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The clinical course of patients with recently diagnosed early stage chronic lymphocytic leukemia (CLL) is highly variable. We examined the relationship between CLL-cell birth rate and treatment-free survival (TFS) in 97 patients with recently diagnosed, Rai stage 0-II CLL in a blinded, prospective study, using in vivo 2H2O labeling. Birth rates ranged from 0.07 to 1.31% new cells per day. With median follow-up of 4.0 years, 33 subjects (34%) required treatment by NCI criteria. High-birth rate was observed in 44% of subjects and was significantly associated with shorter TFS, unmutated IGHV status and expression of ZAP70 and of CD38. In multivariable modeling considering age, gender, Rai stage, expression of ZAP70 or CD38, IGHV mutation status and FISH cytogenetics, only CLL-cell birth rate and IGHV mutation status met criteria for inclusion. Hazard ratios were 3.51 (P=0.002) for high-birth rate and 4.93 (P

Abstract: Many patients with chronic lymphocytic leukemia (CLL) will develop treatment resistance to Bruton tyrosine kinase (BTK) inhibitors. Phosphatidylinositol-3-kinase (PI3K) inhibitors, including umbralisib, have significant clinical activity in relapsed/refractory CLL, but prolonged exposure is associated with potential toxicities. Owing to the synergistic antitumor effects of combined PI3K and BCL-2 inhibition, we sought to explore the feasibility of response-adapted, time-limited therapy to optimize disease control while mitigating the risks of prolonged treatment. We conducted a phase 1/2 clinical trial to determine the safety and efficacy of venetoclax in combination with umbralisib and the anti-CD20 monoclonal antibody, ublituximab, (U2-VeN) in patients with relapsed/refractory CLL (N = 46) and Richter transformation (N = 5). After 12 cycles, treatment was stopped for patients with CLL who achieved undetectable minimal residual disease (uMRD). Adverse events of special interest included diarrhea in 50% of patients (11% grade 3/4), and aspartate aminotransferase and/or alanine aminotransferase elevation in 15 patients (33%), with 3 (7%) grade 3/4. There were no cases of tumor lysis syndrome related to venetoclax, with outpatient initiation in 96% of patients. The intent-to-treat overall response rate for CLL was 98% with best response of 100% in evaluable patients (42% complete responses). The end-of-treatment rate of uMRD at 10-4 in bone marrow was 77% (30/39), including a 71% uMRD rate among 14 patients refractory to prior BTK inhibitor. Time-limited venetoclax and U2 is safe and highly effective combination therapy for patients with relapsed/refractory CLL including those who have been previously treated with covalent BTK inhibitors. This trial was registered on www.clinicaltrials.gov as #NCT03379051., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Background: Lymphoma treatment may be associated with new-onset atrial fibrillation (AF), especially among patients treated with Bruton tyrosine kinase inhibitors (BTKi)., Objectives: The authors sought to assess the risk of new-onset AF, AF risk factors, and the impact of AF on mortality in patients with lymphoma and no history of AF., Methods: The University of Rochester Medical Center Lymphoma Database was used to identify patients. The primary outcome was any AF episode identified using the International Classification of Diseases-10th Revision codes. Multivariable Cox regression was used to assess the risk of AF through the use of a time-dependent covariate for treatment overall as well as separate time-varying measures of BTKi (mainly ibrutinib) and non-BTKi treatment. The relative risk of all-cause mortality was determined using Cox proportional hazards analysis., Results: Among 1,957 lymphoma patients, the rate of AF at 5-years following initiation of BTKi treatment was higher (25%) compared to those receiving non-BTKi therapy (8%), and those receiving no treatment (4%). Multivariable analysis showed that BTKi treatment was associated with pronounced increased risk for AF compared to no treatment (HR: 5.07 [95% CI: 2.88-8.90; P  < 0.001]). Non-BTKi treatment was associated with an increased risk of AF compared to no treatment (HR: 1.82 [95% CI: 1.14-2.89; P  = 0.012]). Risk factors for the development of AF included age ≥64 years, male sex, hypertension, and lymphoma treatment. New AF was associated with an increased risk for subsequent mortality (HR: 3.71 [95% CI: 2.59-5.31])., Conclusions: Patients undergoing lymphoma treatment, especially those with high-risk features, may benefit from AF surveillance., Competing Interests: Dr Zent has received research funding from Acerta/AstraZeneca and 10.13039/100013252TG Therapeutics. Dr Aktas has received research funding from AstraZeneca. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2023 The Authors.)

