepwise dynamic predictive algorithm (PSDPA) for the time-to-first-treatment of the individual patient. The PSDPA introduces a personalized Score, reflecting the evolution in the patient's follow-up, employed to develop a reference pool of patients. Score evolution's similarity is used to predict, at a selected time point, the time-to-first-treatment for a new patient. Additional patient's biological information may be utilized. The algorithm was applied to 20 CLL patients, indicating that stricter assessment criteria for the Score evolution's similarity, and biological similarity exploitation, may improve prediction. The PSDPA capitalizes on both the follow-up and the biological background of the individual patient, dynamically promoting personalized prediction in CLL.

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.

Accelerated Chronic Lymphocytic Leukemia and Richter Transformation in the Era of Novel Agents

BACKGROUND

Tremendous developments in the field of chronic lymphocytic leukemia (CLL) in recent years have led to a revolutionary change in the treatment approach, which today is based on targeted treatments with a good response and optimal prognosis. Nevertheless, CLL can present or progress to "accelerated CLL" (A-CLL) or to "Richter transformation" (RT) and these two entities have a more aggressive course and are still characterized by challenges in the fields of diagnosis and therapy. In the current review, we summarized the latest knowledge in terms of diagnostic approaches to A-CLL, available treatments and clinical trials, for both A-CLL and RT which still pose an unmet need and require additional basic and clinical investigations.

SUMMARY

A-CLL is a rare and underdiagnosed entity that probably stands in the "gray zone" between CLL and RT, generally holding an intermediate prognosis. Its diagnosis is mainly based on histological findings including expanded proliferation centers, increased mitotic activity, and/or high Ki-67 index. Due to its rarity, its treatment approach has still not been defined, but it seems that novel agents, especially Bruton tyrosine kinase inhibitors (BTKi), are effective. As for RT, the standard therapy still consists of chemo-immunotherapy followed by stem-cell transplantation for fit responders with a dismal prognosis. New approaches are recently adopted including B-cell inhibition via novel agents (BTKi, venetoclax), T-cell engagers (checkpoint inhibitors, bispecific antibodies [BiTe] or the chimeric antigen receptor [CAR] technology), antibody-drug conjugates, or drug combinations. Although both CAR-T and BiTe seem promising, especially when combined with BTKi, evidence is still insufficient, and patients should generally be recruited in clinical trials.

KEY MESSAGES

The field of CLL has been a subject of major advances in recent years, but A-CLL and RT remain topics of "unmet need" and require further studies to identify the best diagnostic approach and a more effective treatment.

Assessment of ibrutinib scheduling on leukocyte, lymph node size and blood pressure dynamics in chronic lymphocytic leukemia through pharmacokinetic-pharmacodynamic models

Ibrutinib is a Bruton tyrosine kinase (Btk) inhibitor for treating chronic lymphocytic leukemia (CLL). It has also been associated with hypertension. The optimal dosing schedule for mitigating this adverse effect is currently under discussion. A quantification of relationships between systemic ibrutinib exposure and efficacy (i.e., leukocyte count and sum of the product of perpendicular diameters [SPD] of lymph nodes) and hypertension toxicity (i.e., blood pressure), and their association with overall survival is needed. Here, we present a semi-mechanistic pharmacokinetic-pharmacodynamic modeling framework to characterize such relationships and facilitate dose optimization. Data from a phase Ib/II study were used, including ibrutinib plasma concentrations to derive daily 0-24-h area under the concentration-time curve, leukocyte count, SPD, survival, and blood pressure measurements. A nonlinear mixed effects modeling approach was applied, considering ibrutinib's pharmacological action and CLL cell dynamics. The final framework included (i) an integrated model for SPD and leukocytes consisting of four CLL cell subpopulations with ibrutinib inhibiting phosphorylated Btk production, (ii) a turnover model in which ibrutinib stimulates an increase in blood pressure, and (iii) a competing risk model for dropout and death. Simulations predicted that the approved dosing schedule had a slightly higher efficacy (24-month, progression-free survival [PFS] 98%) than de-escalation schedules (24-month, average PFS ≈ 97%); the latter had, on average, ≈20% lower proportions of patients with hypertension. The developed modeling framework offers an improved understanding of the relationships among ibrutinib exposure, efficacy and toxicity biomarkers. This framework can serve as a platform to assess dosing schedules in a biologically plausible manner.

Detailed safety profile of acalabrutinib vs ibrutinib in previously treated chronic lymphocytic leukemia in the ELEVATE-RR trial

ELEVATE-RR demonstrated noninferior progression-free survival and lower incidence of key adverse events (AEs) with acalabrutinib vs ibrutinib in previously treated chronic lymphocytic leukemia. We further characterize AEs of acalabrutinib and ibrutinib via post hoc analysis. Overall and exposure-adjusted incidence rate was assessed for common Bruton tyrosine kinase inhibitor-associated AEs and for selected events of clinical interest (ECIs). AE burden scores based on previously published methodology were calculated for AEs overall and selected ECIs. Safety analyses included 529 patients (acalabrutinib, n = 266; ibrutinib, n = 263). Among common AEs, incidences of any-grade diarrhea, arthralgia, urinary tract infection, back pain, muscle spasms, and dyspepsia were higher with ibrutinib, with 1.5- to 4.1-fold higher exposure-adjusted incidence rates. Incidences of headache and cough were higher with acalabrutinib, with 1.6- and 1.2-fold higher exposure-adjusted incidence rate, respectively. Among ECIs, incidences of any-grade atrial fibrillation/flutter, hypertension, and bleeding were higher with ibrutinib, as were exposure-adjusted incidence rates (2.0-, 2.8-, and 1.6-fold, respectively); incidences of cardiac events overall (the Medical Dictionary for Regulatory Activities system organ class) and infections were similar between arms. Rate of discontinuation because of AEs was lower for acalabrutinib (hazard ratio, 0.62; 95% confidence interval, 0.41-0.93). AE burden score was higher for ibrutinib vs acalabrutinib overall and for the ECIs atrial fibrillation/flutter, hypertension, and bleeding. A limitation of this analysis is its open-label study design, which may influence the reporting of more subjective AEs. Overall, event-based analyses and AE burden scores demonstrated higher AE burden overall and specifically for atrial fibrillation, hypertension, and hemorrhage with ibrutinib vs acalabrutinib. This trial was registered at www.clinicaltrials.gov as #NCT02477696.

A fixed-duration immunochemotherapy approach in CLL: 5.5-year results from the phase 2 ICLL-07 FILO trial

In previously untreated, medically fit patients with chronic lymphocytic leukemia (CLL), research is focused on developing fixed-duration strategies to improve long-term outcomes while sparing patients from serious toxicities. The ICLL-07 trial evaluated a fixed-duration (15-month) immunochemotherapy approach in which after obinutuzumab-ibrutinib induction for 9 months, patients (n = 10) in complete remission (CR) with bone marrow (BM) measurable residual disease (MRD) <0.01% continued only ibrutinib 420 mg/day for 6 additional months (I arm), whereas the majority (n = 115) received up to 4 cycles of fludarabine/cyclophosphamide-obinutuzumab 1000 mg alongside the ibrutinib (I-FCG arm). Primary analysis at month 16 showed that 84 of 135 (62.2%) patients enrolled achieved CR with a BM MRD <0.01%. Here, we report follow-up at median 63 months. Peripheral blood (PB) MRD was assessed 6 monthly beyond the end of treatment using a highly sensitive (10-6) flow cytometry technique. In the I-FCG arm, the PB MRD <0.01% rate (low-level positive <0.01% or undetectable with limit of detection ≤10-4) in evaluable patients was still 92.5% (74/80) at month 40 and 80.6% (50/62) at month 64. No differences in the PB MRD status were apparent per to the IGHV mutational status. In the overall population, 4-year progression-free and overall survival rates were 95.5% and 96.2%, respectively. Twelve deaths occurred overall. Fourteen serious adverse events occurred beyond the end of treatment. Thus, our fixed-duration immunochemotherapy approach produced deep and sustained PB MRD responses, high survival rates, and low long-term toxicity. A randomized trial is needed to compare our immunochemotherapy approach with a chemotherapy-free strategy. This trial was registered at www.clinicaltrials.gov as #NCT02666898.

Role of microRNAs in Chronic Lymphocytic Leukemia

Chronic Lymphocytic Leukemia (CLL) is the most common form of leukemia in adults, with a highly variable clinical course. Improvement in the knowledge of the molecular pathways behind this disease has led to the development of increasingly specific therapies, such as BCR signaling inhibitors and BCL-2 inhibitors. In this context, the emerging role of microRNAs (miRNAs) in CLL pathophysiology and their possible application in therapy is worth noting. MiRNAs are one of the most important regulatory molecules of gene expression. In CLL, they can act both as oncogenes and tumor suppressor genes, and the deregulation of specific miRNAs has been associated with prognosis, progression, and drug resistance. In this review, we describe the role of the miRNAs that primarily impact the disease, and how these miRNAs could be used as therapeutic tools. Certainly, the use of miRNAs in clinical practice is still limited in CLL. Many issues still need to be solved, particularly regarding their biological and safety profile, even if several studies have suggested their efficacy on the disease, alone or in combination with other drugs.