Background: Adolescent and Young Adults (AYAs) are an underserved, high-risk population. Identifying health care utilization patterns, and particularly acute care visits, is important as these are high-intensity, expensive services. We investigated whether differences exist in health care utilization between the AYA lymphoma population compared to their older adult counterparts., Materials and Methods: Two correlated outcomes were used to measure health care utilization: 4 or more acute visits (emergency department or urgent care) and number of nonacute visits (office or telephone visits). We studied 442 patients with aggressive lymphoma patients 15 years or older at time of diagnosis managed at our cancer center within 2 years of their diagnosis. A multivariate generalized linear mixed model simultaneously estimated the effect of baseline predictors on 4 or more acute care visit with robust Poisson regression and nonacute visit counts with negative binomial regression allowing for a within-subject random effect., Results: AYAs had increased risk of having ≥4 acute visits (RR = 1.96; P = .047) compared to their older counterparts. Obesity (RR = 2.04, P = .015) and living less than 50 miles from the cancer center (RR = 3.48, P = .015) were independently associated with higher risk of acute care usage. Acute care visits for psychiatric or substance use related reasons were significantly higher (P = .0001) among AYA (10/114, 8.8%) vs. non-AYA (3/328, 0.9%)., Conclusion: Disease-targeted interventions to address high acute health care utilization is needed amongst AYAs. Additionally, early multidisciplinary involvement after cancer diagnosis particularly with psychiatric expertise amongst AYAs and palliative care involvement in both groups is needed., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Bruton tyrosine kinase inhibitors are an effective therapeutic agent for previously untreated patients with chronic lymphocytic leukemia but require indefinite treatment that can result in cumulative toxicities. Novel combinations of agents that provide deep remissions could allow for fixed duration therapy. Acalabrutinib, unlike ibrutinib, does not inhibit anti-CD20 monoclonal antibody-dependent cellular phagocytosis, making it a suitable partner drug to rituximab. Using standard dosing (375 mg/m2) of rituximab causes loss of target membrane CD20 cells and exhaustion of the finite cytotoxic capacity of the innate immune system. Alternatively, using high-frequency, low-dose (HFLD), subcutaneous rituximab limits loss of CD20 and allows for self-administration at home. The combination of HFLD rituximab 50 mg administered twice a week for 6 cycles of 28 days with the addition of acalabrutinib starting in week 2 was evaluated in a phase II study of 38 patients with treatment naive chronic lymphocytic leukemia. Patients achieving a complete response with undetectable minimal residual disease after 12 or 24 cycles of acalabrutinib could stop therapy. All patient responded, including one with a complete response with undetectable minimal residual disease in the peripheral blood and bone marrow at 12 months who stopped therapy. At a median follow-up of 2.3 years 2 patients with high-risk features have progressed while on acalabrutinib monotherapy. We conclude that HFLD rituximab in combination with acalabrutinib is an effective and tolerable self-administered home combination that provides a platform to build upon regimens that may more reliably allow for fixed-duration therapy. This trial was registered at www.clinicaltrials.gov #NCT03788291., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Monoclonal antibody induced infusion reactions (IRs) can be serious and even fatal. We used clinical data and blood samples from 37 treatment naïve patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) initiating therapy for progressive disease with a single 50 mg dose of intravenous (IV) rituximab at 25 mg/h. Twenty-four (65 %) patients had IRs at a median of 78 min (range 35-128) and rituximab dose of 32 mg (range 15-50). IR risk did not correlate with patient or CLL characteristics, CLL counts or CD20 levels, or serum rituximab or complement concentrations. Thirty-five (95 %) patients had cytokine release response with a ≥ 4-fold increase in serum concentration of ≥ 1 inflammatory cytokine. IRs were associated with significantly higher post-infusion serum concentrations of gamma interferon induced cytokines IP-10, IL-6 and IL-8. IP-10 concentrations increased ≥ 4-fold in all patients with an IR and were above the upper limit of detection (40,000 pg/ml) in 17 (71 %). In contrast, to only three (23 %) patients without an IR had an ≥ 4-fold increase in serum concentrations of IP-10 (highest 22,013 pg/ml). Our data suggest that cytokine release could be initiated by activation of effector cells responsible for clearance of circulating CLL cells with IRs occurring in those with higher levels of gamma interferon induced cytokines. These novel insights could inform future research to better understand and manage IRs and understand the role of cytokines in the control of cytotoxic immune responses to mAb., Competing Interests: Declaration of Competing Interest PBM and CSZ report funding for research through the University of Rochester from AstraZeneca and TG Therapeutics, CSZ reports funding for research through the University of Rochester from GenMab, and PMB reports serving as a consultant for Pharmacyclics, AbbVie, Genentech and Seattle Genetics. The other authors report no potential conflicts of interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Introduction: Splenic B-cell lymphomas are rare and understudied entities. Splenectomy is frequently required for specific pathological diagnosis in patients with splenic B-cell lymphomas other than classical hairy cell leukemia (cHCL), and can be effective and durable therapy. Our study investigated the diagnostic and therapeutic role of splenectomy for non-cHCL indolent splenic B-cell lymphomas., Methods: Observational study of patients with non-cHCL splenic B-cell lymphoma undergoing splenectomy between 1 August 2011 and 1 August 2021 at the University of Rochester Medical Center. The comparison cohort was patients categorized as having non-cHCL splenic B-cell lymphoma who did not undergo splenectomy., Results: Forty-nine patients (median age 68 years) had splenectomy (SMZL n = 33, HCLv n = 9, SDRPL n = 7) with median follow up of 3.9 years post splenectomy. One patient had fatal post-operative complications. Post-operative hospitalization was ≤ 4 days for 61% and ≤ 10 days for 94% of patients. Splenectomy was initial therapy for 30 patients. Of the 19 patients who had previous medical therapy, splenectomy changed their lymphoma diagnosis in 5 (26%). Twenty-one patients without splenectomy were clinically categorized as having non-cHCL splenic B-cell lymphoma. Nine required medical treatment for progressive lymphoma and of these 3 (33%) required re-treatment for lymphoma progression compared to 16% of patients following first line splenectomy., Conclusion: Splenectomy is useful for the diagnosis of non-cHCL splenic B-cell lymphomas with comparable risk/benefit profile and remission duration to medical therapy. Patients with suspected non-cHCL splenic lymphomas should be considered for referral to a high-volume center with experience in performing splenectomies for definitive diagnosis and treatment., Competing Interests: Competing interests disclosure The authors have no relevant conflicts of interest to disclose., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background There are limited data on risk of arrhythmias among patients with lymphoproliferative disorders. We designed this study to determine the risk of atrial and ventricular arrhythmia during treatment of lymphoma in a real-world setting. Methods and Results The study population comprised 2064 patients included in the University of Rochester Medical Center Lymphoma Database from January 2013 to August 2019. Cardiac arrhythmias-atrial fibrillation/flutter, supraventricular tachycardia, ventricular arrhythmia, and bradyarrhythmia-were identified using International Classification of Diseases, Tenth Revision ( ICD-10 ) codes. Multivariate Cox regression analysis was used to assess the risk of arrhythmic events with treatments categorized as Bruton tyrosine kinase inhibitor (BTKi), mainly ibrutinib/non-BTKi treatment versus no treatment. Median age was 64 (54-72) years, and 42% were women. The overall rate of any arrhythmia at 5 years following the initiation of BTKi was (61%) compared with (18%) without treatment. Atrial fibrillation/flutter was the most common type of arrhythmia accounting for 41%. Multivariate analysis showed that BTKi treatment was associated with a 4.3-fold ( P <0.001) increased risk for arrhythmic event ( P <0.001) compared with no treatment, whereas non-BTKi treatment was associated with a 2-fold ( P <0.001) risk increase. Among subgroups, patients without a history of prior arrhythmia exhibited a pronounced increase in the risk for the development of arrhythmogenic cardiotoxicity (3.2-fold; P <0.001). Conclusions Our study identifies a high burden of arrhythmic events after initiation of treatment, which is most pronounced among patients treated with the BTKi ibrutinib. Patients undergoing treatments for lymphoma may benefit from prospective focused cardiovascular monitoring prior, during, and after treatment regardless of arrhythmia history.

A significant body of literature has been generated related to the detection of measurable residual disease (MRD) at the time of achieving complete remission (CR) in patients with hairy cell leukemia (HCL). However, due to the indolent nature of the disease as well as reports suggesting long-term survival in patients treated with a single course of a nucleoside analog albeit without evidence of cure, the merits of detection of MRD and attempts to eradicate it have been debated. Studies utilizing novel strategies in the relapse setting have demonstrated the utility of achieving CR with undetectable MRD (uMRD) in prolonging the duration of remission. Several assays including immunohistochemical analysis of bone marrow specimens, multi-parameter flow cytometry and molecular assays to detect the mutant BRAF V600E gene or the consensus primer for the immunoglobulin heavy chain gene (IGH) rearrangement have been utilized with few comparative studies. Here we provide a consensus report on the available data, the potential merits of MRD assessment in the front-line and relapse settings and recommendations on future role of MRD assessment in HCL., (© 2022. The Author(s).)

Hairy cell leukemia (HCL) is a rare lymphoproliferative disorder, comprising only 2% of all leukemias. The Hairy Cell Leukemia Foundation (HCLF) has developed a patient data registry to enable investigators to better study the clinical features, treatment outcomes, and complications of patients with HCL. This system utilizes a centralized registry architecture. Patients are enrolled at HCL Centers of Excellence (COE) or via a web-based portal. All data are de-identified, which reduces regulatory burden and increases opportunities for data access and re-use. To date, 579 patients have been enrolled in the registry. Efforts are underway to engage additional COE's to expand access to patients across the globe. This international PDR will enable researchers to study outcomes in HCL in ways not previously possible due to the rarity of the disease and will serve as a platform for future prospective research.