The Nanomechanical Properties of CLL Cells Are Linked to the Actin Cytoskeleton and Are a Potential Target of BTK Inhibitors

Chronic lymphocytic leukemia (CLL) is an incurable disease characterized by an intense trafficking of the leukemic cells between the peripheral blood and lymphoid tissues. It is known that the ability of lymphocytes to recirculate strongly depends on their capability to rapidly rearrange their cytoskeleton and adapt to external cues; however, little is known about the differences occurring between CLL and healthy B cells during these processes. To investigate this point, we applied a single-cell optical (super resolution microscopy) and nanomechanical approaches (atomic force microscopy, real-time deformability cytometry) to both CLL and healthy B lymphocytes and compared their behavior. We demonstrated that CLL cells have a specific actomyosin complex organization and altered mechanical properties in comparison to their healthy counterpart. To evaluate the clinical relevance of our findings, we treated the cells in vitro with the Bruton's tyrosine kinase inhibitors and we found for the first time that the drug restores the CLL cells mechanical properties to a healthy phenotype and activates the actomyosin complex. We further validated these results in vivo on CLL cells isolated from patients undergoing ibrutinib treatment. Our results suggest that CLL cells' mechanical properties are linked to their actin cytoskeleton organization and might be involved in novel mechanisms of drug resistance, thus becoming a new potential therapeutic target aiming at the normalization of the mechanical fingerprints of the leukemic cells.

Indirect comparisons of efficacy of zanubrutinib versus orelabrutinib in patients with relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma or relapsed or refractory mantle cell lymphoma

We conducted two indirect comparisons to estimate the efficacy of zanubrutinib versus orelabrutinib in Chinese patients with relapsed or refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) or R/R mantle cell lymphoma (MCL). An unanchored matching-adjusted indirect comparison (MAIC) was performed in R/R CLL/SLL patients. Individual patient data from zanubrutinib trial (BGB-3111-205) were adjusted to match the aggregated data from the orelabrutinib trial (ICP-CL-00103). A naïve comparison was performed in R/R MCL for the different response assessment methodology and efficacy analysis set between the zanubrutinib (BGB-3111-206) and orelabrutinib (ICP-CL-00102) trials. Efficacy outcomes included ORR and PFS. In R/R CLL/SLL patients, after matching, IRC-assessed ORR was comparable (86.6% vs. 92.5%; risk difference, -5.9% [95% CI: -15.8%-3.8%]); IRC-assessed PFS was similar with a favorable trend in zanubrutinib over orelabrutinib (HR, 0.74 [95% CI: 0.37-1.47]) and the 18-month PFS rate was numerically higher in zanubrutinib (82.9% vs. 78.7%). In R/R MCL patients, naïve comparison showed investigator-assessed ORR was similar (83.7% vs. 87.9%; risk difference, -4.2% [95% CI: -14.8%-6.0%]), and CR rate was significantly higher in zanubrutinib over orelabrutinib (77.9% vs. 42.9%; risk difference, 35.0% [95% CI: 14.5%, 53.7%]). Investigator-assessed PFS was similar with a favorable trend (HR, 0.77 [95% CI: 0.45-1.32]) in zanubrutinib over orelabrutinib and the 12-month PFS rate was numerically higher in zanubrutinib (77.5% vs. 70.8%). MAIC result showed zanubrutinib demonstrated favorable PFS over orelabrutinib for R/R CLL/SLL patients. The naïve comparison showed zanubrutinib had favorable PFS and higher CR rate than orelabrutinib for R/R MCL patients.

Outcomes in Patients with High-Risk Features after Fixed-Duration Ibrutinib plus Venetoclax: Phase II CAPTIVATE Study in First-Line Chronic Lymphocytic Leukemia

PURPOSE

The CAPTIVATE study investigated first-line ibrutinib plus venetoclax for chronic lymphocytic leukemia in 2 cohorts: minimal residual disease (MRD)-guided randomized discontinuation (MRD cohort) and Fixed Duration (FD cohort). We report outcomes of fixed-duration ibrutinib plus venetoclax in patients with high-risk genomic features [del(17p), TP53 mutation, and/or unmutated immunoglobulin heavy chain (IGHV)] in CAPTIVATE.

PATIENTS AND METHODS

Patients received three cycles of ibrutinib 420 mg/day then 12 cycles of ibrutinib plus venetoclax (5-week ramp-up to 400 mg/day). FD cohort patients (n = 159) received no further treatment. Forty-three MRD cohort patients with confirmed undetectable MRD (uMRD) after 12 cycles of ibrutinib plus venetoclax received randomized placebo treatment.

RESULTS

Of 195 patients with known status of genomic risk features at baseline, 129 (66%) had ≥1 high-risk feature. Overall response rates were >95% regardless of high-risk features. In patients with and without high-risk features, respectively, complete response (CR) rates were 61% and 53%; best uMRD rates: 88% and 70% (peripheral blood) and 72% and 61% (bone marrow); 36-month progression-free survival (PFS) rates: 88% and 92%. In subsets with del(17p)/TP53 mutation (n = 29) and unmutated IGHV without del(17p)/TP53 mutation (n = 100), respectively, CR rates were 52% and 64%; uMRD rates: 83% and 90% (peripheral blood) and 45% and 80% (bone marrow); 36-month PFS rates: 81% and 90%. Thirty-six-month overall survival (OS) rates were >95% regardless of high-risk features.

CONCLUSIONS

Deep, durable responses and sustained PFS seen with fixed-duration ibrutinib plus venetoclax are maintained in patients with high-risk genomic features, with similar PFS and OS to those without high-risk features. See related commentary by Rogers, p. 2561.