A diagnosis of leukemia can have a profound effect on patients' health-related quality of life (HRQoL), however this has not been measured prospectively in patients with hairy cell leukemia (HCL). At the request of patients living with HCL who had identified this gap in knowledge about the disease, we conducted a longitudinal study of HRQoL among patients enrolled in the HCL Patient Data Registry (PDR). From September 1, 2018 to September 1, 2020, 165 patients were enrolled in the study and completed the baseline survey. The Functional Assessment of Cancer Therapy - Leukemia (FACT-Leu) was used to measure patients' HRQoL. Results show that newly diagnosed HCL patients reported the lowest HRQoL, followed by patients in relapse and those on "watch and wait." Factors associated with higher (better) FACT-Leu total scores in the multivariable analysis included older age, higher social support, and greater physical activity. These same factors were associated with lower levels of fatigue. In rare diseases where it is difficult to perform large prospective studies, patient/researcher collaborations are critical for the identification of studies that are of importance to patients and their families in order to maximize the benefits of the research and improve the lives of patients living with HCL., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Competing Interests: The authors declare no conflict of interest.

Chronic lymphocytic leukemia (CLL) is characterized by early and profound immune suppression and reversal of these effects is essential to improve patient outcome. Targeted therapy with small-molecule inhibitors such as ibrutinib is highly effective and tolerable. Emerging data suggest that patients with CLL responding to ibrutinib therapy can recover anti-CLL adaptive immune cytotoxicity. See related article by Baptista et al., p. 4624 ., (©2021 American Association for Cancer Research.)

Phosphoinositide-3-kinase (PI3K) inhibitors have efficacy in lymphoid malignancies; however, inflammatory and infectious toxicities can compromise the treatment course. An improved understanding of these toxicities will guide clinical use and further development. We evaluated the occurrence of treatment-related adverse events (AEs) in a retrospective review of 79 patients treated in standard fashion with PI3K inhibitor monotherapy or with anti-CD20 monoclonal antibodies or as part of a novel combination regimen. Patients treated with a novel combination were at a higher risk of developing a severe AE compared to those treated with standard therapy (HR 1.89, 95% CI 1.02, 3.49; p  = .04). Additionally, previously untreated patients were at higher risk of developing a severe AE compared to previously treated patients (HR 3.19, 95% CI 1.48, 6.84; p  = .003). These results caution against the use of untested PI3K inhibitor combinations in routine practice and suggest that early phase clinical trials should utilize conservative treatment schemas.

Most patients with treatment naïve classical hairy cell leukemia (cHCL) have durable responses with purine nucleoside analogues. In contrast, options are limited for cHCL patients with co-morbidities, purine analogue intolerance, or resistant disease. We report the utility of targeted therapy for nine cHCL patients presenting with treatment naïve cHCL and severe neutropenia and infection (n = 3), purine analogue intolerance (n = 2), or purine analogue resistant disease (n = 4). BRAF inhibitor vemurafenib was started at 240-480 mg twice daily (planned 90-day treatment) and combined with rituximab in seven patients. Therapy was tolerable with no severe adverse events. All patients responded with rapid blood count recovery (median time 1.52 months, range 0.43-4.33). Median progression free and overall survival was not reached at a median follow up of 18.1 months (range 3.2-68.9). These data suggest targeted therapy could be an option for patients unable to be treated with purine analogues., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Unconjugated monoclonal antibodies (mAb) have revolutionized the treatment of B-cell malignancies. These targeted drugs can activate innate immune cytotoxicity for therapeutic benefit. mAb activation of the complement cascade results in complement-dependent cytotoxicity (CDC) and complement receptor-mediated antibody-dependent cellular phagocytosis (cADCP). Clinical and laboratory studies have showed that CDC is therapeutically important. In contrast, the biological role and clinical effects of cADCP are less well understood. This review summarizes the available data on the role of complement activation in the treatment of mature B-cell malignancies and proposes future research directions that could be useful in optimizing the efficacy of this important class of drugs.

Macrophage antibody (Ab)-dependent cellular phagocytosis (ADCP) is a major cytotoxic mechanism for both therapeutic unconjugated monoclonal Abs (mAbs) such as rituximab and Ab-induced hemolytic anemia and immune thrombocytopenia. Here, we studied the mechanisms controlling the rate and capacity of macrophages to carry out ADCP in settings of high target/effector cell ratios, such as those seen in patients with circulating tumor burden in leukemic phase disease. Using quantitative live-cell imaging of primary human and mouse macrophages, we found that, upon initial challenge with mAb-opsonized lymphocytes, macrophages underwent a brief burst (<1 hour) of rapid phagocytosis, which was then invariably followed by a sharp reduction in phagocytic activity that could persist for days. This previously unknown refractory period of ADCP, or hypophagia, was observed in all macrophage, mAb, and target cell conditions tested in vitro and was also seen in vivo in Kupffer cells from mice induced to undergo successive rounds of αCD20 mAb-dependent clearance of circulating B cells. Importantly, hypophagia had no effect on Ab-independent phagocytosis and did not alter macrophage viability. In mechanistic studies, we found that the rapid loss of activating Fc receptors from the surface and their subsequent proteolytic degradation were the primary mechanisms responsible for the loss of ADCP activity in hypophagia. These data suggest hypophagia is a critical limiting step in macrophage-mediated clearance of cells via ADCP, and understanding such limitations to innate immune system cytotoxic capacity will aid in the development of mAb regimens that could optimize ADCP and improve patient outcome., (© 2020 by The American Society of Hematology.)

Family and migration studies suggest a genetic risk of developing chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL). We hypothesized that CLL patients have an increased risk of additional clonally unrelated B-cell malignancies. To test this, we studied 467 CLL patients (2743 person-years (PYs)) at a single institution over 17 years. The incidence rate (IR) of any additional B-cell lymphoid malignancy was 10.9 per 1000 PYs ( n  = 30, 6.4%). Eighteen (4%) patients had a clonally unrelated B-cell malignancy (IR = 6.6 per 1000 PYs). Standardized incidence ratios (SIRs) were used to compare the incidence of additional clonally unrelated B-cell malignancies in CLL patients to the age- and sex-matched expected rates in the USA generated from the Surveillance, Epidemiology, and End Results (SEER) database. For the subset of 13 patients having data for comparison in the SEER database, the SIR was 5.41 (95% CI = 2.9, 9.3) which is supportive of our hypothesis.

Cancer-related cognitive impairment (CRCI) has not been objectively assessed in chronic lymphocytic leukemia (CLL). It is currently unclear how much of CRCI is attributable to disease, treatment, or both. We used CLL as a novel model to study the differential roles of disease and treatment in CRCI. One hundred and fifty CLL patients (100 treatment-naïve and 50 chemotherapy-treated) including 84 patients with higher-risk of CLL progression completed objective neuropsychological tests. Sociodemographic-adjusted linear regression models examined cognitive outcomes in relation to risk and treatment. Higher-risk patients recalled two fewer words on a memory task ( β  = -1.8, 95%CI -3.3,-0.3) and took 15 s longer on an executive function task ( β  = 15.4, 95%CI 3.1, 27.6) than lower-risk patients, independent of treatment. Treated patients reported greater cognitive difficulties than treatment-naive patients ( β  = -6.1, 95%CI -10.1, -2.2) but did not perform worse on objective measures. Higher-risk patients experienced impairments in executive function and memory suggesting that disease biology contributes to CRCI independent of treatment.

Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) is associated with increased risk for certain cancers, but relatively little is known about the risk for these patients to develop additional B cell malignancies. Here, we review the available epidemiological data on multiple B cell malignancies in CLL, discuss diagnostic methods and proper pathologic evaluation to distinguish CLL from other B cell malignancies, and address clinical challenges and unmet needs in caring for CLL patients with unrelated B cell malignancies and disease transformation. Considerations include CLL patients with unrelated monoclonal B cell lymphocytosis, biclonal CLL, secondary B cell non-Hodgkin lymphomas, and Richter syndrome - both clonally related transformation and de novo large B cell lymphoma. We address the challenges that remain in order to better understand the underlying risk factors and biology that may put CLL patients at increased risk of developing multiple B cell neoplasia.

Phagocytosis is a dynamic process central to immunity and tissue homeostasis. Current methods for quantification of phagocytosis largely rely on indirect or static measurements, such as target clearance or dye uptake, and thus provide limited information about engulfment rates or target processing. Improved kinetic measurements of phagocytosis could provide useful, basic insights in many areas. We present a live-cell, time-lapse and high-content microscopy imaging method based on the detection and quantification of fluorescent dye 'voids' within phagocytes that result from target internalization to quantify phagocytic events with high temporal resolution. Using this method, we measure target cell densities and antibody concentrations needed for optimal antibody-dependent cellular phagocytosis. We compare void formation and dye uptake methods for phagocytosis detection, and examine the connection between target cell engulfment and phagolysosomal processing. We demonstrate how this approach can be used to measure distinct forms of phagocytosis, and changes in macrophage morphology during phagocytosis related to both engulfment and target degradation. Our results provide a high-resolution method for quantifying phagocytosis that provides opportunities to better understand the cellular and molecular regulation of this fundamental biological process., Competing Interests: Competing interestsThe authors declare no conflict of interest. While we thank our funding sources for their support, none of these organizations, including Acerta Pharma LLC, contributed to the concept or design of this project, nor did they contribute to the data acquisition or data analysis presented here., (© 2020. Published by The Company of Biologists Ltd.)

CD20 monoclonal antibody therapies have significantly improved the outlook for patients with B-cell malignancies. However, many patients acquire resistance, demonstrating the need for new and improved drugs. We previously demonstrated that the natural process of antibody hexamer formation on targeted cells allows for optimal induction of complement-dependent cytotoxicity. Complement-dependent cytotoxicity can be potentiated by introducing a single point mutation such as E430G in the IgG Fc domain that enhances intermolecular Fc-Fc interactions between cell-bound IgG molecules, thereby facilitating IgG hexamer formation. Antibodies specific for CD37, a target that is abundantly expressed on healthy and malignant B cells, are generally poor inducers of complement-dependent cytotoxicity. Here we demonstrate that introduction of the hexamerization-enhancing mutation E430G in CD37-specific antibodies facilitates highly potent complement-dependent cytotoxicity in chronic lymphocytic leukemia cells ex vivo Strikingly, we observed that combinations of hexamerization-enhanced CD20 and CD37 antibodies cooperated in C1q binding and induced superior and synergistic complement-dependent cytotoxicity in patient-derived cancer cells compared to the single agents. Furthermore, CD20 and CD37 antibodies colocalized on the cell membrane, an effect that was potentiated by the hexamerization-enhancing mutation. Moreover, upon cell surface binding, CD20 and CD37 antibodies were shown to form mixed hexameric antibody complexes consisting of both antibodies each bound to their own cognate target, so-called hetero-hexamers. These findings provide novel insights into the mechanisms of synergy in antibody-mediated complement-dependent cytotoxicity and provide a rationale to explore Fc-engineering and antibody hetero-hexamerization as a tool to enhance the cooperativity and therapeutic efficacy of antibody combinations., (Copyright© 2019 Ferrata Storti Foundation.)

Background: As oral targeted agents, such as ibrutinib, become more widely used, understanding the impact of suboptimal dosing on overall survival (OS) and progression-free survival (PFS) outside of clinical trials is imperative., Patients and Methods: Data on ibrutinib discontinuation, dose reductions, and treatment interruptions were collected on 170 non-Hodgkin lymphoma and chronic lymphocytic leukemia (CLL; n = 115, 64%) patients treated with ibrutinib at a single institution. Ibrutinib dose adherence was calculated as the proportion of days in which ibrutinib was administered out of the total number of days ibrutinib was prescribed in the first 8 weeks. Kaplan-Meier curves and log-rank tests were used to compare conditional survival outcomes beyond 8 weeks in patients with ≥ 80% dose adherence and patients with < 80% dose adherence., Results: Median OS among those who discontinued therapy for progression was poor (n = 51, 1.7 months; 95% confidence interval, 0.3-3.7). Lower dose adherence (< 80%) was associated with significantly worse PFS (P = .002) and OS (P = .021). However, among CLL patients, lower dose adherence was only associated with worse PFS (P = .043). Patients with early dose reductions had significantly worse PFS (P = .004) and OS (P = .014). Patients with dose interruptions lasting > 1 week had worse PFS (P = .047) but not OS (P = .577)., Conclusion: In this observational study, non-Hodgkin lymphoma and CLL patients experienced poor outcomes after discontinuing ibrutinib for disease progression. The inferior survival related to suboptimal dose adherence of ibrutinib was predominantly due to early dose reduction. These data confirm poor survival in CLL and lymphoma patients alike after ibrutinib discontinuation, and support recommendations for full dose at treatment initiation., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Follicular lymphoma (FL) is a common indolent B-cell malignancy with a variable clinical course. An unfavorable event in its course is histological transformation to a high-grade lymphoma, typically diffuse large B-cell lymphoma. Recent studies show that genetic aberrations of MYC or its overexpression are associated with FL transformation (tFL). However, the precise molecular mechanisms underlying tFL are unclear. Here we performed the first profiling of expression of microRNAs (miRNAs) in paired samples of FL and tFL and identified 5 miRNAs as being differentially expressed. We focused on one of these miRNAs, namely miR-150 , which was uniformly downmodulated in all examined tFLs (∼3.5-fold), and observed that high levels of MYC are responsible for repressing miR-150 in tFL by binding in its upstream region. This MYC-mediated repression of miR-150 in B cells is not dependent on LIN28A/B proteins, which influence the maturation of miR-150 precursor ( pri-miR-150 ) in myeloid cells. We also demonstrated that low miR-150 levels in tFL lead to upregulation of its target, namely FOXP1 protein, which is a known positive regulator of cell survival, as well as B-cell receptor and NF-κB signaling in malignant B cells. We revealed that low levels of miR-150 and high levels of its target, FOXP1, are associated with shorter overall survival in FL and suggest that miR-150 could serve as a good biomarker measurable in formalin-fixed paraffin-embedded tissue. Overall, our study demonstrates the role of the MYC/ miR-150 /FOXP1 axis in malignant B cells as a determinant of FL aggressiveness and its high-grade transformation., (© 2018 by The American Society of Hematology.)

Ibrutinib demonstrated superior response rates and survival for treatment-naïve chronic lymphocytic leukemia (CLL) patients in a pivotal study that excluded patients younger than 65 (<65) and/or with chromosome 17p13 deletion (del[17p13]). We examined outcomes and toxicities of CLL patients who would have been excluded from the pivotal study, specifically <65 and/or those with del[17p13]. This multicenter, retrospective cohort study examined CLL patients treated with front-line ibrutinib at 20 community and academic centers, categorizing them based on key inclusion criteria for the RESONATE-2 trial: <65 vs ≥65 and present vs absent del[17p13]. Of 391 included patients, 57% would have been excluded from the pivotal study. Forty-one percent of our cohort was <65, and 30% had del(17p13). Patients <65 were more likely to start 420 mg of ibrutinib daily; those who started at reduced doses had inferior PFS. The most common adverse events were arthralgias, fatigue, rash, bruising, and diarrhea. Twenty-four percent discontinued ibrutinib at 13.8 months median follow-up; toxicity was the most common reason for discontinuation, though progression and/or transformation accounted for a larger proportion of discontinuations in <65 and those with del(17p13). Response rates were similar for <65 and those with del(17p13). However, patients with del(17p13) had inferior PFS and OS. Ibrutinib in the front-line setting has extended beyond the population in which it was initially studied and approved. This study highlights and compares important differences in ibrutinib dosing, treatment interruptions, toxicities, reasons for discontinuation, and survival outcomes in two important patient populations not studied in RESONATE-2., (© 2018 Wiley Periodicals, Inc.)

CD20 monoclonal antibodies (CD20 mAb) induce cellular cytotoxicity, which is traditionally measured by antibody-dependent cellular cytotoxicity (ADCC) assays. However, data suggest that antibody-dependent cellular phagocytosis (ADCP) is the primary cytotoxic mechanism. We directly compared in vitro ADCP versus ADCC using primary human cells. After establishing the primacy of ADCP, we examined next-generation CD20 mAbs, including clinically relevant drug combinations for their effects on ADCP. ADCP and ADCC induction by rituximab, ofatumumab, obinutuzumab, or ocaratuzumab was measured using treatment-naïve chronic lymphocytic leukemia (CLL) target cells and either human monocyte-derived macrophages (for ADCP) or natural killer (NK) cells (for ADCC). Specific effects on ADCP were evaluated for clinically relevant drug combinations using BTK inhibitors (ibrutinib and acalabrutinib), PI3Kδ inhibitors (idelalisib, ACP-319, and umbralisib), and the BCL2 inhibitor venetoclax. ADCP (∼0.5-3 targets/macrophage) was >10-fold more cytotoxic than ADCC (∼0.04-0.1 targets/NK cell). ADCC did not correlate with ADCP. Next-generation mAbs ocaratuzumab and ofatumumab induced ADCP at 10-fold lower concentrations than rituximab. Ofatumumab, selected for enhanced complement activation, significantly increased ADCP in the presence of complement. CD20 mAb-induced ADCP was not inhibited by venetoclax and was less inhibited by acalabrutinib versus ibrutinib and umbralisib versus idelalisib. Overall, ADCP was a better measure of clinically relevant mAb-induced cellular cytotoxicity, and next-generation mAbs could activate ADCP at significantly lower concentrations, suggesting the need to test a wide range of dose sizes and intervals to establish optimal therapeutic regimens. Complement activation by mAbs can contribute to ADCP, and venetoclax, acalabrutinib, and umbralisib are preferred candidates for multidrug therapeutic regimens. Cancer Immunol Res; 6(10); 1150-60. ©2018 AACR ., (©2018 American Association for Cancer Research.)

Venetoclax is a BCL2 inhibitor approved for 17p-deleted relapsed/refractory chronic lymphocytic leukemia with activity following kinase inhibitors. We conducted a multicenter retrospective cohort analysis of patients with chronic lymphocytic leukemia treated with venetoclax to describe outcomes, toxicities, and treatment selection following venetoclax discontinuation. A total of 141 chronic lymphocytic leukemia patients were included (98% relapsed/refractory). Median age at venetoclax initiation was 67 years (range 37-91), median prior therapies was 3 (0-11), 81% unmutated IGHV , 45% del(17p), and 26.8% complex karyotype (≥ 3 abnormalities). Prior to venetoclax initiation, 89% received a B-cell receptor antagonist. For tumor lysis syndrome prophylaxis, 93% received allopurinol, 92% normal saline, and 45% rasburicase. Dose escalation to the maximum recommended dose of 400 mg daily was achieved in 85% of patients. Adverse events of interest included neutropenia in 47.4%, thrombocytopenia in 36%, tumor lysis syndrome in 13.4%, neutropenic fever in 11.6%, and diarrhea in 7.3%. The overall response rate to venetoclax was 72% (19.4% complete remission). With a median follow up of 7 months, median progression free survival and overall survival for the entire cohort have not been reached. To date, 41 venetoclax treated patients have discontinued therapy and 24 have received a subsequent therapy, most commonly ibrutinib. In the largest clinical experience of venetoclax-treated chronic lymphocytic leukemia patients, the majority successfully completed and maintained a maximum recommended dose. Response rates and duration of response appear comparable to clinical trial data. Venetoclax was active in patients with mutations known to confer ibrutinib resistance. Optimal sequencing of newer chronic lymphocytic leukemia therapies requires further study., (Copyright© 2018 Ferrata Storti Foundation.)

Melanoma is significantly more common and is associated with a poorer prognosis in patients with an underlying B-cell malignancy. This study reports on the management of patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) and a subsequent diagnosis of melanoma. In the Wilmot Cancer Institute CLL cohort, which includes 470 patients followed for 2849 person-years, 18 patients (3.8%) developed 22 melanomas. Fourteen melanomas were invasive, a significantly higher rate as compared with the age and sex matched general population (standardized incidence ratio [SIR] 6.32 (95% CI 3.45; 10.60). Melanomas were most often detected (n = 15; 68.2%) through active surveillance in a dermatology clinic. Most melanomas (n = 17; 77.3%) were detected at a non-advanced stage (pathological stage grouping < III). The most common management was wide local excision without sentinel lymph node biopsy (n = 13, 59.1%). Management for the 4 (18.2%) patients with metastatic disease included the immune checkpoint inhibitor (ICI) pembrolizumab (n = 1), systemic chemotherapy with dacarbazine (n = 1), and palliative care (n = 2). The patient treated with ICI is in sustained remission of her melanoma after 23 cycles of therapy while her TP53 disrupted CLL continues to respond to ibrutinib therapy. We conclude that patients with CLL may benefit from active surveillance for melanoma leading to early excision of locally-manageable disease. In patients with metastatic melanoma, combined treatment with targeted kinase inhibitors and ICIs can be successful and tolerable. Larger prospective studies should be considered to further evaluate these approaches., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

We studied the risk of infections in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL). Major infections were defined as requiring hospital admission or intravenous antimicrobial treatment. Incidence rate (IR) ratios (IRR) were used to compare infection rates. Of 263 CLL patients followed for 936.9 person-years, 60% required treatment for progressive CLL (66 received ibrutinib). Infections occurred in 71.9% patients (IR 92.4/100 person-years) with 31.9% having major infections (IR 20.3/100 person-years) and infections causing 37.5% of deaths. CLL treatment was associated with significantly higher risk of major (IRR 3.31, 95% CI 2.10, 5.21) and minor (IRR 1.78, 95% CI 1.43, 2.22) infections. Compared to their previous chemoimmunotherapy patients receiving salvage ibrutinib therapy (n = 47) had a significantly increased risk of a major infection (IRR 2.35 95% CI 1.27, 4.34). The risk of infection in CLL patients remains high even with use of less immunosuppressive therapies.

We examined complement-dependent cytotoxicity (CDC) by hexamer formation-enhanced CD20 mAb Hx-7D8 of patient-derived chronic lymphocytic leukemia (CLL) cells that are relatively resistant to CDC. CDC was analyzed in normal human serum (NHS) and serum from an individual genetically deficient for C9. Hx-7D8 was able to kill up to 80% of CLL cells in complete absence of C9. We conclude that the narrow C5b-8 pores formed without C9 are sufficient for CDC due to efficient antibody-mediated hexamer formation. In the absence of C9, we observed transient intracellular increases of Ca 2+ during CDC (as assessed with FLUO-4) that were extended in time. This suggests that small C5b-8 pores allow Ca 2+ to enter the cell, while dissipation of the fluorescent signal accompanying cell disintegration is delayed. The Ca 2+ signal is retained concomitantly with TOPRO-3 (viability dye) staining, thereby confirming that Ca 2+ influx represents the most proximate mediator of cell death by CDC., (Copyright © 2017 Elsevier Inc. All rights reserved.)